Induktionsheizvorrichtung.

摘要

In an induction heating apparatus which comprises a high frequency power source for inducing eddy currents into a plated steel sheet, electronical means are provided in order to vary the frequency of the power source. The variation of the frequency is obtained by providing a phase angle signal of the voltage phase at the output of the high frequency inverter, which phase angle signal is used to create a phase delay. The delay or advance of the voltage phase creates a variation of the frequency which is beneficial in conditions where a constant frequency would produce standing wave irregularities of the interface area between the steel sheet and the plated layer which is heated and vibrated by the induced currents and magnetic fields.