Re: Ugly Carbon Track in Terry Filter (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Mon, 18 Jun 2007 08:25:36 +0100
From: James Howells <james@xxxxxxxxxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Ugly Carbon Track in Terry Filter (fwd)

Two replies in a day  - from me
BLACK PLASTIC !
I used to work in the plastic Moulding game and some black plastics can /do 
have carbon in them
Even if they don't, contamination from previous runs is easily hidden by the 
strong colours  - purging of the previous material  is not taken to the 
extent it would be with white , yellow or other colours.

I used a IKEA Teflon chopping board for my TERRY FILTER and still got 
massive HV tracking .................... I marked it out with a soft lead 
pencil.
http://uk.pg.photos.yahoo.com/ph/jmshwlls/detail?.dir=eea3re2&.dnm=4718scd.jpg
http://uk.pg.photos.yahoo.com/ph/jmshwlls/detail?.dir=eea3re2&.dnm=4718scd.jpg&.src=ph
Oh the follies of youth ( 59)  and inexperience
Protected by www.SpamJab.com {UgzndUInruKjv2Cy9r}



----- Original Message ----- 
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Monday, June 18, 2007 3:10 AM
Subject: Ugly Carbon Track in Terry Filter (fwd)


>
> ---------- Forwarded message ----------
> Date: Sun, 17 Jun 2007 18:33:45 -0700
> From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Ugly Carbon Track in Terry Filter
>
> Hi all,
>
> Last week while running the "you know what" out of one of my coils, I
> killed a Terry Filter [TF] which was physically installed on top of the
> NST. The TF was mounted in a black plastic box. The wall thickness of
> the box was 1/8". It worked well for quite some time, but all of a
> sudden "poof". I powered the coil down immediately of course. Then to
> help troubleshoot the problem, I powered the coil back up looking for a
> sign of failure. Well, a bright orange glow inside the TF box told me
> that was the problem area. I removed the TF and the coil ran great once
> again.
>
> Today, I performed an autopsy on the TF. I originally opened the box up
> and saw what I thought was burned areas around MOV's, resistors, and
> caps. But today I dissected the TF and realized the assumed problem area
> was just 2nd hand soot from a carbon track which occurred in the plastic
> box itself. The actual components were fine.
>
> Here's a pic of the disassembled TF:
> http://www.classictesla.com/temp/Img_3816.jpg
>
> The board I used is in front, the Lid to the box included the RF ground
> electrodes and large resistors, and the box itself is behind it all (not
> really visible in the pic). It's just an empty box that the board lays 
> into.
>
> Here's a pic of the bottom side of the lid showing the carbon track
> (it's a good one):
> http://www.classictesla.com/temp/Img_3818.jpg
>
> Pretty obvious the problem, eh? That carbon track is about 2 inches
> long. Here is what I think occurred and I don't think the box had
> anything to do with it (sort of). I was running full power. I think a
> topload strike hit the TF putting an very high voltage at the TF capable
> of causing the carbon track. I've done the same thing with an RSG
> support made of G10 and that carbon track was very similar but about 5
> inches long.
>
> These things happen. No big deal. Easy enough to repair.
>
> Just wanted to share one of those odd moments.
>
> Take care,
> Bart
>
>
>
>