摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high frequency inverter which makes it possible to perform soft switching of switches from a short circuit to an open circuit, to cause an induction heating load to support all of metals, and to perform output control in a wide range from a heavy load to a light load. <P>SOLUTION: A high frequency inverter comprises: a set of inverter units each of which includes two switches connected in series, antiparallel diodes connected in parallel to respective switches, and a resonant tank branching from a connection midpoint between the switches; and a heating load unit in which a load resistor, a load inductor and a power-factor compensation capacitor are connected in series. Then, the set of inverter units connected in parallel to each other is connected in parallel to a direct current power source, and the connection midpoint of the switches are connected to each other via respective resonant tanks. Furthermore, the heating load unit is connected between a connection midpoint of two resonant tanks and a negative electrode side of the direct current power source. Thereby, an output current flowing through the heating load unit is controlled by a phase difference angle control of a resultant instantaneous current vector of currents flowing out from the connection midpoint between respective switches. <P>COPYRIGHT: (C)2013,JPO&INPIT |