| 摘要 |
An improved non-contact type arc starter for a welding apparatus is disclosed. A diode (25) is reversed biased when a high output DC voltage is provided by a power supply (26). When the arc is struck, the diode becomes forward biased allowing arc current to flow. The striking of the arc is detected by the dropping out of a relay coil (60) which in turn closes a contact set activating a solenoid coil (65). The solenoid coil (65) is part of a contactor having contact set (32) which closes, shunting the diode. This prevents the diode from carrying full welding current for more than several hundred milliseconds maintaining the junction temperature of the diode at a low value and allowing immediate restart after the arc is extinguished.
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