[Prev][Next][Index][Thread]
Re: Peak cap voltage, was 12kV, 30ma TC specs, 42" spark
From: FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
Sent: Wednesday, September 10, 1997 5:24 AM
To: tesla-at-pupman-dot-com
Subject: Re: Peak cap voltage, was 12kV, 30ma TC specs, 42" spark
<< John, Malcolm & all,
> Nice experiment, John! Even though you're firing synchronously every
> half cycle, you're still seeing the impact of resonant rise. This
> experimentally confirms an earlier question regarding whether you'd get
> resonant rise if you synchronously fired on each AC half-cycle.
Bert,
Thanks. Do you mean resonant rise in the charging circuit,
it seems to me that 120BPS sync operation would be better
for resonant rise in the charging circuit than a higher break-rate
would be, since there's more time available for the resonant rise to
occur.
> Under these conditions, Glasoe ("Pulse Generators") predicts voltage
> rise of Pi/2 times input voltage. Peak input voltage is about 20.4 kV
> from your potential transformer, leading to a predicted peak of 31.2 kV
> versus 32 kV measured - pretty close agreement! If you "missfire" just
> once, or only fire synchronously 1/cycle, the predicted value climbs to
> Pi*20.4 or about 64 kV (:^()! And it potentially (NPI) gets much worse
> with asynchronous firing!
Ho! I agree, ain't it great!
> While your potential transformer will shrug off this transient, a neon
> would probably be toast! This definately confirms the moral of not
> running a neon with an async gap, especially if close to 60 Hz
> resonance. However, it also speaks to the issue of conservatively rating
> your tank cap!!
Very true. My cap is rated at 90kV. Sometimes, when my gap
electrodes wear, I may miss some firings before I re-adjust the gap,
of course, the safety gaps should fire.
John Freau
> -- Bert --
>>