[Robotgroup] Generator info for Sam

[thecomers at juno.com]

I pulled out one of the gear motors from my Mindstorms 1.0 set. It is this motor:

http://www.legoeducation.com/store/detail.aspx?KeyWords=motor&by=20&ID=453

This is a 9 volt DC gear motor. I hooked a voltmeter to the terminals, gave the output shaft a spin, and was able to generate 5 volts. If I could get a good spin on the motor, I probably could have gotten a higher voltage (maybe 6 or 7 volts).

Then I hooked up a high-intensity white led directly to the terminals of the motor and spun the output shaft slowly. I was easily able to light the led for a fraction of a second. I did not try to give it a hard spin because 5 or 6 volts might burn out the led. To protect teh led, you might want to add a resistor in series to the circuit. There are calculators on the web to calculate the value of the resistor you need, or someone can show you how to do the calculation.

Thanks,
Bob Comer