Re: TI-H: Temp sensor failing

To: ti-hardware@lists.ticalc.org
Subject: Re: TI-H: Temp sensor failing
From: "Richard Piotter" <richfiles1@hotmail.com>
Date: Tue, 11 Nov 1997 21:52:56 PST
Reply-To: ti-hardware@lists.ticalc.org

I'm not sure, but excessive heat while soldering may do the trick. Once 
I tested a chip to find its range, got it to 294 degrees F!!! I was 
amazed, but when it got to 92 degrees, it shot down to 32 F (0 C). I 
believe that if you hold the soldering iron too long, it causes the chip 
to expand more than it was designed to. It works because the expansion 
pushes things together, but when it cools, it contracts and messes up. 
Try it again with a new circuit and just barely touch the soldering iron 
to heat the chip. They are designed so the case conducts the heat 
straight to the silicon sensor inside and that means it is extra 
sensitive to your soldering iron

>
>Does anyone know why my temp sensor always reads 0?  I've built two of 
them
>now.. but one never reads higher than about 10 or so, and the other 
only 0.
>Anyone have any suggestions?
>
>


Richard Piotter

E-Mail:
richfiles1@hotmail.com
richfiles@usa.net

The Richfiles:
<A 
HREF="http://www.geocities.com/SiliconValley/Lakes/5081/Richfiles.html">The 
Richfiles TI Page</A>
<A HREF="http://www.geocities.com/Area51/Lair/8510/Richfiles.html">The 
Richfiles Model Building Page</A>


______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com