ABSTRACT
This chapter provides a comparison of the different types of power supplies used for various induction heating (IH) and heat treating applications. Very early power supplies used high-power vacuum tubes in an oscillator circuit to generate the radio frequency that was used for IH. For a transistor to be useful in an IH application, it must block high voltage, carry high current, and switch ON and OFF very quickly. Physical constraints imposed by the environment in which the induction processing is to be done can also play an important part in the selection or application of the power supply. The uncontrolled rectifier must be used with an inverter section capable of regulating the power supply output. Line notching occurs when two semiconductors with the same polarity in a rectifier are simultaneously conducting. The inverter section of the power supply switches the DC or voltage to produce a single-phase AC output.
