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Last Updated on: Sunday, December 31, 2017 02:40 PM

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More  Alarm Circuits   Micro Power   Temperature Control
 Temperature Sensors

Over-Temperature Micro-Power Alarm
Designed by Dave Johnson, June 4, 2000

The circuit is powered for years by a single 3 volt lithium battery. It sounds an alarm when the temperature exceeds a certain point. With some minor changes the circuit could also be configured for an under temperature (freeze) alarm. The circuit uses a cheap but accurate thermistor as the temperature sensor.

Click on Drawing Below to view PDF version of Schematic

Circuit Low Power Over-Temperature Alarm designed by Dave Johnson, P.E. (June 4, 2000)
 

More  Alarm Circuits   Micro Power  
Temperature Control
Temperature Sensors

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