Miniature Faucet-driven Hydroelectric
ECE 345 Senior Design
July 1st, 2004
Eric Muller (firstname.lastname@example.org)
Dan Nowak (email@example.com)
Jiaxiao Zhang (firstname.lastname@example.org)
TA: Mo Zhou
Our group will design and build a Miniature Faucet-driven Hydroelectric Generator.
Designed to use water from a faucet for emergency power in blackout situations, the
device will be as compact and user-friendly as possible. It will consist of a small 12V DC
motor used as a generator, driven by a turbine connected to the faucet, and converted to
120VAC 60Hz power via a DC/AC power inversion circuit and transformer. We will also
power (from the generator itself) a small flow sensor and LED output display showing the
faucet's flow, necessitating more power conversion to 5V. Our goal is to get 50W of
usable power, not counting the additional load of the sensor and display. This is a real-
life application of power principles and a challenge on many levels: design, construction,
and utilization towards a fully functioning device.
The main goal of this project is to generate 120V at 60Hz, up to 50W of power for
household use. We are converting and harnessing (water) energy to provide a viable
source of domestic power. This product is intended to function during emergencies, as a
backup power supply for crucial household devices.
Benefits of the Miniature Faucet-driven Hydroelectric Generator to the end consumer:
Household emergency backup power supply.
Non-polluting power generation.
Water provides inexpensive and readily available „fuel‟ source.
Easy alternative to gasoline-powered generators.
Safe (non flammable) components.
Product Features of the Miniature Faucet-driven Hydroelectric Generator:
Easy installation of device to water faucet.
Water drainage is built into device.
Self-contained compartment minimizes water spray, spillage.
120VAC at 60Hz output.
50W maximum load.
Water Sensor PIC Chip Display
Turbine DC/DC Converter DC/AC Inverter
Water: Water flow from a standard household faucet, directed through a hose, serves
as the driving force for the turbine. The kinetic and potential energy from the water is
transformed to rotational energy by the wheel and turbine.
Sensor: A sensor embedded in a pipe will monitor steady flow rate. This output will be
fed to the PIC chip, for further analysis. The sensor is a 12V paddle wheel sensor with
constant square wave voltage varying frequency output representative of feet-flow-per-
PIC: The PIC chip takes sensor voltage input and computes the relative power
associated (from calculations programmed into the chip). The conversion from feet-flow-
per-second is done taking into account the PVC tubing volume and length. This value
will be passed to the display.
Display: The display takes as input the value from the PIC chip and displays it in an easy
to read format.
Turbine: The turbine will be a resin wheel with fins (Pelton wheel). Enclosed in a box, it
is attached to the motor shaft to drive the generator. A nozzle directed water spray will
be aimed to drive the turbine and consequently, the motor.
Motor/Generator: The motor is a pre-built 12V permanent magnet DC motor, 1750 rpm,
used as a generator. The turbine turns the shaft of the motor, with motor leads
connected to the DC/DC converter.
DC/DC Converter: The input of the DC/DC converter comes from the leads of the motor.
Motor output voltage varies with motor speed and water pressure. The voltage is
boosted from the 12V DC generator input to 170V at the output of the DC/DC converter.
A feedback and control will be used to regulate the voltage at a steady 170V.
DC/AC Inverter: The DC/AC inverter takes 170VDC as input from the DC/DC converter
and generates 120VAC at 60Hz for the output. This is consistent with standard electrical
device needs for this market.
Electrical Outlet: A standard electrical outlet will be attached for easy power supply to
Performance Requirements: 120VAC ±5% output at 60Hz, 50W desired power output
Schematics and additional data:
Please see additional attached sheets
Flow velocity range: 0.5 to 33 ft/sec (0.15 to 10 m/sec) either direction.
Output signal: Square wave, 5 to 24 Vdc Peak-to-peak
Output frequency: ~ 12.8 Hz/ft/sec (42 Hz/m/sec)
Estimated frequency range inputted to PIC chip:
Min: Assuming 0.5 ft/sec
0.5 ft/sec * 12.8 Hz/ft/sec = 6.4 Hz
Max: Assuming 33 ft/sec
33 ft/sec * 12.8 Hz/ft/sec = 422.4 Hz
Source faucet static pressure: 58 psi
“head” = 2.31 * P = 134 ft.
flow rate = 8.44 GPM (gal/min)
Theoretical input power = 0.1 * “head” [ft.] * flow [GPM]
Theoretical input power = 118 W
Note: All equations are taken from http://www.absak.com/design/hydro.html
PIC Program data flow chart
0/0 or 1/0 SETVALUE
Flyback Converter Topology
Output Power Desired: 50W
Assume 75% efficiency of DC/DC and DC/AC Converter
Input Power from Motor: 66.6W
Assumed Input Voltage at Max Load: 8V
Input Current: 8.325 A
FET Requirements: VDS = 8V, ID = 8.325A
Peak current through Primary:
ID 8.325 A
I peak 20 .8 A
Duty _ cycle 0.4
Output Capacitor size is largest available to reduce ripple into the DC/AC inverter. This
capacitor needs to be able to handle 170VDC which is a 270µF 400V capacitor.
Output Voltage Desired: 170VDC
Output Power Desired: 50W
Output Current: 0.294 A
Duty Cycle = 0.4
Vout N 2 D 170V N 2 0.4
Vin N1 1 D 8V N1 0.6
Turns Ratio: 8:256
N 2 31 .88
Operation in discontinous mode
L primary AL N 2 160nH * 64 10.24H
Lsec ondary 160 nH * 65536 10 .49 mH
Fswitching = 25kHz
(1 D) 2 R
2 f switching
Primary Inductance is less than critical inductance and theoretically will be in
Switching Frequency Calculations:
f switching 25kHz
f switching 25kHz
CT 880 pF
Dead Time Calculations:
d 145 CT .1276 s
To determine switching frequency observed CT and RT plot on datasheet. Will test to fine
tune frequency. Also will fine tune dead time in order to get a more sinusoidal wave
using a potentiometer.
Apparent Power Efficiency of Motor:
Tests done using two motors coupled. The first motor was connected to a DC power
supply at 12V and the second motor was loaded with a varying resistance. An
oscilloscope was used to observe and calculate RMS values. This is not true power but
apparent power and not an accurate way of calculating motor efficiency but will give a
general idea of motor losses.
Vin (V) Iin (A) Pin (VA) Vout (V) Iout (A) Pout Efficiency
12.00 3.15 37.8 11.1 0.392 4.35 11.5%
12.01 4.58 55.0 10.3 1.82 18.75 34.1%
12.01 5.39 64.7 9.86 2.59 25.54 39.5%
12.01 6.60 79.27 9.32 3.75 34.95 44.1%
Testing will be done modularly. Each block will be tested individually before
integration into the entire system, and again after integration.
Specifically: Components of the turbine: wheel and nozzles will be tested for
optimal placement and usage for better rpm. The motor will be tested using a 2 motor
coupled system to simulate water flow and estimate power loss from mechanical
inefficiency. With this simulation, we will be able to check the motor/generator against
varying speeds (water pressures) to determine optimum speed (rpm). The PIC chip and
display will be tested by comparing the observed display with the flow display inherent to
the sensor using formula calculations. Testing the DC/DC converter will involve
checking the voltage and current at various points. The input and output power will also
be observed to measure efficiency. The signals at the output of the DC/AC inverter will
be observed on the oscilloscope to make sure proper voltage and current outputs are
Fluid flow formulas will be used to project possible flow and project power. This
will be contrasted against actual flow and power generated to determine efficiency of our
system. From these, we will be able to tweak the setup to increase efficiency, to inherent
limitations and load loss.
Both the wheel/turbine and DC/DC Converter are significant aspects of the
design. Due to limitations with the wheel turbine, we will evaluate more tolerances on the
A good feedback control system will be implemented to regulate inconsistencies
in the motor, and still give a steady 170VDC (tolerance of ±5% ripple) output. This
ensures a better quality 120VAC signal. To test this we will input a variety of voltage
values into the circuit. This can be compared against the output voltages and plotted to
find the corresponding efficiency values. We expect to be able to achieve 80%
IV. Cost and Schedule
Part Mft Part
No. Manufacturer No. Description Application Price Qty Total
Pelton Wheel Turbine $115.00 1 $115.00
Motor / $150.00 1 $150.00
Litton 42143 Motor JDH-3150-D-1C Generator
Hayward FloSite 2000 Flow Sensor $150.00 1 $150.00
Industrial FLR-2000 Sensor
10ft (2in. diam) PVC Frame $5.00 2 $10.00
5ft (4 in. diameter) PVC Frame $5.50 1 $5.50
Misc. PVC Connectors Frame $35.00 - $35.00
Misc. Plumbing Parts Turbine $30.00 $30.00
Microchip PIC chip PIC $8.00 1 $8.00
SLM LCD Display 1 $50.00
Shelly 23281BSA Display $50.00
Machine New Motor End Cap -
Shop parts+ labor, approx. $25.00 1 $25.00
ECE Back Motor Cap
Machine Adaptor - parts+ labor,
Shop approx. $25.00 1 $25.00
Grainger 2X897 bearing $11.20 2 $22.40
R1 1k 1/4W res DC/DC $0.03 2 $0.06
R2 12 1W res DC/DC $0.10 1 $0.10
R3 100k 1/4W res DC/DC $0.03 1 $0.03
R4 3k 1/4W res DC/DC $0.03 1 $0.03
R5 Caddock MP930 0.05 30W res DC/DC $3.00 1 $3.00
C1 NIC 2200uF 25V cap DC/DC $0.15 1 $0.15
C2 HVR 270uF 400V cap DC/DC $0.40 1 $0.40
C3 470uF 16V cap DC/DC $0.07 1 $0.07
C4 100pF cap DC/DC $0.10 1 $0.10
U1 TI UC3846 PWM controller DC/DC $1.70 1 $1.70
M1 ON semi MTP50N06 42V DC/DC $3.50 1 $3.50
D1 Fairchild 1N4936 400V 1A Fast R DC/DC $0.05 1 $0.05
D2 ON semi 1N5338 5.1V 5W Zener DC/DC $0.27 1 $0.27
T1 Micrometals T300-26D Powder Iron core DC/DC $6.00 1 $6.00
Magent wire 14 AWG wire DC/DC $17.00 1 $17.00
Magnet wire 26 AWG wire DC/DC $18.00 1 $18.00
R1 15k 1/4W DC/AC $0.03 1 $0.03
R2 100 1/4W DC/AC $0.03 1 $0.03
C1 1uF 25V DC/AC $0.07 1 $0.07
Q1-Q4 Fairchild FQP17N40 400V 16A FET DC/AC $2.01 4 $8.04
U1-U2 IRF IR2110 HI LO Gate Drive DC/AC $3.95 2 $7.90
U3 ON Semi SG3526N PWM controller DC/AC $2.25 1 $2.25
Grand Total $694.68
(Unless noted, tasks are for entire group). TA/Prof. consultation bi-weekly, as needed.
Week One (June 14th) - COMPLETED
General discussion of project and preparation of project proposal.
Research on the individual modules: Turbine and Motor Design/Implementation
(Eric Muller); Sensor, PIC chip, Display (Jiaxiao Zhang); DC/DC Conversion
Circuit and feedback), DC/AC Inversion Circuit (Dan Nowak)
Week Two (June 21st) - COMPLETED
Design of individual modules: Mechanical turbine/motor interaction, tubing,
nozzle configuration (Eric); PIC chip selection, sensor-PIC interaction,
highest-level PIC code, tube placement (Jiaxiao); DC/DC, DC/AC circuits,
feedback control, transformer design (Dan).
Acquisition of parts: wheel, tubing, nozzle, motor, box supplies (Eric); PIC chip,
sensor, pipe (Jiaxiao); DC/DC, DC/AC resistors, transistors, transformers,
capacitors, etc. (Dan).
Week Three (June 28th) - COMPLETED
Further research, design, and testing on individual modules (see above).
Final research and preparation for design review.
Group meeting to familiarize each other with research, design and status.
Preparation for the design review.
o July 1st - Design review.
Week Four (July 5th)
Begin construction, implementation and testing of the individual modules:
Turbine, motor/generator (Eric); Sensor-PIC chip, Display (Jiaxiao); DC/DC,
DC/AC, Outlet (Dan).
Preliminary preparations for the mock-up demos.
Week Five (July 12th)
Conduct mock-up demos.
Week Six (July 19th)
Put modules together for system testing and analysis.
Week Seven (July 26th)
o July 29th – Final demo.
Begin preparations for formal presentation.
o July 30th - Give presentation.
Start preparing final report.
Week Eight (August 2nd)
Finalize final report.
o August 2nd - Submit final report
Design Project Tasks 6.2 6.3 6.4 7.1 7.2 7.3 7.4 8.1
Research, write proposal
Finalize design, order parts
Build hardware, write software
Final demonstration, present project