LM3911 electric heater automatic temperature controller

LM3911 is a high-precision temperature detection and output control integrated circuit. It outputs a voltage proportional to the temperature at 10mV/oC
. The control output terminal has a large driving capacity and can drive a relay or a load of up to 35V. LM3911 electric heater
automatic temperature controller is shown in the figure.
    Cl, VD1, C2, etc. form a step-down, rectifier and filter circuit to provide DC power to LM 3911. RP is used to
set the temperature action point; when the temperature is higher than the action point, the output is high level, V is cut off, BCR is also cut off, and the heating load RL
does not work; conversely, when the temperature is lower than the set action point, the load RL works, Start heating. When the heating temperature reaches a predetermined
value, heating is stopped again, and this cycle forms an automatic temperature control process.