Instructables

How can I charge a NiCa battery with a small DC (permanent magnets) motor spinning the shaft by hand?

I can run a small FM radio with this motor spinning the shaft (via the belt pulley) by hand. I think the motor produces at least 3V/40mA. I tried to charge a nicad(800 mAh) by adding a diode to the power wire but it failed. All I need is a circuit(schematic) to charge a battery. Help, please!

NachoMahma5 years ago
. Does this help or hinder?
   |-------|<---|------------|   | -          |            |  Gen         V Mtr       Battery   | +          |            |   |------------|----A Mtr---|
  • Generator
  • Volt Meter
  • Ampere Meter
  • -|<- - the best I could come up with for a diode
.
. Somebody double-check me.
kostya (author) 5 years ago
Thanks a lot. Just hooked up 1N5819 to the positive power line. Everything works fine.
frollard5 years ago
Try turning the motor with a multimeter attached to find out which lead is + and which is -. It should output pulsed DC in when you rotate that direction... attach the + and - to the battery in the correct polarity, but with the diode hooked up so the motor DOESNT turn when you connect the circuit.