RE: Terry's DRSSTC

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Steve Conner" <steve.conner@xxxxxxxxxxx>

>I think it would be cool if the DRSSTC drive could be sort of a "drop in"
>replacement and work on existing coils...  More to think on there...

A couple of months ago I hooked up a DRSSTC driver to my old Tesla-2
spark-gap coil. This was about the worst coil you could have chosen for the
experiment as it was designed with a high impedance primary (lots of turns
and small capacitor) with relatively loose coupling. With only 400V going
into a primary that was designed for 20,000V it could have been pathetic.
But I thought I would try it anyway- if it worked with this coil it would
probably work with anything.

To cut a long story short, it worked, and produced 36" arcs at about 80 bps,
which compared very well to the 40" at 400bps it achieved with spark gap
power. I found that primary current feedback worked better than the usual
secondary current feedback on this setup.

Unfortunately there was a disastrous IGBT blowout before I got any pictures
of it operating, and I never did get round to fixing it and trying again.
But I have witnesses who will swear that it really happened ;)

The blowout was probably caused by a combination of too much current, not
enough gate drive, and not enough cooling.

Steve C.