Re: [CAD_CAM_EDM_DRO] Transformer and voltage drop

Hi Jon, everyone,

> But, for a 1.8 KVA transformer, the 0.7 V drop per amp seems way
> too much. I'm assuming you must be running the 30 V AC
> secondaries in series. 1.8 KVA at 60 V AC should be 30 A!
> So, at no load, you read 60 V AC, and at 30 A you read 39 V?

Yes, the secondaries are in series. I can't load it up to full power
(30A) with the resistors, lamps, and ovens I'm using for load testing,
but the trend is there...

> Since you
> mention the inrush limiter, you don't need (or want) this
> feature.

Good advice, thanks. I removed the current limiter, and the AC load test
now gives a much more reasonable voltage drop of about 0.3 Volts per
amp. That matches the ca 0.3 Ohm or so resistance that can be measured
over the secondaries with a multimeter.

But I still see a big voltage drop when connecting the bridge rectifier
and caps and loading up the psu:
http://www.anderswallin.net/2007/07/transformer-test/

I tried this with two different bridge rectifiers just to be sure...

Please tell me I don't have to invest in some expensive PFC circuit like
suggested in some comments...

thanks,

Anders