Liquid Crystal Displaying Weld Current Waveform And Controlling For A Secondary Rectifying Spot Welding

With a series of unique characteristics such as low input capacity, high thermal efficiency, big power factor, excellent welding joints, and so on, the single phase secondary rectifying spot welding has widely been used in industry. However, the controlling system of single-phase secondary rectifying spot welding machine is basically AC spot welding machine's, so it is not fit for special spot welding technology.Therefore, hardware circuits of controlling system on the single secondary rectifying spot welding and liquid crystal system to display current waveforms are designed on base of an 89C52 SCM and a SED1335F LCD controller. Based on theoretic analysis, the precise mathematic mode of controlling system and a reasonable phase-shifting range of controlling angle are established, and in allusion to the rising slope of current waveforms, a new method on magnetic compensation is put forward on the base of pre-technologic experimentation for single phase secondary rectifying spot welding. During the course of designing software, a step of /% and controllingangle a are set to 0.25% and 0.018? respectively, and the voltage is compensated inhalf-cycle, which evidently enhances controlling system's precision. In this thesis, all of programs are made with C51 and Assembler. What's more, it is helpful to read, transplant, maintenance, and also to shorten develop cycle that subprograms about reading weld parameters, voltage and magnetic compensation, liquid crystal display and delay are respectively designed to a single module.The hardware and software system above has successfully been debugged, and the debug results prove it available that the system can achieve single phase secondary rectifying spot welding process and real-time display weld current waveforms on the liquid crystal screen, which accords with design purpose.In a word, the system of single-phase secondary rectifying spot welding controlled by an 89C52 SCM and real-time displaying weld current waveforms with liquid crystal is of important engineering value in the future.