you can use adjacent holes on the power and ground traces.
2. BUILD THE POWER SUPPLY
Now you’re going to mod the flashlight
charger to make your hand crank generator.
2a. Salvage the crank and its circuit board.
Flip the flashlight over and remove the 4
screws located in the corners of the outer
housing. Remove the outer housing.
Remove the screws holding the hand crank
in place, then remove the screws holding the
larger circuit board in place (Figure I).
Cut the wires running between the 2 circuit
boards. You’ll be left with the crank still connected to the larger board (Figure J).
2b. Unsolder the battery.
Remove it from the board. You’ll replace it
later with 3 NiCads for longer life.
2c. Hook up the switch and new batteries.
Solder a wire from the positive terminal of the
crank circuit board (marked) to one of the
switch’s outer terminals.
Solder the positive wire from the battery
holder to the middle terminal of the switch
(Figure K). Insert the 3 NiCad batteries into
the battery holder (4-battery holder shown
2d. Connect it to the project circuit board.
Now connect the 2 loose wires you added in
Step 1b: solder the wire from pin 8 on your
voltage regulator to the remaining outer terminal of the switch, and solder your crank
ground wire to the negative terminal of the
crank circuit board (Figure K).
You now have a simple rechargeable power
supply. In one switch position, batteries are
connected to the crank and can be recharged.
In the other position, batteries are connected
to your circuit to provide power. This way, the
crank is never directly linked to your circuit
because that could cause damage.
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