1: the use of STM8 industrial microcontroller control center.2: strong and weak electricity through optocoupler isolation, safe operation.3: the power line and the foot switch line adopts the screw free fast connection terminal, more convenient and .4: input time, current using high-precision single potentiometer, to input, convenient5: on-board power supply, state, foot, trigger indicator, working state clearly visible.The control panel of the spot welding machine is a controller which is independently developed for the DIY or the simple resistance welding. The principle of silicon controlled phase shifting triggering is adopted to adjust the time and the current to achieve the of welding.the design of zero crossing detection circuit to that the phase shift accuracy.the controller is compatible with 100A .digital control interface, you can display the current time and current .time input 1-50, unit (1 cycles is 20ms), current input (30-99%)Types:40AColour:RedMaterial: ABSSize: 8 x 6 cmPackage Contents:1 x Main Board1 x Display Board1 x Cable