Pneumatic-electric vertical welding arc length controller based on FPGA

The utility model discloses a pneumatic-electric vertical welding arc length controller based on an FPGA, which comprises three trolley walking given circuits, a motor voltage negative feedback current regenerative feedback circuit, an isolating optical coupling circuit, an AD conversion circuit, a front/back-surface welding gun staying given circuit, a welding control signal circuit, an FPGA control circuit, a DC motor driving circuit and a welding gun swinging control circuit. With the advantages of equal-speed wire feeding and trolley speed-changing climbing at the same time, the pneumatic-electric vertical welding arc length controller can well control the stability of electric arcs when in welding.