POWER PLANTS

GENERATORS AND ALTERNATORS


| May/June 1981



Generator

Route 1, Box 163, Lenaby, Minnesota 56651

I read the article, 'Building a Backyard Powerplant' by Carl Lathrop and I thought it was very interesting.

I have a bit of information pertaining to generators and alternators that those who are interested in powerplants might find interesting.

Have you ever wondered what causes the mechanical load on a generator? Even a big generator turns over really easy by hand, but bring it up to speed and start using electricity and you'll notice that the more current you use the harder the engine pulls.

This had me curious, so I set out to find why. In one experiment, I took a small heater blower motor from a junked car. First I connected it to a battery to see if it would run, which it did and by running, it would leave a residual magnetism in the field core. I next hooked it to an electric motor, and turned it in the opposite direction that it turned as a motor. The electric motor turned it like nothing, until I touched both of the heater motors wires together and it created such a load, the HP electric motor had a job running it.

That little experiment proved that it's the currents flow that produces the load. No current flowing in the generator, and no load on the motor.