Re: [CAD_CAM_EDM_DRO] Re: Big, Cheap Power for Steppers

> The "coil window" in standard industry "E-I Cores" has
> been sized after years of practical learning-curve, so it will contain JUST
> the right copper for correct Volt Amps for that size iron-core. That is, if
> you go stuffing wads of "non-transformer insulation" in there with the
> copper you use, you won't come CLOSE to being able to wind sufficient
> Amp-Turns for reasonable efficiency. Oh, you might get enough voltage, or,
> alternately, enough current-capacity, but surely NOT the voltage AND current
> ("V-A") intended for whatever 750 VA or 1 KVA transformer you are trying to
> modify!

Jan makes an interesting point - it is probably impossible to rewind a
microwave oven transformer and keep the original VA rating. Even if
you had varnished magent wire, it would be hard to get the thicker
wire to fill the gap as completely as the fine wire does. HOWEVER, it
appears to me taht people are taking 750 to 1000 VA microwave
transormers and rewinding them to use at 250 VA or maybe less (50
volts 5 amps?) So it doesn't matter if the resulting device must be
substantially derated.

Chris Stratton

-------------------------------------------------
Christopher C. Stratton
Engineer, Instrument Maker, and Horn Player
ccs@... 617 628 1062
http://web.mit.edu/~stratton/www/brassbuild.html