WELDING GENERATOR - A.C SUPPLY
In tapped reactor method, output current is regulated by taps on the reactor. This has limited number of current settings.
In the moving coil method of current control, relative distance between primary and secondary windings is changed. When coils are more separated out current is less.
magnetic shunt method,
position of central magnetic shunt can be adjusted. This changes the magnitude of shunt flux and therefore, output current.
When central core is more inside, load current will be less and vice versa.
In continuously variable reactor method, output current is controlled by varying the height of the reactor. Greater the core insertion, greater the reactance and less the output current. Reverse is true for less height of core insertion
In saturable reactor method, the reactance of the reactor is adjusted by changing the value of d.c excitation obtained from bridge rectifiers by means of rheostat. When d.c current in the central winding of reactor is more, reactor approaches magnetic saturation. This means the reactance of reactor becomes less. Vice versa happens on the
A welding transformer is a step down transformer that reduces the voltage from the source voltage to a lower voltage that is suitable for welding, usually between 15 and 45 volts. The secondary current is quite high. 200 to 600 amps would be typical, but it could be much higher.The secondary may have several taps for adjusting the secondary voltage to control the welding current. The taps are typically connected to a several high-current plug receptacles or to a highcurrent switch. For welding with direct current (DC) a rectifier is connected to the secondary of the transformer.
There may also be a filter choke (inductor) to smooth the DC current. The entire transformer and rectifier assembly may be called a transformer or welder, but "welding power supply" would be more appropriate term.
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