TABLE OF CONTENTS
PARAGRAPH DESCRIPTION PAGE
1.0 INTRODUCTION 1
2.0 EQUIPMENT DESCRIPTION 2
2.1 General Description 2
2.2 Controls 3
2.2.1 Main AC Power ON/OFF 3
2.2.2 High Voltage Controls 3
184.108.40.206 High Voltage ON/OFF 3
220.127.116.11 High Voltage HI/LO Model Select 4
18.104.22.168 High Voltage POLARITY (+/-) Select 4
22.214.171.124 High Voltage COARSE and FINE Adjust 4
2.2.3 Operating Mode Controls (LO and HI Ranges) 4
126.96.36.199 Manual Mode 4
188.8.131.52.1 Manual/Auto Mode Select 5
184.108.40.206.2 DISCHARGE Control (Manual Mode) 5
220.127.116.11.3 HOLD Button 5
18.104.22.168 Automatic Mode 5
22.214.171.124.1 MAN / AUTO Mode Select 5
126.96.36.199.2 DISCHARGES Selector 5
188.8.131.52.3 INTERVAL Adjust 6
184.108.40.206.4 METER CAL 6
2.3 Indicators 7
2.3.1 Status Indicators 7
220.127.116.11 High Voltage Mode 7
18.104.22.168.1 Voltage Range 7
22.214.171.124 High Voltage ON 7
126.96.36.199 Polarity Mode 7
188.8.131.52 Charge/ Discharge Indicators 8
2.3.2 Numeric Readouts 8
184.108.40.206 Charging Voltage Readout 8
220.127.116.11 AUTO MODE Count Indicator 8
2.4 Output Panel 9
3.0 OPERATION 10
3.1 Initial Set-Up 10
3.2 Charging Voltage Set-Up 11
3.2.1 HOLD switch 11
3.2.2 Check COUNT/HOLD Switch 11
3.2.3 HI/LO Voltage Select 11
3.2.4 Polarity Select 11
3.2.5 High Voltage ON 11
3.2.6 High Voltage Level Adjustment 12
3.3 MANUAL Mode of Operation 12
3.3.1 MANUAL Mode Selection 12
3.3.2 Discharge Pulse Generation 12
3.4 AUTOMATIC Mode of Operation 12
3.4.1 AUTOMATIC Mode Selection 13
3.4.2 INTERVAL Adjustment 13
PARAGRAPH DESCRIPTION PAGE
3.4.3 Discharge Pulse Count Setting 13
3.4.4 Automatic Discharge Pulse Generation 13
3.4.5 Interrupting the Count in the AUTO MODE 14
18.104.22.168 HOLD Button 14
22.214.171.124 RESET Button 14
4.0 CALIBRATION AND WAVEFORM VERIFICATION 15
4.1 Human Body Model 15
4.1.1 Set-up 15
4.1.2 Calibration Procedure 17
126.96.36.199 Rise Time and Ringing at 4kV 18
188.8.131.52 Peak Current at 4kV 20
184.108.40.206 Fall Time at 4kV 19
220.127.116.11 Additional Information 19
4.2 Machine Model – ESD-S5.2 (Optional) 19
5.0 DUT TESTING PROCEDURE 22
5.1 Set-Up 22
5.2 Test Procedure 22
5.3 Testing to Method 3015.7 and ESD-S5.1 23
5.3.1 Control Settings 23
5.3.2 Testing Procedure 24
5.4 Testing to ESD-S5.2 (Machine Model) 24
5.5 Charged Device Model Testing-Std Model 910 Configuration 24
5.6 Charged Device Model Testing – Optional Configuration 25
5.6.1 Description 26
5.6.2 Operation 26
6.0 MAINTENANCE AND INTERNAL CALIBRATION 26
6.1 General 26
6.2 System Description – Functional Block Level 26
6.2.1 Overview 27
6.2.2 Detailed Description 28
18.104.22.168 Initial Application of Power 28
22.214.171.124 High Voltage Turn-On 29
126.96.36.199 Automatic High Voltage Power Supply Shut Down 29
188.8.131.52 Polarity Selection 32
184.108.40.206 HI/LO Voltage Mode Selection 32
220.127.116.11 High Voltage ON Detector 32
18.104.22.168 AUTO/MANUAL Mode Selection 33
22.214.171.124 Automatic Mode-Timer Interval Generation 33
126.96.36.199 AUTO MODE Indicator Operation 34
188.8.131.52 End of Test Detection – AUTO MODE 34
184.108.40.206 Charge/Discharge Timing 34
220.127.116.11 Relay Drivers 35
18.104.22.168 Charge/Discharge Indication 35
22.214.171.124 CHARGING VOLTAGE DPM and Scaling Networks 36
126.96.36.199 H.V. Relay Module 37
188.8.131.52.1 Charge/Discharge Cycle 37
184.108.40.206.2 HI/LO Voltage Mode Selection 37
220.127.116.11 Low Voltage Power Supply 38
18.104.22.168 High Voltage Power Supply 39
6.3 Trouble Shooting and Repair 40
PARAGRAPH DESCRIPTION PAGE
6.3.1 Removal of Top and Bottom Covers 40
22.214.171.124 Top Cover Removal 40
126.96.36.199 Bottom Cover Removal 40
6.3.2 Trouble Shooting Guide 41
6.4 Internal Adjustments 41
6.4.1 High Voltage Power Supply Output & DPM Calibration 41
188.8.131.52 High Voltage Mode Charging Voltage Level Calibration 42
184.108.40.206 Charging Voltage DPM Calibration HI Mode 47
220.127.116.11 LO Voltage Mode Charging Voltage Level Calibration 47
18.104.22.168 Charging Voltage DPM Calibration / Low Mode 48
6.4.2 Output Pulse Timing Sequence Calibration 48
22.214.171.124 Initial Set-Up, Oscilloscope Synchronization and 48
Calibration of LB-U12
126.96.36.199 Calibration of U11, Discharge Pulse Width 49
188.8.131.52 Calibration of U15,Charge Relay Timing 49
184.108.40.206 Final Check of Timing Sequence 49
6.5 Human Body Model Values 50
6.5.1 Changing the Capacitor and Resistor 50
6.6 Line Voltage Selection 51
6.6.1 Sub-Assembly Location 51
6.6.2 Interconnect Information 51
7.0 WARRANTY 54
TABLE OF CONTENTS – FIGURES
FIGURE DESCRIPTION PAGE
1.1 Human Body Model Test Circuit 1
2.1 Automatic Mode Timing Cycle 6
2.2 Output Panel 9
3.1 Controls, Indicators, Outputs and Adapter Modules 11
4.1 Current Waveform per Method 3015.7 16
4.2 Standard DUT Clamp Module Test Set-Up 16
4.3 DUT Socket Module Test Set-Up 17
4.4 Rise Time and Ringing Waveform at 4kV 18
4.5 Peak Current at 4kV 18
4.6 Discharge Pulse Fall Time Measurement At 4kV 19
4.7 Current waveform through a short to ground 21
4.8 Current waveform through a 500 Ohm resistor to ground 21
5.1 Programming IC Adapter Modules 23
5.2 MM classification and stress levels 24
6.1 Model 910 Electrostatic Discharge Simulator 29
Simplified Block Diagram
6.2 Electrostatic discharge Simulator 30
Detailed Functional Block Diagram
6.3 Output Pulse Timing Sequence 34
6.4 Model 910 Electrostatic Discharge Simulator 37
High Voltage Relay Module
6.5 High Voltage Power Supply- H.V. Test Point Location 47
6.6 HBM Plug-In RC Networks 50
6.7 P.C. Board Location 52
6.8 Sub-System Interconnection 53
The rapid advancement in the electronics industry during the past decade has placed an
ever increasing importance on the understanding of electrostatics and its effect on
electronic devices and systems. Electrostatic discharge is a common cause of
microelectronic circuit failures. Some of these devices can be seriously damaged or
destroyed by an electrostatic discharge below 20 volts. The sensitivity to ESD of other
parts has also become evident through use, testing and failure analysis. The trend in
technology towards greater complexity, increased packaging density and hence thinner
dielectrics between active elements result in parts becoming even more sensitive to ESD.
Failure mechanisms of electrical and electronic parts due to ESD typically include thermal
breakdown, metalization melt and bulk breakdown which are power dependent; and
dielectric breakdown, metalization to metalization arc over, surface breakdown and
surface inversion which are voltage dependent.
ESD can also induce latent failure mechanisms in both MOS structures and bipolar
junctions in discrete devices and in microcircuits. This latent failure mechanism results in
performance degradation and eventually a failure.
Personnel are prime sources of ESD for damaging electrical and electronic parts.
Electrostatic charges generated by rubbing or separating of materials are readily
transmitted to a person’s conductive sweat layer charging that person. When a person
handles or comes in close proximity to an ESD sensitive part, that part can then be
damaged from a direct discharge by touching the part or by subjecting the part to an
electrostatic field. The ESD from a human body can be reasonably simulated for test
purposes from the circuit shown in Figure 1.1.
Human Body Model Test Circuit
This circuit is the one specified in Mil-Std-883E, Method 3015.7 and ESD-S5.1 to represent a
human body for ESD testing. The human body capacitance, however, may be as high as
several thousand picofarads, but more typically 50 to 250 pf. Studies have shown that
approximately 80% of the population tested have a capacitance of 100 pf or less. The variation
in human capacitance is due to factors such as variations in the amount and type of clothing
and shoes worn by personnel and differences in floor materials. Human body resistances can
range from 100 to 100,000 ohms, but is typically between 1,000 and 5,000 ohms for actions
which are considered pertinent to holding or touching ESD sensitive parts or containers of ESD
sensitive parts. The variation in human body resistance is due to factors such as the amount of
moisture, salt and oils at the skin surface, skin contact area and pressure. A value of 1,500
ohms provides a reasonable lower human body resistance value. In view of the above, Mil-Std-
883E specifies a Human Body Model (HBM) using 100 pf discharged through 1,500 ohms. For
power sensitive parts, a change to a worst case Human Body Model capacitance (i.e., greater
than 100 pf) could result in damage to ESD sensitive parts at voltage levels below those shown
in Mil-Std-883E, Appendix 1. Therefore, a part which has been classified as non-ESD sensitive
could actually be ESD sensitive under more stringent Human Body Model conditions. For
voltage sensitive ESD parts, a variation in the capacitance value in the test circuit will not affect
ESD sensitivity. A decrease in Human Body Model resistance will increase the voltage and
power delivered to the ESD sensitive part and could adversely affect voltage and power
sensitive ESD sensitive parts at lower Human Body Model voltage levels. The Human Body
Model specified is considered a reasonable test circuit for evaluating the sensitivity of ESD
sensitive parts because personnel are generally the most common source of damaging ESD.
The Model 910 Electrostatic Discharge Simulator is an instrument specifically designed to
simulate the electrostatic discharge produced by human handling and meets all of the testing
requirements specified in Mil-Std-883E, Method 3015.7, ESD-S5.1 and JEDEC TEST METHOD
The Machine Model (MM) as defined in ESD-S5.2 is “An electrostatic discharge simulation test
based on a discharge network consisting of a charged 200 picofarad capacitor and (nominally)
zero ohms of series resistance. Actual series resistance and inductance are specified in terms
of the current waveform through a shorting wire. The simulation test approximates the
electrostatic discharge from a machine.” The Machine Model network is available as an option
to the Model 910.
To provide more comprehensive testing of components, the Model 910 utilizes individual plug-in
resistor and capacitor networks.
2.0 EQUIPMENT DESCRIPTION
The Model 910 Electrostatic Discharge Simulator is designed to produce simulated
discharge pulses which meet the requirements of Mil-Std-883E, Method 3015.7,
and ESD-S5.1. The pulse amplitude may be set to any level from approximately 20
volts to 8.25kV, and may be either positive or negative. Two voltage ranges are
provided; 0 to 2kV and 0 to 10kV. A digital readout is provided which indicates the
voltage level stored in the Human Body Model (HBM) capacitor prior to discharge.
In the Low Voltage Mode (0 to 2kV), the Digital Panel Meter (DPM) provides an
adjustment resolution of +1 volt. In the High Voltage Mode the resolution is +10
volts. Device testing may be performed either manually or automatically. In the
Manual Mode, the generation of each discharge pulses is controlled by the user. In
the Automatic Mode, the user selects the number of discharge pulses desired (0-9)
and the time interval between each pulse. When the DISCHARGE button is
depressed the correct number of discharges is produced. A HOLD button is
provided to halt the test sequence in the Automatic Mode or to prevent an
unintentional discharge in the Manual Mode.
Indicator lights on the front panel display the mode selected, the status (ON or
OFF) of the high voltage power supply output and the charge/discharge state of the
unit. A single digit LED indicator is also provided to indicate the number of
discharge pulses produced in the Automatic Mode and is extinguished in the
Adapter modules are available for holding a wide variety of devices and providing
for their connection to the OUTPUT terminals of the Discharge Simulator.
A front panel accessible calibration adjustment is provided to allow the user to
calibrate the digital panel meter to correspond to the actual charge on the HBM
capacitor. A detailed description of all controls and indicators is provided in the
All controls for operation of the Discharge Simulator are located along the front
edge of the unit. Four types of controls are used: two position push button
switches, momentary push button switches, rotary controls, and a ten (10) position
rotary switch. The states of the two position push button switches are indicated by
panel markings above and below each switch. The marking above each switch
defines the mode with the switch in the up position. Accordingly, the marking below
defines the state with the switch in the down position.
2.2.1 Main AC Power ON/OFF
This self latching (push-on-push-off) switch controls the AC power input to the unit.
When placed in the down position, the AC power will be ON and the front panel
indicator lamps will be illuminated.
2.2.2 High Voltage Controls
220.127.116.11 High Voltage ON/OFF
This switch (push-on-push-off) controls the high voltage output of the
simulator. When in the down position, the high voltage output is
turned on enabling the HBM capacitor to be charged to the level
shown on the DPM. When this switch is in the OFF position (up), the
high voltage output is disabled.
18.104.22.168 High Voltage HI/LO Model Select
This switch (push-on-push-off) selects either the LO Voltage Range
(0 to 2kV) when in the up position or the HI Voltage Range (0 to
10K) when in the down position. The unit will change modes only if
the HIGH VOLTAGE ON/OFF switch is in the OFF (up) position.
The mode LEDs directly below the DPM indicate the mode
selected. NOTE: If the indicator lights indicate a mode which is
different from that selected by the push buttons, the user must turn
off the high voltage. The unit will then automatically switch to the
correct mode. This is a safety feature which protects the unit’s
internal components from switching when high voltage is present.
22.214.171.124 High Voltage POLARITY (+/-) Select
This switch (push-on-push-off) selects the polarity of the discharge
pulse which is to be generated by the Discharge Simulator. When
in the up position, a positive pulse is produced and when down, a
negative pulse is produced. NOTE: As with the HI/LO Mode select
switch, the Simulator will only respond to a change in the setting of
the POLARITY select switch when the HIGH VOLTAGE ON/OFF
switch is in the OFF position.
126.96.36.199 High Voltage COARSE and FINE Adjust
These two controls adjust the level of the high voltage stored in the
Human Body Model capacitor. This voltage will be near zero with
both controls fully counterclockwise and increases as each control
is rotated clockwise. As its name indicates, the COARSE adjust
control is used to set the high voltage level close to the desired
level. The FINE adjust control is used for precise setting of this
level. The adjustment range of the FINE control is approximately
600 volts; thus, if this control is set to its mid-position (12 o’clock)
before the COARSE control is set, it will allow the output level to be
adjusted by approximately +300 volts about the COARSE control
2.2.3 Operating Mode Controls (LO and HI Ranges)
188.8.131.52 Manual Mode
184.108.40.206.1 Manual / Auto Mode Select
This push-push switch, when in the MAN (up) position,
places the unit in the MANUAL mode. The AUTO MODE
numeric indicator will be extinguished in this mode.
220.127.116.11.2 DISCHARGE Control (Manual Mode).
This momentary push button switch causes the Simulator
to produce one discharge pulse each time it is depressed.
In this mode, the user should allow a minimum of about
one (1) second between discharge pulses. If the
discharge button is depressed more rapidly than once per
second, an incomplete discharge cycle may be produced.
18.104.22.168.3 HOLD button
This push-push button, when in the COUNT (up) position,
allows one discharge pulse to be produced with each
depression of the DISCHARGE button. When placed in
the HOLD (down) position, the Simulator is prevented
from producing an output discharge pulse. This button
should normally be left in the HOLD (down) position
except when tests are being conducted. Using this control
in this manner will insure that output pulses are obtained
only when required and not at other times such as power
up or during changing of test samples.
22.214.171.124 Automatic Mode
126.96.36.199.1 MAN/AUTO Mode Select
This push-push switch, when placed in AUTO (down)
position, places the unit in the Automatic Mode. In this
mode, the AUTO Mode numeric indicator will be
188.8.131.52.2 DISCHARGES Selector
This ten-position switch selects the number of discharge
pulses that will be automatically produced by the
Simulator once the DISCHARGE button is depressed. It is
set before the start of a discharge test sequence by
rotating the control until the number on the control knob
flange, corresponding to the desired number of pulses, is
opposite the black pointer on the control panel.
184.108.40.206.3 INTERVAL Adjust
This rotary control is functional only in the Automatic Mode and
determines the time interval or delay between discharge pulses. The
control is rotated clockwise to increase the time interval from a
minimum of approximately 0.5 seconds to a maximum of 30 seconds.
It should be noted that the interval setting of this control corresponds
to the approximate “cool down” period between discharge cycles.
Since each discharge cycle lasts about .650 seconds, the minimum
discharge period (pulse to pulse duration) is about 1.1 seconds. This
timing relationship is illustrated in Figure 2.1.
Automatic Mode Timing Cycle
220.127.116.11.4 METER CAL
This calibration control is used to decrease the
value of the displayed charging voltage relative
to the actual voltage stored in the Human Body
Model capacitor. Adjustment of this control is
discussed more fully in section 4.0. This control
has been set at the factory and should be left in
this position unless the instrument is being
The Model 910 Electrostatic Discharge Simulator employs solid state (LED)
indicators for all status and numeric readouts. These are located on the
vertical sloping portion of the enclosure above the control panel.
2.3.1 Status Indicators
18.104.22.168 High Voltage Mode
22.214.171.124.1 Voltage Range
Two indicators are provided to indicate which
of the two voltage modes the unit has been set
for. The GREEN indicator will be on when
the unit is in the LO Voltage (0 to 2kV) mode
while the AMBER indicator will glow when the
HI Voltage Mode has been selected. These
indicators, which display the actual mode
programmed, are controlled by the HI/LO
select switch and the HIGH VOLTAGE
ON/OFF switch. When the High Voltage
switch is in the ON (down) position, changes in
the setting of the HI/LO mode select switch will
be ignored by the system, and the status lights
will not alter their indication. (See Section
126.96.36.199 High Voltage ON
This single red indicator will be illuminated when the
high voltage power has been turned on. It is a signal to
the operator that high voltage may be present
depending on the setting of the HI Voltage COARSE
and FINE adjust controls.
188.8.131.52 Polarity Mode
Two indicators are provided to show which polarity has
been selected. An illuminated GREEN light indicates
that the output discharge pulse will be POSITIVE
relative to system ground while AMBER indicates that
the pulse will be NEGATIVE. Like the High Voltage
Mode indicators, the polarity may be changed via the
High Voltage +/- Polarity select switch only if the High
Voltage ON/OFF switch is in the OFF (up) position.
184.108.40.206 Charging/Discharge Indicators
Two indicators are provided to display the
Charge/Discharge status of the Simulator. When the
GREEN Charge indicator is illuminated, the internal
circuits are in the Charge Mode, allowing the Human
Body Model capacitor to be charged to the desired
voltage level. The AMBER Discharge light will flash
when a discharge cycle is taking place, and the HBM
capacitor is connected to the OUTPUT terminal.
2.3.2 Numeric Readouts
220.127.116.11 Charging Voltage Readout
This readout is a 3½ digit LED display which provides the
operator with a direct indication of the high voltage level that is
charging the Human Body Model capacitor. In the LO Voltage
Mode (GREEN “LO (V)” indicator on), the readout indicates the
charging voltage directly in volts. In the HI Voltage Mode
(AMBER “HI (kV)” indicator on), a decimal point will appear on
the display and the charging voltage will be displayed in kilovolts.
Thus, in the HI Voltage Mode, a display of 6.83 indicates a
charging voltage of 6,830 volts (or 6.83 kilovolts). The display
also indicates the polarity of the charging voltage by the insertion
of a + or – to the left of the most significant digit.
In the LO (0 to 2kV) Voltage Mode, the readout is capable of
displaying a maximum level of 1,999 volts. If the operator sets
the Charging Voltage to a level above this maximum, the readout
will either begin to flash 1999 or blank out, depending on the type
of display used, indicating an overscale condition. This is normal
and the readout will not be damaged by settings above the
+1,999 volts. If it is desired to test above +1,999 volts, the HI
Voltage Mode should be used and the proper readout will be
18.104.22.168 AUTO MODE Count Indicator
This display is a single digit LED numeric indicator which
displays the discharge pulse count in the Automatic Mode. In the
Manual Mode, this indicator is not illuminated. When the RESET
switch is depressed, the AUTO Mode count indicator will reset to
zero and hold this count until the discharge cycle is started.
Once the discharge cycle is started, the AUTO Mode count
indicator will automatically increase its count by one for each
discharge pulse produced. Upon reaching the count set on the
DISCHARGES selector, automatic test cycling is terminated and
the AUTO Mode indicator will hold the final pulse count until the
RESET button is again depressed.
If, during an automatic test cycle, the HOLD button is depressed,
the AUTO Mode pulse counter will display the total number of
discharges produced up to the time the HOLD button was
depressed. If the HOLD button is now placed in the COUNT (up)
position, and the DISCHARGE button is depressed, the test
cycle will resume and the remaining pulses as set on the
DISCHARGES control, will be produced.
2.4 Output Panel
The Output Panel, shown in Figure 2.2 is located on the right side of the instrument
and contains the RESISTOR, CAPACITOR, GROUND, and CURVE TRACER
output jacks. The R-C modules are easily replaced by unplugging them from the
The CURVE TRACER output is a standard banana jack that is connected to a high
voltage relay. When the system is in the Charge Mode the relay is closed
connecting the CT output to the Discharge Resistor. This connects the CT output to
the pin under test: When the system is in the Discharge Mode the relay opens,
thereby disconnecting the CT output from the DUT. It again closes when the system
returns to CHARGE. This enables the user to check the DUT both prior to and after
a discharge without removing any connectors.
The CURVE TRACER output is not connected when shipped from the factory. If the
user wants to use this function the top cover must be removed and the CT .040” pin
must be plugged into the .040” jack located on top of the discharge relay. DO NOT
USE ABOVE 5kV. Induced voltages may damage the Curve Tracer. User must
determine suitability before using.
Figure 2.2 Output Panel
3.1 Initial Set-Up
3.1.1 Before connecting the Simulator to the AC line, set the controls on the
front panel to the following positions:
1. POWER ON/OFF - OFF (up)
2. HIGH VOLTAGE ON/OFF - OFF (up)
3. High Voltage COARSE and FINE adjust – both fully counterclockwise
4. COUNT/HOLD switch - HOLD (down)
3.1.2 Before connecting the AC line cord to the power outlet, check the
VOLTAGE SELECT switch on the rear panel to ensure that the unit is
set for the correct line voltage. This switch enables the user to select
100, 110, 220 or 240 VAC, 50/60 Hz operation.
3.1.3 Attach the appropriate Test Adapter Module by pressing it gently into the
four mounting jacks located on the front panel as shown in Figure 3.1.
3.1.4 Secure the device under test (DUT) to the holding fixture on the test
adapter plate using the spring loaded clamp. If necessary, manually
adjust the sliding post to provide the proper spring loaded force on the
DUT. NOTE: When properly adjusted, the DUT will be securely held
but may be removed by sliding the spring loaded half of the holding
fixture to the right.
3.1.5 Plug the red minigrabber test lead into the red OUTPUT jack and the
black minigrabber test lead into the GND jack. If a curve tracer or other
test instrument is to be used to check the characteristics of the Pin Pair
of the DUT before and after a discharge sequence, plug it into the
CURVE TRACER output banana jack.
3.1.6 Connect the test lead spring loaded minigrabbers to the appropriate
leads on the DUT. For the best possible output waveshape, the leads
should be positioned such that they are away from one another by a
minimum of ¾” and away from the unit’s chassis (ground). The test
leads should not be reversed when the opposite polarity is desired.
3.1.7 Turn on the Discharge Simulator power by placing the POWER ON/OFF
switch in the ON (down) position. The Power ON state will be indicated
by illumination of the colored status indicators and possible minor
flickering of the Charging Voltage readout. The AUTO Mode indicator
may or may not be illuminated depending on the setting of the
AUTO/MAN select switch.
3.2 Charging Voltage Set-up
The Procedure described in this section is common to both the Manual and
the Automatic Mode and should be followed independent of the mode
3.2.1 HOLD Switch
3.2.2 Check to see that the COUNT/HOLD switch is in the HOLD (down)
3.2.3 HI/LO Voltage Select
Select the desired operating voltage by placing the High Voltage HI/LO
switch in the LO position (up) for testing below 2000 volts or in the HI
position (down) for testing at or above 2000 volts.
Controls, Indicators, Outputs and Adapter Modules
3.2.4 Polarity Select
Set the POLARITY switch to the desired output pulse polarity: up for
positive, down for negative.
3.2.5 High Voltage ON
Depress this pushbutton to turn on the high voltage.
3.2.6 High Voltage Level Adjustment
Rotate the FINE adjust control clockwise until the pointer is in the
twelve o’clock position. Rotate the COARSE adjust control clockwise
until the approximate desired voltage level is indicated on the
CHARGING VOLTAGE readout. Now re-adjust the FINE control to trim
the voltage reading to the final level. Allow several seconds for the
reading to stabilize, then, if necessary, re-adjust the FINE control. The
unit is now ready to produce the desired output pulse.
3.3 MANUAL Mode of Operation
In the MANUAL Mode, the operator is in complete control of the number of pulse
discharges and the interval to be impressed on the DUT. To operate the
Discharge Simulator in this mode, follow the procedure in sections 3.1 and 3.2,
then proceed as described in the following sub-paragraphs.
3.3.2 MANUAL Mode Selection
Set the AUTO/MAN button to the MAN (up) position.
3.3.2 Discharge Pulse Generation
Set the COUNT/HOLD button to the COUNT (up) position. Depress the
DISCHG. button once each time a high voltage discharge pulse is
required. The AMBER DISCHARGE indicator will flash each time an
output pulse is produced. At least one second should be allowed
between pulses for the “cool down” period. After the DUT has been
subjected to the desired number of pulses, place the COUNT/HOLD
button in the HOLD (down) position, and turn off the high voltage supply
by placing the High Voltage ON/OFF switch in the OFF (up) position.
To resume testing, turn on the High Voltage, if necessary re-adjust the
FINE control, set the COUNT/HOLD button to COUNT, and when ready,
depress the DISCHG. button.
3.4 AUTOMATIC Mode
In the Automatic Mode, the operator selects the number of discharge pulses
desired and the interval between pulses. Upon depression of the RESET
then the DISCHG. buttons, the Simulator proceeds to automatically generate
the selected number of pulses at the chosen interval. The HOLD button may
be used to hold the count at any time before the selected count is reached.
To operate the Automatic Mode, follow the set up procedures in 3.1 and 3.2
then proceed as described in the following sub-paragraphs.
3.4.1 AUTOMATIC Mode Selection
Set the MAN/AUTO switch to the AUTO (down) position. The AUTO
Mode numeric indicator will now be illuminated.
3.4.2. INTERVAL Adjustment
The INTERVAL adjust control, which provides for setting the “cool
down” time interval between discharges is an uncalibrated control,
and if accurate timing is required, must be calibrated against an
external reference (e.g., digital watch, stopwatch with sweep hand,
etc.). To accurately set the INTERVAL control, turn off the internal
High Voltage Supply by setting the High Voltage ON/OFF switch to
OFF (up). Set the INTERVAL control to 9, the COUNT/HOLD switch
to COUNT, depress the RESET switch, and when ready, depress the
DISCHG. Switch. Using an external timing reference, measure the
time interval between flashes of the AMBER DISCHARGE light.
Adjust the INTERVAL control until the desired “cool down” period is
obtained. (NOTE: The discharge cycle time has been set during
assembly to .65 seconds, hence, the “cool down” time will be the time
measured between flashes of the amber DISCHARGE light minus
.65 seconds. Refer to Figure 2.1). After calibration, set the
COUNT/HOLD switch to HOLD and turn on the High Voltage supply
setting the High Voltage ON/OFF switch to ON.
3.4.3 Discharge Pulse Count Setting
To select the number of discharge pulses, rotate the DISCHARGE
selector until the desired number is opposite the point marking on the
3.4.4 Automatic Discharge Pulse Generation
Set the COUNT/HOLD button to the COUNT (up) position. Depress
the RESET button to set the AUTO MODE counter to zero. When
ready to start the automatic test sequence, momentarily depress the
DISCHARGE button. The Automatic Mode timing sequence starts
with the interval delay, hence, the first discharge pulse will not occur
until the INTERVAL time has lapsed. Upon reaching the end of the
first interval, the AMBER DISCHARGE indicator will flash, the AUTO
MODE indicator will advance to the count of one and the first
discharge pulse will be generated. This sequence will continue until
the AUTO MODE readout displays the same number as set on the
DISCHARGES Selector. At the time, the test is concluded, the
Simulator automatically stops generating output discharge pulses,
and the AUTO MODE readout displays the final count of the number
of discharges produced.
Nothing further will occur unless the operator wishes to repeat the
test sequence. To do this, momentarily depress the RESET button,
then depress the DISCHARGE button. The automatic discharge
cycle will be repeated
After completion of testing, place the COUNT/HOLD button in HOLD
and set the High Voltage switch to OFF.
3.4.5 Interrupting the Count in the AUTO MODE
To stop the discharge pulses in the AUTO MODE before the full
count is reached, two (2) methods may be used.
22.214.171.124 HOLD Button
If the HOLD button is depressed while automatic testing is in
progress, and the full count as set on the DISCHARGES
control has not yet been reached (AUTO MODE indicator
DISCHARGES setting), the discharge pulses will be stopped
and the AUTO MODE indicator will hold the discharge pulse
count as produced up to that point. To complete the
unfinished count, set the COUNT/HOLD button to COUNT
and then depress the DISCHARGE button. Unless the
DISCHARGE button is depressed after the COUNT/HOLD
button is set to COUNT, the automatic discharge sequence
will not be resumed.
126.96.36.199 RESET Button
If the RESET button is depressed while the automatic
discharge is in progress, the AUTO Mode count will
immediately reset to zero, and, upon release of the RESET
button, and depression of the DISCHARGE button, the
discharge sequence will start again, from zero.
THE DISCHARGE SIMULATOR IS CAPABLE OF PRODUCING HIGH VOLTAGE
OUTPUT PULSES OF UP TO 10,000 VOLTS AT A STORED ENERGY LEVEL OF
ABOUT 75x10-4 JOULES. WHEN IT IS NECESSARY TO HANDLE THE DUT OR ANY
OF THE OUTPUT INTERCONNECT TEST LEADS, IT IS RECOMMENDED THAT THE
HIGH VOLTAGE ON/OFF SWITCH BE PLACED IN THE OFF POSITION AND THE
COUNT/HOLD BUTTON BE SET TO HOLD.
4.0 CALIBRATION AND WAVEFORM VERIFICATION PROCEDURES
4.1 Human Body Model – Mil-Std 883E, Method 3015.7, ESD-S5.1 & JEDEC
These test methods require system calibration utilizing the discharge pulse
current waveform. The Human Body Model is C=100pf and R=1500 ohms.
The waveform must be verified using both + and –4kV charging voltages.
The discharge current must be within +10% of the specified Ip value ( 2.67
Photographs of the rise time, fall time, and peak current calibration are
Figure 4.1 shows the waveform requirements specified in Method 3015.7
A high speed oscilloscope and current probe with a bandwidth of at
least 350 MHz and a visual writing speed 4 cm/nsec minimum are
required. Scopes satisfactory for this measurement are the
Tektronix Model 2467 high speed oscilloscope or the Model 7834 or
7934 storage oscilloscopes. A Digital Storage Oscilloscope (DSO)
may also be used if its frequency (350 MHz or better) and sampling
rate (1 GS/sec or better is used. Tektronix TDS 300 and 3000 series
oscilloscopes meeting this criteria are satisfactory. Tektronix Models
CT-1 or CT-2 current transducers are satisfactory for detecting the
The 50 ohm impedance of the current probe must be matched to the
input impedance of the oscilloscope. For those scopes with only a 1
Megohm input impedance, an adaptor is available to match the 50
ohm impedance of the probe to the 1 megohm impedance of the
Because of the very high frequencies being measured it is
recommended that the current probe cable be double shielded.
pulse shall have the following characteristics:
Tr (rise time) 2-10 nanoseconds
Td (decay time) 150 +20 nanoseconds
Ip (peak current) within +10%
Ir (ringing) The decay shall be smooth, with
ringing, break points, double time
constants or discontinuities less
than 15% Ip maximum, but not
observable 100 nanoseconds after
start of the pulse.
Current Waveform per Method 3015.7
A 1.25 inch, 18 gauge wire is required to connect the current probe to the output
connectors of the Model 910. Figure 4.2 shows the test set-up for the standard DUT
clamp module and Figure 4.3 shows the test set-up for an IC Adapter Module.
Standard DUT Clamp Module Test Set-Up
DUT Socket Module Test Set-Up
The current probe (Tek CT-1) is polarized and is marked with a + on one side. When
verifying a positive discharge pulse, the OUTPUT signal from the 1.5K ohm resistor
should be connected to this side. When verifying a negative discharge pulse, the GND
connection should be connected to this side. No changes in scope setting are
4.1.2 Calibration Procedure
188.8.131.52 Rise Time and Ringing at 4kV
Set the scope vertical amplifier sensitivity to 2 volts/Div and the
time base to 5 nsec/Div. Switch the vertical amplifier out of the
CAL position and adjust the vernier such that a discharge pulse
will go from the “0” graticule marking to the “100” graticule
marking as shown in Figure 4.4. The rise time is defined as the
time for the leading edge to rise from the 10% point to the 90%
point. The specification calls for a rise time between 2 and 10
nsec. For the Model 910 ESD Simulator the rise time will
normally fall between 2.5 and 6 nsec. The peak-to-peak ringing
must be less than 15% of Ip.
Rise Time and Ringing Waveform at 4kV
184.108.40.206 Peak Current at 4kV
Set the scope vertical amplifier sensitivity to the calibrated 2
volts/Div. and keep the time base set to 5 nsec/Div. Adjust the
vertical position such that the base line is on the first graticule
line. This now provides a voltage measurement range of 16
volts. If the CT-1 probe is used then the total current
measurement range is 3.2 amps (CT-1 Probe calibration is 5
volts/amp). Probes with different calibration will necessitate
using different scope vertical amplifier settings. At a charging
voltage of 4kV, the peak current, Ip, must be 2.67 amps +10%
(2.40-2.93 amps). Figure 4.5 shows the peak current at 4kV.
Peak Current at 4kV
220.127.116.11 Fall Time at 4kV
Set the scope vertical amplifier sensitivity to the UNCAL 2
Volts/Div. setting as was done for the rise time measurement.
Set this time base to 20 nsec/Div. The discharge pulse should
resemble that shown in Figure 4.6. The fall time (decay time)
must be 150 +20 nsec from the 100% point to the 37% point.
Discharge Pulse Fall Time Measurement at 4kV
18.104.22.168 Additional Information
The measurement of the current waveform can be significantly
affected by the test instrument used. Excessive ringing and poor
waveform characteristics could be a result of an incorrect test set-
up or an oscilloscope that is not adequately shielded.
The charging voltage calibration is preset at the factory. No field
adjustment should be made to the METER CAL adjustment.
The Model 910 incorporates a curve tracer output. The CURVE
TRACER output connector is connected to the output side of the
discharge relay when in the CHARGE Mode and is disconnected
from this point during the DISCHARGE cycle. This switching
function is accomplished by a high voltage relay. This relay, since
it is part of the discharge circuit, does affect the purity of the
discharge waveform. Disconnecting this relay from the discharge
relay will reduce the ringing associated with the current waveform.
ESD-S5.1 also requires an additional calibration waveform using
a 500 ohm resistor to ground.
Other standards such as the JEDEC standards reference Method
3015.7 and/or ESD-S5.1. The specific standard to which testing
will be performed should be referred to for the correct calibration
of the Model 910 ESD Simulator.
4.2 Machine Model – ESD-S5.2 (Optional)
This standard requires system calibration utilizing the discharge pulse
waveform obtained from a 200 pf capacitor discharged through 0 Ohms to
ground. The same oscilloscope and current transducer setup used for HBM
verification are used for the MM verification waveforms.
The waveform must be verified using both + and -400 Volts through both a
short circuit to ground and through a 500 Ohm resistor. Other stress levels of
100, 200 and 800 Volts may be performed using only the discharge through
a short to ground.
A photograph or printout of the waveforms are required.
Figure 4.7 shows the waveform requirements for the discharge through a
short to ground at 400 Volts and Figure 4.8 shows the waveform
requirements through the 500 Ohm resistor to ground.
The MM capacitor is keyed so when MM testing is selected the HI
RANGE is disconnected and only the LO RANGE can be used. This
allows MM testing from less than 20 Volts to 200 Volts.
Current waveform through a short to ground
Current waveform through a 500 Ohm resistor to ground
5.0 DUT TESTING PROCEDURE
Set the High Voltage controls to the desired Range and Polarity. Turn the
HIGH VOLTAGE ON and adjust for the desired voltage level. Set the
COUNT/HOLD switch to HOLD (button pushed in).
Insert the DUT into either the clamping fixture or the appropriate optional
zero insertion force socket adapter module. Connect the minigrabber or to
the desired pin pairs when the clamping fixture is used.
If one of the socket adapter modules is used follow the procedure
described in Figure 5.1 on how to program the module for the desired pin
group configurations. Use the .080” plug cables to connect the socket
module to the Simulator output jacks.
5.2 Test Procedure
If manual operation is desired, select MAN mode (button up). Set the
COUNT/HOLD button to COUNT. Depress the DISCHARGE button to
initiate a discharge across the DUT. Each time the DISCHARGE button is
depressed a discharge will occur.
To reverse polarity, turn the HIGH VOLTAGE to OFF and set the
COUNT/HOLD button to HOLD, depress the POLARITY button for either +
or -, then turn the HIGH VOLTAGE back on and set the COUNT/HOLD
button to COUNT. NOTE: The HIGH VOLTAGE must be turned off before
Polarity or Range can be changed.
If the AUTO Mode is desired, set the OPERATING Mode controls to AUTO
and HOLD. Select the number of discharge pulses (1-9) and cool down
interval period button to start the test sequence. The first discharge will
occur after the INTERVAL time selected has elapsed. Each discharge will
register on the AUTO Mode display until the total number of cycles have
To interrupt the test cycle, set the COUNT/HOLD button to HOLD. To
resume the test, depress the DISCHARGE button. To start a new cycle,
depress the RESET button, then depress the DISCHARGE button.
Programming IC Adapter Modules
5.3 Testing to Method 3015.7 and ESD-S5.1
A sample of devices shall be characterized for the device ESD failure
threshold using voltage steps of 500. 1000, 2000 and 4000 Volts as a
minimum. Finer voltage steps may optionally be used to obtain a more
accurate measure of the failure voltage. Testing may begin at any voltage
step, except for devices which have demonstrated healing effects,
including those with spark gap protection, which shall be started at the
lowest step. Cumulative damage effects may be eliminated by retesting at
the failure voltage step using a new sample of devices starting at one or
two voltage steps lower than the failure threshold.
5.3.1 Control Settings
Initially set the Range to LO, the Polarity to + and adjust the level to
500 volts. Select the AUTO Mode and set the number of
DISCHARGES to 3 and the INTERVAL (cool down period) to a
minimum of 1 second.
5.3.2 Testing Procedure
Refer to the appropriate test standard being used to establish the
correct testing protocol (starting voltage, number of discharges, pin
5.4 Testing to ESD-S5.2 (Machine Model)
Machine Model testing is described in ESD-S5.2 which is available from the
ESD Association at 7900 Turin Road, Rome, NY 13440. This Standard
defines five component classification levels and four stress levels as shown
in Figure 5.2. Testing protocol and pin combinations are also defined.
MM classification and stress levels
5.5 Charged Device Model Testing - Standard Model 910 Configuration
The standard Model 910 is not specifically designed to perform Charged
Device Model testing. However, the charging system of the Model 910
incorporates a 400 Megohm resistor in the charging circuit. This allows an
isolated device to be charged slowly enough not to cause an ESD discharge
as specified in current CDM standards. ETS can provide a module with a
lead and a minigrabber that replaces the plug-in capacitor module plus a
ground lead. It is up to the user to configure the placement of the DUT per
the applicable standard.
To perform a CDM test, the following procedure may be used:
1. Set the HVPS to the desired voltage level then turn the HVPS to
2. Connect the red mini-grabber to the desired pin(s).
3. Turn on the HVPS.
4. Remove the minigrabber from the DUT and immediately touch the
specified pin(s) with the short ground black lead provided .
5.6 Charged Device Model Testing - Optional CDM Modification
The standard ETS Model 910 ESD Simulator can perform both
Human Body and Machine Model discharges. In both cases a
capacitor is charged and then discharged through a resistor (which
can be as low as 0 Ohms) via a relay closure. The rise times
associated with these Models are in the nanosecond range.
The Charged Device Model (CDM) is when the device is charged and
then discharged directly to ground. To create a CDM the Device
Under Test (DUT) is charged as if it was the capacitor and then
discharged by grounding the desired pin using a reed relay. The
existing 400 megohm resistor in series with the charging circuit
provides a slow enough rise time as not to damage the DUT. The
ESD Association STM 5.3 for charged device model testing specifies
a minimum series resistance of 100 megohms. The rise times
associated with a CDM discharge are in the picosecond range.
The Model 910 can be configured to perform CDM testing. The
modification consists of adding a 3-position switch to control the
charging function, the addition of a grounding relay with its own
dedicated input banana jack and a charging module that replaces the
ETS does not specify CDM waveforms that may be obtained from
the Model 910. However, experience has shown that CDM testing
using the Model 910 gives satisfactory results in describing the
CDM sensitivity of devices.
To perform HBM and MM testing the added lever switch must be in
the up (HBM/MM) position. This connects the charging relay to the
charging circuit. When this switch is in the center (OFF) position, the
charging relay is disconnected and no high voltage will be present at
the Capacitor Module.
To perform CDM testing, first place the HBM/MM lever switch in the
OFF (center) position, then replace the capacitor module with the
CDM module, the one with the red banana jack installed. Next, plug
the red MM minigrabber cable into the red charging module banana
jack and the black cable into the green grounding jack. NOTE: The
MM cables are the ones without the black shrink tubing around
the banana plug. Connect the red minigrabber to the pin(s) on the
DUT that is being charged and the black minigrabber to the pin(s) that
are to be discharged.
Turn on the High Voltage and adjust to the desired voltage level and
polarity. Depress and hold the spring-loaded lever switch for
approximately one (1) second. Immediately upon releasing the switch
depress the DISCHARGE pushbutton switch. This will activate the
dedicated grounding relay. Repeat the CHARGE/DISCHARGE cycle
for each test.
6.0 MAINTENANCE AND INTERNAL CALIBRATION
The purpose of this section is to provide information about the design and
function of the Model 910 Electrostatic Discharge Simulator. This
information will enable the user to check and/or adjust the few internal
timing sequences which control the CHARGE/DISCHARGE cycle and to
make simple repairs should a component failure occur. The fault diagnosis
and repair procedures covered here will enable faults to be located to the
user replaceable plug-in IC level. Repairs involving replacement of
soldered-in components should be made by qualified personnel only and
may be best handled by returning the equipment to ETS. Should it become
necessary to return the equipment for repair, it is necessary that it be
adequately packed for shipping ( use of the original shipping container and
packing is highly recommended ) and that a detailed description of the
malfunction be furnished with the equipment. It is further recommended
that ETS be contacted prior to the return of any equipment.
THIS EQUIPMENT UTILIZES VOLTAGES WHICH RANGE FROM ZERO
TO NOMINALLY 10,000 VDC. FURTHER, ITS PRIME SOURCE OF
POWER IS 115 (OR 220 VAC) 50/60 Hz. ALTHOUGH PRECAUTIONS
HAVE BEEN TAKEN TO PROTECT AGAINST SHOCK HAZARD,
EXTREME CAUTION SHOULD BE EXERCISED ONCE THE TOP OR
BOTTOM COVERS ARE REMOVED. FAILURE TO OBSERVE THIS
WARNING MAY RESULT IN SERIOUS INJURY TO PERSONNEL
6.2 System Description-Functional Block Level
Contained in this section is a functional description of the Discharge
Simulator circuits. Signal flow paths will be traced from their origins,
through control logic and timing to their destinations as output or display
functions. Also provided will be circuit board and component reference
designation information which should aid the user in locating specific
components. Table 6.1 should be used as a key to this information.
Symbol Component Location and Identification Key
LVPS LOW VOLTAGE POWER SUPPLY
HVPS HIGH VOLTAGE POWER SUPPLY
CP CONTROL PANEL
LB LOGIC BOARD
HVRM HIGH VOLTAGE RELAY MODULE
DRM DISPLAY / READOUT MODULE
DPM DIGITAL PANEL METER
Figure 6.1 is a simplified block diagram which shows the functional
relationship between the major blocks in Table 6.1. As can be seen,
the system circuits are contained on seven (7) printed circuits boards
with part numbers ETS-901 through ETS-907. Figure 6.2 is a
Detailed Functional Block Diagram of the Model 910 ESD Simulator.
All operator initiated functions are generated via the system Control
Panel (CP). The Control Panel interfaces with the Logic Board (LB),
the High Voltage Power Supply (HVPS) and the Display/Readout
Module (DRM). It also provides the Power ON/OFF function for the
system. The line voltage is wired directly to the Power Control switch
on the P.C. Board, so care must be exercised when the bottom cover
is removed and the system is under going maintenance, repair and/or
The Logic Board (LB) receives its inputs from the Control Panel (CP)
and generates timing and control signals which are used by most of
the other assemblies (HVPS, HVRM, DRM, DPM). The HVPS
receives an ON/OFF signal and output level information directly from
the CP as well as other control signals from the LB. The AUTO
Mode illumination signal is also generated by the CP and is fed
directly to the DRM.
The High Voltage Relay Module (HVRM) contains two (2) high
voltage relays which are controlled by the LB and provide the
charging and discharging functions related to producing the ESD
output pulse. Care must be exercised in this area during
maintenance since voltages on the order of +10kV can be present
even when the system is off and has been disconnected from the AC
The HVRM also contains resistor networks which limit current surges
during charging and generate an output signal for the DPM.
The Display/Readout Module (DRM) displays mode information,
CHARGE, DISCHARGE, and H.V.ON status, and contains the 0-9
Numeric AUTO Mode indicator. It is controlled primarily by the LB.
The High Voltage Power Supply (HVPS) generates the charging
voltage which is used to produce the ESD Output Pulse. It can
generate up to +10kV as determined by the CP and LB.
The Low Voltage Power Supply (LVPS) accepts unregulated power
from the AC Line via the power transformer. It produces regulated
D.C. outputs of +5,+12, and –12 volts and unregulated D.C. outputs
of +22 and +34 volts.
The DPM is a 3½ digit LED readout capable to reading up to 1999.
Readings in excess of this cannot be displayed and are indicated by
either on/off flashing or blanking of the indicator. In the Low Voltage
Mode, the meter reads directly in volts. In the High Voltage Mode, a
decimal point is illuminated and, in conjunction with an internal
controlled automatic scale change, the meter reads in kV. This DPM
assembly contains circuits which are very sensitive to High Voltage
discharges, consequently it is recommended that the DPM be
disconnected if the high voltage power supply and/or switching
module is to be serviced.
6.2.2 Detailed Description
The overview in the preceding paragraph will now be expanded to
provide specific information which will be of value in repairing this
unit. References will be made to specific components involved in the
processing of the signals discussed. The mnemonics shown in Table
6.1 will be used and may be followed by one or more specific
component reference designators.
22.214.171.124 Initial Application of Power
The system is designed to power up (CP-S1) in the reset
state. If in the AUTO Mode when power is applied, the
AUTO Mode indicator will display zero and the system will
remain in the CHARGE state until the DISCHARGE button
(CP-S9) is depressed. The initial start up reset is
generated by LB-U6 which resets LB-U3, U7 and U1.
126.96.36.199 High Voltage Turn-On
The HVPS is enabled by depressing the High Voltage ON
push button which applies power to the driver stage of the
HVPS. The output level of the variable L.V. supply is
determined by setting of the FINE and COARSE controls
(CP-R1-COARSE and R2-FINE).
188.8.131.52 Automatic High Voltage Power Supply Shut Down
The Logic Board (LB) contains a circuit (LB-U10) which
monitors the CP switch settings (CP-23 & S4) and the
states of the polarity control flip flop (LB-U9) and the HI/LO
flip flop (LB-U8). If an error exits between a CP switch
setting and any flip flop state, a signal called RPSD
(Remote Power Shut Down) is generated (LB-U10) and
reduces the H.V. output to zero. RPSD is fed to the Driver
and Variable L.V. sections of the HVPS.
When RPSD is a logic “1” (+5 Volts) both sections of the
HVPS are shut down as a fail safe measure.
Model 910 Electrostatic Discharge Simulator
Simplified Block Diagram
Model 910 Electrostatic Discharge Simulator-Detailed Functional Block Diagram
184.108.40.206 Polarity Selection
Polarity selection is initiated at the Control Panel (CP-S4).
The two (2) signals generated set (or reset) the polarity
control flip flop (LB-U9). If the High Voltage switch is in the
ON position when the polarity switch is activated, LB-U9
will ignore the CP-S4 signals and will not change state.
Instead, RPSD is generated causing the H.V.P.S. to shut
down. If the H.V. switch is off when CP-S4 is activated, the
polarity control flip flop (LB-U9) will change state
accordingly. The positive polarity lamp and relay driver for
the green positive polarity indicator (DRM-DS5) and the
positive polarity select relays (HVPS-RL1 and RL2) is LB-
Q7. The negative polarity lamp and relay driver is LB-Q8.
The signal it produces drives the amber negative polarity
Polarity selection is accomplished at the H.V. level by
switching action of the four (4) H.V. relays (HVPS-RL1, 2,
3, & 4) in the HVPS.
220.127.116.11 HI/LO Voltage Mode Selection
Mode selection is initiated at the Control Panel (CP-S3).
The two (2) signals originate at the CP set (or reset) the
HI/LO Mode control switch is activated, LB-U8 will not
change state. Instead, the HVPS is shut down via the
action of LB-U10 and the RPSD signal. The output of the
HI/LO Mode control FF (LB-U8) is fed to lamp and relay
drivers. The LO Voltage Mode lamp driver is LB-Q4. Its
output drives the green low voltage indicator (DRM-DS2).
The High Voltage Mode driver is LB-Q6. Its output drives
the amber HI Mode indicator (DRM-SD3) and the scale
change relay (HVRM-RL3).
18.104.22.168 High Voltage ON Detector
To prevent hot switching of the various relays used
throughout the system and to provide the equipment
operator with a visual indication when a charging voltage
is present, a voltage sensing circuit is employed. The
output of the Variable L.V. Supply is fed to the HV ON
detector (LB-U13 and U14). The HV ON detector is a two
(2) state circuit consisting of an amplifier (LB-U14)
followed by a comparator (LB-U13). The comparator (LB
-U13) output is fed to the H.V. lamp driver (LB-Q2). The
lamp driver output is fed back to the Polarity and Mode
Control circuits to act as an inhibit signal as described in
22.214.171.124 and 126.96.36.199. The lamp driver output also drives
the red H.V. ON lamp (DRM-DS4). A failure in the H.V.
ON detection circuit which causes the H.V. ON indicator to
stay on will inhibit Mode and Polarity changing by the
188.8.131.52 AUTO/MANUAL Mode Selection
Auto/Manual selection is accomplished by activating the
AUTO/MAN button on the control panel (CP-S6). This
switch performs three (3) functions. When in the Manual
mode (MAN), it resets the AUTO Mode Run/Hold flip flop
(LB-U7, U1) preventing the automatic generation of H.V.
output discharge pulses. It also enables the manual pulse
generator (LB-U4) so that output pulses may be
generated at will by the user, and extinguishes the AUTO
Mode indicator (DRM-DS1).
In the Automatic Mode, the AUTO/MAN select switch
illuminates the AUTO Mode 0-9 indicator (DRM-DS1), and
removes the Reset from the Run/Hold flip flop (LB-U7,
U1), allowing output pulse generation to occur
automatically (upon depression of the DISCHARGE
button (CP-S9)). It also selects the AUTO Mode trigger
pulse which is generated by the AUTO Mode interval timer
184.108.40.206 Automatic Mode-Timer Interval Generation
When the AUTO Mode is selected by depressing the
AUTO/MAN button (CP-S6), automatic output pulse
generation is enabled. Upon depressing of the
DISCHARGE button (CP-S9), the Run/Hold flip flop is set
to the RUN state. LB-Q1 is turned off allowing capacitor
LB-C2 to start charging. The charging rate is determined
by the setting of the INTERVAL control (CP-R3). At the
end of the timing interval, the output of the interval timer
(LB-U5) goes back to zero. This generates the AUTO
Mode trigger pulse which starts the automatic output pulse
generation sequence. The timing of the next interval is
delayed until the output pulse timing sequence is
220.127.116.11 AUTO MODE Indicator Operation
Each time the interval timer (LB-U5) reaches the end of a
timed interval, it generates a low going trigger pulse. This
signal is inverted by gate LB-U7 and is applied as a clock
to the binary counter LB-U3. The binary counter output is
converted to the drive signals for the AUTO Mode
indicator by the binary to 7-segment decoder driver (LB-
U2). When the RESET button is depressed (CP-S8), the
binary counter (LB-U3) is reset via the negative going
output of U6. The output of the 7-segment decoder driver
(LB-U2) is fed to the 7-segment LED display (DRM-DS1)
and causes the proper number to be displayed.
18.104.22.168 End of Test Detection – AUTO MODE
The output of the binary counter (LB-U3) is decoded by the
action of the DISCHARGES selector (CP-S5) and a logic
decoder gate (LB-U1) in the 0-9 comparator block. When
the binary counter output (LB-U3) reaches the count
selected by the DISCHAGRES selector (CP-S5), decoder
gate (LB-U1) produces a reset signal which resets the
COUNT/HOLD control flip flop in the discharge control
block until the DISCHARGE button is again depressed to
start a new test sequence.
22.214.171.124 Charge/Discharge Timing
The proper sequence and pulse duration of the
Charge/Discharge timing is determined by three (3) one-
shot timers, LB-U11, 12, and 15. The Charge/Discharge
timing sequence is initiated each time a trigger pulse
(either AUTO or MANUAL) is generated. The trigger pulse
(negative going) causes one shots U12 and U15 to
activate. LB-U15 controls the charging interval while U12
generates a delay to allow the charging relay ( HVRM-RL4)
in the H.V. Mode to drop out. When a U12 completes its
time out, U11 is triggered causing the actual output pulse
discharge period to be generated. The timing sequence
and nominal time duration for each one-shot period is
shown in Figure 6.3. The high voltage discharges produced
during normal operation do not interfere with the output
pulse timing sequence. This circuit consists of components
LB-Q17, 18 and 19.
Output Pulse Timing Sequence
126.96.36.199 Relay Drivers
The drive signals required by the charge and discharge in
the HVRM are developed by relay drivers on the LB. Table
6.2 lists each driver and the relay it drives.
Charge/Discharge Relay and Driver Identification
Relay Function & Type Driver
HVRM-RL4 H.V. Mode-Charge (SPST) LB-Q10
HVRM-RL5 H.V. Mode-Discharge (SPST) LB-Q15
188.8.131.52 Charge/Discharge Indication
The GREEN CHARGE indicator (DRM-DS7) is illuminated
when the HBM storage capacitor is being charged by the
appropriate charging relays (see Table 6.2). This
corresponds to the time when the output of LB-U15 is low
(zero). The driver for this indicator is LB-U15.
The AMBER DISCHARGE indicator (DRM-DS8) is
illuminated whenever the discharge relay (HVRM-RL5) is
activated and the Human Body Model capacitor is being
discharged into the Device Under Test. The driver for this
indicator is LB-Q15 which also drives the H.V. discharge
184.108.40.206 CHARGING VOLTAGE DPM and Scaling Networks
This indicator is a 3 ½ digit LED display which indicates
the level of the charging voltage being produced by the
HVPS. Since the DPM is capable of displaying up to a
maximum to +1999 volts D.C., it is necessary to scale
down the high voltage levels produced by HVPS. This
voltage scaling is performed in the HVRM by a divider
network consisting primarily of a 100 megohm precision
resistor (HVRM-R2) and several smaller precision
resistors (HVRM-R3,4,5 and 6). A small reed relay
(HVRM-RL3) is used to provide scale changing from the
HI to LO Modes. Two (2) resistors are used for calibration
purposes (HVRM-R4 and R6) in the HI and LO Modes
A second attenuator network on the DPM is provided to
allow the user to calibrate the CHARGING VOLTAGE
Meter with the actual high voltage pulse produced and to
compensate for output losses (if any). The front panel
accessible Voltage Calibration Control (DPM-R3) allows
for a reduction of the DPM indication by up to 50% of the
true charging voltage level.
220.127.116.11 H.V. Relay Module
The HVRM block in Figure 6.1 has been redrawn in Figure
6.4 to better illustrate its function. The high voltage input
from the HVPS is fed to the H.V. scaling network where it
is scaled down for use by the CHARGING VOLTAGE
Meter. A DPM output select signal drives a scaling relay
(HVRM-RL3) to shift the level accordingly for the HI/LO
Modes. The scaling relay is activated (contacts closed) in
the HI Mode.
The high voltage charging current is limited by a limiting
18.104.22.168.1 Charge/Discharge Cycle
During the charging period, the Charge
Relay (HVRM-RL4) is energized by a H.V.
Mode charge relay drive signal causing the
storage capacitor (HVRM-C4) to charge.
The H.V. Mode Charge Relay then opens,
and after a delay, the H.V. Mode Discharge
Relay drive signal causes the H.V.
Discharge Relay (HVRM-RL5) to close,
applying the energy stored in the H.V. HBM
storage capacitor to the output via the H.V.
Mode Human Body Model resistor (HVRM-
R8). After completion of the H.V. Mode
discharge cycle, the Discharge Relay opens,
the Charge Rely closes, and the H.V. HBM
capacitor is recharged in preparation for the
next discharge cycle.
22.214.171.124.2 HI/LO Voltage Mode Selection
when the LO Voltage Mode is selected, a
control signal (HVM=1) is sent to the HVPS
which causes a scale change relay to open.
This enables the correct DPM voltage
range to be selected. In the HI Mode, this
relay is closed, again selecting the proper
voltage scaling for the DPM
Model 910 Electrostatic Discharge Simulator – High Voltage Relay Module
126.96.36.199 Low Voltage Power Supply
The LVPS interfaces with the power line via the
power transformer, T1. Its outputs provide
both regulated and unregulated voltages which
are used by the unit’s various sub-assemblies.
Table 6.3 lists the outputs provided and the
components associated with producing each
LVPS Components Table
Output Voltage Output Test Point Transformer Components
Reg +5v E17 E1, 2, 3 D 1&2, C1 &4, U1
Reg +12 (Relay) E15 E4, 5, 6 D3, D5, C2, C5, U2
Reg +12 (L) E13 E4, 5, 6 D3, D5, C2, C6, U3
Reg -12 E12 E4, 5, 6 D4, D6, C3, C7, U4
UnReg +32 E16 E7, 8 D7, C8, C9
All components on the LVPS are soldered-in. Repairs should be made
with the proper equipment and by qualified personnel only.
188.8.131.52 High Voltage Power Supply
The variable L.V. section of the H.V.P.S. is a
series regulator whose output is determined by
the settings of the FINE and COARSE controls
(CP-R2, R1) and the status of the RPSD signal
(See section 184.108.40.206 or 220.127.116.11). The heart of
the series regulator is U1, and two (2) current
amplifiers, Q1 and Q2. Q1 is the high current
stage which is driven at a somewhat lower level
by Q2. Resistors R11 and R21 are used to
calibrate the maximum outputs of the supply in
the low voltage and high voltage modes
The output of the supply varies from zero to
+2.4 volts (nominal) in the LO Mode and 0 to
+12 volts (nominal) in the HI Mode. These
output voltages may be monitored at Terminal
E12. Transistor Q11 reduces the supply output
to zero when RPSD is a logic “1”. Q4 and Q5
program the output range of the supply as a
function of the mode selected. A logic “1” on
Terminal E28 programs the supply for the H.V.
Mode (supply output will be 0 to +12 volts).
The second functional block in this supply is the
gated drive stage which contains transformer T1
and transistors Q5, 6, 7, 8, and 9. Transistor
Q9 is an on-off gate which is controlled by the
remote shutdown signal (RSPD). It determines
the 13KHz oscillator circuit (T1, Q5, and Q6)
on/off status. The oscillator is on when Q9 is on
(in saturation). The secondary of T1 drives the
bases Q7 and Q8 which are the drivers for H.V.
step up transformer.
The third functional block is the multiplier and
polarity selection stage. Here, two (2)
independent X7 multipliers are employed, one
for each polarity. They each multiply the output
of T2 to the desired charging voltage level.
Polarity selection is accomplished by the action
of polarity select relays RL1, RL2 to select a
positive output and relays RL3, RL4 to select a
negative output. The drive signals for polarity
selection are on terminals E30 and E31 for the
positive and negative modes respectively. A low
signal (0 volts) on a given terminal signifies the
selection of that mode (e.g. “0” volts on E30
when a positive polarity output has been
6.3 Trouble Shooting and Repair
This paragraph covers some of the possible failure modes and provides a
table which should aid repair personnel in locating the faulty components.
Partial disassembly of the housing is also covered.
1. Because of the high voltage present in this unit, extreme care must be
exercised when working on the unit with its cover removed. Failure to
use reasonable care can result in serious injury to personnel and/or
damage to the equipment.
2. To protect the CHARGING VOLTAGE DPM against high voltage
transients which may occur with the cover removed, it is recommended
the DPM be disconnected during trouble shooting.
6.3.1 Removal of Top and Bottom Covers
18.104.22.168 Top Cover Removal
To gain access to the LB, LVPS, DPM, and the
HVRM the top cover must be removed. To
accomplish this, remove the four (4) flat head screws
(two on the right side and two on the left side) that
secure the cover to the frame. Slide the cover off by
lifting slowly in the vertical direction.
22.214.171.124 Bottom Cover Removal
To gain access to the CP and the underside of the
HVPS, it will be necessary to remove the bottom
cover. To accomplish this, first remove the three (3)
screws located on the underside of the unit directly
below the front control panel. Two (2) of the three (3)
screws will be in the center of each of the two (2)
rubber bumpers. With the unit in its normal
(horizontal) position, remove the four (4) flat head
screws on the sides of the unit (two on the left side
and two on the right). Lift the unit vertically by
holding the rear panel and the front edge of the front
of the panel. The frame will separate from the bottom
cover. Place the frame on a suitable surface for
6.3.2 Trouble Shooting Guide
Listed in Table 6.4 are some of the possible faults which may
occur, their most probable causes and recommended actions to
take to correct the fault. Most repair actions listed involve the
replacement of plug-in components. If the fault requires
replacement of a soldered-in component, the repair should be
made by a qualified person using the proper equipment. If this is
not possible, it is recommended that the unit be returned to
Electro-Tech Systems, Inc. for repair.
Before proceeding with detailed trouble shooting, fault
location , and/or replacement of components, remove the
top (and bottom) cover(s) and perform a visual
inspection of all internal P.C. boards and cables. Check
to see that all cable plugs are properly seated in their
respective sockets and that all plug-in integrated circuits
are fully seated. A loose connector or IC can cause the
system to malfunction.
6.4 Internal Adjustments
6.4.1 High Voltage Power Supply Output and DPM Calibration
There are only two (2) adjustments provided on the HVPS board.
These adjust the maximum output of the supply in each of the two
(2) modes. HVPS-R21 adjusts the output of the HI Mode and
should always be adjusted before R11, which calibrates the output
in the LO Mode.
Be sure power is OFF and the High Voltage FINE and COARSE
controls are both fully counter clockwise before removing the
cover or attempting to do any work on the HVPS. Disconnect
the DPM connector to avoid damage if an arc is drawn during
126.96.36.199 High Voltage Mode Charging Voltage Level Calibration
Connect a high voltage measuring instrument with an
input resistance in excess of 1,000 megohms and an
input voltage rating of at least 10,000 volts D.C. to the
output of the HVPS. Remove the CAPACITOR module
from the OUTPUT panel which is the red 0.80” pin jack.
See Figure 6.5.
Set the High Voltage Voltmeter to a scale that will enable
10,000 volts to be measured. Place the RUN/HOLD
button in the HOLD (down) position, the POLARITY
button in the (+) position, the VOLTAGE Mode button in
HI, turn on the AC power and place the H.V. ON/OFF
button in the ON position. Rotate the FINE voltage
control so that it is at its approximate mid-position
(pointer at 12 o’clock). Set the COARSE control until it is
fully clockwise. While observing the H.V. Voltmeter
reading, rotate the High Voltage calibrate resistor
adjustment (HVPS-R21) screw until the meter reads
FAULT or MALFUNCTION SUSPECT BOARD and/or COMPONENT ACTION
1. Nothing works-DPM and lights do 1. Check line cord and main AC fuse 1. Test/Replace if bad.
not illuminate-relays do not activate. 2. LVPS - Main power transformer 2. Test/Replace if bad.
2. All indicators work properly but none 1. LVPS - U2 1. Check LVPS test terminal
of the relays activate. E15. If no +12 volts is present,
3. No discharge pulse is produced but 1. HVRM - Faulty RL5 1. Check Relay coil and replace if open.
work properly. 2. HVRM - Open R1 2. Test for proper resistance, replace
3. HVRM - Faulty or improperly 3. Check for proper mounting-or
mounted C4 replace if faulty.
4. No discharge pulse and DISCHARGE 1. LB-Q15 1. Q15 bad-replace.
light does not flash. 2. LB-U11 2. Check U11-replace if bad.
5. Charging Voltage DPM provides proper 1. LB-U13, U14 1. Replace U13 and/or U14 as required
H.V. readout but H.V. ON light does not to restore proper operation.
come on when H.V. is present. 2. DRM-DS4 2. LED bad-replace.
3. LB-Q2 3. Q2 bad- replace.
6. H.V. ON indicator stays on even with 1. LB-U13, 14 1. Same as above.
H.V. switch in OFF position.
FAULT or MALFUNCTION SUSPECT BOARD and/or COMPONENT ACTION
7. HI/LO Mode select does not function. 1. LB-U8 1. U8 bad-replace.
Indicator lamp indication does not 2. CP-S3 2. S3 bad-replace.
8. HI or LO indicator lamp stays on when 1. LO lamp stays on: LB-Q4 1. Q4 bad-replace.
opposite mode is selected. 2. HI lamp stays on: LB-Q6 2. Q6 bad-replace.
9. Polarity mode select does not function. 1. LB-U9 1. U9 bad-replace.
Indicator lamp indication does not change. 2. CP-S4 2. S4 bad-replace.
10. + or – lamp stays on when opposite 1. +lamp stays on: LB-Q7 1. Q7 bad-replace.
polarity is selected. 2. –lamp stays on: LB-Q8 2. Q8 bad-replace.
11. HOLD button does not stop discharges 1. CP-S7 1. S7 bad-replace.
from being produced.
12. HOLD button stops output pulse, but 1. CP-S7 1. S7 bad-replace.
unit continues to count in AUTO mode. 2. LB-U1 2. U1 bad-replace.
13. CHARGING VOLTAGE DPM reads zero 1. DPM 1. Test DPM and
when H.V. button is ON and FINE and replace if faulty.
COARSE controls are turned clockwise. 2. HVRM-R2, R3, R4, R5, R6 2. Check H.V. divider for open
Normal H.V. output pulse is produced resistor and replace if faulty.
3. DRM-R2, R3 3. Check resistors for open circuit.
Replace if faulty.
14. Charging Voltage DPM reading HVRM-RL3 1. Test and replace if defective.
Is about 1.5X too high in the HV mode.
FAULT or MALFUNCTION SUSPECT BOARD and/or COMPONENT ACTION
15. Charging Voltage DPM flashes 1999 1. DPM 1. DPM defective - replace.
with H.V. off.
16. Indicator lamps do not light but unit DRM-DS2, 3, 4, 5, 6, 7, 8 1. LED indicator
functions properly. lamp is defective - replace.
17. No H.V. output- 1. HVPS-U1 1. Replace.
a. H.V. button ON and controls set for 2. HVPS-Q1 2. Bad-replace.
b. H.V. output. 3. CP-S2 3. Test-if open, replace.
c. DPM is functioning properly and reads
zero. 4. LB-U10 4. Replace.
5. HVPS-Q11 5. Replace.
6. HVPS-Q10 6. Replace.
7. HVPS-Q9 7. Replace.
18. H.V. output does not go to zero when 1. HVPS-U1 1. S7 bad-replace.
FINE and COARSE controls are fully CC 2. HVPS-Q2 2. Replace.
3. HVPS-Q1 3. Replace.
4. CP-R1, R2 4. Test-replace if defective.
19. AUTO MODE-Indicator does not 1. LB-U 1. Replace.
light in AUTO MODE. 2. DRM-DS1 2. Replace.
3. CP-S6 3. Check and
replace if bad.
20. AUTO MODE Indicator does not 1. LB-U6 1. Replace.
reset to zero when RESET button is 2. LB-U3 2. Replace.
depressed. 3. CP-S1 3. Check and replace if bad.
FAULT or MALFUNCTION SUSPECT BOARD and/or COMPONENT ACTION
21. AUTO MODE – unit does not start 1. LB-U7, U1, U4, U5, Q1 1. Replace in order shown
when DISCH button is depressed. until proper operation is
DISCHARGE light does not light. restored.
22. AUTO MODE- DISCHARGE light comes 1. LB-U7, U3 1. Replace in order shown
on but AUTO MODE counter does not until operation Is restored.
display count other than zero.
23. AUTO MODE- pulses are produced and 1. LB-U1 1. Replace.
unit counts normally, but does not stop 2. CP-S5 2. Test and replace if bad.
when count on DISCHARGES selector
188.8.131.52 Charging Voltage DPM Calibration HI Mode
Follow the procedure in the preceding paragraph then,
after adjusting the output of the HVPS via HVPS-R21,
adjust the High Voltage Mode DPM calibrate resistor
(HVRM-R4) until the DPM reads +8.25 kV.
High Voltage Power Supply – H.V. Test Point Location
Calibration of the DPM must be done
with the front panel CAL adjustment turned to its fully
184.108.40.206 LO Voltage Mode Charging Voltage Level Calibration
Follow the basic set-up procedure outlined in 220.127.116.11
above except set the VOLTAGE Mode button to LO, then
set the High Voltage ON/OFF switch to ON. Select a
scale on the High Voltage Voltmeter such that 2,000 volts
can be accurately read. Adjust the LO Voltage Mode
calibrate resistor (HVPS-R11) adjustment screw until the
High Voltage Voltmeter reads 2,000 volts D.C.
18.104.22.168. Charging Voltage DPM Calibration/Low Mode
Follow the procedure above (22.214.171.124), then reduce the
settings of the FINE and COARSE control until the High
Voltage Voltmeter reads +1,900 volts. Adjust the LOW
Voltage DPM cal resistor (HVRM-R6) until the DPM reads
Performance of the Calibration procedures in 126.96.36.199
through 188.8.131.52 above, using a precision H.V. Voltmeter,
will insure that the proper high voltage charging levels will
be produced by the HVPS and that the DPM will indicate
the proper levels. Calibration of the output discharge
pulse should also be performed to verify both the pulse
level and wave shape. The Voltage CAL adjustment may
then be used to increase the stored voltage level relative
to the DPM indication to compensate for possible losses
in the output cabling and load (See 4.0 for output pulse
shape and amplitude verification).
6.4.2 Output Pulse Timing Sequence Calibration
Covered in this paragraph is the procedure to be followed to verify
and/or adjust the timing of the three (3) delay timers on the Logic
Board (LB-U11, 12 and 15). The proper timing for these three (3)
circuits is shown in Figure 6.3.
184.108.40.206 Initial Set-Up, Oscilloscope Synchronization and
Calibration of LB-U12
With the AC power OFF, remove the top cover of the
Discharge Simulator and locate the logic board. Locate
U12, the integrated circuit timer that generates the
Initial Delay Time shown in Figure 6.3, and connect its
output (U12-Pin 3) to the Channel-1 input of a dual
trace oscilloscope with a calibrated time base and the
ability to sync to the vertical Channel-1 input.
A “Dip-Clip” (Pomona Electronics) or equivalent IC test
interface device is recommended for securing the
scope test probe to the IC timer. The output pulse to
be observed will be positive going with a nominal
amplitude of +4 volts and a period of 100 milliseconds.
Turn on the AC power and, while depressing the
DISCHARGE button with the H.V. OFF and the Mode
set for MAN, adjust the scope to sync to the positive
edge of this pulse. A sweep speed of 20 msec/cm is
recommended. Measure the pulse width and, if
necessary, adjust R28 until the observed pulse width is
100 +10 milliseconds.
220.127.116.11 Calibration if U11, Discharge Pulse Width
Follow the procedure outlined in 18.104.22.168. Then connect
the Channel-2 input of the dual trace scope to U11-pin
3. While still synchronizing the scope to the positive
going edge of U12-pin 3, observe and measure the
output pulse width of U11, pin 3 on Channel-2. A
sweep speed of 50MS/CM is recommended. If
necessary, adjust R25 to achieve a pulse width of 200
22.214.171.124 Calibration of U15, Charge Relay Timing
Follow the procedure in 126.96.36.199, then connect the
Channel-2 scope input to U15-pin 3. Synchronize the
scope to the Channel-1 input, U12-pin 3 (positive
edge). Using sweep speed of 0.1 sec/cm, observe and
measure the output pulse width of U15-pin 3. If
necessary, adjust R39 such that the pulse width is 650
188.8.131.52 Final Check of Timing Sequence
Using the dual trace capability of the oscilloscope in the
“chopped” mode, and synchronizing to the positive
going edge of LB-U12-pin 3, use the Channel-1 and 2
scope inputs to verify that the outputs of U12, 11 and
15 (pin 3) correlate with Figure 6.3 with respect to
timing relationship and pulse widths. If all
measurements agree with Figure 6.3, the timing
sequence is correct and no further adjustments are
necessary. If the measurements are not correct, repeat
the procedures in 184.108.40.206, 220.127.116.11 and 18.104.22.168 and then
re-check all timing against Figure 6.3.
HBM Plug-In RC Networks
6.5 Human Body Model Values
The Model 910 Electrostatic Discharge Simulator is supplied with the Human
Body Model capacitor and resistor values that result in a capacitance and
resistance at the output jack of 100pf +10% and 1,500 ohms +2%
6.5.1 Changing the Capacitor and Resistor
The capacitor and resistor are plug-in modules located on the front
OUTPUT Panel as shown in Figure 6.6. To change values, simply
remove the capacitor and resistor modules by pulling them out of
the panel. Both modules are connected to the output network via
0.80” pin jacks.
The capacitor module can be opened by unscrewing the brass
thumb screw to add additional capacitors.
The 100 pf capacitor module contains capacitors whose value,
when added to the intrinsic capacitance of the discharge relay will
result in 100 +10pf being measured at the output terminal. Most
910s have an intrinsic capacitance of 100 pf, hence the
capacitor module will not contain any additional capacitors.
Before removing the capacitor module, connect the output to
ground and initiate the DISCHARGE button several times to ensure
that the capacitor is fully discharged.
6.6 Line Voltage Selection
The Model 910 can operate from line voltages of 100, 110, 220 and 240
VAC, 50/60Hz. The correct line voltage is selected using the LINE
VOLTAGE selector module located on the rear panel of the unit.
For line voltage of 100 or 110 volts a ¾ amp Slo-Blo 3AG fuse should be
used. For line voltages of 220 or 240 volts a 3/8 amp Slo-Blo 3AG fuse
should be used.
6.6.1 Sub-Assembly Location
Figure 6.7 is a top view of the Model 910 Electrostatic Discharge
Simulator. Shown are the board assembly locations as well as the
calibration resistors on each board.
6.6.2 Interconnect Information
Figure 6.8 is a diagram which shows how the various sub-system
assemblies are interconnected. The balloon associated with each
cable shows the number of conductors in each cable. Care should
be taken when re-connecting cables, since failure to insert a given
cable into its proper socket and/or failure to orient the cable plugs
properly can result in a system malfunction and/or component
failure. Pin #1 is the Brown wire and is designated by a Black Dot
on both the cable and the board.
P.C. Board Location
Electro-Tech Systems, Inc. warrants its equipment, accessories and parts of its manufacture to
be and remain free from defects in material and workmanship for a period of one (1) year from
date of invoice and will, at the discretion of Seller, either replace or repair without charge,
F.O.B. Glenside, similar equipment or similar part to replace any equipment or part of its
manufacture which, within the above stated time, is proved to have been defective at the time it
was sold. All equipment claimed defective must be returned properly identified to the Seller (or
presented to one of its agents for inspection). This warranty only applies to equipment
operated in accordance with Seller’s operating instructions.
Seller’s warranty with respect to those parts of the equipment which are purchased from other
manufacturers shall be subject only to that manufacturer’s warranty.
The Seller’s liability hereunder is expressly limited to repairing or replacing any parts of the
equipment manufactured by the manufacturer and found to have been defective. The Seller
shall not be liable for damage resulting or claimed to result from any cause whatsoever.
The warranty becomes null and void should the equipment, or any part thereof, be abused or
modified by the customer of if used in any application other than that for which it was intended.
This warranty to replace or repair is the only warranty, either expressed or implied or provided
by law, and is in lieu of all other warranties and the Seller denies any other promise, guarantee,
or warranty with respect to the equipment or accessories and, in particular, as to its or their
suitability for the purposes of the buyer or its or their performance, either quantitatively or
qualitatively or as to the products which it may produce and the buyer is expected to expressly
waive rights to any warranty other than that stated herein.
ETS must be notified before any equipment is returned for repair. ETS will issue an
RMA(Return Material Authorization) number for return of equipment.
Equipment should be shipped prepaid and insured in the original packaging. If the
original packaging is not available, the equipment must be packed in a sufficiently large box (or
boxes is applicable) of double wall construction with substantial packing around all sides. The
RMA number, description of the problem along with the contact name and telephone number
must be included in formal paperwork and enclosed with the instrument. Round trip freight and
related charges are the owner’s responsibility.
WOODEN CRATES MUST NOT BE USED. PACKAGING OF DELICATE INSTRUMENTS IN
WOODEN CRATES SUBSTANTIALLY INCREASES THE CONTENT’S SUSCEPTIBILITY TO
SHOCK DAMAGE. DO NOT PLACE INSTRUMENTS OR ACCESSORIES INSIDE OTHER
INSTRUMENTS OR CHAMBERS. ELECTRO-TECH SYSTEMS, INC. WILL NOT ASSUME
RESPONSIBILITY FOR ADDITIONAL COST OF REPAIR DUE TO DAMAGE INCURRED
DURING SHIPMENT AS A RESULT OF POOR PACKAGING.