Project Proposal
ECE 445
Portable Hand Crank
Cell Phone Charger or Flash Light
Proposed by: Adam Weber
Robert Dunn
TA: Tony Mangognia
Team #18
Introduction:
Title:
We have decided to make a Portable Hand Crank Cell Phone Charger with an LED light
that can be used anywhere. We selected the project because we both have an interest
in power generation and management. Also we both like the outdoors and think this
devise would convenient to have when on extended outdoor trips. This devise would
come in handy when there is a power outage and you need a flash light, it always
seems like the batteries are dead in flash lights. This devise seems both practical and
convenient.
Objectives:
Goals: We would like the circuit to be able to maintain a 5 minute phone call or 5
minutes of lighting with less than 2 minutes of charging. This would be done by
providing 5 Vand 600 mA to the load of the circuit after one and half minutes of charge.
Also if continues cranking was applied then you would get continues lighting or phone
call.
Functions: The hand crank generator will feed into a rectifier to make the
voltage all positive. After the rectifier will be a voltage regulator, which will steady the
Voltage out at 5 volts so the cell phone is not damaged. The regulator will charge an
ultracapacitor. The ultracapacitor will store the charge so you can talk when not
cranking the generator.
Benefits:
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Always able to make a phone call
Free quick charge for emergency calls.
A handy light
No batteries
Features:

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Light and Compact
Right or Left hand use
Built in circuit protection
Easy switch between Flash Light and Cell Phone Charger.
Generator
The hand crank generator will turn the mechanical energy that is created when a person
turns the crank into electrical energy that will be used to charge the battery. The
electricity that is created from the hand generator is not suitable for charging up the cell
phone battery, so it must be converted using further components. After the electricity is
created by the generator, the next step is to feed it to the rectifier.
Rectifier
The power coming in from the hand generator is AC. In order to recharge the batteries,
it must first be converted to DC. This is done using a rectifier constructed from 4
diodes, which provides full wave rectification. Full wave rectification causes the
negative voltages to be converted to positive voltages. The DC power produced by the
rectifier is not constant, however, so it must be passed on to the voltage regulator.
Voltage Regulator
The voltage regulator takes the unstable DC power from the rectifier and outputs a
constant DC voltage to be stored in the capacitor.
Ultracapacitor
The ultracapacitor is where the power from the voltage regulator is stored. It will charge
as long as the crank is being turned, and will discharge into either the cell phone battery
or LED light depending on which way the switch is turned.
LED Light
The LED light will turn on once the capacitor is fully charged.
Switch
The switch selects whether the capacitor will power the LED light or the cell phone
battery.
LED Flashlight
An LED light powered by the ultracapacitor will illuminate when it is selected by the
switch.
Cell Battery
The cell phone battery is charged by the ultracapacitor.
Performance Requirement
Output Voltage: 5 V
Output Current: ~600 mA
The device, once assembled, should be small enough to be portable.
The output voltage and current would ideally occur when the crank is being turned
between 1-2 rotations per second.
The output voltage should work for most cell phone batteries because 5V is close to the
voltage that most cell phone chargers put out.
The output current will probably vary depending on how fast the hand crank is turned.
Cell phone wall chargers have a wide variation of current output, and 600 mA is around
the average. A higher current output would be better than a lower, but it may be difficult
to achieve with our hand crank generator.
Verification:
Testing Procedures: We will design the circuit in separate and independent steps.
Each part will be able to be built separate from each other. Also we will be able to do
test each part separate. We first design the Generator and Rectifier. After we have that
working we will then make the voltage regulator. After the design of the Voltage
regulator we will design the ultracapacitor and the switch circuit.
Generator and Rectifier: For this test we will crank the generator to produce our
voltage and then have the load of the rectifier be the oscilloscope so we will be able to
see the voltage value in real time. We will make sure the voltage has a sufficiently high
rms value of 12V and is completely rectified.
Voltage Regulator: The voltage regulator can be built independently of the Generator
and Rectifier. We will use the function generator to produce a similar wave form so we
can test the voltage regulator while also building the generator and rectifier. We will
make sure the voltage regulator supplies a 5 volts with very little variance as we can
change the frequency of the function generator to simulate different speeds of the hand
crank.
Ultracapacitor: We will test to see the output capabilities of the ultracapacitor. We will
make sure it can supply the needed voltage and power to run the phone, or the flash
light.
Tolerance Analysis: We will look at the rectified signal of the hand crank generator.
We will need to know the range of revolutions per second(rps) that will produce a
working signal of 12V rms. This is important because the rest of the circuit will depend
on the value being near 12V rms. Also we need to give the operator a working range of
rps to stay within. Then we can build the voltage regulator will be designed on that fact.
Also we will have to test and see that the generator can supply enough current for the at
that rps rest of the circuit.
Cost and Schedule:
Cost Analysis:
Labor: ($75.00/hour)*2.5*(10 hours/week)*(12 weeks) = $22,500.00
Parts:
Hand Crank Generator
4 diodes
Ultracapacitor
LED
Bright LED
Plastic casing
Switch
Resistors
Capacitor
Op amp
Zener diode
Total
$15.00
$0.05 each
$20.00
$0.10
$5.00
$5.00
$3.00
$1.00
$0.20
$5.00
$0.10
$54.35
Grand Total: Labor + Parts = $22,554.35
2/16
2/23
3/2
Adam
Research preliminary design & parts
Research generator, rectifier, cell
phone battery ratings
Finalize design and order parts
Prepare for design review
Build and test generator and rectifier
3/9
3/16
3/23
3/30
4/6
4/13
4/20
4/27
Refine designs
Build complete circuit
Spring Break (catch up if behind)
Mock up demos
Final design
Run final tests and troubleshooting
Work on final presentation and paper
Project demos
2/2
2/9
Robert
Research preliminary design & parts
Research voltage regulator,
ultracapacitor, LED lights
Finalize design and order parts
Prepare for design review
Build and test voltage regulator,
ultracapacitor, LED lights
Refine designs
Build complete circuit
Spring Break (catch up if behind)
Mock up demos
Final design
Run final tests and troubleshooting
Work on final presentation and paper
Project demos