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Re: Figure this out.
At 10:25 PM 1/22/97 -0700, you wrote:
>Subscriber: DavidF4797-at-aol-dot-com Wed Jan 22 21:42:14 1997
>Date: Wed, 22 Jan 1997 14:18:21 -0500 (EST)
>From: DavidF4797-at-aol-dot-com
>To: tesla-at-pupman-dot-com
>Subject: Re: Figure this out.
>
>In a message dated 97-01-22 03:41:24 EST, you write:
>
>> ANY time we Coilers use a Neon
>> Transformer we are Gamblin' with the Odds because of that Case Center Tap
>> Problem. It is the Single Greatest Cause of Grief and Frustration, because
>> just when you think you've got the Perfect Neon... ZAP! Your Neon's Fried!
>
>
>I have come to the conclusion after using many types of transformers from
>many different manufacturers that the problem is not one so much of centertap
>grounding as it is with hot spots and corona that form wihin and between the
>windings of the neon secondary. The first transformer that I ever used I
>still have and it still works flawlessly (its a 15kv 60ma.) The reason is
>that early on I removed it from its case and melted the tar off by soaking it
>a week in paint thinner. I then built a plexigalss case for it which I then
>filled with synthetic refridgeration compressor oil (which has excelent
>dielectric strenght and cooling properties). I have run a medium sized coil
>with that transformer flat out (3to 4 ft arcs with minimal terminal
>capacitance and a 4"diam by 18" high secondary) continuously for 15 to 20
>minutes at a time for a total of nearly *20 hours* of operation both with and
>without saftey chokes and *without* a saftey gap.
>
>
>-DavidF-
I'll have to go along with David on this one.
I have diassembled a number of dead neons. These came as dead units
from neon shops and one neon I killed myself.
The number one failure mode is carbon tracking through the potting
compound. This happens even when used in their intended service lighting
neon signs.
Once the carbonized potting compound is removed these transformers once
again will operate. And due to improved heat flow by being out in
the open they will stand considerable abuse.
I have a pair of Jefferson Electric 12kv/60s that I saved from the dumpster.
Both were DOA and were revived by unpotting them. One of them I removed
a number of shunts from and it puts out 90 ma. I have beat this transformer
to death and it perks along quite happily.
I had considered putting these in oil but they seem to be just fine
fired dry.
Those of you who have recently lost neons should consider unpotting
one just too see for yourself.
Mike Hammer
mhammer-at-misslink-dot-net