Schematics > Security and other sensors and detectors > Frost Alarm
Frost Alarm
Notes:
The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees
celsius. A suitable bead type thermistor is found in the Maplin catalogue. The
100k pot allows this circuit to trigger over a wide range of temperatures. A
slight amount of hysteresis is provided by inclusion of the 270k resistor. This
prevents relay chatter when temperature is near the switching threshold of this
circuit.
Also check the conversation about this project at the community. Post you
questions here.
Title: Frost Alarm
Source: www.electronics-lab.com
Published on: 2005-02-10
Reads: 311
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