| 摘要 |
<p>A power supply for electric arc welding, particularly gas tungsten arc welding, is described. The supply operates from conventional, alternating potential, and provides either a direct current or an alternating current with a rectangular wave shape to a load. The supply includes an input transformer, and two current paths, each of which includes an inductor and a controlled rectifier. A control circuit initiates conduction of the rectifiers at appropriate times selected to obtain the desired load current. In preferred embodiments, the control circuit includes differential amplifiers which enable comparison of the output current to a control current, adjustment of the ratio of the currents in the two current paths, and adjustment of the gain and time constant of the control circuit.</p> |
