[Prev][Next][Index][Thread]

Fo vs. performance

Hi All,

	When one uses a pole transformer (220/14400  10kW) for charging a primary
cap, you can charge pretty large caps indeed (such as 180nF).  This allows
one to operate a coil with a very low fundamental frequency (like 30kHz).
The lower frequencies have the advantage of using lower primary currents
and running very large secondary coils.  I was wondering if there are any
draw back to those low frequencies?  Perhaps there is an "optimal"
frequency one should design to?

	I have been punching some of the numbers into MicroSim just to see what
goes on there.  I could use a few numbers if anyone has them handy for
50amp variacs and pole transformers.

What is the DC resistance of a 50amp variac winding (the full end to end
resistance)?  This predicts some of the voltage droop in operation.

What is the no load current draw of a variac with rated input voltage applied?

What is the DC resistance of the primary and secondary windings of a
"typical" pole pig?

What is the no-load current draw of a pig at rated input voltage?  I think
it is about 0.25 amp.

I don't have these parts handy so I thought I would ask around.  These
values define some important model parameters for pigs and variacs.

Thanks!

Cheers,

	Terry
	terrellf-at-uswest-dot-net