SU513800A1 - AC arc welding device - Google Patents

Description

3

The ends of all the windings are connected together and fed to the welded product 5. The beginning of the secondary windings 2 and 3 through two pairs of parallel-connected thyristors 6, 7 and 8, 9 are connected to the electrode 10. The continuity of the arc current is maintained by a low-current circuit consisting of an additional winding 4 power supply transformer 1 and Drossel I.

The device works as follows.

In the positive-half-cycle of the mains ("plus at the beginning of the windings"), thyristors 6 and 8 conduct the current. The current passing time through the thyristors depends on the phase of the control pulses and can be adjusted from 0 to. In the negative half-period of the mains voltage, the thyristors 7 and 9 conduct.

The voltage drop across open thyristors is incomparably less emf. windings 2 and 3, and therefore the difference in the magnitudes of the voltage drops across the thyristors does not violate the equality of the currents in the windings 2 and 3 and the thyristors 6, 8 and 7, 9.

When the thyristors are closed, the arc current is maintained due to the additional power supply circuit — from winding 4 through choke 11. This current is many times less than the main current of the secondary windings and the installed power of the device is insignificant.

Change thyristor switching phase, 4

To regulate the welding current in the required range.

The proposed device was tested in a power source for welding aluminum5 alloys and, when tested, showed good results.

Claims (1)

Invention Formula 10 Device for arc welding on alternating current, containing a welding transformer, on the magnetic core of which there is a primary winding connected to the network, and a secondary one made in the form of two windings, the main one connected to the electrode through a block of anti-parallel-connected valves and an additional low-power one connected to the electrode through a choke, characterized in that, in order to increase the power of the device and at the same time eliminate the flow of equalizing currents through the thyristors, the main secondary winding the transformer is made in the form of several coils arranged symmetrically relative to each other on the transformer magnetic core and having an equal number of turns, with the beginning of the coils connected to the electrode through anti-parallel connected thyristors, and the ends are assembled into a common 0 point and connected to the product.