| 摘要 |
There is constructed a constitution such that a shunt resistor 30 is interposed in series with a portion capable of measuring an output current of a unidirectional power source portion 1 of a high frequency heating apparatus and a voltage generated at the shunt resistor 30 is outputted by a buffer 31 . Further, an operational amplifier 3101 having a high input impedance is used for the buffer 31 . Further, a diode bridge 101 and a semiconductor switching element 205 are fixed to a common heat radiating plate 33 , the heat radiating plate 33 is formed with a notched portion 33 a to thereby ensure insulating distances to the diode bridge 101 and the semiconductor switching element 205 , and the shunt resistor 30 is arranged on a straight line the same as that between the diode bridge 101 and the semiconductor switching element 205. |
