Small power electric heater temperature detection control circuit

Small power electric heater temperature detection control circuit

Shown is a simple low-power electric heater temperature detection control circuit, which is mainly
composed of a power supply circuit and a temperature detection control circuit.
    The power supply circuit is mainly composed of capacitor Cl, resistor Ri, rectifier diodes VD1, VD2, filter capacitor C2 and Zener diode
vs. The temperature detection control circuit is mainly composed of thermistor RT and potentiometer RP. , voltage stabilizing integrated circuit IC, electric heater
and peripheral related components. The output DC voltage of the power supply circuit is divided into two channels: one channel is used as the input DC voltage of the IC; the other channel provides control voltage for the IC after
    being divided by RT, R3 and RP .     When the ambient temperature is low, the resistance value of RT is large, and the partial voltage of the control terminal of LC is high, causing rC to conduct, diode VD3 lights up, VT is triggered and conducts, and the electric heater starts to heat up when the temperature rises. After reaching a certain temperature, the resistance value of RT decreases as the temperature increases, causing the voltage at the control terminal of the integrated circuit to decrease. VD3 goes out, VT is turned off, and EH is powered off to stop heating.