The invention discloses a overheating protective type circuit breaker. By using the arrangement of voltage divider composed of resistance and thermo-sensitive resistance, when ambient temperature rises for certain reasons, the thermo-sensitive resistance can detect it and the value of resistance will increase, this results the alternation of voltage divider��s dividing ratio, which will then trigger the controlled silicon��s control end of the detection integrated circuit triggering control component to conduct though the voltage stabilization diode, making the releasing wire of the electric leakage releasing device to contact and attract, driving the releasing device of the leakage breaker (switch) or plastic shell breaker, making the movable contact separate from the fixed contact, thus realizing the objective of automatic cutting off of the controlled power circuit. The invention also possesses the functions of leakage detection, overload detection and short-circuit detection. |