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Re: New Testing




From: 	Esondrmn-at-aol-dot-com[SMTP:Esondrmn-at-aol-dot-com]
Sent: 	Friday, September 12, 1997 8:42 AM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: New Testing

In a message dated 97-09-12 03:34:02 EDT, you write:

<< Hi Ed,
 
 Sorry to hear that you are still having problems with your system.  As
 we've discussed in private email, my system is practically identical to
 yours.  I too am running a 6" coil with a 5kVA pig (most of the time!),
 225amp arc welder without resistors, Superior Powerstat, rotary gap (4 gap
 series unit Ed Wingate just built for me), and RG213 HV feed cables.  I
 just added a pair of .05uF 50kV pulse caps in series for .025uF tank
 capacitance...same as you.  Our systems couldn't be much more similar.  My
 tank circuit interconnects are a combination of heavy copper bussbar and #1
 welding cable.   I am not running any static gaps in series with my rotary,
 and the rotary fires very smoothly with the variac at only about 2/3 max.
 At 14.4kV I would think that your .19" total gap would be fine.  Then
 again, it couldn't hurt to just throw a jumper across those static gaps and
 take them out of the circuit as a test.
 
 Questions:
 
 -Are you setup with the gap or the cap across the HV lines from the pig?
 
 -Any chokes or bypass caps?  I seem to remember some in a photo of your
 setup.  Have you tried taking these out to see if something is shorted?
 
 -How is voltage out of the variac to the pig?
 
 This must be frustrating, particularly after having waited so long for that
 CP cap to come back.   It's a puzzle indeed.
 
 
 
 Charles Brush >>

Charles,

Thanks again for the reply.  It does sound like our systems are almost
identical.  I do envy your capacitors.  They should be bullet proof.  I still
worry about loosing mine again.

My HV feed lines come in and connect directly across the gap.  One side to
the static gap and the other side to the rotary.  The static gap and rotary
are connected together with no other connections at that point.

Good memory.  My filter board does have filter caps on it that were used with
neon transformer power supplies but are out of the circuit for the pole pig
supply.  About the only thing on that board is the safety gap and two series
chokes, about 20 turns of #12 wire on large ferrite cores.  They probably
don't do a thing, but I leave them in the circuit.

The voltage out of the variac goes up to full line voltage.

I replaced all the contacts on the rotary gap last night, reset the contacts
as close as possible and reduced the two feed lines to the cap from three
RG213 wires in parallel to two.

I am puzzled why the system won't run at all with any resistance in parallel
with the welder - it used to run better with that configuration.  I will try
it without the parallel resistance and without the static gap if necessary.

Ed Sonderman