Abstract: | The use of pulsing current for gas-metal-arc welding has increased the versatility of the method because of the ease of varying the average current to suit the application. A power supply consists of two properly designed constant-potential power sources in parallel to provide two levels of current. The pulse current is supplied by a half-wave rectifier, and background current by a filtered, three-phase rectifier. The dynamic characteristics must be considered to get good arc stability during current commutation between the two supplies. |