| 摘要 |
<p>An AC-fed rectifier (1) charges a capacitor (2) connected to the prim. winding (5a) of a transformer by prim. semiconductor switches (4a,4b) with collectors and emitters interconnected by respective free-wheeling diodes (3a,3b). Separate sec. windings (5b,5c) supply respective current paths incorporating rectifying diodes (6,8), controlled semiconductors (10,11), free-wheeling diodes (7,9) and a common smoothing choke (12) and arc welding electrodes (13). The rate of switching of the semiconductors determines the frequency of operation of the welding equipment and they are combined in a midpoint circuit operated in push-pull so that the two sec. current paths are alternately conductive.</p> |
