Patent ID: 6127650
Filing Date: 2000-10-03
Classification: B23K

Abstract:
A welder comprising:an electromagnetic switch electrically connected to said welder and operable to gate power to be supplied to said welder, said electromagnetic switch having a turn-off voltage at or below which said electromagnetic switch opens, said electromagnetic switch including a self-hold switch electrically connected to said electromagnetic switch such that said self-hold switch closes when said electromagnetic switch is activated;a control circuit electrically connected to said electromagnetic switch, and having an operating voltage, and operable to control activation of said electromagnetic switch based on a welder start signal, said control circuit including a branch circuit operable to close in synchronization with the welder start signal so as to activate said electromagnetic switch and operable to open a predetermined time after the welder start signal; anda self-holding circuit, electrically connected to said electromagnetic switch and said control circuit, operable to hold said electromagnetic switch closed via said self-hold switch when said electromagnetic switch is activated, and to open said self-hold switch when the operating voltage of said control circuit lowers to not more than the turn-off voltage of said electromagnetic switch so as to allow said electromagnetic switch to open.