Welding machine circuit

Shown are ordinary and portable maintenance electric blanching machines. It combines the arc welding transformer T and the reactor L into a whole, which not only
has the electrical connection but also the contact connection. The circuit of an
  AC welding machine is shown in Figure 2-15b: When the knife switch HK is closed, the electric welding machine is powered on. When the knife switch HK is pulled down, the welding machine stops working. This circuit is commonly used in electric welding machines . And it is the simplest kind of circuit .