Electric welding machine output current primary side sampling control circuit and method

Provided are an electric welding machine output current primary side sampling control circuit and method. A primary side current sampling circuit collects primary side current of an inverter main loop of an electric welding machine and outputs a current signal to a current conversion circuit, the current conversion circuit converts the current signal into a voltage signal, a current holding comparison circuit outputs feedback voltage according to the voltage signal, and a PI adjusting unit dynamically adjusts the output current of the electric welding machine according to the feedback voltage. The magnitude of the output current of the electric welding machine is indirectly reflected by collecting the primary side current of the inverter main loop of the electric welding machine, the collected current is processed, the PI adjusting unit dynamically adjusts the output current of the electric welding machine according to the processing result, a transformer is adopted to sample the primary side current, which i