Re: [CAD_CAM_EDM_DRO] Re: Converter or Inverter for 2hp Bridgeport mill - OT?

washcomp wrote:

>I don't pretend to be an expert on generators either, but I remember
>seeing steam engine plants from the late 1800's whch had a small
>generator hooked up to supply EMF to the coils of a much larger
>generator (or maybe dynamo, foret whether it was for AC or DC).
>
>
>

Ooh! I KNOW we are going to get jumped on soon for straying off topic!

But, that is called the exciter, and is used on a LOT of synchronous
alternators, as well as on DC generators.

One of the odd features of alternators is that you can adjust the power
factor
of the output for either leading or lagging power factors by changing the
amount of field excitation. There is also a device called a synchronous
condenser which is a synchronous AC machine where the field is
intentionally controlled to correct the power factor of the entire plant.
I was at an auction where a 1951 armed vehicle plant was being cleared
out, and they had a pair of Ingersoll-Rand air compressors, 50 to 100 Hp
each, one cylinder, 300 RPM with motors set up as synchronous
condensers. So, these things were used later than I would have thought.

Jon