Re: Of Resistors, First Light, and SparkGaps

["Tesla list" <tesla@pupman.com>]

Original poster: "Terry Fritz" <twftesla@uswest.net>

Hi Simon,

At 08:44 AM 12/23/2000 -0500, you wrote:
>
>Hi all.
>
>Well, the days has finally arrived, I'm ready for first light.
>Before I do, I have just a few questions.
>
>1] The 100W Resistors in the NST Protection unit. For RE. to the question,
>you might want to look at:

http://au.rs-c.dk/servlet/dk.stibo.module.ShowModuleServlet?moduleId=5124333

>Although they are heatsinked, they get pretty darn hot quite quickly [~1
>min] to the point where they are almost too hot to touch.. Is this ok? If
>you look at the picture, you can see that there is not much space between
>the connecter and the heatsink. This is causing some problems; if I tap my
>sparkgap at too many gaps, it just arcs from connector to heatsink on the
>resistor. [This is despite insulating taps [which I didn't expect to do
>much] and HDPE [which I though would] Any Ideas? I have got some silicon,
>do you think that would do the trick?

I would not recommend the metal encased types like this since arcing to the
case may be a problem.  However, just be sure that the cases are floating
and let that silicon flow freely :-)) 

Don't worry about the heat.  Those resistors normally run super hot.  I
think they are rated to 200C!!  The ceramic versions can hit 350C!  They
are just little space heaters...

Great luck on your first light!!

Cheers,

	Terry