AC welder

Abstract

The invention discloses an AC welder which comprises a switch, a first fuse, a second fuse, a welder transformer, a transformer, an AC contactor, a time relay, a sensitive relay and a resistor. By the aid of an additional no-load automatic stop protection circuit, the AC welder can operate normally when a welding electrode contacts with a workpiece to power the AC contactor, and can stop operating when the welding electrode does not contact with the workpiece to fail the AC contactor. Therefore, no-load automatic stop of the AC welder is achieved, electric shock can be prevented, no-load loss can also be reduced greatly, and safety and energy conservation of the AC welder are improved.

Description

technical field [0001] The invention relates to the technology of an AC electric welding machine, in particular to an AC electric welding machine with a no-load self-stop protection circuit. Background technique [0002] As we all know, an AC welding machine is a welding machine that converts the electric energy of alternating current into welding energy. Its circuit control principle is as follows: figure 1 As shown, it includes switch 1, fuses 2, 3, welding machine transformer 4, welding rod 5 and workpiece 6, wherein switch 1 passes through fuses 2, 3 and power supply side terminal 4 of welding machine transformer 4 respectively. 1 、4 2 Connection, output terminal terminal 4 of welding machine transformer 4 3 Connect workpiece 6 and ground together with it, output terminal 4 4 Connect with electrode 5. When the switch 1 is closed, the output terminals 4 3 、4 4 There is a welding voltage between them, so that the electrode 5 is charged to work. This AC welding machi...

AI Technical Summary

Problems solved by technology

In the process of welding, it is usually necessary to replace the welding rod frequently. At this time, if the welding rod is charged, it is easy to cause electric shock accidents due to irregular operation or improper protection.

In addition, if the AC welding machine continues to work, its internal circuit and various circuit components in it are prone to failure or moisture and the shell of the AC welding machine is charged, which is also prone to electric shock accidents

[0005] 2. Manual welding is generally intermittent welding. When the AC welding machine is no-load, there is still no-load current passing through the coil, which will cause a lot of no-load loss.

For example, assuming that the no-load loss of an AC welding machine is 400W, and the utilization rate of the AC welding machine in the welding operation is 50%, working 8 hours a day, 25 days a month, the no-load loss within one year can be as high as 480KW, which is equivalent to the electricity consumption of a family for 5-6 years, and the power loss is quite serious

In addition, if the power is cut off during intermittent welding to save power, switching on and off the power too frequently will not only reduce the work efficiency, but also bring safety hazards to the welders.

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