The Research On IGBT Latter Inverter Square Wave AC TIG Welding Machine

With the more and more widely using on the magnesium,aluminum and their alloys,we have to force the urgent needs to further research on the welding technology of the medal materials.This paper applied analog circuit as the core to design the IGBT double inverter square wave TIG welder which based on the requirements and common difficulties and in order to improve the nature of alloys,the design will help make high quality welded joints.This paper elaborates on the design process of every part of IGBT double inverter square wave welder,and also produces the elements,analog control registers,high frequency arc firing apparatus and anti-interference measure in detail,this paper also shows the design essential,choices of elements and parametric computations carefully.The welder control system is as core as the analog circuit,it works on the way of modulating PWM by pulse.The simulating circuit drives the IGBT elements to control the parameters of current wave form,amplitude of the power source.The quality output of the analog circuit depends on the filter circuit,after regulating,the core element SG3525 will produce two kinds of pulse signals which separately pass on the integrated component M57959 L and TLP250,the process will drive the IGBT elements and force to the useful welding electricity,the waves collected by the linear HS sensor in real time will feedback to the circuit with buffer amplifier in order to adjust the instantaneous circuits without delay.Several experiments analyzed the principle of the circuit controlling,reliability and noise resistance,which also show the details in the paper.It gives some corresponding suggests and ways to prove the problems such as oxidation,pore,transfiguration,nature decreasing of weld beads,etc.the protecting circuits are also designed specific for the usual problems of over current and overheat.These experiments design several methods of anti-jamming by studying kinds of interference factors and the reasons how they come out.According to the no-load and load experiments,the welder power source is reasonable,anti-interference,fewer elements,simple and convenience,the parameters of welding circuit,duty cycle,decreasing time and pulse frequency can be adjusted separately,external characteristics and scheduled parameter also can be output in the circuit.It is simpler to weld magnesium,aluminum and their alloys in various complicated conditions and to get high quality welded joints.This paper detail several useful advices for the problems such as the preset parameter,data storage and wave output during works,and it lays the foundation for the future series of the development of the alloys and welder technology.