ＹＮＪ—１型ＹＡＧ激光器，因手术治疗中出现激光功率失控故障造成治疗中途停止。其现象是激光功率突然增大，电流从１８Ａ突增到４０Ａ，激光器发出嗡嗡响声，调节功率控制钮基本无作用。１故障分析该激光器是以同步移相触发方式，控制三相半控式整流电路中可控硅的导通角度 The YNJ-1 type YAG laser stopped the treatment midway because of a laser power failure during surgical treatment. The phenomenon is that the laser power suddenly increases, the current suddenly increases from 18A to 40A, the laser emits a buzzing sound, and the adjustment of the power control knob has no effect basically. 1 Failure Analysis The laser is a synchronous phase-shift triggering method to control the conduction angle of the thyristors in the three-phase semi-controlled rectifier circuit.