| 摘要 |
PURPOSE:To protect an inverter against high-frequency noise of a high voltage during an electric discharge by a method wherein a switching element and an impedance element are connected in series, this connected assembly is connected in parallel with an output of the inverter and a control circuit for conduction control of the switching element is installed. CONSTITUTION:High-frequency power is generated by using a high-frequency power generator 1 on the low-voltage side; the high-frequency power is converted into electric power of a prescribed high voltage through a boosting transformer 2; the electric power is supplied to a laser oscillator 10; in this assembly, a series circuit composed of a switching element 11 and an impedance element 12 is connected between output terminal of the high-frequency power generator 1; a control circuit 13 for conduction control of the switching element 11 is installed. For example, said switching element is a switch which has been constituted by connecting transistors of self-arc distinguishing elements in inverse- parallel; said impedance element 12 is a resistance. The switch 11 is controlled by using the control circuit 13 in such a way that it is in a nonconducting state until a point of time t2' a little before a point of time t2 and that it is in a conducting state until a point of time t2'-t3'. |
