Features POTENTIOMETER: The spot welder control board adopts high accuracy simple potentiometer, input time and current, has stable performance. MICROCONTROLLER: Adopt for STM8 industrial control center microcontroller, strong and weak currents are insulated through optocouplers to ensure safe operation. RELIABLE CIRCUIT: Adopting a reliable zero crossing detection circuit to ensure the accuracy of SCR phase shifting and clear and visible working status. BOARD STRUCTURE: This controller board is compatible with 40A thyristor, including control panel, display panel, cable matching, and red and green buttons. BOLT TERMINAL: The power cord and pedal switch cord are quickly connected to terminals with bolts, making them convenient and reliable. Specification: Item Type: Spot Welder Control Board Material: PCB Color: Red Use: The control panel of the spot welding machine is an independently developed controller for DIY or simple resistance welding Package List: 1 x Spot Welder Control Board 2 x Nuts 2 x Gaskets Package List 1 x Spot Welder Control Board 2 x Nuts 2 x Gaskets