| CO2 gas shield arc welding is a high efficient and high qualitative welding method. However, it is until now that the problem like large spatter and bad formation of weld bead have not been solved success, which restricts the CO2 welding form being popularized and applied. With the further application of microcomputer in the field, applying wave controlled technology to CO2 power source is one of direction which to solve focus of welding spatter. In this topic, a new CO2 arc welding power source is researched which is based on the technology of microcomputer and wave control. In terms of the character of short circuit transfer of CO2 welding, the process is made into seven subsection. During the neck of metal becoming, rising the current velocity make it coming into being, and at the later of short circuiting transfer, the welding current is detracted, as is make the bridge breaking at the low energy and depend on Surface tension finishes the transfer without splash. During the process, the real time current and voltage values information are obtained and sent to the microcomputer for processing, then the wave of current and voltage is produced by the control of microcomputer at the output end which is suit for the short circuiting transfer.In this paper, basing on analyzing the reasons for splashing of CO2 welding the control project of short circuiting transfer is probing. Generally, there is shortcoming that controlling peak value of the welding electric current is not satisfy in surface tension transfer control technology, so the method that using the current feedback during short circuit middle period, applying PI to control current. The half bridge inverter type main circuit is applied which have ability of resisting no-balance. To transmit the wave shape of current and voltage which is suitable for each step of the CO2 short circuit subsections, the care design hardware circuit is used. According to PWM principle, utilizing high-speed and exact attribute of single chip control, out character of the power source that comes up to every subsection of short circuit transfer of CO2 welding is obtained.The used chip as control is the single chip 80C196KC. Some source ports,such as HSI.1 HSI.2 and A/D etc, are used in this paper. At the same time there are keyboard and display circuit and alarm system, which is for setting and displaying parameter in advance and alarming the system malfunction. Interruption service technology is used in design of software, which can disposal every kind of malfunction in time and real time control. The structure of software adopts the subroutine thinking which is in focus and easy to debug and modify. In order to improve the system stability, hardware and software synthesis measures are adopted for the disturbance problem.In this paper, the research has born out that the project is workable., especially it is more quickly and exactly because of applying some methods in checking short circuit status.
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