Research On The Anode And Grid Circuit For High Power RF Laser Power Supply

High-power RF slab CO₂laser is main source in gas laser cutting and welding field. Thekey technology of the slab laser includes slab structure, optical cavity, power supply, andmatching techniques. The thesis mainly focused on30kW self-excited RF power supply, themain research contents are followed.（1） The anode high-voltage circuit of RF power supply was analyzed. Filtering circuit,boosting circuit, soft-start circuit and rectifying circuit were contained in the circuit. Thethree-phase power was send into the liner filter, the transformer could change it into AC highvoltage, during the transforming the tube need to be protected,so the soft-start circuit waschoose to control the starting of the high voltage. The AC high voltage was sent to therectifying circuit, and the DC high voltage was put out. The DC high voltage was passedthrough filtering circuit, and high-frequency harmonics could be filtered by the filteringcircuit. At last the DC high voltage could be put into the anode of the tube.（2） The circuit for detecting the high voltage was designed. The levels of current andvoltage could be detected by the circuit. The power supply of the RF power supply could becut off and alarming information could be given to PLC when the current or voltage wenthigher. At this time the levels of current and voltage could be efficaciously detected by thecircuit and the RF power supply could be operated stably.（3） Debugging jobs were done on the grid circuit and amplifying circuit. Throughstudying the experimental results, the improvements of the system were founded.（4） PWM modulator was designed. Pulses of different duty factors and frequenciescould be put out by the modulator. The modulator could communicate with PLC. Signalscould be given to control the laser power from PLC.This thesis was an important part of the research on high power, high beam quality CO₂gas laser. The circuit could be operated stably in the power supply. The research on CO₂gaslaser has importantly practical significance.