Patent ID: 7241979

Claim:
A non-electromagnetic wave temperature controller for a heating cable, comprising: a temperature control unit connected to the heating cable that includes first and second electrical heating wires arranged in parallel and a Negative Temperature Coefficient (NTC) thermistor, and configured to compare a temperature signal voltage, which is output from the first electrical heating wire, with a reference voltage and to output a temperature control signal; a control rectification unit configured to return a heating current from an end of the second electrical heating wire connected to a power source through second and first ends of the first electrical heating wire toward the power source when conduction is achieved by control of the temperature control unit; and a reverse overcurrent protection device including: a first diode connected in parallel to the first electrical heating wire in a direction opposite to a direction of the heating current; a zener diode connected in parallel to the heating current U-turn rectifier; and a second diode connected in parallel to the second electrical heating wire in a direction opposite to a direction of the heating current; wherein a fuse is cut by the reverse overcurrent protection device when an overcurrent is generated by short circuit of the control rectifier, and wherein the electrical heating wires realize a non-magnetic field state by canceling opposite magnetic fields during temperature detection and heating.