The control panel of the spot welding machine is a controller that has been independently developed for the DIY or the simple resistance welding. The principle of silicon controlled phase shifting triggering has been adopted to time and current to achieve the purpose of welding. The most important features of this controller: 1: the use of STM8 industrial microcontroller control center. 2: strong and weak electricity via optocoupler insulation, operation. 3: the power line and the foot switch line adopts the screw fast connection terminal, more convenient and reliable. 4: input time, current using high-precision single potentiometer, reliable input, convenient 5: on-board power supply, state, foot, trigger indicator, working state clearly visible. 6: the design of reliable zero-crossing detection circuit that the SCR phase shift accuracy. 7: the controller is compatible with 40A scr. 8: digital control interface, you can view the current time and current settings. 9: time input 1-50, unit cycle (1 cycle is 20 ms) colour:red Material:plastic Package Contents: 1* NY-D01 40A Digital Display Spot Welding Machine Transformer Controller Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.