One of the no-load automatic stop circuits of relay type AC arc welding machine

The average usage rate of the electric welding machine is very low, and a large excitation current will flow when there is no arc in the secondary. In order to
reduce the unnecessary power consumption when not welding, a no-load automatic stop device can be used. (1) One circuit of the no-load automatic stop circuit
of the relay type AC arc welding machine is as shown in the figure. The AC contactor KM is selected from CJ20-20A, 380V, and the contacts can be used in parallel; the relay KA is modified from the 522 type. In order to ensure reliable operation, the difference between its pull-in and release voltages must be less than 15V; the time relay is modified from the JS7 type. In order to prevent arc interruption in the middle, the pull-in voltage should be higher than 45V.