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how does 3 phase transformer work

I need to convert square wave, 400hz, 24VAC to 115VAC three phase. I am wondering if its possible to use a 3 phase transformer "in reverse" (not backwards) to convert 24V input to 115V output? If so, how does this work? I understand single phase, but how does a three phase transformer generate three phases output from a single phase input? Are the windings located in some fashion which creates a phase shift?

And it would be great if someone sold these off the shelf. My power requirement is about 50W. Would it be feasible to make my own somehow?

Thanks!

Reply to
acannell
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No it doesn't.

Reply to
cbarn24050

More generally, if you have anything other than single phase (two or more phases with phase difference != n* pi), you can use transformers (eg. the Scott T connection), at least in theory.

Best regards, Spehro Pefhany

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Reply to
Spehro Pefhany

A synchro is a device that can transform one phase into three. But these three outputs will have different amplitudes (used to calculate the axe position) and there is no axe position for which all three outputs will have the same amplitude.

Why convert 24VAC 400Hz single phase to 115VAC 400Hz triple phase? If you need to generate axe position information you could use simply a synchro (and sine instead of square). If you are making a power supply you'll need three phases of 24VAC.

115VAC 400Hz low-power power supplies are very hard to get. The smallest OTS solution I've found was a single-phase 1KW 400Hz supply at 2500 euro. I've even found a smaller one (
Reply to
Deefoo

You can use a three phase transformer to convert 24V to 115V but only if you have 3 phase 24V to start with

-- Dan Hollands

1120 S Creek Dr Webster NY 14580
Reply to
Dan Hollands

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Oops, you're right, the outputs are not phase shifted. Sorry.

--DF

Reply to
Deefoo

I need to convert square wave, 400hz, 24VAC to 115VAC three phase. I am

** Err - it doesn't.

A 3-phase transformer is one that operates with three phases in and out.

** If your only available power supply is 24 volts at 400 Hz ( aircraft ? ) then it is no simple ask.

.......... Phil

Reply to
Phil Allison

not sure what you said but

I think if you have two phases that are 90 deg apart, (call them I and Q if you like) then by combining these two in the correct proportion and polarity, you can create any other phase you want.

Mark

Reply to
Mark

You could go for a three phase power inverter. Or you could go for a motor generator.

50W is a pretty low power for a three phase device - are you sure you need three phase AC?

On 30 Oct 2005 21:16:26 -0800, snipped-for-privacy@wwc.com etched in cyberspace:

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Reply to
Octa Ex

50W is Easy - assuming 50W in total and not per phase - and since nobody makes 400 Hz stuff, there might even be a (niche) market for it.

You can f.ex. use an analogue three-stage ring oscillator to generate the three-phase system and three audio amplifiers to generate the outputs. It is also possible to do it digitally. If the loading of each phase is asymetric, you might need to control the output voltage on each of the phases individually via a feedback loop.

You do not have to use a three-phase transformer; three single-phase units connected in "star" connection will work equally well. Single-phase is easier to get hold of.

I should draw this.

Reply to
Frithiof Andreas Jensen

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