Subject: Re: In search of special temperature sensitive Zener
Date: Sat, 11 Jan 2003 11:01:58 -0800
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Are you sure it's a zener?
Put 3V backwards and make sure it conducts.
May just be a clamp for some other part of the
Typical low voltage zener has a very soft knee.
able to shunt it with a resistor if it doesn't
mess up the
tempco too badly.
If it really is a zener, you might be able to do
with an LM317 and a couple of thermistors.
Robert Sharpe wrote:
> I am trying to replace a temperature sensor in an air conditioner unit (as
> part of a custom installation) to decrease the minimum temperature that can
> be set.
> The existing information I have is :-
> - The zener diode looks like a 1/8 w dark yellow axial with clear band in
> - The operating voltage is about 3v.
> - The voltage decreases at about 40mV/C
> - Using a diode checker (with unit powered off) showed 0.6 v drop in one
> direction only, high resistance is other direction.
> I need to determine the type of diode and get a replacement that has
> slightly lower nonimal voltage (about 2.8v at room temp) but with the same
> temp coeff.
> If anyone can help at all I would be very grateful.
> I have tried :-
> - searching Maplin
> - searching RS-components and
> - searching the web
> with little luck (I can get plenty of 3v zeners but not with about the right
> temperature coefficient).
> Thanks in advance,
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