The present invention relates to an inversion arc welding power supply with several external characteristic outputs. It includes inversion main circuit and control circuit; the control circuit includes forward channel, single-chip computer control portion and backward channel; the forward channel includes working mode selection module and parameter preset module; the single-chip computer control portion includes single-chip computer, I/O interface and A/D converter; the backward channel includes data acquisition circuit, PWM pulse width modulation circuit, drive circuit and detection protection circuit; the data acquisition circuit includes current sampling circuit and voltage sampling circuit. |