Features: This control panel of the spot welding machine is independently developed for the DIY or the simple resistance welding. The principle of silicone controlled phase shifting triggering is adopted to adjust the time and the current to achieve the purpose of welding. Equipped with digital display, you can see the time and current directly, simple and easy to use. Strong and weak electricity is isolated by optocoupler, safer to operate. Using high precisions single bit potentiometer, to ensure reliable and convenient input. A reliable zero-crossing detection circuit to ensure that the SCR phase shift accurate. There are two type 9V 40A or 9V 100A for choose you to choose according to your demands.