Voltage detection circuit with self-locking function for electric welding machine

Abstract

The invention discloses a voltage detection circuit with a self-locking function for an electric welding machine, which comprises an isolation circuit unit, a self-locking circuit unit, a driving circuit unit and a switching circuit unit connected in sequence, wherein the isolation circuit unit is connected with a voltage input port, and the switching circuit unit is connected with a capacitor voltage doubling unit of the electric welding machine; the isolation circuit unit is used for isolating fluctuation of input voltage and setting a voltage threshold value; the self-locking circuit unit is used for locking to send a conduction control signal to the driving circuit unit only when the voltage is greater than a set value; the driving circuit unit is used for outputting a control signal to control the on-off of the switching circuit unit; and the switching circuit unit is used for controlling on and off of the capacitor voltage doubling circuit. By improving the circuit structure, whether the voltage doubling circuit needs to be started or not can be judged by automatically detecting the input voltage, the self-locking function can be achieved, and compared with the prior art, thestructure is simple, the function is stable, the cost is low, and the effects are good.

Description

technical field [0001] The invention relates to the field of electric welding machines, in particular to a voltage detection circuit with self-locking function for electric welding machines. Background technique [0002] Some electric welding machines on the market can be applied to both 220V and 380V commercial voltages. When the connected voltage is 220V, it is necessary to start the capacitor voltage doubler circuit of the welding machine, and when the connected voltage is 380V, it is not necessary to start the capacitor voltage doubler circuit. [0003] At present, most of the welding machines on the market are equipped with generators. The grid input voltage of the welding machine will fluctuate frequently. Sometimes the voltage drops from 380 volts to more than 100 volts in an instant, and then jumps to more than 380 volts in an instant. At this time, the traditional The electric welding machine starts the capacitor voltage doubler circuit module of the circuit board,...

AI Technical Summary

Problems solved by technology

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a voltage detection circuit with self-locking function for electric welding machines, which can detect the current input voltage The size, control the start-up of the voltage doubler circuit of the electric welding machine, aims to solve the problem that the existing electric welder mistakenly starts the voltage doubler circuit when the voltage fluctuates, resulting in damage to the electric welder due to excessive input voltage

Images