Re: rotay spark gap

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Dave Lewis by way of Terry Fritz <twftesla-at-qwest-dot-net>" <hvdave-at-earthlink-dot-net>

Might be a phase problem, ie your gap is lining up at the zero crossing of
the cap voltage.   What kind of
motor are you using?   The one I built has one of those hysterisis motors
which has no fixed pole.   The
phase setting is more or less random when I spin it up.    I've had luck
adjusting it by flicking the
power to the motor off for a quick second or so.  After a few dozen flicks
I'll luck into the correct
phase setting.   I like to set mine so the gap fires at the very peak of
the cap voltage waveform, I
monitor one of the NST outputs on my scope to know if I've got it right.
Once I get it going I dont shut
it off.   A strobe would be handy for this.

Good luck
Dave Lewis
(novice coiler)

Tesla list wrote:

> Original poster: "colin.heath4 by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <colin.heath4-at-ntlworld-dot-com>
>
> hi all,
>         iv ran up my srsg today and had no joy really .
> i only got it to fire when the gap slowed down after shutting down the
power to
> the motor.
> could this be due to the gap between the post and electrode being too wide
> im using a mot supply with voltage doubling
> any help will bew much appreciated
> many thanks
> colin heath