| The RC snubber circuit in inverter main circuit, the signal detecting circuit during the short circuit of CO2 (Carbon Dioxide) welding, and the MCU waveform control system are all designed and debugged in the dissertation.MatLab—based arc welding simulation model of bridge inverter main circuit is established. The working course is analysed detailedly by the model, and then the design method of RC snubber circuit is put forward. The RC snubber circuit got by that way can improve the reliability of the main circuit.The signal of arc voltage without distortion is got by use of photo-coupled isolator 6N136 to insulate signal voltage from arc voltage. And the relative appropriate voltage detecting the signal of short circuit is provided. The liquid bridge shrink detecting circuit based on du/dt is designed. The clipping circuit is applied to eliminate the effect on the liquid bridge shrink detecting circuit from arc voltage successfully, which improves the capability of anti-jamming of itThe simulation model of waveform control system is established, the waveform control scheme and the system parameter is analysed by the simulation model. These establish the foundations for the debugging of the whole system.The control system based on MCU is devised, which can pre-setup the parameters, collect the data and protect itself. The signal of false short-circuit is eliminated by means of software to ensure the validity of signal processing and improve the capability of anti-jamming of the control system.
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