Abstract: A power supply circuit for a magnetron adapted to supply microwave energy to an electrodeless discharge bulb is disclosed. The circuit comprises a rectifier coupled across a commercial AC voltage source, a filter for smoothing the output of the rectifier, an inverter for converting the DC voltage supplied from the filter into a high frequency AC voltage, a step-up transformer for stepping up the high frequency AC voltage outputted from the inverter, and a rectifier which rectifies the high voltage AC output of the transformer into a unidirectional voltage which is supplied to the magnetron. The inverter switching is controlled by a pulse width modulation control circuit to maintain the magnetron output power at a predetermined level.

Abstract: A metallic vapor laser apparatus comprises a discharge tube, a first pulse circuit (200) for generating a first pulse voltage for causing laser oscillation and a second pulse conduit (16) disposed separately from the first pulse circuit and generating a second pulse voltage delayed from the generation of the first pulse voltage by a predetermined time. The metallic vapor laser apparatus is constructed such that, after the first pulse voltage is applied to the discharge tube, the second pulse voltage is applied to the discharge tube and an output voltage of the second pulse circuit (16) is less than an output voltage of the first pulse circuit (200).

Abstract: The invention relates to a plasma apparatus where plasma is generated utilizing microwave discharge and laser excitation is performed and plasma processing is performed. More specifically, in a plasma apparatus where a microwave from a microwave oscillator is transmitted through a microwave transmission path to a microwave circuit, and plasma is generated by a microwave discharge within the microwave circuit, a plasma generating medium for generating the plasma is filled in a space formed between a conductor wall constituting a part of the microwave circuit and a dielectric installed opposite to the conductor wall, and the microwave circuit forms microwave mode having an electric field component orthogonal to the boundary between the dielectric and the plasma.

Abstract: In a metal vapor laser, (e.g. copper vapor laser), the innermost heat shield (15) of Mo, Ta or W, which is disposed with a predetermined gap (preferably sufficiently larger than 0.3 mm) to the outer surface of the seal tube (8), is connected at respective ends to the anode terminal (2) and the anode (5), so that inductance of discharge load is considerably decreased.

Abstract: An arc welding power source utilizing welding current from a two-step voltage conversion comprising a first target value setting circuit means for setting a first current target value V.sub.1 corresponding to a desired value of welding current, a current control circuit for controlling the welding current in accordance with the first current target value V.sub.1, a second target value setting circuit means for setting a second current target value V.sub.2 higher than the first current target value for satisfying a predetermined current waveform in response to an abrupt load variation, and a rapid operation current control circuit for controlling the welding current in accordance with the second current target value V.sub.2. Thus, even if the welding load tends to abruptly vary and the welding current tends to largely exceed the first current target value V.sub.1, the welding current is clipped by the second current target value V.sub.