High temperature warning circuit.

R1= 820 ohm D1= 5.6V 0.5W Zener K1= 6V 200 ohm Relay

R2-3= 1Kohm D2-3= 1N4148 BZ1= Buzzer

C1= 220uF 16V Q1-2= BC550C S1= 1x2 Switch

TR1= 2.2Kohm Trimmer TH1= Thermistor 10Kohm at 25 องศา BATT= Battery 9V or external supply