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Re: 3-phase current - you don't need caps or ider motors!
> I knew I had this somewhere, but it took me a while to find it. There is
a
> way
> to change 2 phase power to 3 phase using only two transformers! It is
> called a Scott transformer, and was used by power companies to go from 2
> phase to 3 phase or 3 phase to 2 phase power. You do not have the puny
> power limitations of capacitor systems, nor do you have to use a large
> motor/generator setup. I found this in my 1939 Coyne home electrial
The Scott connection requires true 2 phase power, with the phases 90
degrees apart. Residential service is, of course, center tapped single
phase. You can make the 90 degree phase shift with capacitors, but then,
why not just make 3 phase power.
For driving a power supply, an RC phase shift network like they use in
welders has to be the way to go. No moving parts, etc. Sure, the phase
balance gets terrible at low loads (why you wouldn't want to do this for
running a motor), but for a power supply, it isn't even an issue. I'll
figure out the equations and post them in the next couple of days.