| 摘要 |
PURPOSE:To lighten a welding transformer, by heightening output frequency wherein phase control elements are used for each phase of three-phase input. CONSTITUTION:Phase control elements 1, 2, 3 are mounted to three-phase input, and the phase of three-phase each phase is controlled within a range that an angle of conduction is smaller than an electrical angle of 60 deg. and supplied to three primary winding 4, 5, 6 installed to a welding transformer 9 with a single magnetic path 8. The output of secondary winding 7 is fed to welding load 11 through an output wave-form shaping portion 10. When phase is controlled in this way, input is changed into a single-phase threefold frequency form as a fundamental wave, and output is also turned into a threefold frequency form, thus heightening frequency, then miniaturizing the welding transformer. |
