Temperature Window Switch
This circuit, is basically a resistance sensing window switch, except that the resistor takes the form of an NTC thermistor and the circuit thus responds to temperature. TH1 must have a resistance in the range 500ohm 9Kohm. RV1 is used to set half supply volts on the RV1 TH1 junction at the mean temperature.

R1=4.7Kohm
TH1=NTC thermistor 500ohm.....9Kohm
Q2=BC214L
R2=2.2Kohm
D1-2=1N4148
RL1=12V Relay >120ohm
RV1-2-3=10Kohm pot. D3=1N4001
Source : users.otenet.gr/~athsam/
Keywords :
Temperature,
Window,
Switch
Writer : delon |
8 Feb 2011 Tue  
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