Temperature Monitor with IC LM741 or LM301

My Friend want circuit Temperature Monitor for control relay. I find on internet , See to This Web http://www.mitedu.freeserve.co.uk/Circuits good article circuit. The Temperature Monitor use IC LM741 or IC 301 for test Temperature control relay switch.
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Using a thermistor in the position shown makes a heat activated sensor. A change in temperature will
alter the output of the opamp and energize the relay and light the LED. Swapping the position of the
thermistor and 47k resistor makes a cold or frost alarm.

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