The last erg

From:  Barton B. Anderson [SMTP:mopar-at-uswest-dot-net]
Sent:  Monday, June 08, 1998 8:30 PM
To:  Tesla List
Subject:  Re: The last erg

LR, can you elaborate on the H-bridge design?

Tesla List wrote:

> ----------
> From:  L.Robertson [SMTP:LWRobertson-at-email.msn-dot-com]
> Sent:  Sunday, June 07, 1998 10:11 PM
> To:  Tesla Builders
> Subject:  The last erg
> Hi folks...
>  I reconfigured my DC coil to use only 0.012 uF ,
> thus increasing available PPS . Using .025 uF
> I could only get about 150 PPS out of the two
> 15kV 60 ma NSTs even with resonant charging.
> I had to reduce my top load to a 4" X 24" home
> made torus to get resonance.
> Starting out at a few PPS multiple sparks shot out
> around the torus , probably 8 or more simultaneously.
> As the H-bridge rotary ramped up and DC power
> was increased the sparks coalesced at around 200
> PPS into only one which roiled around striking
> everywhere.
> I could vary the length of the streamer with power
> from a foot long to good solid 48 inch connects to
> grounded objects. Decrease the power and still one
> streamer would dance around as long as the spark
> gap was alight.
> The gap runs very reliably, and exhibits a sort of
> 'hystereses' effect where it will either not fire at all
> at low voltage or it fires at every presentation above
> some threshold voltage. There seems to be no setting
> where it fires intermittently. Maximum speed is 230
> PPS. I hope to build one to bring the rate up to 400
> PPS or so sometime soon. At least when I move to
> a pole transformer I won't need to worry about current
> limiting - the gap speed sets the power consumption.
> Unfortunately my coil has outgrown my garage. Guess
> it's time to invest in a shed.
> LR