1. STM8 industrial single chip microcomputer is the main control core. 2. Strong and weak light are isolated through optocoupler, which makes operation . 3. The power line and foot switch line adopt screw free quick connect terminal, which is more convenient and reliable. 4. High precision unit potentiometer is used for input time and current to reliable and convenient input 5. On board power supply, status, pin, trigger indicator, and working status are clearly visible. 6. The reliable zero crossing detection circuit is designed to the accurate phase shifting of silicon controlled rectifier. 7. The controller is compatible with 40A-100A thyristor. 8. The digital control interface can display the current set time and current. 9. Time input 1-50, unit cycle (one cycle is 20ms), current input (30-99%) Product name: spot welder control panel Model: -D01 Thyristor current: 40A During installation: the motherboard should be far from the large transformer! Not on the transformer! Because large have strong electromagnetic interference! Note: The spot welder control board is independently developed by DIY or simple resistance welding and controller. The welding is achieved by adjusting the time and current based on the principle of thyristor phase-shift trigger color:Red Material:PCB+metal Package Contents: 1 x control board 1 x display panel 1 x connecting line 2 x twist caps Only the above package content, other are not included. Note: Light reflection 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.