Quote:
Originally Posted by Ecky
I'm not sure what benefits there would be to lowering its RPM, unless perhaps it's more efficient at one RPM than another.
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It's output is limited at lower RPMs. It will try to make up for it by boosting the field voltage, but it will hit a wall/limit and not be able to output any more without spinning faster. (as shown by cars with small alternators that can barely keep the voltage up at idle with a decent load put on)
Rather like an engine, it will have maximum efficiency when kept close to it's peak output. Peak output for a given RPM will always be better than partial at a higher RPM.
Plus, hey, they usually have fans build on/in them, so there will be a tiny bit less power "wasted" by the fan spinning slower.