PROTECTIVE CIRCUIT FOR HIGH FREQUENCY HEATING DEVICE AND HIGH FREQUENCY HEATING DEVICE HAVING SAME

摘要

A protective circuit for a high frequency heating device and a high frequency heating device having same, the protective circuit for a high frequency heating device comprising: an input winding (1), a sampling winding (2), a phase comparison module (3), a voltage comparison module (4), and a controller (5); the input winding (1) is connected to the switching device of the high frequency heating device; the sampling winding (2) is disposed relative to the input winding (1) and is used to sample a voltage signal on the switching device; the phase comparison module (3) and the voltage comparison module (4) are respectively connected to the sampling winding (2); the phase comparison module (3) outputs a first comparison signal according to a voltage phase signal in the voltage signals; the voltage comparison module (4) outputs a second comparison signal according to the comparison between the voltage amplitude of the voltage signal and a preset reference voltage; the controller (5) controls the switching device to synchronously switch on and off according to the first comparison signal, and protects the switching device according to the second comparison signal. The protective circuit for a high frequency heating device improves the circuit reliability of the high frequency heating device, and reduces accumulated error caused by a plurality of resistors connected in series, thus saving cost.