Abstract: The heat radiating device of an induction heater comprises a body, a heat radiating unit, and a ventilating unit. The body comprises a bottom housing provided at the front end thereof with a plurality of air admitting holes. The heat radiating unit is mounted on the air admitting holes and composed of a fan. The ventilating unit is disposed in the upper portion of the rear end of the body and provided with a ventilating seat and a horizontal air duct with an outlet whose level is higher than the bottom of the mounting portion of the body. The cool air is drawn in form the air admitting holes while the hot air is let out from the ventilating holes of the ventilating unit.
Abstract: A power transistor driving circuit for use in an electromagnetic induction heating device comprises an induction coil circuit and a driving circuit. The induction coil circuit is provided with an induction connected with an oscillating circuit made up of capacitances and resistances. The oscillating circuit is provided with at least one power transistor for producing a high frequency switching. The driving circuit comprises at least one quick switching circuit provided with two transistors between which a resistance and an inductance are connected therewith in series. One end of the inductance is connected with the gate of the power transistor for accelerating the reverse current flow of the gate so as to shorten the switching time of the power transistor and to reduce the switching power loss of the power transistor at the time when the power transistor is turned off.