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!

Comments

[NachoMahma]

. 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]

Thanks a lot. Just hooked up 1N5819 to the positive power line. Everything works fine.

[frollard]

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.