Neat general use heat sensor ~ AD22105
 

http://www.analog.com/static/importe...D22105_fbs.gif


http://www.analog.com/static/importe...ts/AD22105.pdf

* User-Programmable Temperature Setpoint
* 2.0°C Setpoint Accuracy
* 4.0°C Preset Hysteresis

* Wide Supply Range
(+2.7 Vdc to +7.0 Vdc)
* Wide Temperature Range
(- 40°C to +150°C)

It can output a ground to drive a relay driver (or solid state relay) when the
pre-set is hit. Nice for fans, pumps & etc.
With a high limit of 300F, these might be useful on car radiators too.
Use them to limit charge current if batteries get too hot.?.


I might use these in a simple home monitoring system I want to build.
Just an display panel in the kitchen that would show if the temperatures
of the heating boiler, basement or outdoors went out of normal ranges.

Two chips on the boiler could be pre-set for the max and min limits.

I was also thinking about using them with the TTL I/O of a small micro controller that would signal me with an alarm and send me the status
using a simple beeper.. Using Morse code of all things. :)

That I can use! Thanks for the posting.