BOEING377 wrote:
The wind generator crowd swear that in the case of single wire alternators, low
speed output is better on a low power alt (eg one capable of 30 amps max) than
a high power one (eg 100 amps). Is this true? If so why?

Probably because of the limited power available. The torque required to
turn the alternator is governed by the current in the field coil. The
regulator sees only the vlotage going to the battery and has no idea how
much power is avilable to turn the alternator. When the regulator sees
power is required it loads up the field coil to increase output. The
bigger the alternator, the more torque is required so the wind can't
spin the larger one as fast.

The power that an alternator puts out relative to RPM is a curve that
starts off steeply and levels out. Optimum RPM is about at the point
where the curve starts to level out. Even with specially designed low
speed alternators that point is more than 2,000 RPM. The wind generator
designers want to get the RPM as far up the steep part of the curve as
fast as possible with the available power. It is much better to get 60%
of capacity out of a 30 amp alternator than 10% out of a 100 amp
alternator.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
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