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									                       Table of Contents

Chapter 1 Introduction ……………………………………………………3

    1.1    Abstract …….……………………………………………………………………..3
    1.2    Introduction of project .…………………………………………………..3
    1.3    Motivation ……………………….……………………………………………….3
    1.4    Requirements ………………………………………………………….……….4
    1.5    Specification ……………………….……………………………………………4

Chapter 2 RF Remote System……………………………………………7

    2.1    Overview ...........…………………………………………………………….7
    2.2    Encoder ..........................…………………………………………….8
    2.3    Address/Data Programmable Pins ……………….…………………10
    2.4    Enabling the HT-640 ……………….…………………………………….14
    2.5    Decoder……………….………………………………………………………….16
    2.6    Motherboard ………………………………….……………………………….21
    2.7    Receiver ……….………………………………………………………………..25
    2.8    Transmitter …………….……………………………………………………..28
    2.9    FCC rules and regulation ……………………………………………….29
    2.10   Antenna ………….……………………………………………………………..30
    2.11   2nd Alternative to our project ……………..………………………..31
    2.12   Modulation Amplifier …………….……………………………………….32
    2.13   Half Wave Rectifier ………………….…………………………………….35
    2.14   Full Wave Rectifier …………………………………………………………36

Chapter 3 Radial Security Function and Overview.……………42

    3.1 Control Unit Function ……………..…………………………………….42
    3.2 Speed Regulator ……………………………………………………………45
    3.3 Alarm ………………………….…………………………………………………49
    3.4 Boolean Functions ………………….…………………………………….52
      3.4.1   Alarm ………………..…………………………………………………52
      3.4.2   Speed Regulator ………………………………………………….53
      3.4.3   Control Unit …………………………………………………………54
    3.5 Control Unit Software …………….…………………………………….56
    3.6 Micro Controller …………..……………………………………………….61

Chapter 4 Vehicle Alarm…………………………….…………….…70

    4.1   Common Theft ………………………………………..…………………72
    4.2   Sensing Intruders ………………………………………………………73
    4.3   The Controller ………………………..…………………………..…….74
    4.4   Typical Installation ………………………………………………….…75
    4.5   Pulsating Circuit ………………….………….………………….……..77
    4.6   Viper.……………………………………………………………………………81
    4.7   Black Widow……………………..…………………………………………82
    4.8   Cyclops Alarm System………..………………………………………83
    4.9   The Design …………….…………………………………………………..84

Chapter 5 Speed Regulator …………………….…………………..87

    5.1   Schematic ………………………………………………………………….87
    5.2   Vehicle Speed Control ……….………………………………………89
    5.3   Fuel Cut-Off ………………………………………………………………95
    5.4   A Typical Speed Controller..……………………………………..99

Chapter 6 Global Positioning System……………………..…..104

    6.1 Radial Security GPS system………….………………………..105
    6.2 Magellan 310, 12 channel GPS navigator…….………..106
      6.2.1    Drawback of Magellan 310…….………………………107
    6.3 Installation of Vehicle Locator Unit…………………………108
    6.4 NT-100 Expansion Module……………………………………..110
    6.5 Motorola M12 Oncore GPS Module..……………………..112
      6.5.1    Communication between the GPS receiver
              and a laptop…….…………………………………………..114
    6.6 Encoder……………………………………………………………………122
    6.7 Transmitter.…………………………………………………………….128
    6.8 Receiver at remote location.………………………………….129
    6.9 Encoder…………………………………………………………………..131
    6.10 Laptop…………………………………………………………………….136

Contribution of Group Four Members…………..…………..137
Group Information and Meeting Schedule.…………….….138
Testing and Prototyping…………….……………………………141
Summary and Conclusion………….…………………………….142


The purpose of this project is to design and implement an economical
and reliable automotive theft deterrent system known as Radial
Security. This project will consist of wireless communication, an
alarm, speed regulator, and a GPS module. In order to make this
project a reality, we will be using a PIC16F788 micro controller as the
brain of the system. Triggering a fault between the VSS and the ECM
will activate the speed regulator. The alarm circuit will activate the
horn. Wireless communication’s purpose is to notify the user of
automotive theft, which will be based on communication between RF
transmitter and receiver. Finally, with the GPS, the person will be able
to locate their vehicle by using their PC.


Would you feel violated if your automobile is stolen and there is no
way of tracking it? Well, Radial Security will be your answer. The
system will give you the luxury of having a sophisticated automobile
security system. It is a synergy of GPS, radius detector, speed control
and alarm.

The device, called Radial Security, will mainly be used by automotive
dealers. It is designed to enhance security while increasing their profit
center. The project will focus on the following:

      Track the automobile
      Decelerate and maintain a constant speed of 10 miles per hour
       once the vehicle has exceeded a quarter mile radius.
      Displays location of the vehicle on a receiving unit
      Activates an alarm after a quarter mile radius from the
       dealership’s location.

   To produce a cost effective security device, that will reduce
     automotive theft.
   To provide an opportunity to work with wireless communication.
   To apply discipline’s knowledge to real world applications
   Contribute to the enhancement of security system
   To graduate this summer with a class A project


The device will be a removal unit which will focus on the following:

  1st Stage (functions of the internal car device)
      Transmit GPS information to a designated central processing
      Trigger internal alarm in the vehicle.
      Calculate radial distance from dealership to car.
      Decrease vehicle’s speed to 10 miles per hour.

     2nd Stage (functions of the CPU)
      Used to display the GPS location.

     3rd Stage (dealership office)
      Transmitter.
      GPS receiver.


While conducting our research on this project, our goal is to produce a
system which will at most meet the following specifications:

     •   Control unit size 20cm X 26cm X 8cm
     •   Portable RF size 20cm X 13cm X 8cm
     •   GPS 5cm X 9cm X 2cm
     •   RF signal range less or equal to ¼ mile (402 m)
     •   Frequency of 400KHz
     •   Overall weight ~ 3lb
     •   Alarm sounds at 120 dB
     •   Speed control decelerate automobile to 5 mph
     •   Alarm source 12volt DC
     •   RF module 5volt
     •   GPS 5± 0.25VDC
     •   Computer software will run under Windows 95/98/2000


   Alarm                               PIC16F877 Micro

                                                         On/Off Light

                                                          RF communication

                Car Ignition Voltage

               Figure 1: Conceptual Art

Figure 2: Radial Security Block Diagram

                               Chapter 2

                         RF Remote System



One of the main function of Radial Security is to activate the control
unit after a specify parameter has been exceeded. Such physical
capability required a remote control system, which may be any system
with controls or commands delivered to the main unit from a distance,
in this case by radio frequency transmission. The unit on the vehicle
has receiver that will communicate with a transmitter place at a fix
location. The receiver and transmitter will continuously communicate
regardless if vehicle is on or off. Binary code will be sent from the
transmitter to the receiver. If the system is in range it sends a one bit
code to the receiver, if it is out of range a zero bit code will be sent,
which will alert the control unit. Such phenomena are possible with the
help of a transmitter, receiver, encoder, decoder, and rectifier. Below
is a diagram of the remote system.

  Dealer Office              Signal            unit
                             0’s; 1’s             FM

                                            0;           1;
 CW Tone                                    trigger      OK


                  Figure 2.1: Remote system diagram



The system shown in figure 2 can only be implemented if the data is
encoded. Encoder is basically a circuit that codes a given format, which
can be changed to a format compatible with the circuitry it interfaces
with. In the case of our project we are using the HT-640, which is
equip with a 12-bit parallel code consisting of 8 address bits and 4
data bits. All the code will not be use in our project because the
communication between the transmitter and receiver only requires 0’s
and 1’s. There are other encoder’s that are cable of doing more code,
but our project calls for only a couple of data transaction, which can be
done by a basic encoder such as the HT-640. The HT-640 encoders
offer flexible combinations of programmable address/data to meet
various application needs. It is power up with a 2.4V~12V voltage
source and has a low power and high noise immunity CMOS. It also
has a built-in oscillator with low standby current and a three words
transmission. The HT-640 has a simple layout, which makes
implementation very easy to build.

          Figure 2.2: HT-640 Diagram
*Reprinted with permission of Ming Microsystems, Inc


Address/Data Programmable Pins

The data that will be transmitted from the transmitter to the receiver
is programmable and will be transmitted via RF. In our case 0’s and
1’s, this still requires encoding and decoding. When the data is
transmitted it has to be change to a serial format in order to be
compatible with the transmitters input. The address/data pin will be
preset to logic high, low or floating. The high will be use to indicate 1’s
and the low will be use to indicate 0’s. A diagram of the
programmable address/data pin and how it can be set to one of the
following three logic states is shown below.

                       Figure 2.3: Waveform
         *Permission to use figure was Ming Microsystems, Inc

Since the decoder’s output only has two states it interpreted the open
state data as logic low. When the transmission enable signal is
applied, HT-640 scans and transmits the status of the 4 bits of
address/data. If the trigger signal is not applied, the chip consumes
1_A of standby current, otherwise it stay in its original position. Below
are diagrams of the pins layout, followed by a representation table of
the address/data pins.

                     Figure 2.4: Pins Diagram
      *Reprinted with the permission of Ming Microsystems, Inc

   Figure 2.5: Encoder address and data Layout
*Reprinted with the permission of Ming Microsystems, Inc

Table 2.1: Encoder selection and Address/Data represents
            Addressable pins according to the decoder requirements.

Part No.   Addres     Address/D    Data    Dumm      Oscillator   Trigger
             s         ata No.     No.        y
Function    No.                             Code
HT600           9         5         0         4         RC           TE
HT640       10            8         0        0          RC           TE
HT680           8         4         0        6          RC           TE
HT6187          9         0         3        6          RC        D12,D1
                                                     oscillator   4,D15
HT6207      10            0         4        4          RC         D12-
                                                     oscillator    D15
HT6247      12            0         6        0          RC        D12-17

Table 2.2: Pins description

  Pin      I/O         Internal                  Description
 Name                connection
 A0-A11     I       TRANSMISSION   Input pins for address A0-A11 setting
                         GATE      Can be set to VDD,VSS, or left open
 AD10-      I       TRANSMISSION   Input pins for address/address( A10-A17)
 AD17                    GATE      setting
                                   Can be set to VDD,VSS, or left open
D12-D17     I         CMOS IN      Input pins for data D12-D17 setting and
                      Pull-low     transmission
                                   Can be set to VDD or left open
 DOUT       O        CMOS OUT      Encoder data serial transmission output
  LED       O        NMOS OUT      LED transmission enable indicator
   TE       I         CMOS IN      Transmission enable, active high
 OSC1       I         Oscillator   Oscillator input pin
 OSC2       O         Oscillator   Oscillator output pin
 VSS        I          -------     Negative power supply(GND)
 VDD        I          -------     Positive power supply


Enabling the HT-640

For the HT-640 encoders, transmission is enabled by applying a high
signal to the TE pin. Once the transmission has been enabled, the HT-
640 encoder performs a three-word transmission cycle. As long as the
transmission enable or pin D12-17 is held high the cycle will continue
repeating itself. A flowchart representation is shown below.

If the transmission enable falls low, the final out will be completed and
stop as shown below.


                     Figure 2.6: Encoder cycle
       *Permission to use figure granted Ming Microsystems, Inc



Since the system has to encode, it also has to have the capability of
decoding. A decoder is basically a circuit that received a signal or data
of a specific format (usually that of its compatible encoder) and
changed it into a format compatible with the circuitry that it interfaces
with. Since we have chosen to use the HT-640 encoder we have to use
the HT-648L decoder, it is one off the decoder compatible with HT-
640. The HT-640 sends a 12 bit, in our case, a 4 bit serial format and
the decoder is responsible for intercepting the code and change it into
a format that the our design circuit understand. The code is check to
ensure that the bits match the address of the decoder, which is the job
of the motherboard. If the incoming address is correct, the last 2 bits
of the 4 bit code are passed on to the data outputs of the receiver.
When code is verified to be valid it is then given an ID that will remain
until the incoming signal is no longer present. For our project we want
the 2 bits code to remain in the stay state that they were set at by the
last transmission. They will only change if the new transmission is
activated. The HT-648L is basically one of the easiest decoder to work
with, which is ideal for the transaction we expecting of our project.

               Figure 2.7: HT-648L
*Reprinted with permission of Ming Microsystems, Inc

HT-648L only requires 2.4V~12V, which gives us the capability to use
the vehicle power supply. Since the HT-640 encoder has a low power
and high noise immunity CMOS, the compatible decoder also is
required to have the same. It has a low standby current and is
capable of decoding 18 bits of information. For the purpose of our
project it will only be decoding 4 bit of information. There are 8~18
address pins, 0~8 data pins and a built-in oscillator, which operate of
a 5% resistor. The HT-648L receives address and data from the
encoders that is transmitted by a carrier using an RF transmission
medium. It then continuously compares the input data with its local
address. If no errors or unmatched codes are encountered, the input
data codes are decoded and then transferred to the output pins. The
VT pin goes high to verify that the transmission ID is valid. A list of
decoder selection and description pin is shown below.

Table 2.3: Decoder selection

  Function Address No. Data           VT Oscillator     Trigger

Item                       No/Type

HT602L       12            2      L X     RC oscillator DIN active “Hi”

HT604L       10            4      L X     RC oscillator DIN active “Hi”

HT605L        9            5      L X     RC oscillator DIN active “Hi”

HT611        14            0      -   X   RC oscillator DIN active “Hi”

Data type: M represents momentary type of data output.
           L represents latch type of data output.
           VT can be used as a momentary data output.

Table 2.4: Pins description

Pin Name   I/O    Internal            Description
A0-A17     I      TRANSMISSION        Input pins for address A0-A17
                  GATE                setting
                                      Can be set to VDD,VSS, or left
D10-D17    I      TRANSMISSION        Output data pins
DIN        I      CMOS IN             Serial data input pin
VT         O      CMOS OUT            Valid transmission

OSC1       I      Oscillator          Oscillator input pin

OSC2       O      Oscillator          Oscillator output pin

VSS        I      -------             Negative power supply(GND)

VDD        I      -------             Positive power supply

A signal on the DIN pin then activates the oscillator which in turns
decodes the incoming address and data. The decoders continuously
check the received address. If the encoder address codes match the
contents of the decoder’s local address, the bits of data will then be
decoded this will then activate the output pins. The VT pin will be set
to receive high for a valid transmitted signal. The valid transmitted
signal will last until the address code is incorrect or no signal has been
received. The output of the VT is high only when the transmission is
valid. Otherwise it is always set to low. Flow chart representation is
shown below.

                          Flow chart

                     in                      Disable VT & ignore the
                                             rest of this word

                   Address bits              No

                  Store data           Yes

                   Match                      No
                   stored data?


     No           2 times of

                Momentary data
                to output & activate

               Address or data error


For the flow chart representation shown on the previous page, the
oscillator is disabled in the Standby state and stays activated as long
as a logic high signal is applied to the DIN pin. The DIN should be kept
low if there is no signal input.



All of the function mention will not be possible without the help of the
encoder and decoder motherboard. The motherboard operates like
any other board found in computer. It gives the encoder and decoder
the access to everything, more like buses that deliver goods to
customers. The board has to be compatible with the HT-640 encoder
and the HT-648L decoder. We choose to build our own board, but
because of the limited amount of time we have to work on the project
we will use the design and specs of the HT-12 motherboard. The
board is simple and capable of processing the small amount of data
used in our project. A more complicated board is not necessary for
our project because the data we have to process is small, but for
projects that has much more data transaction will require a much
more complicated board. The project will require two boards, one for
the transmitter encoder and one for the receiver decoder. Layout of
the board is shown in figure 2.8. The board is easily implemented and
can be power by the vehicle power source.

               Figure 2.8: Motherboard Diagram
      *Reprinted with the permission of Ming Microsystems, Inc

Specifications for HT-12E encoder board

The HT-12E mother is capable of handling a 12 bit address/data code
allowing 4096 different code combinations. Our project only requires 2
combinations, so we will build our board to handle a 4 bit address/data
which will allows approximately 1024 combinations. Still too much for
our project, but we want to leave room for future implementation.
Below is a schematic and specification table of the HT-12E

                 Figure 2.9: HT-12E schematic
        *Reprinted with permission of Ming Microsystems, Inc

Table 2.5: HT-12E


  Operating Voltage:                12VDC


  Length:                           2-11/16" (68.00mm)

  Width:                            1-3/4" (45.00mm)

  Height:                           7/16" (12.00mm)


  Operating Temp:                   0°C to 40°C
  Storage Temp:                     -20°C to 80°

             Operating Voltage:          12VDC


             Length:                     3-3/16" (81.00mm)
             Width:                      2-3/8" (61.00mm)
             Height:                     1/2" (12.70mm)

             Operating Temp:             0°C to 40°C

             Storage Temp:               -20°C to 80°

      **Both table were reprinted with permission of Ming Microsystems, Inc

As I mention previously the encoder and decoder required its own
board, since the time for this project is limited we will use the spec of
the HT-12E to build the encoding motherboard. We will also follow the
specs given for HT-12D board to build the decoding motherboard. A
specification table is shown above. The HT-12D is ideal for our project
because it is designed for receiving 4 bit data codes, not for rapid data
transmission. Schematic for the HT-12D is shown in figure 2.10.

                  Figure 2.10: HT-12D schematic
         *Reprinted with permission of Ming Microsystems, Inc



The back bone of the RF communication lies on two components, the
receiver and the transmitter. A receiver is a circuit capable of
accepting and processing light, sound, or electromagnetic waves of a
specific frequency. In the case of our project a signal or data will be
sent at a certain radio frequency by the transmitter, the receiver will
then extract the incoming data or signal. The extracted data is then
sent out in serial format to the decoder board. The extracted data is
then use to trigger the control unit if the data bits don’t match. Our
receiver will be built into the unit place on the vehicle; it will
continuously communicate with a transmitter that is place at a
specified location. See figure 2.10. Since the transaction we require
of our project is limited, the ideal receiver to use is the Ming RE-99.

The RE-99 is ideal for almost any application needing a wireless
control system. Since our application requires the ability to send data
codes, the TX-99 transmitter and HT-12E encoder, combined with the
RE-99 receiver and HT-12D decoder will be the perfect solution for our
project. As mention before, the receiver will not be built from scratch,
but below is a table and schematic specification on how to build the

          Figure 2.11: RE-99 schematic
*Reprinted with permission of Ming Microsystems, Inc

             Table 7: RE-99 Specification

               Operating Voltage:    5VDC

               Operating Current:    1.6mA
               Frequency:            300 MHz

               Circuit Type:         LC Based AM

               Operating Temp:       0◦C to 40◦C

               Storage Temp:         -20◦C to 80◦C

               Length:               1-3/16”
               Width:                2-3/8”
               Height:               11/16”
               Weight:               1.6oz (.056gms)

Until now I have not mention anything about the range of the receiver,
but the range is the least things to worry about. The operating range
for this receiver is dependent on the choice and position of the
antenna. The antenna operates like any other antenna used in our
everyday life. Meaning it has the same dependence, such as shape,
type and surrounding. Also keep in mind that the space around the
antenna is as important as the antenna itself. We know that
electromagnetic field plays an important roll in our surrounding, so it is
best to keep the antenna away from other metal in the system such as
batteries and PCB ground plane.



What would a remote system be without a transmitter? A transmitter
is basically a circuit with an output sent through the air by light, sound
or electromagnetic waves at a specific frequency. In the case of the
our project, the output is an amplitude modulated radio frequency of
around 310MHz. Think of it as an output of electromagnetic waves
representing an input data code. The transmitter for our project will
be place at a fix location, for example a dealership office. It will
continuously transmit information (1’s and 0’s) to the receiver, which
is located in the vehicle unit. Our project requires a basic transmitter
that is capable of transmitting 4 bit data, which led us to the Ming TX-

The TX-99 is a 300MHz AM RF transmitter board. It offers 4 bits of
data providing up to 16 different codes and 8 bits of address, which
ensure that data sent from your transmitter are passed on to the RE-
01 data outputs. Like the receiver the transmitter will not be built
from scratch, if you choose to build it from scratch just follow the
schematic and specification table shown below.

                   Figure 2.12: TX-99 schematic
         *Reprinted with permission of Ming Microsystems, Inc

             Table 8: RE-99 Specification

              Operating Voltage:   5VDC

              Operating Current:   1.6mA
              Frequency:           300 MHz

              Circuit Type:        LC Based AM

              Operating Temp:      0◦C to 40◦C

              Storage Temp:        -20◦C to 80◦C

              Length:              3/4” (19.05mm)
              Width:               1-3/4”
              Height:              1/2” (12.70mm)
              Weight:              0.3oz (.011gms)



Something I fail to mention is the FCC rules and regulations. The part
15 rule stated that a license is required for anyone operating with
radio frequency of 902-928 MHz. The RF modules that we are using do
not require licensing to operate (280-310 MHz ISM band). These
modules are not FCC approved, but have been designed to comply
with FCC Part 15 Rules and Regulations.



The TX-99/re-99 has a loop trace antenna on board and does not
require the addition of a wire antenna, but for precautionary reasons
we will add a ¼” wire antenna because it is fairly short and works very
well. A ready made antenna can be purchase to fit your design need,
we just prefer to make our own. Below are antennas of different sizes
and shapes.

Keep in mind that if you want to increase the range just increase the
length of the antenna, such as a half or full wave; however, a lengthy
antenna is sometimes hard to conceal.

                 Figure 2.12: HT-12E schematic
        *Reprinted with permission of Ming Microsystems, Inc



The second way of implementing our project might be the quickest and
easiest way to getting it done. The most complicated thing in our first
chose was the fact of transfer data (0’s and 1’s) between the
transmitter and receiver. That was the main reason for the encoder
and decoder, which time consuming. The 2nd way of implementing the
project cut out the need for encoding and decoding. A Half or full
wave rectifier, along with a voltage comparator would replace the
encoder and decoder. The project would still require the use of the
transmitter, receiver, and antenna.

The transmitter will be placed at a fix location and power up by an AC
voltage supply. The input will be an AM input, just because it satisfies
our frequency range. The receiver will still be place in the vehicle unit
and expected to output an AM output. Both receiver and transmitter
will have a ¼” antenna attach.

                         n                  t
                                            e   Vehicle
     Dealer Office             FM signal    n   unit
 FM                                         a     FM

   CW Tone

         Figure 2.13: Transmitter/Receiver signal overview


Modulation Amplifier

The signal will leave the receiver and enter an amplifier. The
amplifier’s job is to take the voltage signal and amplify it to a voltage
equal to the threshold voltage found at the output of the comparator.
For our project we prefer the amplify gain to be greater than 40dB. A
large bandwidth and wide voltage supply range is also require. We will
not try to build such amplifier because of the limited time we have to
work with; instead we will purchase the OPA132. The OPA132 has
bandwidth of 8MHz, wide voltage range of ±2.5 to ±18V and high
open loop gain of 130dB. It also has other features such as input
current of 50pA max, low noise of 8nV/Hz (1 kHz), distortion of
0.00008% and low offset voltage of 500mV max. See figure below.

                 Figure 2.14: Full-wave rectifier
         *Reprinted with permission of Douglas Helm from TI

OPA132 is free from phase inversion and overload problems often
found in op amps. It provides excellent common-mode rejection and
maintains low input bias current over its wide input voltage range. The
loop gains are stable and provide excellent dynamic behavior in wide
range of load conditions, such as high load capacitance; however, the
power supply pins should be bypassed with 10nF ceramic capacitors or

The connection pins 1 and 8 are use for the offset voltage, which is
laser trimmed and usually requires no user adjustment. If one wish to
adjust the offset voltage just connect a potentiometer as shown in
Figure 2.14; however, this adjustment should be used only to null the
offset of the op amp, not to adjust system offset or offset produced by
the signal source.

         Figure 2.15: OPA132 Offset Voltage Trim Circuit
         *Reprinted with permission of Douglas Helm from TI


       *Reprinted with permission of Douglas Helm from TI


Half Wave Rectifier

When the signal leaves the receiver, it will go into a half-wave or
full wave rectifier. The wave is said to be rectified when the
positive and negative portions of it has been separated from each
other. A half wave rectifier does just that; it takes the positive or
negative potion of the wave and discards the other. We will not
use the half-wave, but if one was to be use we would build our
own with slight modification of the input and final resister value
entered in the circuit shown below.

                                   10 K

                     10 K

                 Figure 2.16: Half-wave rectifier
              *Reprinted with permission of Ken Bigelow

    The way that the half-wave rectifier above operates is that it
    accepts an incoming waveform and inverts it. Keep in mind
    that only the positive going portions of the output waveform
    actually reach the output. The first diode will shunts any
    negative going output back to the input, which prevents it
    from being reproduced.

    The second diode allows positive going output voltage to reach
    the output. As a result, the output voltage is a true and

   accurate (but inverted) reproduction of the negative portions
   of the input signal.


Full Wave Rectifier

A full-wave rectifier is a device that has two or more diodes arranged
so the load current flows in the same direction during each half cycle
of the AC supply. The full wave rectifier is much more precise then the
half-wave rectifier, which led us to the decision of using it in our
project. It keep both halves of the input signal and render them both
with the same output polarity, while the half wave keeps only the
original input signal that are positive (or negative). A full wave
rectifier can be purchase; however, with minor adjustment we will use
the schematic shown below to build the rectifier for our project. We
will turn all the diodes in the opposite direction to obtain a positive
voltage output.

                 Figure 2.17: Full-wave rectifier
              *Reprinted with permission of Ken Bigelow

     Dealer Office              FM signal         unit
 FM                                                 FM

   CW Tone

                                                  Half- wave

                                                               DC signal

             Figure 2.18: 1st half of the system diagram

After the signal has been received, it goes into the rectifier as an AC
voltage signal. It will then leave the rectifier as a DC voltage signal. If
worked exactly as planed, the signal will then go into a comparator.

A comparator basically compares two voltages to determine which is
In our case the input AC voltage transmitted by the transmitter and
the DC threshold voltage at the comparator. When the input voltage is
less than the threshold voltage, the output is driven to a low saturated
state, which will trigger the micro-control unit. If the output voltage is
the same as the input voltage the system does nothing. We will use
the 1’s and 0’s representation high and low. If the system is high, it
will send a 1 to a digital switch box. If the system is low it will send a
0 to the box. The comparator will continuously compare voltage and
will not activate the switch until there is a decrease in the output

We will not build the comparator used in our project, instead will
purchase the LM111 or the LM311. They both have the capability of
performing the transaction in our project. They are also designed to
operate over a wide range of supply voltages: from standard ±15V op
amp supplies down to the single 5V supply used for IC logic. They can
drive lamps or relays, switching voltages up to 50V at currents as high
as 50 A.

Both the inputs and the outputs of the LM111and the LM311 can be
isolated from system ground, and the output can drive loads to
ground, positive supply or negative supply. It has the capability of
offset balancing and strobe. They might be slower than many other
comparators, but they are much less prone to spurious oscillations.
The LM111 performance is over a -55°C to +125°C. The LM311 has a
temperature range of 0°C to +70°C. Below is specification for both

Table 2.10: LM111 Comparator

Parameter                 Condition                        Min     Type     Max     Unit
Input Offset Voltage      25°C, RS50k                              0.7     3.0     mV
Input Offset Current      TA =25°C                                  4.0     10      nA
Input Bias Current        TA =25°C                                  60      100     nA
Voltage Gain              TA =25°C                          40     200              V/m
Response Time             TA =25°C                                 200               ns
Saturation Voltage        VIN-5 mV, IOUT =50 mA                   0.75     1.5      V
                                     TA =25°C

Strobe ON Current         TA =25°C                                  2.0     5.0      mA
Output Leakage Current    VIN5 mV, VOUT =35V                       0.2     10       nA
                                 TA =25°C, ISTROBE =3 mA

Input Offset Voltage      RS50 k                                           4.0      mV
Input Offset Current                                                        20       nA
Input Bias Current                                                          150      nA
Input Voltage Range       V + =15V, V þ =-15V, Pin 7       -14.5   13.8,-   13.0      V
                          Pull-Up May Go To 5V                      14.7

Saturation voltage        V + 4.5V, V þ =0 VIN-6 mV,             0.23     0.4         V
                          IOUT8 mA
Output Leakage Current    VIN5 mV, VOUT =35V                       0.1     0.5         µA

Positive Supply Current   TA =25°C                                  5.1     6.0      mA
Negative Supply Current   TA =25°C                                  4.1     5.0      mA

Table 11: LM311 Comparator

Parameter                 Condition                 Min       Type       Max    Unit
Input Offset Voltage      25°C, RS50k                         0.7       3.0    mV

Input Offset Current      TA =25°C                             6.0       10     nA
Input Bias Current        TA =25°C                             100       100    nA
Voltage Gain              TA =25°C                   40        200              V/m
Response Time             TA =25°C                            200                ns
Saturation Voltage        VIN-10 mV, IOUT =50 mA             0.75       1.5     V
                                    TA =25°C

Strobe ON Current         TA =25°C                             2.0       5.0    mA
Output Leakage Current    VIN5 mV, VOUT =35V                  0.2       10     nA
                          TA =25°C, ISTROBE =3 mA
                          V þ = Pin 1 = -5V
Input Offset Voltage      RS50 k                                        4.0    mV
Input Offset Current                                                     20     nA
Input Bias Current                                                       150    nA
Input Voltage Range                                 -14.5   13.8,-14.7   13.0    V
Saturation voltage        V + 4.5V, V þ =0                   0.23       0.4     V
                          VINþ6 mV, IOUT8 mA
Positive Supply Current   TA =25°C                             5.1       6.0    mA
Negative Supply Current   TA =25°C                             4.1       5.0    mA

These specifications apply for a voltage source of ±15V and ground pin
at ground. The offset voltage, offset current and bias current
specifications apply for any supply voltage up to ±15V. The offset
voltages and offset currents given are the maximum values required to
drive the output within a volt of either supply with a 1 mA load.

    Dealer Office           FM signal         unit
FM                                                FM

  CW Tone                                         Amplifier

                                              Half- wave

                                          Input Voltage      DC signal


                                        Threshold voltage
                                        use for comparison        DC

                                              Threshold voltage

                                            High                Low

                Figure 2.19: Overall system diagram

                               Chapter 3

              Radial Security Function and Overview


Control Unit Function

The purpose of the control unit on the Radial Security automotive theft
deterrent system is to turn on an alarm and a speed regulator based
on certain conditions. The control unit will receive its inputs from a RF
communicator’s receiver and the car’s ignition. Once the RF
communicator’s voltage is below the threshold voltage (5 V), or the RF
frequency’s distance is less than a certain distance, in this case ~
402m and the car’s ignition is on, a logical one should be sent to the
Control Unit (See Fig 3.1 and 3.1a). When the control unit receives
the logical one, the control unit will then activate the car alarm and the
speed regulator (For more information on the alarm and the speed
regulator please see section 3.2). Once the RF frequency is within the
proper range (less than 402m) or is above the threshold voltage, the
unit will then receive a logical zero, indicating the control unit should
turn off the alarm and speed control unit.

      Outputs                                                Inputs

      Alarm                                                    RF Communication

                                    Control Unit
  Speed Regulator
                                                                  Car Ignition

              Figure 3.1: Block diagram of control unit

Check RF

 Check car

RF                    Yes
volts < 5 volts and          Turn on alarm         Turn on Speed
car ignition on?                                   Regulator


   Figure 3.1a: Flowchart based on checking for voltage

 Check RF

  Distance in

   Check car

  distance and car             Turn on alarm           Turn on Speed
  ignition on?                                         Regulator

Figure 3.1b Flowchart based on checking for distance

The flowcharts shown on Figure 3.1a and 3.1b, shows the different
options we can use to let the control unit activate the alarm and speed
regulator. In the first option, (Fig. 3.1) we check the RF
communication until it reaches below a threshold voltage and if the
ignition is on. Once it is below the threshold voltage in the RF, we
then let the control unit know that RF is out of range. The control unit
will then activate the alarm and speed regulator once the ignition is
on. In the second option (Fig 3.1a) we check the distance between the
RF receiver and transmitter. Once that distance is broken, we once
again let the control unit know the RF is out of range and to send the
signal to activate the alarm and speed regulator. Based on our
research we plan on using the voltage activity to trigger the control
unit. The reason being is the voltage is more discrete (is the voltage
on or off) as opposed to having to keep checking the distance. For
more information on that choice please see the section of RF


Speed Regulator

The purpose of the Speed Regulator is to make sure the automobile
doesn’t exceed a certain speed limit (in this case 10 mph) once the RF
communication no longer exists. When the ignition is started on the
automobile and the RF communication is broken, the speed regulator
will then be activated. (For example, if an automobile is stolen and
the person exceeds a certain distance (~402m) their speed will
decelerate to 10 mph. When the speed regulator activates, the person
cannot go faster than 10 mph until the RF communication is re-

While researching, we came up upon different avenues to reduce the
automobile’s speed. When we first started this project, we were
planning to just turn off the vehicle once the distance was broken.
However, that posed a problem because if the car turned off in the
middle of an intersection, there would be a liability because it could
cause an accident. Another, more safer approach, would be either
cutting off the fuel supply to the vehicle or talking to the speed
governor to let the car know not to exceed a certain speed. For more

information on our approach to slow the automobile down, please see
the Speed Regulator section. Figure 3.3 shows what we are trying to
achieve with the speed regulator.

                   Speed                Control
                   Regulator            Unit

         Figure 3.2: Block Diagram of Speed Regulator

Control Unit

Check RF

  Voltage <     Yes
  threshold           Send Voltage to
  voltage             Speed Regulator


                          Car                 Activate
                          ignition      Yes   Speed
                          on?                 Regulator


                         Keep voltage
                         to Speed

     Figure 3.3: Speed Regulator Flowcharts

           Speed                      Control        RF voltage <
           regulator                  Unit           threshold

Figure 3.4: Block Diagram when Speed Regulator when ignition is off

             Speed                    Control        RF voltage<
             regulator                Unit           threshold

Figure 3.4a: Block Diagram for Speed Regulator when ignition is on

Base on the figures above, we see how the Speed Regulator acts when
the ignition is on or off. It should be noted that once the control unit
senses that the RF voltage is below the threshold voltage, the control
unit will send a voltage to the speed regulator (Figure 3.4). The Speed
Regulator will then be activated once the ignition is on (Figure 3.4a)



The purpose of the alarm is to sound a siren after the vehicle has
broken RF communication. The hope is that a loud alarm and a vehicle
traveling 10 mph will draw attention to whomever is trying to steal it.
The logic behind activating the alarm is similar to that of the Speed
Regulator. When designing the alarm, our goal is to make it sound at
least 120 decibals.

                     Alarm               Control Unit

                 Figure 3.5: Alarm Block Diagram

Control Unit

Check RF

  Voltage <      Yes
  threshold             Send Voltage to
  voltage               Alarm


                            Car                 Activate
                            ignition            Alarm

                           Keep voltage
                           to Alarm

            Figure 3.6: Alarm Flowchart

             Alarm                    Control       RF voltage<
                                      Unit          threshold

      Figure 3.7: Alarm Block Diagram when ignition is off

              Alarm                    Control       RF voltage<
                                       Unit          threshold

     Figure 3.7a: Alarm Block Diagram when ignition is on

Please note Figures 3.7 and 3.7a behave similar to the Speed
Regulator block diagrams (Figure 3.4 and 3.4a).

3.4 Boolean Functions

3.4.1. Alarm

The car alarm will sound if and only if the alarm is on and the control
unit sends it a high voltage.

      Control Unit (C)
                                                    Alarm (A)
             Power (P)

           Figure 3.8: Alarm Controller Block Diagram

          Table 3.0a: Conditions for the Alarm to Sound

            Control Unit        Alarm
                On               On

Based on the conditions to sound the alarm, the Boolean Equation
formulated is:
A = PC.

A – Alarm
P – Power
C – Control Unit

Table 3.0b: Truth Table For Alarm to Sound
     P               C           A
     0               0           0
     0               1           0
     1               0           0
     1               1           1

             Figure 3.9 Digital Circuit for Alarm to sound


Speed Regulator

The speed regulator will activate only when the power is on and
control unit sends high voltage.

         Control Unit (C)       Speed
                                Controller       Speed Regulator (S)
                Power (P)

             Figure 3.10 Speed Controller Block Diagram

Table 3.1: Conditions for the Speed Regulator to Activate
 Control Unit        Speed
        On             On

Based on the conditions to activate the speed regulator, the Boolean
Equation formulated is: S = PC.

S – Speed Regulator
P – Power
C – Control Unit

     Table 3.2: Truth Table For Speed Regulator to activate

           P            C             S
           0            0             0
           0            1             0
           1            0             0
           1            1             1

          Figure 3.11 Digital Circuit for Speed regulator


Control Unit

The control unit will send high voltage to both the Speed Regulator
and Alarm only when the RF voltage is below the threshold voltage and
the control unit and car ignition is on.

RF Communication (R)
                              Control Unit
            Power (P)                            Voltage (V)

       Car Ignition (I)

             Figure 3.12 Control Unit Block Diagram

Table 3.3: Conditions for Control Unit to turn on Speed Regulator and

                   R             P                I
                   Off           On              On

Based on the conditions to sound the alarm, the Boolean Equation
formulated is:
V = RPI.

V – Voltage
P – Power
I – Car ignition
R – RF Voltage

       Table 3.4: Truth Table For Control Unit

             P            R                  I        V
             0            0                  0        0
             0            0                  1        0
             0            1                  0        0
             0            1                  1        0
             1            0                  0        0
             1            0                  1        1
             1            1                  0        0
             1            1                  1        0

            Figure 3.13: Digital Circuit for Control Unit


Control Unit Software

Based on what we want the control unit to do, from a logical
standpoint, we could have used an inverter (7404 chip) with a two
input AND gate (7408 chip) and two outputs. This way we could have
used the car ignition and the RF communication as inputs while the
alarm and speed regulator would be the outputs.

We chose not to use the AND gate method because we wanted to
allow for flexibility just in case someone wanted to add or take away
some of the features. The pseudocode below will show how the
control unit will operate. For a flowchart, please see Figure 3.14:

main ()
     // the endless loop is used to check voltage and the car ignition
     while (1)
           check if there is voltage on the RF communication;
           check if the car ignition is on;
           if (RF communication < threshold voltage and car ignition
               = on)
                  sound the alarm;
                  activate the speed regulator;
                  turn off the alarm;
                  turn off the speed regulator;

Because we plan on going with a micro controller, we should be able to
read the status of the car ignition and the RF communication through
Input ports while sending the signals to activate alarm and speed
regulator through an Output ports. The only thing with using a micro
controller is we may need an Analog to Digital (A/D) converter for the
ignition and RF converter in order to read two bits (1 to signal on and
0 to signal off). As far as the output goes it will also be two bits, one
to indicate on and off. An amplifier will also be used because the
micro controller may not have enough amps (A) and volts (V) to power
up the alarm and speed regulator. We may also need some type of
voltage regulator for the car ignition so as not to burn out the micro


       Check RF

      Check car ignition

       Car ignition on
          and RF
                                               Activate speed
       communication             Sound alarm     regulator
         voltage <


       Turn off Alarm

        Turn off Speed


Figure 3.14: Control Unit Software Flowchart

In order to see if the control unit logic was correct, the following C++
code was written to simulate different scenarios based on the RF
communication and the car ignition. It should be noted that the user
would be entering whether or not the RF communication and the car
ignition will be on or off.

/* Purpose: This program is used to simulate what the control unit in the Radial Security
System, an automotive theft deterrent, will act based on certain conditions */
// Inputs: Status of the car ignition and RF communication (on or off)
// Output: The status of Radial Security (on or off)

/* volts        ->      tells us if the RF communication voltage is on (1) or off (0) */
/* car_ignition -> tells us if the car ignition is on (1) or off (0)                  */

#include <iostream.h>
#include <conio.h>

#define on 1

void main ()
      int volts;
      int car_ignition;
      int threshold = 5;

       while (1)
              cout << "What is the RF voltage?" << endl;
              cin >> volts;
              cout <<endl<< "Is the car ignition on (press 1) of off (press 0)?"<< endl;
              cin >> car_ignition;

               if (volts < threshold && car_ignition == on)
                        cout <<endl<<"The Car alarm has been turned on"<< endl;
                        cout <<"The Speed regulator has been activated"<< endl<<endl;
                        cout <<"The control unit is off"<<endl<<endl;


          Figure 3.15 Output of Control Unit Simulation

As seen in Figure 3.15, the control unit arms the alarm and speed
regulator based on our design specification. It should also be noted
the program polls the devices to make sure if something has changed
as far as the status of the car ignition and/or the RF communication,
the alarm and speed regulator will respond appropriately.


Micro controller

As stated earlier before, we could have gone the hardware only route
by using an INVERTER combined with an AND gate. In order to prove
this method works, we developed vhdl code simulating the dataflow of
the INVERTER with an AND gate. The code below is the vhdl code we
developed for control unit:

--The following is the hardware description of the control unit for the Radial Security
--Automotive theft deterrent system. This code builds an INVERTER and an AND gate.
-- The output from the inverter will be used as an input to the AND gate as well as
-- another input, car ignition.

--The entity below is used to build the inverter gate
entity inv1 is
Port(r: in bit; r1: out bit);
end inv1;

--Architecture function below is used to describe how the inverter gate will act.
architecture df of inv1 is
r1 <= not r after 2ns; --2 nanosecond delay for inverter gate
end df;

--The entity below is used to build the AND gate
entity and2 is
port (c,r: in bit; a,s: out bit);
end and2;

--Architecture function below is used to describe how the AND gate will act.
architecture df of and2 is
a <= c and r after 2ns;
s <= c and r after 2ns;
end df;

--The entity below is used to build the Control Unit for Radial Security

entity Control Unit is
port(x1,x2: in bit; y,z: out bit); --used to describe the inputs and outputs for the control
end Control Unit;                   --unit.

--Architecture function below is used to describe how the Control Unit will act.
architecture ex1 of Control Unit is
signal r1: bit;
r1 <= not x1 after 2ns;
z <= r1 and x2 after 2ns;
y <= r1 and x2 after 2ns;
end ex1;

entity tbsystem is
end tbsystem;
architecture ex of tbsystem is
signal RF_ volts, car _ignition, alarm, speed_ regulator, bit;
component Control Unit
port (x1, x2: in bit; y,z: out bit);
end component;
for all: Control Unit use entity work. Control Unit(ex1);

out: Control Unit port map(RF_volts,car_ignition,alarm,speed_regulator);
RF_volts <= '0' after 10ns, '0' after 20ns, '1' after 30ns, '1' after 40ns, ;
car_ignition <= '0' after 10ns, '1' after 20ns, '0' after 30ns, '1' after 40ns;
end ex;

                     Figure 3.16: Output for Control Unit

The screen shot above (Figure 3.16) shows the output generated by
the vhdl code on the previous two pages. Based on the output above,
the alarm and speed regulator will activate (rising edge) only when the
RF volts are below the threshold voltage (low line or logical 0) and the
car ignition is on (high line logical 1). Otherwise, the alarm and speed
regulator are off (falling edge).

However, we choose to go with a micro controller because of if we
decide to add any extra features, it gives us more flexibility. When
choosing a micro controller, we have to keep the following
specifications in mind:

   -   Has to be cost effective and efficient
   -   Run on low power
   -   Needs A/D converter
   -   At least 4 I/O ports
   -   Able to read at least 2 bits
   -   At least 2 MHz
   -   Should be able to be program multiple time

Because our specifications are not that cumbersome, just about any
micro controller would suffice. The only problem with selecting a
micro controller is to find one which is easy to program and is cost and
power efficient. Based on that, we have narrowed it down to three
micro controllers, the Jstamp, Motorola MC68HC11, and the
PIC16F877. A brief summarization of the micro controllers is shown in
Table 3.5 .

              Table 3.5: Micro controller comparison chart

Micro         ROM RAM         EEPROM A/D        Inputs Output I/O Cost
Controller    (Bytes) (Bytes) (Bytes) Converter Only   Only   Pins US$

MC68HC11A8      8K     256      512        Yes      11      12     15        N/A

   Jstamp      N/A     48K      N/A        Yes       6       2     24      109.00

 PIC16F877     N/A     368      256        Yes       0       0     33        7.90

Based on my experience, the Jstamp (see Figure 3.17) micro controller
would most likely be the quickest to program just as long as you know

Java. Another good thing about the Jstamp is if we choose to use it;
we could add extra features to it (i.e. temperature sensing of
transmission, axis, etc). In addition, because the Jstamp also runs on
low power, we could have it run off the car battery. The only
drawback with this micro controller when compared to the PIC16F877
and MC68HC11 is that it is the costliest of the three.

             Figure 3.17: Photo of Jstamp micro controller
                 **Reprinted with permission of systronix

  The next micro controller we looked into was the Motorola
  HC68HC11A8 series (see Figure 3.18). As stated earlier, this also
  fits our specifications as far as what we want our micro controller to
  do. It has an A/D converter as well as more than enough ports to
  work with. The upside with using this micro controller is that
  despite being assembly language, it is easily program. Another plus
  is we most likely have the most experience with programming it
  thanks to our Computer System Design 1 (CSD1) class. This was
  going to be our original choice; however, my CSD1 teacher told me
  that we may not have the programmer for the micro controller.
  This would result in us having to buy the development kit, which
  usually cost a lot of money, more than allowed in our budget.
  However, the main reason I choose not to go with this micro
  controller was that it was hard for me to find one to order.

Figure 3.18: 68HC11A8 micro controller and pin assignments
            **Reprinted with permission of Motorola

The final micro controller and ultimately the one we are going to go
with is the PIC16F877 (see Figure 3.19). Just as the other micro
controllers listed above, this one is also more than suitable for our
purposes. The reason we choose this micro controller as opposed to
the others is that we can get them free, thanks to the Autonomous
Vehicle Design Class. If we could not get them free, it really did not
matter because they are relatively cheap and common. Another plus
with the PIC16F877 is we also have a programmer readily available to
us. The PIC16F877 is also simple to program because it only has
about 35 instruction sets used for programming. It also should be
noted, from a programming aspect, we would have a C compiler for
the PIC16F877. This means we can program the micro controller
using C language as opposed to assembly. The only downside with
programming a PIC16F877 is it has a few registers so you would have
to be careful when programming not to overwrite important

             Figure 3.19: PIC16F877 Micro controller
            **Reprinted with permission of microchip.com

Figure 3.20: PIC16F877 Block Diagram
 **Reprinted with permission of microchip

Another good aspect of the PIC16F877 is that all of the ports are bi-
directional. This gives us the flexibility of configuring the amount of
inputs and outputs we could use. Based on figure 3.20, we can pretty
much envision how the other devices (RF communicator, speed
regulator, car ignition, and alarm) will interact with the micro
controller. This Assuming that each device uses one port and three
pins, we would interact the devices with the micro controller as

- Assuming the RF communication device did not have an A/D
  converter, we would use the A/D pins RE0-RE2.
- Assuming the car ignition did not have an A/D converter, we would
  use A/D pins RA0- RA2
- The alarm would connect to pins RC0 - RC2.
- The speed regulator would connect to pins RD0 - RD1.

To sum up our assessment of the micro controller we could have
choose anyone of them. The ultimate deciding factor in choosing the
micro controller was the price (see Table 5).

                               Chapter 4

Vehicle Alarm

               **Reprinted with permission of Karim Nice

A car alarm can be as simple as a siren and one or more sensors. To
hook up a simple car alarm all you need are some wires, sensors, a
switch and a siren. A much more complicated alarm consists of more
parts. Instead of some wires and a siren the more complex ones have
many different parts which include sensors, radio receiver, auxiliary
battery, and a computer control unit that monitors everything and
sounds the alarm. That is called the brain of the system. The brain of
the system is the main part in the entire alarm system. Everything is
connected to the brain of the system. It is what controls the sensors
on you vehicle. Different sensors controls different parts of your car,
for example, you might have sensors on your door so when someone
tries to open the car door your alarm will sound. You could even hook
the brain to sound the alarm when someone cuts off the main power
to the car. You can also hook up other sensors to the brain. The most
basic sensor in this complex alarm is the sensors for the door. If the
alarm is activated and you open the door it will activate the alarm. It
is like the light in your vanity mirror. When the mirror is open there is
a button that releases and turns on the vanity light so you are able to
see. The sensors on the door work the similar way. There is one way
to get around the system and that is with a valet switch that is hidden
in a location that is not common. Maybe like your fuse box under the
dash of you car. This will deactivate the entire alarm. Most modern
alarms monitor the voltage of the entire car’s electrical circuit. If there
is any change such as a drop in voltage that sends the brain a

message letting it know that someone interfered with the electrical
system. Even though door sensors are effective, the only down fall
they have is you only get limited protection. Not everyone trying to
break into your car want to use the doors, so the door sensors are

As for the basic car alarm systems, figure 4.1, they rely on door
sensors only, the more advanced car alarm systems rely on shock
sensors to keep your car safe. Shock sensors are not real hard to
understand, mostly if anyone jolts, pushes, hits your car the sensor
sends a message to the brain to sound the alarm. When a signal is
sent to the brain of the alarm, depending on the intensity of the jolt or
hit to the car, the brain decides whether it is going to sound the full
alarm or just a horn and beep sound to scare someone off. There are
numerous ways to connect the shock sensors.

              **Reprinted with permission of Tom Harris

                              Figure 4.1

For example, you have a long, flexible metal contact positioned just
above another piece of meal. You can use a simple switch to configure
it. If touch together, it sends a flow of current between them. So,
when you car is jolted or hit, the pieces of metal sway and they hit
each other as the car is hit or moved in any way, which then sounds
the alarm. The only problem with this setup is that is that the brain
can not tell between a strong force of wind or a jolt or a hit. More
advanced systems with shock sensors hold a different setup for
installing the sensors. For example, a setup where there is a central
electrical contact in cylinder housing, several smaller electrical
contacts at the bottom of the housing and a metal ball that can move
freely in the housing. In a resting position it touches both the central
electrical contact and one of the smaller electrical contacts. This holds
a connection so the alarm is resting. Once the housing is shaken or
pushed the ball rotates around and that closes the circuits until the
ball stops and the alarm is still at rest. Now if there was a more
severe shove to the car the ball will rotate more closing more of the
circuits at once and that will send a message to the brain to sound the
alarm. Even though the shock sensors will protect your car, most
alarm come with other sensors along with the shock sensors.

4.1   Common Theft

The most common way that thieves break into your car is through
your windows. So along with the shock sensors, window sensors will
be very reliable. Most window sensors are a microphone connected to
the brain. When a window breaks and the glass shatters it has a
distinctive sound, the sound comes from the patterns of air-pressure
fluctuations. The microphone then converts to electricity currents of
that certain frequency and the in return sends it to the brain. As the
frequency passes to the brain the current go through a crossover (this
electrical device will only conduct electricity within certain frequency
ranges). The configuration of a crossover is set up to only conduct
current with that of the frequency of breaking glass. This current in
return will trigger the alarm. Other ways to detect breaking glass
and/or the opening of the door will be to measure the air pressure in
the car.

4.2 Sensing Intruders

Another way of detecting intruders is by monitoring air pressure levels.
The difference of pressure between the inside and the outside of the
car pulls the air in the car when opening a door or when forcing a
window creating change in pressure. With a loud speaker driver you
can detect the fluctuation of air pressure with a movable cone and an
electromagnet. The electromagnet, figure 4.2, should be surrounded
by a natural magnet that will be attached to the movable cone. The
electromagnet will allow electric currents to flow back and fourth and
causes it to move in and out, which in return pushes and pulls on the
movable cone. This forms air pressure fluctuation in surrounding air.
These fluctuations are known to us as sound. By moving an
electromagnet within the surrounding magnetic field creates electrical
current. As the brain registers current flowing from the electromagnet
it registers increase of pressure inside the car. This then suggest an
open door, open window or loud a noise. All sensors do a significant
job in detecting a break in.

                    Figure 4.2: Alarm Sensors
         **Reprinted with permission of Black Widow Security

Most car thieves are after individual pieces of your car, not the entire
car. They can do most of their work without every opening a door or a
window. Thieves who own tow trucks can just lift up your car and take
the entire thing. Perimeter scanners are a security system device
which monitors what goes on around the car. A basic radar system is
the most common perimeter scanner which consists only of a radio
transmitter and receiver. Like any other radar system the transmitter
sends out signals in the receiver monitors those signals. By this the
radar system determines nearness of a surrounding object. Tilt
detectors are an alarm system which can protect theft with a tow

truck. The tilt detector consists of a series of mercury switches. Each
switch contains two electrical wires and a ball of mercury which is
located inside of a contained cylinder. Mercury (liquid metal) flows like
any other liquid. However, it conducts electricity like solid metal. A
mercury switch contains two wires one of which goes all around the
bottom of the cylinder while the other wire only goes partially from
one side. The mercury is always in contact with the wire that extends
to the cylinder however breaks contact with the wire that extends part
way. The cylinder tilts the mercury then shifts to come in contact with
the wire that extends part way, which will close the circuit which runs
through the mercury switch. When the cylinder tilts in the opposite
direction the mercury then rolls away from the second wire opening up
the circuit. Most tilt sensors have more then one switches which are
positioned at varying angles. Some of which are in close position and
some of which are in open position. When a theft changes the angle of
your car close switches will open and opened switches will close. Once
the switches become off balance and the central brain is alerted.

4.3 The Controller

                     Figure 4.3: Alarm remote
         **Reprinted with permission of Black Widow Security

To control the brain of your alarm system remotely you will have some
kind of portable key chain transmitter. The transmitter works the
same way as a radio control toy using radio wave pulse modulation to
send messages. The primary purpose of this key chain is to have a
way to turn your alarm on and off. As the transmitter controls your
system the pulse modulation acts as a key. Each system has different

communication language so others can not access your car with
another transmitter. A device called a code grabber is a device which
thieves use to make a copy of your key which can disarm your alarm.
To keep this from happening you must use a rolling code algorithm.
The rolling code algorithms will establish and encrypt a new code
every time you activate the alarm.

4.4 Typical Installation

                 Figure 4.4: Installing an Alarm
         **Reprinted with permission of Directed Electronics

     1. Install the light emitted diode (LED). Drill a 5/16th hole then
     put the LED in. The wire should be run to the module. Once the
     wire has reached the module, plug it in.

     2. Install the Siren, figure 4.5, in engine compartment using self
     tapering screws.

     3. Mount the valet switch somewhere the thief cannot easily
     detect it. Plug the valet switch into the module.

     4. Carefully determine the parking light wire. This would make
     the vehicle’s parking lights flash when the alarm is activated.
     Connect the wire from the module into the parking light wire.

5. Connect the 12 volt wire to the positive side of the car

6. Determine the ignition wire, figure 4.4. It is the wire that is
usually refers to as the remote wire. How to determine this
wire? When the vehicle’s key is place in the run position, the
wire would be energized. When the vehicle’s key is return to the
off position, the wire would not be energized. Once this wire has
been determined, connect it to the module.

                Figure 4.5: Alarm Horn
    **Reprinted with permission of Directed Electronics

7. Connect the black or the negative wire to a common ground.
Usually that common ground is the metallic frame of the vehicle.
Drill a new ground with a ring terminal and self tapping screw, if
a common ground cannot be found.

8. Find door trigger wire then connect to it. This wire is usually
energizes when the door is open.

There are several brands of alarms to choose from:

Gargoyle system has a set of on-Guard Series Alarm with Anti-code
Grabbing Technology System. It includes a dynamic coding protection
with an anti-code grabbing technology. The system provides on-board
relays for door locks; dome light, starter disable remote auxiliary
outputs, and a dedicated negative pulsed car horn output. It also
includes two set of 4 button multi-channel transmitters, multi-car
remote control capability, audible/visual arm/disarm with intrusion
alert, code learning receiver with anti-scan technology, dual stage
electronic shock sensor, alarm pre-warning signal, on-board flashing
light relay, remote keyless entry, 2 remote auxiliary channels,
programmable silent arm/disarm, 6-tone, 125 disable siren, active re-
arming mode.

SuperRage Combination Security and Remote Engine Start System
include two 4 button multi-channel transmitters with SecureGlow. It
has a dedicated arm and lock, disarm and unlock, remote start, and an
auxiliary feature buttons. It also transmits on 433 MHZ Electronic dual
stage shock protection. The dynamic code anti-code grabbing
protection, Code learning receiver, and the audible/visual arm/disarm
with intrusion alert are one of the many feature of the system. It also
consist of an alarm pre-warning signal, remote panic, LED status
indicator, remote keyless entry, passive or active arming, auto
lock/unlock with vehicle ignition, active re-arming mode, three remote
start attempt, single tone, 125 dB siren, and a silent arm/disarm. This
security system qualifies for insurance discounts, and gas or diesel
engine operation.

Another miscellaneous alarm system is the Compact Water-Resistant
Siren. It includes an115 dB pain generator compact water-resistant
siren. The Auto & Stereo Alarm includes the alarm that locks into your
cassette player with a deadbolt which can only be removed with the

4.5 The Pulsating Circuit

This additional circuit is added to the system to give the extremities of
the security system a pulsating effect. The vehicle’s horn and parking
light could be connected to this circuit. Instead the horn, maintaining
a constant tone, will have an instant on and off effect. Normally a
flasher, figure 4.6, is used to give the pulsating effect of horn and the

light. This circuit will incorporate a Schmitt trigger. It will consist of
three transistors, six resistors and a capacitor. The capacitor will
generate a square which is the desired on and off effect.

                             Figure 4.6
         **Reprinted with permission of Black Widow Security

An additional pulse waveform can be generated with another diode and
resistor in the circuit (see p. 78). The two NPN transistors are
connected with a common emitter resistor. The value of the resistor is
3.9 K Ohm. This will cause the conduction of the transistor to turn off
the other transistor. The PNP transistor is controlled by one of the
NPN transistor. It will provide the required pulsating effect. A square
wave will be the output from the collector the PNP transistor. When
the circuit is in operation, the capacitor initially charges then
discharges through the feed back resistor from the output voltage. If
the capacitor voltage rises above the voltage of the base at transistor
(Q1), the transistor (Q2) will start to conduct. This will cause the
transistor (Q1) and transistor (Q4) to turn off. The output voltage will
fall to zero. It will send a lower voltage to the base of transistor (Q1).
The capacitor will start to discharge toward zero. When the capacitor’s
voltage approaches below the voltage at the base of transistor (Q1),
the transistor (Q2) will turn off. It will trigger transistor (Q1) and (Q4)
to turn on and the output will rise to the supply voltage. The capacitor
again will start charging then discharging. The cycle will be repeated.

The switching is accomplished with resistors R1, R3 and R5. When the
output is too high, the combination of resistor R3 and R4 in parallel
with resistor (R1) determines the voltage at the base of transistor
(Q1). The resistor (R4) will be compared to be the smaller resistor. If
the three resistors (R1, R3 and R5) are equal, the switching levels
would be approximately 1/3 and 2/3 of the voltage applied to the
circuit. There are usually many various combinations of resistor values
that could be used. The resistor (R4) should be low enough to lower

the output signal to the required amplitude. For example, if the load
draw was about 1mA and the low voltage was ½ volt, the required
resistor (R4) would be approximately 510 ohms. The transistor (Q4)
will supply current to the load and also through the resistor (R4), when
the output is too high. The combination of the feedback resistor and
the capacitor determines the frequency. If the switching levels are 1/3
and 2/3 of the supply voltage, the cycle interval will be about the
product of the feedback resistor, the capacitor and the constant
(0.693). This formula is similar to the 555 timer formula. In the
circuit, the first stage would be when the capacitor voltage falls to the
low trigger voltage. This process will cause the transistors Q2 to
switch off and Q1 and Q4 to switch on. The second stage represents
the rise in the capacitor voltage. It will cause transistor Q2 to conduct
while Q1 and Q4 will turn off. Third stage would be when the
conditions in the first stage occur. The stages start to repeat itself.

4.6 Viper

                         Figure 4.7: Car alarm
            **Reprinted with permission of Directed Electronics

Viper 500 ESP includes the vehicle recovery system (VRS), positive
and negative polarity output for the door lock, two 4 button remotes,
and three channels with five zones. Viper 300 ESP includes two 2
button remotes, parking light flash, and three receiver channels with 4
zones. The Viper 800 ESP includes two 4 button transmitters, super
high frequency, ESP transmitter Code linking, custom configure
memory seats and mirrors, seven receiver channels, built-in power
door locks, parking light flash, built-in dome light supervision, power
trunk/channel 2, and eight zones. The Viper 600 ESP includes a built
in power door locks, parking light flash and a built-in dome light
supervision. It also consists of a power trunk/channel 2, three
receiver channels with five zones.

Viper, figure 4.7, is one of the award winning car alarms that will
protect your car. With the press of a button on a small hand remote,
you are able to unlock your doors, pop your trunk, vent power
windows, open the sunroof and even start your engine. This brand of
car alarm features quit a bit of stuff to keep your car protected. For all
those people who have decoders that can figure out the code of your
car alarm with this Viper car alarm it offers you 68 billion rolling codes.
The codes keep on changing, so a thief will not be able to break the
code to your alarm. It also has different tones including a silent mode,
with that mode the lights flash. If someone bumps your vehicle, it will

initiate a warning sound to let people know that your vehicle is armed
and to stay away. When a thief tries to start the engine of your car
this alarm has an automatic engine disable function. So your engine
will not even be able to turn over. It would be like you have a dead
battery. With a dead battery your car is no good to the thief, if they
even get that far. This alarm has many more features. It has a status
LED to let you know the status of your alarm. Along with the sounds
that this alarm holds it has a feature that makes ones parking lights

4.7 Black Widow

The Black Widow security system is a 3 channel micro processor
controlled vehicle security system. Not only is it a remote controlled
security system it is also a pager receiver. The pager lets you know if
your car is being broken into or vandalized. The pager will work up to
3000 feet away and operates on the FM band for cleaner transmission
which will allow you to transmit and receive confirmation of you
vehicles status. The pager also has a color LCD display so see the
status of your car alarm. The remote control has a built in flashing
parking light relay. You can even start your car with your remote
control/pager. You are able to do anything and everything with your
remote control. Arm/disarm your alarm. You are able to program
your engine start time. The ease of this control you are able to lock
and unlock the doors of your car. Along with many other standard
features of the alarm system you also have options that this alarm
offers. You are able to make your alarm just for you by adding plug in
glass breakage sensor, back up battery siren, remote window control
module and power trunk release.

4.8 Cyclops Alarm System

                   Figure 4.8: Cyclops car alarm
                  **Reprinted with permission of Joe

Cyclops Car Alarm System, in figure 4.8, is easy to install that it can
be installed by anyone. This type of alarm uses an “intelligent relay”
that replaces the starter fuel pump or ignition relay only in selective
vehicles. 2001 Dodge Intrepid installation is shown above. This
system is not very sophisticate so it can be installed in less then 5
minutes by anyone.

This type of alarm not only protects your car it also saves money on
car insurance. To deactivate the alarm system on your car all you
need to do is to insert a digitally coded key plug into your cigarette
lighter or any other outlet in your car. You are also able to use a
remote code hopping transmitter. This alarm is unique in many
different ways. One unique way is that this alarm when installed there
are no wires and visible signs of an alarm system, the car will just not
start unless you deactivate the alarm with your coded key. Another
unique characteristic is that you won’t get any annoying false alarms.

4.9 The Design

In the alarm circuit a delay is implemented into the design. The delay
in the design would be an additional theft deterrent. If the thief was
trying to disable the sound of the alarm by cutting the alarm circuit
wires, it would add additional time to thief time frame. There would a
ten seconds delay in the system. The thief would not be sure if he has
gotten the correct wire. This ten seconds delay would increase the
time the thief has to use in order to deter the system. Based on the
circuit the capacitance would initially store a charge. When the
voltage is initially applied the alarm is also activated. If the thief
luckily cut the accurate wire, the capacitor would start to discharge.
This will maintain the current state of the system. Once the capacitor
is completely discharge, the alarm relay would be inoperative (see
p.84). The relay would return to the normal position. The sounds of
the alarm would cease. The diode (D1) in the system is to establish a
unidirectional current flow, once the source is turn off or wires cut.
The 1.5 Ohm is to substitute for the load of the relay. The meter in
the simulation is to observe the various voltages drops when voltage is
applied or off.

                           Figure 4.9 Transistor

The transistor, figure 4.9, in the circuit is the switching device instead
of an amplifier. The switch effect is similar to turning the lights on or
off in ones house. The transistor consists of three components. The
base, collector and the emitter are the major components. The
collector is responsible for the larger electrical supply. The base is
responsible for the switch effect. It controls the supply of the larger
electrical current. The emitter is responsible for letting the large
current supply to leave the transistor. When various amount of
current is applied to the base, the current that is going through would

be regulated. If the transistor acts like an amplifier, a very small
current could be used to control a large current supply. This method is
usually used for creating binary codes for digital processors. Using
this method it is necessary to have a threshold voltage that is over five
volts. The five volts will be use to open the collector. When the
transistor is used as a switch, five volts would turn the system on. If
the volt is below five volts, the system will be in the off position. The
properties of the transistor are composed of semi-conductive
materials. Most people think of materials being either conductive or
non-conductive. A conductive material is considered to be metals. A
non-conductive material is considered to be wood, plastic, glass or
ceramic. Another name for non-conductive material is an insulator.
Most non-metallic crystalline structures are also considered to the
insulators. The crystals could gain a different electrical conductive
property by forcing the silicon or germanium crystals to grow with
impurities, such as boron or phosphorus. The transistor is created by
forcing the material between two plates, the collector and the base,
together. When current is applied to the base of the semi-conductive
material, electrons will gather until it is able to discharge.

There are two types of transistors which are the junction transistor and
the field effect transistor. There are two types of junction transistors.
They are the p-type and the n-type. In the design, our group will be
using the NPN type transistor. The junction transistor consists of a
thin piece of a semi-conductor material between two thicker layers of
an opposite type of material. The NPN transistor is determine when
the outside layer is n-type and the middle layer is a p-type. The
middle layer is considered to be the base. One the external layer
would be the emitter, while the other layer would be the collector. The
junction is where the collector, emitter and base meet. For the NPN
transistor to work correctly, the proper voltages should be applied.
The voltage that is applied to the base must be more positive than the
voltage at the emitter. The voltage that is applied to the collector
must be more positive than the voltage at the base. The voltage
applied is usually from a battery source. The emitter will usually
supply the electrons. The base will draw the electrons from the
emitter. This process will happen due to the more positive charge of
the base from the emitter. The flow of electrons creates a movement
of electricity through the transistor. As the current passes from the
emitter to the collector, it goes through the base. If there are small
changes in the voltage at the base, it could impact large changes in
the current leaving the collector.

                                Chapter 5

Speed Regulator Unit

This feature is another feature of the Radial Security. It is a device
that consists of two main electronic circuits. The speed regulator
circuit and the fuel cut-off circuit are embedded in the same unit. The
speed regulator unit only activate when a signal is sent to the speed
control circuit. Based on our design it only controls automatic
vehicles. When the speed regulator system is activated, it will
minimize the speed of the vehicle and also disengage the fuel supply
for approximately 3-5 seconds. The speed regulator feature is
applicable for minimizing the theft rate of the vehicle. It slows the
automobile down to a safe drivable distance. Initially the speed
regulator was design to stop the vehicle instantly but that process
would lower the levels of safety. For example, a driver is robbed of her
car at the stoplight. As the vehicle proceeds from the reference point,
the alarm will activate. The speed controller suddenly stops the
vehicle. If the thief has stop in the intersecting, he will be vulnerable
for an accident by the on coming traffic. As Engineers, we have to be
positive contributor to the humane society. Therefore safety is always
a key when designing innovation for the humanity. When the speed
controller is activated, the minimize speed of the vehicle will be below
10 miles per hour.

5.1   Schematic

The schematic diagram represents a general overview of the Speed
Controller Device. It integrates speed control circuit and the fuel cut-
off into one device.

                          Control Unit      Speed Control
         RF Signal

                                  Figure 5.1

When the vehicle has exceeded the calibrated distance from the
reference point, the radio signal sends a signal to the control unit. The
control unit interprets the signal then triggers the speed regulator.
Figure 4.1 gives a general overview of the process for activating the
speed regulator. One of the circuits in the Speed Regulator Unit is

speed control circuit, which is figure 5.2. In the de-energize state, the
vehicle speed sensor (VSS) makes a continuous path to the engine
control module (ECM). When the speed control relay is activated, the
continuous path from the vehicle speed sensor (VSS) to the engine
control module (ECM) will be disengaging. The disengaging process
would trigger a fault to the vehicle engine control module. Engine
control module would temporarily disengage the transmission. The
automobile would be the decelerating state. The vehicle’s
transmission would not engage until it is traveling about 10 mile per
hour. The vehicle will still be drivable but it would not go over 10
miles per hour. This feature is controlled by the engine control module
(ECM). It is trying to protect the vehicle from an error it sense that
could damage the transmission. In actuality, the transmission would
not be affected. We are creating a device that would manipulate the
engine control module (ECM) to operate to our expected out comes.

  Signal from          Control
  Control Unit         Relay

                           Pulsating 5 Vdc      Module

                                 Figure 5.2

The fuel control relay (figure 5.3) is also embedded in the Speed
Regulator Unit. It works similar to the speed regulator relay but it has
a 10-15 seconds delay. In the de-energize state the fuel solenoid
makes a continuous path the fuel pump. When the relay has received
it signal from the control unit it will disengage the path to the fuel
pump. The fuel pump pause the fuel flow to the injector for 10 to 15
seconds. This additional process will achieve the slowing down process

of the vehicle from 75 mile per hour. After the 10-15 seconds delay,
the fuel pump circuit is re-engaging. This will provide power to the

                           Fuel Control                Fuel
                           Relay with a              Solenoid
        Signal from           Delay
        Control Unit         (10-15
        (12Vdc)             seconds)

                                                   Fuel Pump

                               Figure 5.3

5.2   Vehicle Speed Control

                               Figure 5.4
              **Reprinted with permission of Chuck Kopelson

Our design restraints limited our group innovations of creating a
successful universal security system. An ideal vehicle speed control
should be embedded into the engine control module (ECM). This
device is considered to be the computer of the automobile system. It
acts like the brain for the vehicle. It will decide what actions to take
when the module receives a fault in any system. Since our group does
not have the opportunity to design and prototype at the initial stages
of the vehicles production, our unit will be compatible with all
automatic engine control module. At this time, our product will be
considered an after the market device when fabrication is complete.

How does the vehicle speed sensor works? The vehicle speed sensor,
figure 5.4, is a device that is mounted on the transmission. The device
is usually an inductive type switch or an electronic Hall switch. As the
vehicle speed sensor is sensing the revolution of transmission gears, it
is also sending a pulsating 5 Vdc to the electronic control module
(ECM). The signal is also used indirectly to power the speedometer.
The vehicle speed sensor is factored when regulating the transmission
shifting controls and the cruise controls. The speed is usually
determined by comparing the number of revolution of the transmission
over a fixed period of time. The vehicle speed sensor can measure the
number of revolution from the transaxle shaft output or the
transmission. The increase pulsation of the vehicle speed sensor
output depends on the increase of the number revolutions in the
transmission. The vehicle speed sensor is only responsible for
monitoring the counts of the transmission. Embedded in the engine
control module a digital clock is used to measure time. The engine
control module is programmed to continuously analyze the pulsating
output from the vehicle speed sensor against the internal clock. This
process will determine the actual speed of the vehicle. Whenever the
automobile is in the forward motion, theoretically the vehicle speed
sensor will be sending a signal to the engine control module. When
the vehicle is operating at low speeds, for example 3 to 5 miles per
hour, the vehicle speed sensor would not be able to send a strong
pulsating signal to the engine control module. When the engine
control module has received that fainted signal, it is programmed to
disregard that signal.

Initially there were two types of vehicle speed sensors. In the early
80’s General Motors used an optical vehicle speed sensor for their
automobiles. The optical vehicle speed sensors work off a
conventional speedometer cable. The optical vehicle speed sensor was
located in the back of the instrument panel inside the speedometer
head. It uses a light emitting diode (LED), photo cell, and a two

bladed mirror reflector. The mirror reflector would generate an
electrical signal. The LED is powered and gives off light when the
ignition switch is on. Inside the instrument panel, the speedometer
cable spins the two bladed reflectors when the vehicle is in motion.
The two bladed reflectors will rotate through the LED beam. It will
disrupt the beam twice for each revolution. No LED beam reaches the
photo cell when the two bladed mirrors are not breaking the beam. As
the mirror passes through the LED beam, the beam is projected to the
photo cell. The photo cell generates an electric signal when it comes
in contact with the LED beam. The output signal would be similar to
the signal in figure 5.5. The on and off projection to the photo cell
produces a pulsating signal. As the on and projection increases, the
signal of the pulsation will also increase. The engine control module
(ECM) will also interpret the pulsating signal then determine the
accurate vehicle speed.

                            Figure 5.5
                 **Reprinted with permission of Chuck Kopelson

Later that time frame there was new design for vehicle speed sensor.
The design was based on magnetic impulse. This sensor is available in
most new vehicle. Even though there might be two types of vehicle
speed sensor, our design will be compatible with both. The magnetic
vehicle speed sensor, figure 5.6, will replace the speed cable if the

vehicle has a digital instrument panel. When this type of vehicle speed
control was used, the pulsation generated an alternating current
voltage. The engine control module could not handle that type of
pulsating signal. From the early vehicle speed sensor to the engine
control module a buffer module was included. The buffer module
would convert the vehicle speed sensor pulsating output to a digital
output. The engine control module will be more able to compute the
pulsating digital output. As technology increase, the buffer module
was eliminated from the circuit. The pulsating digital output is now
achieved through an internal conversion.

                             Figure 5.6
               **Reprinted with permission of AC Delco

     The vehicle speed sensor is design to be in adverse conditions. It
faces strenuous heat, vibration, and corrosion from the transmission.
It is a reliable device with a long life expectance. Whenever the
vehicle speed sensor fail, it is usually cause by the physical damage of
the transmission. For example, the sensor was experiencing a
continuous environment of excessive heat in the transmission. In the
optical vehicle speed sensor dirty reflecting mirrors could cause a
problem. It would inhibit the process of generating a pulsating signal
from the light. Since the engine control module is considered to be
the brain of the vehicle, it would respond accordingly. When the
vehicle is in motion and the engine control module has not received a
signal for the vehicle control module, the engine control module would
trigger a set of codes.

                             Figure 5.7
               **Reprinted with permission of AC Delco

For General Motors (GM) the code would be 24. For Ford the code
would be 27, 29, and 452. For Chrysler the code would be 28 and 15.
The speedometer and the odometer cannot work when the vehicle
speed sensor sends no signal especially when the vehicle is in motion.
For instance, if a vehicle receives the code 24, it would experience an
increase in fuel consumption, poor idle quality or stalling. This method
is helpful in bring the vehicle to a low speed. On some vehicles the
engine control module will trigger a temporary fuel shut down
sequence that would decelerate the vehicle. When the security system
is activated, the engine control module would receive a continuous
fault from the vehicle speed sensor. For example, if the engine control
module receives a temporary fault from the vehicle speed sensor, the
vehicle would experience an intermittent sudden loss in power and
poor performance. The vehicle would return to its normal operation
after its temporary fault from the vehicle speed sensor. In figure 5.7,
the normal operation to of vehicle speed sensor (VSS) send an
oscillating signal to the engine control module (ECM).

                            Steering Wheel Controls
                             Vehicle Speed Signal
                              Clutch Pedal Switch
                              Brake Pedal Switch

                                 Cruise Control

Throttle                                               Actuator

                                                        Cable to control
                                                        the throttle valve

           Throttle Valve

                               Figure 5.8

5.3   Fuel Cut-off

The fuel cut off circuit is necessary for restricting the power to the
vehicle. The fuel cut off circuit will only be engage temporarily. When
the engine control module (ECM) receives a fault from the vehicle
speed sensor (VSS), it usually triggers the fuel cut off circuit. Not
engine control module behaves in the same manner. With our fuel cut
off circuit the vehicle will definitely slowing down to our desired speed.
In the vehicle the purpose of the fuel circuit is to provide a
combination of fuel and air mixture. This mixture occurs in the engine
of the automobile. Usually the fuel to air mixture is proportional to the
speed of the vehicle. It would be various loads that the engine
experience. On a standard vehicle the emission controls, the fuel
pump, the carburetor and intake manifold are the standard part of the
fuel system.

In the older vehicle, the carburetor is more common. The carburetor
is mainly use for providing the correct air and fuel mixture. In figure
5.9, it shows the basic process of the carburetor under different loads.
Based on the engine load or vehicle speed, the carburetor carefully
measures the amount of fuel vapor that is supplied to the air. Since
this a complicated process, prefect carburetion is difficult to achieve.
Perfect carburetion is usually not met due to various engine loads,
temperature and speeds. If the engine was started in a cold
environment, the carburetor would distribute a small amount of rich
fuel to the air and fuel mixture. While the vehicle is in the idle
position, suction to the air and fuel mixture increases as the throttle
on the carburetor closes. This strong suction to the air and fuel
mixture creates a thick spray of fuel through the nozzle from the float
bowl. The float bowl will be in the filled position because the
supported needle valve closes when the float bowl is full. As one
presses the accelerating pedal, more fuel is provided. The accelerating
pedal is link to a throttle plate that opens. It also opens the choke
plate. It is responsible for sending force air through the barrel.

                            Figure 5.9
      **Reprinted with permission of Holley Custom Speed Shop

When the float bowl is empty, the supported needle valves allow more
fuel to rush in. The accelerating pedal also engages the fuel pump
that, provide fuel through out the system from the fuel tank. Keeping
the fuel flow in one direction is constantly a challenge especially when
the fuel pump is turn off. In order to main that one direction, low
pressures has to be establish in the carburetor and lower pressures in
the cylinders. Since atmosphere is our reference pressure therefore all
the other pressure that exists through out the fuel system has to be
lower than the atmospheric pressure. The lower pressure is normally
created by air or liquid flowing through the narrow center of the barrel.
In the cylinder the downward movement of the piston would create a
lower pressure that exists in the carburetor. While the piston goes
down, fuel is siphoned from the carburetor. The precisions of creating
low pressure through out the system would cause a one direction of
fuel transport.

Today, most of the vehicles use fuel injectors instead of carburetor
systems. In the fuel injection system most of the complicated parts
are eliminated. With the fuel injection system, fuel is directly sprayed
into the cylinders. This is sometimes referred to as the combustion
chamber. The injectors of fuel system are located in the combustion
chamber. The fuel injectors calculate the quantity of air and fuel
mixture before spraying into the combustion chamber. The fuel
injector, figure 5.10, is considered to be an electromechanical device.
It consists of a solenoid that controls the flow of fuel. When an electric
current is applied to the injector coils, it creates a magnetic field. That
magnetic field causes the armature to move upward. This upward

movement allows the flow out of the nozzle. As fuel leaves the nozzle,
it is under a strong pressure. The shape of the tip of the nozzle allows
the fuel to be sprayed in a cone shape pattern. When the electric
current is not applied, the armature goes back into the original
position. In the older vehicles, the mechanical fuel injectors are
prominent. It uses the governor and a throttle linkage. The
mechanical fuel injectors are mainly used in diesel vehicles. In the
electronic fuel injector the fuel has no resistance to overcome besides
insignificant friction losses. The pressure in the injectors can be set
very low values. This process would cause the injectors to obtain a
maximum atomization. The fuel control unit determines the amount of
fuel that is dispersed from the injectors tip.

                            Figure 5.10
         **Reprinted with permission of Hilborn Fuel Injection

The engine control module would control the fuel to the engine during
a cold start or under excessive loads. The fuel system works under
constant pressure. The injectors could be program to have continuous
flow or a variable timed injection. When the electrical fuel injector is
compared to the mechanical fuel injector, the electrical fuel injector
has an impressive set of advantages. It has fewer moving parts and
the components operate in the given engine temperature. There is no
need for special pumps, pulsation in the fuel lines and critical filtration
requirements. Beside the electronic injectors are cheaper and they
last longer.

Our fuel control device would temporarily stop the flow of the fuel
through out the fuel system. It would disable the fuel pump
temporarily. The fuel pump is merely design to maintain enough
pressure, delivery and circulation. If there is no low pressure in the
fuel system, the fuel cannot follow through out the fuel system. The
fuel could flow in any direction to gravity in the fuel lines. The fuel
pump would maintain that constant pressure flow especially in one
direction between the pump and the injectors. This method is also

necessary for keeping the fuel from boiling. If the fuel is not been
circulated, a vapor lock will occur. The vapor lock would occur where
the fuel line is bent. As the fuel evaporates, the gases would be trap
in the position where the fuel line curve. When there is an air or vapor
lock in fuel line, the result would be loss in engine performance. In
the carburetor, if there is an excessive pressure in the fuel line could
cause the float needle to be offset. This would a high fuel level in the
float chamber. The driver of this vehicle would notice high fuel
consumption over a period of time. A fuel pump generally deliver
approximately ten gallon of fuel per hour at an excessive engine
speed. Even though there are several types of fuel pump, they will
produce the same effect.

The mechanical fuel pump consists of a vacuum booster section. The
vacuum booster section is managed by a fuel arm. As the first stroke
or suction, the fuel pump arm starts operating when the camshaft
begins to rotate. A vacuum is created in the pump chamber when the
diaphragm and the level is pull down against the diaphragm spring.
This suction or vacuum process will hold the outlet valve closed while
the inlet valve remains open. It will cause the fuel to flow through the
inlet valve of the pump chamber and the filter screen. The diaphragm
is pushed up by the diaphragm spring on the return stroke. Fuel is
allowed to flow the outlet to the carburetor when the outlet valve
opens and the inlet valve closes. The operating level cannot move by
the pump arm. It is connected to the pump arm which allows a free
downward movement. The pump arm pushes the arm to follow the
cam without moving the level. The diaphragm spring can push the
lever upward. This movement occurs when the pressure in the
carburetor is less than the pressure around the diaphragm spring. The
fuel will flow to the carburetor from the fuel pump. This only occurs
when the float needle is not seated and the passage in the carburetor
float chamber is open.

                            Figure 5.11
                  **Reprinted with permission of Joe

The electrical fuel pump, in figure 5.11, replaces the diaphragm
component that exists in the mechanical pump. It is actuated by an
electrical solenoid. Most vehicles today use this type of fuel pump.
The fuel pump continuously operates while the vehicle’s engine is
running. It maintains a constant pressure in the fuel system. The
constant pressure in the fuel lines could provide a maximum fuel
supply, if the vehicle’s engine required it. If the engine requires less
fuel, the fuel pump does not send a full potential. The fuel system has
the potential due to the displacement type of the system. The system
is not a positive displacement type like the mechanical pump. The
turbine in the fuel system will run without the pumping of fuel. Unlike
the mechanical counterpart, there is no need for inlet and outlet valves
in the pump therefore the fuel flow freely through the turbine.
Normally a relay is used in the circuit for the fuel pump. This should
stop the fuel flow in the event of an accident occurs.

5.4   A Typical Speed Controller

It must be a wonderful feeling to cruise down the interstate with no
traffic. Vehicle speed control has been with us for several years. This
system consists of mechanical and electrical components. When you
refer to a driver about controlling the speed of an automobile, he
would state that the brakes and the gas pedal control the speed of the
automobile. Some driver would actually think that he is the brain for
the vehicle. He would not understand the engine control module is the
device that controls the speed. The vehicle speed sensor sends an
electrical pulse to the computer. It is mounted at the shaft of a
transmission. The transmission is use for driving the wheels of the
vehicle. The frequency of the pulse increases as the vehicle speed
increases. The engine control module will try to match the desired

speed to the corresponding frequency pulse. When the cruise control
is set, the vehicle will try to maintain a constant pulse from the vehicle
speed sensor. The control box of the cruise control primarily had three
functions. The vehicle speed is stored when the set button of the
cruise control is engage. When the cruising speed is cancel, the
desired cruising is still program into the control memory. The cruising
speed would be erase from memory when the vehicle ignition is turn
off. The cruising speed that is stored in the memory is compared. It
compares the pulse from the vehicle speed sensor with the stored
value in the control module. The control module will send a pulse to
the vacuum controlled diaphragm.

                            Figure 5.12
              **Reprinted with permission of Karim Nice

The vacuum controlled diaphragm is connected to the accelerator
linkage. Figure 5.12 represent the vacuum control diaphragm. The
cruise control module regulates the amount of vacuum the diaphragm
receives. As the pulse increases, the more the vacuum pressure
increases to the diaphragm. The increase in vacuum pressure
increases the force on the accelerator linkage. The cruise control
module will try to compare the new desired speed to the current
speed. Force will still be applied to the accelerator linkage until the
vehicle reaches the new desired speed. Therefore the vacuum
pressure is constantly applied until the control module triggers a
constant pressure. The number of pulses is compared to maintain the
new desired speed.

                            Figure 5.13
              **Reprinted with permission of Karim Nice

When the vacuum control diaphragm was set from the cruise control,
it would hold the actuator in place. Depressing the gas pedal would
increase the throttle position of the vehicle. The actuator is connected
to the gas pedal. In the picture above, figure 5.13, one of the cables
is connected to the gas pedal and the other is connected to the
vacuum diaphragm. Increasing the vacuum would increase the
throttle position. This would increase the speed of the vehicle while it
is in the cruising mode.

In the fuel circuit a delay is also implemented into the design. The
delay is in the design would also be an additional theft deterrent.
When security system is activated, the fuel circuit would be energized.
The fuel circuit would temporarily cut off the fuel to the engine. It
would be approximately 5 to 7 seconds cut-off in the system. The
thief would be limited to a powerless vehicle. This few seconds should
be enough to lower the vehicle’s speed. Due to the safety of the on
coming traffic and the pedestrians, the thief would have access for
moving the vehicle at a low speed. Based on the design the capacitor
would act like a short in the circuit (see p.101). The 1.5 Ohm is
simulating the load of the relay in the design. This process would by-
pass the fuel relay. Hence the relay would be energized temporarily.

Initially when the voltage is applied to the circuit, the relay is instantly
energized. After a few seconds the capacitor would be fully charged.
Its properties would behave like a short. This process would
deactivate the relay. The diode (D2) in the circuit would prevent the
capacitor from discharging to the relay circuit. The meter in the
simulation is to observe the various voltages when voltage is applied.

  Table 5.1: Components Cost

                 Unit                                Price
    Transistor PNP                     $2.50
    Transistor NPN                     2.50
    Capacitor (1uF-1pF)                0.85-2.50
    Resistors (3.9ohm-39kohm)          2.00-3.00
    Relay                              3.25
    Diode                              1.95

                     CHAPTER 6

             Global Position System



                     Transmitter   data   Receiver

              Figure 6.1: Implementation layout


Radial Security GPS system

Radial security having features of the radio frequency communication
will be more effective in preventing theft, by having a locator product
on the vehicle. Considering this, a patched antenna will also be used,
instead of the highly visible antenna normally found on the cars. The
antenna will be placed under the bumper/ hood of the vehicle.
Given the time frame of the project, it will be more effective to have
an online global position system tracking service. This is due to the
fact that we have to take into consideration, the accuracy of position
and timing of the vehicle’s location.

Specifications of Radial Security Tracking System
The automotive security unit to be used in the vehicle will be a
removable, inexpensive unit. The project being funded by the group
members looks for an efficient GPS/ navigator with the following

      Cost: < $80.00
      weighs ~ 1lb
      size: 4”x 5”x 1”
      accuracy within 100’
      Hidden antennas/ patch antennas

The design to be built will be a cost efficient unit, where a customer
can find reliability and dependability in a safety device for the retrieval
of a stolen vehicle. The weight and size of the unit is very important as
we want it to be concealable when placed in the vehicle. This will allow
a thief not to know that a vehicle location unit is present in the vehicle.
The GPS unit then needs to have an antenna, such as a patch antenna
that can easily be flushed with the vehicle.


Magellan 310, 12 channel GPS navigator

While researching, the group decided to use a gps system where maps
can be downloaded of desired areas. One such product looked at was
the Magellan 310, 12 channel GPS navigator. The small-sized Magellan
310 allows one to use the software on a laptop or pc navigation
software. The Magellan GPS has the following features:


                                                   Powerful 12-parallel channel receiver
                                                   NMEA data output for PC interface
                                                   DGPS ready
                                                   Super sensitive quadrifilar antenna for
                                                    superior tracking
                                                   EL Backlit display
                                                   20-hour battery life"EZstart" operation
                                                   100 landmarks, 1 reversible route with 10
                                                   3 easy-to-follow graphic navigation
Figure 6.2: Magellan 310                           Displays distance, bearing, heading,
**Reprinted with the permission of Intertrack       direction, steering, speed, time to go,
                                                    elevation, XTE, time and satellite

      Dedicated GOTO, NAV, MARK, MENU and LIGHT keys for
                   quick and easy operation

         Resettable trip odometer
         9 coordinate systems; Latitude/Longitude, UTM, OSGB, Swiss,
          Swedish, Irish, Finnish, French and German
         13 map datums; NAD27, WGS84, AUST84, EUROPE50,
          and GERMAN
         Maximum Speed:950 MPH
         Rugged, durable and weatherproof
         Pocket Size, 6.2" (h) x 2.0" (w) x 1.3" (d) / 15.75 cm x 5.0
          cm x 3.3 cm
         Lightweight, only 6.8 oz / 192.7 gm


Drawback of Magellan 310

For design purposes, it was decided that the global coverage of North
America was not needed. The Magellan 310 GPD proved useful, as
coverage area of the local area is accessible to download to the GPS
unit. We would then track the vehicle by having the GPS unit
communicating with a laptop. The unit meets most of the required
specifications of our design. However, the main aim of the project is to
have a global position unit that would be accessible from a remote
location. The Magellan GPS, being a user-friendly navigation/ tracking
system, would only be accessible while driving in the vehicle. Another
draw back with the unit is that it would not communicate with the
laptop, until after a journey when it had saved desired locations or
routes traveled. This would then be downloaded to a laptop or pc unit.
It was decided not be a good alternative, because if the vehicle were
to be stolen, it would be impossible to track the car and know the
direction in which it is heading. Added to this, the Magellan 310 was
found to be expensive at a price of $200.00, which is out of the
group’s budget.

Intertrack Vehicle Locator Unit

Another alternative looked at was the
online gps service. The online service
has an effective coverage of North
America. Once the vehicle is turned on;
the gps/locator product will also be
powered on. However, the locator unit
will be programmed to have a
deactivation time of two hours after the
vehicle is turned off.

                                           Figure 6.3a: VLU
                               **Reprinted with permission of Intertrack

This will help to better retrieve the vehicle in a quicker time period.
Added to this, having the internet service the vehicle will be more

helpful in viewing the area the car is heading. The vehicle location
unit was selected for its on-line service, as well as added features to
be enhanced by radial security. The unit has multiple ports to add
selected features such as the car alarm system and control of the car
speed. These added features will be design and build by radial
security’s team.


Installation of Vehicle Locator Unit

Being a precision- engineered communication device receiving signals
approximately 20,000 kilometers above the earth’s surface, the area
on which it is positioned is critical to the operation of the device. From
Intertrack installation guide, the antenna must be mounted in an area
where it has a direct view to an open sky. For optimization of
communication the unit needs to be mounted/ installed on the
automobile, where it is in limits of the 10 feet antenna coaxial cables.
It is decided that it would be best for the VLU be mounted in the trunk
of conventional cars, where its dual antenna in clear view of the sky
would be fastened under the rear parcel shelf panel. For other
vehicles such as a pick-up truck, the VLU would be placed under the
dash or a kick panel to be connected with the dual-band antenna,
which is secured under the padding of the vehicles top.
The SUV’s, being a larger model car than the conventional passenger
cars, will support the VLU being installed in a similar manner to the
pick-up truck. The VLU will be placed behind the glove box, or under
the dash connected to the dual-band antenna under the vehicle’s
panel’s top pad. It is important to leave the black harness unplugged
until instructed to do so. Most VLU installation requires only two
connections to be made. Though this sounds simple, it is important to
have a professional technician install the VLU if one is not familiar with
testing the wires, or installation of such alarm safety device. This
ensures a safe installation of the unit to prevent any damage.

Listed below are some of the devices that can be integrated with the
    Alarm System
    Remote Engine Starter
    Remote Keyless Entry System
    Window Control
    Modules
    Trunk Releases

Figure 6.3b: VLU pins layout
**Reprinted with permission of Intertrack

Particular attention will be paid to the alarm system speed controller,
and RF communications systems to be built. The various pin positions
seen above have a specific output attribute. The car alarm system to
be built will be connected to pin number 4.

      Table 6.1: Wiring Harness Function Description

       **Reprinted with the permission of Intertrack


NT-100 Expansion Module

The optional NT-100 expands one output of the Intertrack VLU to two
outputs. As seen in the diagram below. Intertrack has two ports to be
connected to NT-100 Expansion module. The module is especially
useful since the alarm (light flash), radio frequency remote and
vehicle’s speed controller are to be integrated with Radial Security
unit. Below is a scenario of how the alarm system will be connected to
the NT-100 expansion module.

Figure 6.4a: Connecting alarm to the NT-100 expansion
**Reprinted with the permission of Intertrack

Sounding Device Input
The VLU system can be configured to sound an alarm, by connecting
the brown or yellow wire to an output wire from a horn.

                  Figure 6.4b: Sounding Device Input

RF Sensor/ Speed Controller:

 The Blue wire is used as a supplementary input. It will be used to
connect the automotive RF sensor, which in turn will affect the speed
controller and the alarm unit of the vehicle when the automobile has
exceeded its radial specified parameter.

                      Figure 6.4c: Sounding Device Input
                     **Reprinted with the permission of Intertrack

The AEGIS, which is a tracking and remote controller unit of the
vehicle, will be used because it satisfies the requirement of the vehicle
locator unit to be used. Below are the specifications of the unit.


GPS Receiver:     L1 frequency. C/A code Parallel 12
                  channel tracking

Accuracy:         Within 30 meters (100’) 95% of the time

Communications:         3.0W RF transmit on the Aeris network

Inputs (3):       Alarm sense (15 sec.) and 2 Aux.
                  Inputs (2 sec.)

Outputs (5):          Solid-state switch to ground, 2
                  momentary & 1 latched.

Power:            2.0W peak, 9-20VDC operating

Power source:           Vehicle battery plus 1.2 Ah B/U batteries

Current Draw:     80ma nominal/162ma full on/10ma
                  sleep & 1.2 A transmit for 1 second.

Altitude:         -200 to +5,000 meters

Packaging:        Splash & dust proof high impact plastic

Size:             100mm x 50mm x 45mm (4”X 2”X1.5”)

Weight:           Less than 170 grams (6 oz.)

Antenna:          Active Dual-band hidden GPS/Cellular
                  76 X 101.6 X 1.27 mm (3 X 4 X 0.5”)

   The online service was dismissed for several reasons. First, the
   vehicle locator unit has most of the features that will be design by
   the group. This would leave the group with very little or no work
   implement. In addition, the cost of the unit was very expensive.


 Motorola M12 Oncore GPS module

 The final decision made on the gps unit to be use is the Motorola M12
 Oncore GPS module

                     Figure 6.5a: Motorola M12 Oncore
                     **Reprinted with permission of Motorola

      The M12 Oncore GPS unit will be placed in the vehicle. The
      outputted data will be encoded by a transmitter, which will also be
      placed in the vehicle. The transmitter will be serially communicating
      with a receiver at a remote location. This receiver, on the remote
      end will then encode the data to be displayed on a pc unit/laptop


 Communication between the GPS receiver and a laptop

The highly developed receiver unit is especially designed for automotive
applications. The circuit is integrated with an active micro patch
antenna. The GPS receiver receives information of the speed, time, and
direction in which the vehicle is heading by tracking the NAVSTAR GPS
satellites. The signals received are converted down to an IF frequency of
1575.42 MHz and are digitally processed to achieve the navigation

information. The information reaching the receiver is then sent over the
10-pin connector.
The data sent over the pin connector is relayed from the serial
communicator to a transmitter. This data transmitted will be received at
a remote location by a receiver, which will subsequently be decoded.
This information is then relayed to a laptop, where the time, speed and
direction in which the vehicle is traveling is displayed.

 Flowchart 1: Communication of GPS unit to a laptop

                                   M12 Oncore GPS






             Table 6.2: M12 Function Description

*** Reprinted with the permission of Motorola

The M12 GPS unit weighs no more than 25 grams and is
Below are the specifications for the GPS receiver unit

            Figure 6.5b: M12 Layout
            **Reprinted with the permission Motorola



            Table 6.3: Electrical

Specifications M12 cont

RF characteristics of M12

 RF Requirement for Antenna


 **Permission granted from Motorola to use specifications chart


Before the gps signal can be transmitted to the receiver at a remote
location, the data has to be encoded. The HT 600 model will be used to
encode the signal. Below is a schematic diagram of the time edged
triggered encoder.

      Figure 6.6a: Time Edge Trigger Encoder

      **Reprinted with the permission of Ming Microsystems, Inc

Figure 6.6b: Pin Assignment for the TE trigger HT600

**Reprinted with the permission of Ming Microsystems, Inc

The table below describes the pin number and their applications. This
gives a better understanding of each pins purpose when doing the
circuitry of encoder and the transmitter.

Table 6.4: Pin Number and their Applications

       *Reprinted with the permission of Ming Microsystems, Inc

The block diagram shows the various components the HT600 compose
of in order to encode a data.

Figure 6.6c: HT600 Internal Process

**Reprinted with the permission of Ming Microsystems, Inc

The HT600 is time triggered when it is active high. Once time
triggered, it is enabled to receive and encode a three-word
transmission cycle. The encoder will stop its cycle of encoding if the
transmission is set or falls low. The diagram below shows the cycle of
three words encryption and timing transmission.

                           Figure 6.6d: Transmission Timing

Diagram shows corresponding information word for an encoding cycle

      Figure 6.6e: Encoding Cycle

**Both diagrams were reprinted with the permission of Ming Microsystems, Inc

The following table shows three logics that each programmable
pin/data can be set to: high, low, or floating. The status of the 18 bits
address/ data will be scanned and transmitted serially from AO to
AD17 if the transmission enable pin is set high.

Table 6.5: Setting Programmable Pins

** Reprinted with the permission of Ming Microsystems, Inc

The schematic diagram below shows how the FM transmitter will be
connected to the encoder.

Figure 6.6f: Connecting HT600 with a transmitter

** Reprinted with the permission of Ming Microsystems, Inc

The following flowchart gives an overview of how the encoder and
transmitter in the vehicle will communicate with each other.

Flowchart 2: Encoder and Transmitter Communication Layout

**Reprinted with permission of Ming Microsystems, Inc



A transmitter is needed in order to send the data to (obtain by the GPS
unit) a remote location. Below is a schematic diagram of the FM
transmitter, which is operates at broadcast frequency range of 80-130
MHz. The circuit design consists of two NPN transistors. The
transmitter when operated at 9 volts is functional within 300 feet;
similarly at 12 volts it is operable at a range of 400 feet. Signals
transmitted by the transmitter are amplified through the microphone
by Q1, Q2 and C5. The capacitor C6 can be made by doing the
Using 4 inch of the insulated gauge wire, double it and bend it over.
Twist the wire at ½” inch from the open end base. After twisting the
wire for about 1”, cut the looped end of the wire. This will leave ½” of
the wire twisted and another ½” of untwisted wires for the leads.

L1 is made of 6 turns from two 24 gauge insulated wires, which are
wounded around a pencil or ball point pen of about 4mm. After
winding, the two coils are carefully removed from each other and the
antenna is soldered to the coil made. Soldering of the antenna on the
transistor side is done 2 turns up from the bottom. The antenna should
be in the length of 8-12 inches.

Figure 6.7a: Schematic of FM transmitter with Antenna Connection
**Reprinted with permission of PTM


Receiver at Remote Location

Models of the Norpak TTX47X TV Data Receiver are equipped with an
external port to communicate with a serial COM port of a PC as RS232
data. The TTX74X receiver is receptive of data directly from an
antenna or cable. RF Data is received and decoded at a speed of 115,
200 bps, which is delivered to a PC serial port. After encoding of the
signals, transmission is followed from the inside a vehicle. The
encoded data is then received by a gps receiver from a remote
location. This information will be displayed on a laptop to view/ track
the location of a vehicle. An ideal receiver is one being able to
interface with a laptop. Such feature can be found in the Norpak
TTX47X Data Receiver.


The serial port, RS-232 allows direct communication between a PC/
laptop and the TTX74X receiver. The receiver is connected to
oncoming signals through a radio frequency input. The receiver
provides continuous monitoring for any NABTS or WST data. Before
the data is loaded to the laptop processor, the data is configured to
the correct packet address, data mode and forward error corrected to
keep loading at a minimal. The packet address is an authorized
address receiving a designated data stream. Because the receiver
corrects any potential error in the data, the data delivered to the PC/
laptop is the same as the data received by the encoder. The table
shown below provides the specifications of the TTX74X receiver.

Table 6.6: TTX74X Specification
5.57 "w x 1.52 "h x 6.1"d (14.14 x 18.97 x 6.93 cm)
2 lbs. (.9 kg)
Connectors (rear panel)
RF Input: VHF/UHF/CATV F-type or IEC
Video Input: BNC
Output: serial port (D9 female DCE)
PC Requirements
386 or higher PC
9 pin or 25 pin serial port with a 16550 UART for baud rates
higher than 19,200
+5V from external power supply
Tuning System
Front panel indicators: 6 data detect
Operating temperature 32 to 104º F (0 to 40º C);
-40 to 149º F (-40 to 65º C) storage
Humidity 10-90% non-condensing



The data transmitted from the encoder is sent to the decoder. The
decoder sees the address as the first N bits and the last 18-N bits as
the data.

      Figure 6.9a: Address/Data Pins location
      ** Reprinted with permission of Ming Microsystems, Inc

The table below provides description of decoder pins and their
applications. It also shows the pins connected to internal circuitry.

  Table 6.7: Pin Description

** Reprinted with the permission of Ming Microsystems, Inc

The electrical characteristics of the decoder are shown in the table
below. It is important to know the stress level of each parameter to
prevent any damage of the circuitry.

   Table 6.8: Electrical Characteristics

** Reprinted with the permission of Ming Microsystems, Inc

The flow chart on the next page demonstrates the operation of the
decoder. It is seen that if the decoders detects the right address of the
code received, it will store/ latch the data until the next valid data is
received. Likewise, if the address of the code is incorrect it will reject
the rest of the word.

Flowchart 3: Decoder Operation


                        in                      Disable VT & ignore the
                                                rest of this word

                      Address bits              No

                      Store data          Yes

                      Match                      No
                      stored data?


        No           2 times of

                   Momentary data
                   to output & activate

                  Address or data error


** Reprinted with the permission of Ming Microsystems, Inc

The timing diagram of the decoder is shown below.

       Figure 6.9b: Address/Data Pins location
       ** Reprinted with permission of Ming Microsystems, Inc

Schematic diagram of the HT614 and the receiver circuit

     Figure 6.9c: Address/Data Pins location
** Reprinted with permission of Ming Microsystems, Inc

After the data is decoded, it is then sent to laptop to display the gps
information. The encoded will be connected to the laptop through the
RS-232 communication port.



The laptop to be used for demonstration will be contributed by a fellow
group member. It was decided that the laptop would be more
convenient to use for testing purposes.
Through RF communication, the gps tracking system will prove to be
an inexpensive way of tracking one’s vehicle.

Contributions of Group Four Members

     Owen Robinson
          Project Research (Remote System)
          Documentation typed (Chapter 2)
          Build receiver and transmitter board
          Flowcharts pertaining to Chapter 2
          Initial Presentation
          Field Research

     Sunerine R. Ramdial
           Project Research (Micro controller)
           Design control unit
           Documentation typed (Chapter 3)
           Flowcharts pertaining to Chapter 3
           Software Design
           Control unit simulation
           Control unit research
           Initial Presentation
           Field Research

     Collin Dawkins
             Project Research (Speed regulation and Alarm)
             Documentation typed (Chapter 4-5)
             Radial Security Block Diagram
             Circuit Design (Fuel cut off, Speed Control, Pulsating
             Flowcharts pertaining to Chapter 4-5
             Schematics pertaining to Chapter 4-5
             Initial Presentation
             Field Research

     Simonetta Thompson
           Project Research (GPS)
           Build receiver and transmitter board
           Documentation typed (Chapter 6)
           Flowcharts pertaining to Chapter 6
           Initial Presentation
           Field Research

Table 7: Group Information

  Name       Major        Phone            Email Address          Availability
                         Number                                     (Spring
 Sunerine   Computer     (321)662-   Samurai_X_34@hotmail.com     After 6 pm
 Ramdial    Engineer       4777                                   Mon.-Thurs.

  Collin    Electrical   (321)228-   Cd94467@pegasus.cc.ucf.edu   After 6 pm
 Dawkins    Engineer       6745                                   Mon.-Thurs

  Owen      Electrical   (407)622-     Owen_anr@yahoo.com         After 6 pm
 Robinson   Engineer       1562                                   Mon.-Thurs

Simonetta   Electrical     N/A                  N/A               After 6 pm
Thompson    Engineer                                              Mon.-Thurs

Meeting schedule:

Tuesday and Thursday 6:30pm – 10:30pm or whenever possible.


The funding of this project will be contributed by the members of
group four. We did however manage to get a couple of item from
either prior classes or through donations.

Table 8

                                           Cost/unit   Total Cost
             Components         Quantity    (US $)       (US$)
              GPS system           1         100          100
                  LED              5          4           20
            Radio Controlled
                 Car               1         100          100
              Transmitter          2          15          30
               Receivers           2          15          30
               Resistors          N/A         0            0
               PCB board           1         100          100
                 Wires            N/A         0            0
             Battery source        2          50          100
            Micro controller       1          15          15
               Computer            1          0            0
                Amplifier          2          30          60
            Voltage regulator      2          15          30

          Total Amount                                   $585


Testing and prototyping

While it would have been ideal to test out the project on a real
automobile, it was difficult to find someone who would let us
experiment on their car. Instead, we are going to have a simulation
involving a remote controlled car.

The remote control car will have to be one which runs off a
rechargeable battery pack. These types of cars are commonly found
at either Radio Shack or Nikko America ranging from prices $50 to
$350. Due to the limitations of our budget, we will most likely choose
one in the price range of $85 - $150. The car should be able to work
on at least a 9 volt battery.

Once the control unit has been build and we are positive it works
correctly, we will then place it on the RC car. We will then drive the
car a certain distance to in order to trigger the control unit.

When the control unit is triggered, we will have a LED light up telling
us the alarm is being sound. If possible we will try to build an alarm
which will actually make some type of sound indicating the alarm has
been sound.

The speed regulator will be simulated by putting a voltage regulator on
the car battery. The voltage regulator will activate after the control
unit tells it to. This will then cause the car to go from about 9.6 V to
about 5 V. After this voltage drop, the car will then seem as it is
slowing down.

In order to see if the GPS is working correctly, we will have the GPS
send its information (time, longitude, latitude, etc.) to either a PC or a

After we are satisfied with the results, we will then bring the RC car to
a distance which will turn the alarm and speed regulator off. Upon the
completion of this we will be convinced our project works correctly.

Summary and Conclusion

Radial Security is being designed to be an inexpensive, safe,
dependable and a reliable system. The RF communication is used as a
distance triggering device. The main purpose of having a distance
triggering device is to minimize theft of automobile recovery time.
Once an automobile has passed a specified parameter, there will be an
interruption in the continual feed of the RF signals. This break in the
RF communication will activate the control unit. The control unit will
instantaneously activate the horn, vehicle speed sensor and the fuel
cut off relay. The signal from the control module will disable the speed
sensor. Subsequently, a fault will be sent to the engine control
module. Some engine control respond to this signal by cutting of the
fuel. The purpose of our fuel cut of circuit is to work in conjunction
with the engine control module to lower the speed of the vehicle. At
this instance, someone stealing the vehicle equipped with Radial
Security would feel powerless, because he has no control over the
speed of the vehicle. In addition to the RF communication which is use
for tracking, our security system will be integrated with a gps system
to enhance monitoring of vehicle from a remote location. The gps
system communicating with a laptop will give a real time display of
speed, time and direction in which the vehicle is heading from a
distant location. Radial Security is an integration of security devices in
the automotive industry that gives one the luxury of monitoring a
vehicle if stolen.


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