Short-circuit protection circuit of direct-current welding machine

Abstract

The invention relates to a short-circuit protection circuit for the direct current welder, which is characterized in that a group of additional checking signals are superimposed on the output current of the welder, and the logical identification method is adopted for judging short circuit for the welder output. The invention has the advantages of rapid protection speed, high reliability, strong practicability, and other advantages.

Description

technical field [0001] The invention relates to an electric welding machine, in particular to a short circuit protection circuit of a DC electric welding machine. Background technique [0002] Looking at most of the high-frequency inverter welding machines on the market, the internal circuit structure mostly adopts the current-limiting feedback control mode shown in Figure 1. When the circuit detects that the current value exceeds the rated value, it will automatically adjust the PWM controller to limit the maximum output current within a safe and reliable range. Theoretically, this control mode can guarantee the reliable and stable operation of the arc welding power source. [0003] However, judging from the use effect of existing products on the market, most of them still have problems such as short continuous working time, insufficient power reserve, poor reliability, and easy blowing of power MOS tubes during work. Of course, there are many reasons for this, including ...

AI Technical Summary

Problems solved by technology

[0003] However, judging from the use effect of existing products on the market, most of them still have problems such as short continuous working time, insufficient power reserve, poor reliability, and easy to blow up power MOS tubes during work.

Of course, there are many reasons for this, including design mistakes or lack of experience, and some lack of understanding of high-frequency inverter technology applied to arc welding power supplies

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