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Re: 10KV RMS -at- 300MA for less than $100

Subject: 
           Re: 10KV RMS -at- 300MA for less than $100
      Date: 
           Thu, 20 Mar 1997 16:28:02 -0500
      From: 
           chuck seguin <seguinc-at-algonquinc.on.ca>
        To: 
           Tesla List <tesla-at-pupman-dot-com>
References: 
           1


Tesla List wrote:
> 
> Subject:
>         Re: 10KV RMS -at- 300MA for less than $100
>   Date:
>         Sat, 15 Mar 1997 09:23:34 -0500
>   From:
>         Steve Falco <sfalco-at-worldnet.att-dot-net>
>     To:
>         tesla-at-pupman-dot-com
> 
> > Those transformers may not be suitable as TC power supplies. It
> > appears that they may be ferro resonant transformers and even more
> > fragile than neons.
> > I was tempted to get a couple myself but I'm waiting until
> > someone actually reports results.
> > The verdict is still out on these. Since you already ordered 2 of them
> > report back to us what results you get. (even if bad)
> 
> I ordered four of these transformers.  One had quick-disconnect
> terminals and the other three were the "directly connected wire" type.
> I hooked them up as stated on the instruction sheet, with the provided
> capacitor to resonate the iron core.
> 
> I wired the secondaries in series and the primaries in parallel to get
> 10kv out with 120v in.  I found that I had to tighten up my spark gaps
> considerably to get the coil to fire  (I had been using a 12kv neon).
> The spark gaps had a much greener look from the vaporizing copper
> because of the increased current drawn.  I suspect the gaps would not
> last very long with 3 KW of power applied!
> 
> The spark output was down considerably from my 12kv 30ma neon presumably
> because of the lower voltage and because the spark gaps were overloaded
> badly.  A much bigger main capacitor might have helped soak up the extra
> current available.
> 
> Sadly, the transformers only ran for a few seconds, then I saw smoke.
> Turned out the transformer with the quick-disconnect terminals arced
> over between one of the high voltage terminals and the secondary
> windings.  I'm afraid this transformer is totalled, because the paper
> insulation between the secondary layers charred away.  I was using
> protective spark gaps and air-wound choke coils, so these things are
> pretty sensitive.
> 
> I'm not sure if I should send back the two transformers I have not
> touched yet or keep them.  At a few seconds of operation per
> transformer, they are pretty expensive.  If they can be made to hold
> together they would be fantastic... but I'm not sure I want to submerge
> them in oil, which seems the best solution.
> 
>         Steve Falco
>         sfalco-at-worldnet.att-dot-netHi everyone,

I feel that submerging transformers in oil appears to be a safe
alternative to permitting the chance of an 
arc-over.  It may be messier, but offers a longer life to the XFMR (
leaving in place all other chokes and 
gaps).

All comments appreciated.

Chuck