Re: I don't understand (fwd)

---------- Forwarded message ----------
Date: Fri, 19 Dec 1997 13:37:30 EST
From: Esondrmn <Esondrmn-at-aol-dot-com>
To: tesla-at-pupman-dot-com
Subject: Re: I don't understand (fwd)

In a message dated 97-12-18 18:33:46 EST, you write:

<< Hi All,
 I have my Coil up and running with really good performance,
 (37" Discharges).  I am using 2 variacs. One for voltage
 control and the other for current limiting. Both variacs are
 rated at 30 amps. I'm using an EMI filter ran in revervse
 between the current variac and the PT, to help my home AC
 lines. I'm using a Westinghouse potential transformer, 100 to
 1 ratio, 15,000 Vac. I am also using 50,000 volt rated high
 performance neon sign wire running from the PT to the series
 spark gap consisting of 6 tungsten tig welding tips. I also
 have a safety gap right before the spark gap
 I placed an Amp meter in line after the current limiting
 variac and before the PT.  What I noticed is  that it takes
 about 17 amps for the spark gap to fire and the coil runs.
 Then the amp meter starts to peg and wildly swing back and
 forth.  ???
 *Is this what is called "kick back"?
 *Is this coming from the spark gap and is feeding RF or energy
 back through my power system?
 *Is this why chokes are used between the PT and the spark gap?
 Please help me understand?
 Thanks to all,
 Mark Bean


It sounds to me like your static gaps can't quench the current available from
the potential transformer.  Most coils using non internally current limited
transformers require rotary gaps for proper quenching.

I originally had my coil powered with a 12 kv  120 ma neon sign transformer
supply.  One RQ style cylindrical static gap (six gaps of .028") worked fine.
Then I switched to a pole pig and even with current limiting in the primary,
the static gaps were overwhelmed and the primary current went sky high.
Adding a rotary gap to the system fixed the problem.

Ed Sonderman