RE: Phasing parallel coil and core NSTs

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

Original poster: "Vanderputten, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <gvp-at-pvaintl-dot-com>

This is my 8th coil, and my smallest. I always use safety gaps, but more
recently the full FRITZ/LAU style of NST protection and RF grounding. This
particular project is different in scope and simplicity, and my concern was
about the criticality of formal NST protection in this particular case. All
the smaller coils I have seen, even the smaller commercial ones, have no
such protection. The life-threatening aspects of the hobby are basic and
transcend the issue of NST protection - not sure where your concern is.

Gary 

 -----Original Message-----
From: 	Tesla list [mailto:tesla-at-pupman-dot-com] 
Sent:	Wednesday, April 17, 2002 9:56 AM
To:	tesla-at-pupman-dot-com
Subject:	Re: Phasing parallel coil and core NSTs

Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<rheidlebaugh-at-zialink-dot-com>

Gary you are asking " is safety important?"" is your life important?" You
make the choice and dont haunt us if you kill your self.
  Robert  H 

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Tue, 16 Apr 2002 17:36:41 -0600
> To: tesla-at-pupman-dot-com
> Subject: RE: Phasing parallel coil and core NSTs
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Tue, 16 Apr 2002 17:49:13 -0600
> 
> Original poster: "Vanderputten, Gary by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <gvp-at-pvaintl-dot-com>
> 
> 
> 
> -----Original Message-----
> From:  Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Tuesday, April 16, 2002 3:20 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: Phasing parallel coil and core NSTs
> 
> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <Esondrmn-at-aol-dot-com>
> In a message dated 4/15/02 10:18:36 PM Pacific Daylight Time,
> tesla-at-pupman-dot-com writes:
> 
>> 
>> I am making a small 250 w coil powered by 2 identical 5kv/25ma open core
> and
>> coil neon transformers.
>> 1. I noticed that neither will arc to the core and therefore appear not
>> center grounded. Are there issues with phasing the two in parallel?
>> 
>> 2. Should I ground the cores to the mains ground or the RF ground? With
my
>> other coils I ground the case to the RF ground.
>> 
>> 3. Even though it is small, I am installing a Cap and resistor style NST
>> protection circuit. Is this necessary ( I have the spare parts)?
>> 
>> Gary
> 
> 
> 
> Gary,
> I would measure the secondary to core resistance.  If it is open circuit,
> then the core is floating and there is no center tap connected to the
core.
> If it measures one half of the total secondary resistance, then you know
> there is a center tap that is connected to the core.  In this case, I
would
> ground it.
> 
> Check - it is an open circuit.
> 
> 
> To check parallel transformer phasing, set the two transformers up in the
> position that you want to use them and connected the primaries in
parallel.
> Now connect one side of each secondary output together.  With power
applied,
> you should get a very small spark or no spark when the other two secondary
> leads (one from each transformer) are brought together.  You can now
connect
> these secondary leads together.  If you get a large spark, reverse the
> primary connections to one transformer and try the test again.
> Ed Sonderman
> 
> Thanks to all for their helpful comments.
> 
> Gary
> 
> 
>