RU1768363C - Apparatus for ac arc welding - Google Patents

Abstract

The invention relates to electrical engineering, in particular to electrical equipment for arc welding. The purpose of the invention is to improve the quality of welding, achieve smooth control of the welding current by changing the angle of inclination of the external characteristics of the device, as well as increase its reliability in operation and improve energy and weight and size indicators. The device comprises a welding transformer with two primary and one secondary winding and a thyristor switch. Thyristor KEY WIRING The same thing, see tftfH etffi E e and aT8ShSh13Ts teTM1T x magnet wire, in parallel. Smooth adjustment of the welding current is achieved by changing the opening angle of the thyristors. 2 silt

Description

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The invention relates to electrical engineering, in particular to electrical equipment for arc welding.

The aim of the invention is to improve the quality of welding, achieve smooth control of the weld current by changing the angle of inclination of the external characteristics of the device, as well as increase its reliability in operation and improve energy and weight and size indicators.

Figure 1 presents a circuit diagram of a device; figure 2 - external characteristics of the device.

The device (Fig. 1) comprises a welding transformer 1 with a rod-type magnetic circuit 2 and three, two of which primary 3 and 4, wound respectively on one and the other cores of the magnetic circuit 2, and one secondary 5, made on the other magnetic circuit core 2, by power windings and a thyristor switch 6, connected to a control unit 7, which connects the primary windings 3 and 4 in parallel.

 The device operates as follows.

With fully closed thyristors, the supply voltage is supplied to the primary winding 3, which is completely made on one core of the magnetic circuit. At the same time, the external characteristic (Fig. 2) of yctponcTBa due to the increased magnetic flux of scattering and weak magnetic coupling between the arches 3 and secondary 5 windings will have a maximum slope (Fig. 2, curve a) and the device will provide a minimum welding current. When the thyristors of switch 6 are fully open, the supply voltage is supplied to both primary windings 3 and 4, magnetic fluxes from both

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about

Cj

the windings are folded, forming a strong magnetic coupling of the primary 4 and secondary 5 windings, whereby the device will have a rigid external characteristic (Fig. 2, curve b) and provide the rated (maximum) welding current. At all intermediate angles of opening of the thyristors of the switch, b) Intermediate values of the external PG of the device’s characteristics (Fig. 2, curves c, d, and C of the curve doped with the dashed curve), since in this case, during each half-cycle of the supply voltage, the thyristors of the switch 6 switch completely closed state to fully open, which leads to a corresponding switching of the magnitude of the magnetic coupling between the primary 3 and 4 and secondary 5 windings. The ratio of the times of the closed and open states of the thyristors of the switch 6 during each half-cycle of the supply voltage determines the angle of inclination of the external characteristic of the device. Thus, by smoothly changing the opening angle of the thyristors of the key 6, making a smooth change in the angle of inclination of the external characteristics of the device, this achieves a smooth regulation of the welding current without moving elements, without the additional costs of electrical steel and copper.

Compared with the prototype, the technical and economic efficiency of this device is formed by reducing the overall dimensions, simplifying the device, and increasing the reliability of its operation.

Claims (1)

SUMMARY OF THE INVENTION A device for arc welding with alternating current, comprising a welding transformer with a rod type magnetic circuit and three power windings, as well as a thyristor switch with a control unit, characterized in that In order to improve the quality of welding, achieve smooth control of the welding current by changing the angle of inclination of the external characteristics of the device, as well as increase its reliability in operation and improve energy and weight and size indicators, the primary winding is made in the form of two windings of the same number of turns connected to each other via thyristor key in parallel, and all turns of one primary winding are made on one core of the magnetic wire, and all turns of the second primary and secondary windings are made on another the core of the magnetic circuit. FIG. 1 fiua 2 I