SRSG v. DC-RSG

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Daniel A. Kline" <daniel_kline@xxxxxxxxxxx>

Hi All,
For the first time in several years, I'm about to add a rotary spark-gap
to a system. The last time I used a rotary spark-gap, it was
asynchronous, and didn't work well with the setup I had.

This time I'm using a 1.5KVA potential xformer at 14.4kV, and I'll be
testing Maxwell caps and MMC configurations to see which is best for
this particular coil.

I'm wondering if I should try a variable break-rate rotary-gap on a DC
motor, or if I should try a synchronous rotary-gap.

The reason I ask is because I had a cap explode when using an
asynchronous rotary-gap, and I'm concerned that the same thing might
happen if, while testing,  I'm continuously varying the break-rate using
the DC-motor rotary-gap.

I have DC motor handy, and I don't have a sync motor yet, but I've been
wanting an angle-grinder for a while now, so it wouldn't take much
convincing for me to go out and get one for machining the appropriate
AC-motor armature ;)

Also, does anyone know of a decent tachometer circuit I can use in
conjunction with the DC-motor in case I go that route?

Thanks,
Dan K.