A new generation of power supplies for electron beam welding machines

Widely used electron beam welding machines are equipped with heavy power supplies, located in a special oil tank and connected with an electron gun to a high-voltage cable. A special system detects electric discharges in the electron gun space, which may arise during welding and then it tries to switch off the high voltage to interrupt an electric arc. Such disadvantages have been eliminated with the novel power supply described here. The Q of resonance circuit of this supply is stabilized and as a result circulating power appears. During an electric discharge in the gun, power is not sent to the electron gun but circulates between the electronic parts of the resonance circuit without losses and "waits" for the break in the short circuit. The power supply is much smaller and lighter than supplies of similar rating used nowadays. It is connected directly to the electron gun chamber without a high-voltage cable. The first construction of the supply was designed for electron beam welding machine of 5 kW power and 60 kV accelerating voltage. Tests of the new power supply in laboratory and industrial conditions have shown its usefulness for electron beam welding. (c) 2004 Elsevier Ltd. All rights reserved.