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Reply to And anotherone bites the dust

Hi all,
    To save space I'm replying to a number of posts here in one.
SNIPS

FROM Ed Sonderman
>Have you tried running with resistors in series with each high voltage
output
>from the transformers?  On my small 3.0" diameter coil, powered by a 12 kv
>60 ma neon sign transformer, I use only a 3,000 ohm 25w resistor in series
>with each HV feed and have not lost a transformer  -  yet.
>
>Ed Sonderman
>
No I don't have any resistors only two 3mH chokes.  After these problems I
intend filters, resistors etc etc.  I need to SEE whats going on, so getting
a high voltage probe to try scope this stuff is a new objective..

*********************************
FROM John Freau
>
>Sorry to hear about the NST.  For my 12kV, 30ma NST, I never used
>more than a 7/16" safety gap on each side of the NST, using  a loop
>of #10 wire for the safety gap.  I can decrease my spacing to just
>about 1/4" on each side before it fires, using the slightly larger than
>resonant cap.  Are your NST's new or used?
They were new, that is never used, clean nice, damm!
But for the longest time
>I didn't even bother using any safety gaps, or any NST protection
>methods, and still never had any problems.  But I never ran the NST's
>for longer than 1 minute at a time or so.  I think the long runs kills
>them.  Maybe yours are a wimpy brand, if you don't mind me saying?
>
>John Freau
I think I'm a wimpy coiler.  I have never run mine for more than a minute or
so with say a few minutes gap between runs.  The stress is to much, coil and
me :-)

*********************************
>From Reinhard
>
You donīt seem to have a lot of luck with neons. Sorry to hear that.
<
I had my previous Neon for two years using a series static gap then I tried
a sync Rotary and my problems started :-(

> Are these 5kV NSTs center tapped? If I understand you correctly, you are
seriesing the
outputs of the two for 10kV, right?
<

The Neons were Identical units.  They were single output only - no center
tap.  One side was permanently earthed to the case.  I ran them in
anti-phase with a common ground. I do not consider them being in series from
a HV stress point of view in this configuration.

>
Properly set, the voltage across the
safety gaps will never be higher than 5kV. I think it is more the problem
discussed above, as the 5kV is already stressing your neonīs insulation.
<

So is 1/4" with rounded brass electrodes suitable for 5KV safety gap ?

>
More luck to you with new neons!!
Coiler greets from germany,
Reinhard
(P.S: if I were you, I would still bring the coil to the Teslathon. Surely
some coiler would let you use his xformer).
<
Thanks for the encouragement Reinhard - yes I will bring the coil.
*********************************

>From Richie,
>Sorry to hear you lost another transformer,
>
>Are they Tunewell transformers,  because I also blew two 5kV units which
>were not centre tapped as well.  The two units were connected in
>anti-phase with the cases grounded as you described.  Maybe there is
>something about this that they do not like ?
>
>They blew with a closely set static gap.
>
>
> - Richie.
>
> - In sunny Newcastle.

The make of the Neons was/is OLDHAM CLAUDGEN based in Wembley Middlsex.
I must say with all the sympathy I've received it does soften the blow and
now not quite so depressed.

regards
Viv Watts. UK