Re: record sparks then nothing
Subject: Re: record sparks then nothing
From: Terry Fritz <twftesla-at-uswest-dot-net>
Date: Sun, 24 Oct 1999 20:18:51 -0600
Very sorry to hear of your damaged transformer. Resin filled neons or
pretty rare so you should be able to get the tar out and fix it with luck.
I was curious about two things. Did you have a safety gap across the neon
between each high voltage terminal and ground? I would think that would
have saved it.
Also, you say the "primary" of the neon is shorted to ground? Usually, one
of the high voltage "secondary" windings fails. I just wanted to be sure I
got it right.
I try and design systems to be pretty bullet proof so they can survive a
number of imaginable mishaps, but I never considered this before. I would
like to study what happened to see if such things can be prevented.
At 10:53 PM 10/24/1999 +0100, you wrote:
> Tried a bit of tuning on my coil today and got regular 36" sparks to a
>grounded rod. Great I thought then I decided to move the coil slightly as I
>was getting too close to the wall. Wound up the variac again and it ran for
>a few seconds then tripped the mains. Darn I thought. When I looked at the
>coil I noticed that the ground lead had become disconnected,so i had been
>running without a ground for a few seconds at least. I dismantled the
>system and got the megger out. It seems that I have got an ground fault on
>one of the primarys of one of the trannys They are GE 10 kV 50mA they look
>quite old but hopefully they are tar filled rather than resin filled.
>anybody ever dismantled one of these? Oh well looks like it is back to the
>9 Kv 50 f.a.r.t. again for the teslathon unless I get time to sort out my
>radar transformer. That will teach me to be to be too keen to squeeze the
>last bit of spark out!!