| 摘要 |
PURPOSE:To obtain a stable laser output by controlling the DC input voltage of an inverter and a voiceless discharge current flowing through an electrode constantly. CONSTITUTION:A 3-phase AC voltage is rectified by a converter 22, pulsation is removed by a smoothing circuit 3, thereby obtaining a DC voltage. The difference between the DC output voltage and the set value of a DC voltage setter 24 is amplified by an amplifier 25, and the converter 22 is controlled to maintain the DC output voltage constant. An inverter 8 converts the DC ouptut voltage of the converter 22 to the AC voltage of approx. 100kHz, the voltage raised by a step-up transformer 27 is applied to electrodes 14A, 14B, and a voiceless discharge 14 is generated. The voiceless discharge current is detected by a current detector 28, the voltage difference from the set value of the voiceless discharge current setter 33 is amplified by an amplifier 34, the inverter 8 is controlled constantly. |
