Patent ID: 7485832

Claim:
A circuit for preventing over-heat of heat-generating device comprising: a heat-generating device, wherein one end of the heat-generating device is connected with a power source and another end of that is electrically connected to ground; a heater circuit comprising a trigger circuit and a microprocessor, wherein the trigger circuit is connected with the power source and the heat-generating device and the microprocessor is connected with one end of the trigger circuit for controlling circuit conducting and heating the heat-generating device; and a hot protecting circuit comprising a reactive trigger circuit, a resistor and a thermo fuse, wherein the thermo fuse is connected with one end of the heat-generating device; two ends of the resistor are connected with the reactive trigger circuit and the thermo fuse respectively; another end of the reactive trigger circuit is connected with the microprocessor such that once the microprocessor stops signals outputting, the power source, the thermo fuse and the resistor make a loop and the resistor is heated to ruin the thermo fuse for terminating heating.