Re: Transformer (2500 volt)

To: tesla-at-poodle.pupman-dot-com
Subject: Re: Transformer (2500 volt)
From: Tesla List <tesla-at-stic-dot-net>
Date: Sun, 18 May 1997 23:52:20 -0500
Approved: tesla-at-stic-dot-net
Subject:  Re: Transformer (2500 volt)
  Date:   Sun, 18 May 1997 21:15:39 +0500
  From:  "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
    To:  Tesla List <tesla-at-pupman-dot-com>


On Sat, 17 May 1997 20:29:26 -0400 (EDT)
<FutureT-at-aol-dot-com>

> Alfred,
>     Yes, these were residential units, I haven't come across any
> of the industrial ones yet.

I personally like the industrial units better they not only are not 
current limited but seem to be more efficient as well. I'm only 
experimenting with the residential units for the benefit of those
who can't find neon sign transformers nor pole pigs, like our friends 
doun under in Australia.

> I didn't add any insulation; I also didn't disconnect the sec. connection
> from the core.  I grounded the cores of the "middle" two transformers and
> then connected the cores of the "outer" two transformers to the hot sides
> of the middle two (hope this is clear).  During operation, I could see
> corona sparkling between the windings and core. 

This is as I suspected. I did an experiment with a residential 
microwave transformer and hooked it up to a power supply and varied 
the primary voltage from 120-volts to 600-volts and around 300-volts 
I got some arcing between the windings and the core this would 
represent between 8KV to 10KV on the secondary. That is why I asked 
if you added any insulation, I knew they couldn't hold up otherwise.

> This was just a short-term test, so I didn't worry about it.  For longer
> term use I would have dumped the "outer" transformers into oil and
> disconnected the sec wire from the core.  My two outer cores were
> electrically "hot" so I placed them within an insulated cabinet for
> safety.

I would think it would be a lot easier to just disconnect the 
connection between the secondary and the core and putt all the cores 
in oil.
  
> My reasoning here was that maybe extra inductance would reduce
> transformer saturation; these transformers are so inefficient.
> By limiting my input current, the sparks might be a little shorter,
> but my current input might be considerably less.  Just turning down
> the input voltage might be better though.

Cutting back on the current or the voltage ultimately amounts to the 
same thing so I don't think it would make any difference. I suggested 
adding some capacitance to get the primary(s) to resonate with the 60
cycle line and there by gain some efficiency. The more I play with 
the residential microwave transformers the more it looks like the 
best thing to do would be to rewind them and there by get better 
efficiency and up the output per transformer to a more usable 10KV or 
so, then just add the in parallel for greater power.

                               Sincerely

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                           Alfred A. Skrocki
                   alfred.skrocki-at-cybernetworking-dot-com
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