Re: electronic PWM variac

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Ed Phillips <evp@xxxxxxxxxxx>

" > Has anyone tried to turn one of these into an "electronic ballast"
 > that synthesizes the effect of series inductance into a SG coil?

I believe this is how fluorescent light ballast works, and that runs
about $1/watt, which as far as I'm concerned is ridiculously expensive
when you use a MOT for virtually all ballast needs,  shorting the
secondary or tapping the primary as necessary."

	Those things generate voltage at around 50 kHz, where the fluorescent
lamps have a lot better impedance behaviour than at 60 Hz.  In no way of
interest for TC application.  The "buck a watt" figure is way high.
They're very cheap and used in all of the screw-in fluorescents intended
to replace incandescents.  Those retail for about 5 bucks.  This is a
case where I suspect cost is almost independent of power output.  There
are a number of IC's which control the things and the only thing that
varies with output are the switching devices (often powerfets) and a
single inductor and capacitor which set the frequency.

Ed