Description: The principle of silicone controlled phase shifting triggering is adopted to adjust the time and the current to achieve welding. With digital display, you can directly see the time and current. Optocoupler isolates the strong and weak electricity, making the operation safer. Using high-precision single potentiometer to ensure reliable and convenient input. The design of reliable zero crossing detection circuit ensures the SCR phase shift accuracy. Made of high-quality PCB, the control board is long-lasting. The module is 8cm long, 6cm wide and 2cm high. There are 40A or 100A models for you to choose. It is developed for the DIY or simple resistance welding. Item Name: Spot-welder Control Board Material: PCB Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x spot-welder control board