摘要 |
<p>An electric circuit for supplying electrical power having a controlled frequency to a load includes thyristors, each having an anode terminal, a cathode terminal, and a gate terminal for supplying an electric current from the anode terminal to the cathode terminal; transistors, each having a collector terminal, an emitter terminal and a base terminal for switching ON/OFF an electric current from the collector terminal to the emitter terminal; an arm device connected between the cathode terminal of the thyristor and the collector of the transistor; bridge circuit device, having a plurality of arms between one terminal and another terminal of an electrical power source, so that the positive terminal is coupled to the anode terminal of the thyristors and the negative terminal is coupled to the emitter terminal of the transistor, and controlling circuit, connected to the load, for supplying an electric signal to the base terminal of the transistor to apply an electric voltage intermittently to the load, and supplying an electric signal to the gate terminal of the thyristors to supply an electric current periodically in accordance with the desired frequency between the anode and cathode terminals of the thyristor.</p> |