ARC Welding Machine Control Board This is a Welding Machine Control Card. Type ZX7200-01-A1 In this, we will describe the Functioning of the components and the connection of Pins. It is a simple control board that can be easily installed in any kind of welding machine either it is MOSFET based or IGBT based. control board repairing video This board operates with two ICs. 1. UC3525-- It is a 16 pin Regulating Pulse Width Modulator. Its Oscillating range is from 100Hz to 500 kHz. Input voltage 8V to 35V. There are many ways to use this IC (UC3525) in different kinds of circuits but we will describe the way which is used in this circuit according to Pins. Pin no. 2 and 16 are Vref pins. Pin no. 1, 10, and 12 are grounded in this circuit. Pin no. 3 and 4 are NC (not connected). Pin no. 5, 6, and 7 are Oscillator pins. Pin no. 8 is Soft-Start Pin but it is used for Overcurrent safety purposes. Pin no. 9 is used for