Re: Weller WTCP-N problem: No Heat

From: Jim Adney (jadney_at_vwtype3.org)
Date: 08/24/04 

Date: Mon, 23 Aug 2004 21:09:01 -0500

On Sun, 22 Aug 2004 21:33:24 -0500 Jim Adney <jadney@vwtype3.org>
wrote:

>On Sun, 22 Aug 2004 06:28:03 GMT Isaac Wingfield <isw@witzend.com>
>wrote:
>
>>I was speaking from a memory of having used carborundum power resistors
>>years ago in FM broadcast transmitters; they were small for their power
>>rating because they could operate at a very high temperature without
>>much resistance change.

I checked with some other people at work and they pointed out that SiC
is actually a bit of a semiconductor, so it is somewhat conductive and
that's why it can be made into a resistor. No one knew what the
resistor people do to it to vary the resistivity, however.

The semiconductor people are working with it to see if they can make
power semis from SiC that will operate happily at 400 C. If they
succeed, it will be a lot easier to "cool" something that is still
happy at that temp.

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    Jim Adney jadney@vwtype3.org
           Madison, WI 53711 USA
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