Re: MOT-PSU

["Herwig Roscher" <herwig.roscher-at-gmx.de> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Jim Lux wrote to the list:

> Step 1.. measure the turns ratio at no load by putting a known voltage in
> and measuring the voltage out.  Often, you put 110VAC on the HV winding,
> and measure the LV winding.

Jim,

I've performed this method and found a clear difference between the 
voltage ratio measured "forward" and the voltage ratio measured 
"backward". Shouldn't be, but exists.......

> If you can measure the power factor or real power consumed, 
- I shall use the setup you suggested.

> Step 2... short the secondary with an ammeter. Apply power to the primary
> with a variable voltage source until you are drawing the rated current.
- The problem here is, that on the faceplate of the MOTs (if any!) 
there's no "rated current". In some(!) cases the manufacturer states 
the voltage and/or the power - that's it.

> More at http://home.earthlink-dot-net/~jimlux/hv/xfmrmeas.htm
- I've visited your pages and found a lot of useful information, I'll 
read through thoroughly. Thank you, Jim.

Regards

Herwig