Arc Welding Machine Power Source

For striking a welding arc it is crucial to have the preferred present in the welding circuit. Based upon the sort of existing necessary (ac or dc) it could be obtained from the following sources.

1. A welding machine or frequency changer (for ac welding machine).
2. A dc generator of a welding rectifier (for dc welding).
3. The no load or open circuit voltage (OCV) must be higher sufficient to strike an arc, but not so higher as to endanger the welding operator, for instance, for a 2000A transformer the OCV really should not be more than 90 volts by means of for reduced currents of say upto 600A OCV may well be upto one hundred volts.
4. With direct present, the OCV really should be at least 30 to 35 volts although with alternating existing it ought to not be reduced than 50 to 55 volts. An open welding arc can be sustained at 18 to 40 volts.
5. The minimum voltage for arc ignition is 25 volts which should be attained inside 0.05 second for the upkeep of a steady arc.
6. The energy of the welding source really should be adequate to deliver the essential welding existing.
7. It should really be probable to tap the preferred present inside the out there limits either in infinite methods 9stepless regulation) or in a significant quantity of discreet actions (stepped regulation).
8. The voltage of the energy source ought to transform itself swiftly with the change in arc length.
9. The quick-circuit existing really should be inside limits of security for energy source windings.
10. It need to have output qualities which match the arc traits.
11. It should really incorporate a low voltage source for the operation of auxiliary units.
12. It need to have a preferred duty cycle and offer the needed volt-ampere traits.
13. It really should be light in weight, tiny in size, low in price, hassle-free in service and handy to sustain.

Volt-Ampere Qualities of a Welding Energy Source

All welding energy sources have two sorts of operating qualities viz., static characteristic and dynamic characteristic. The static output characteristic can be very easily established by measuring the stable-state output voltage and existing by standard method of loading by variable resistors. Hence, a curve displaying the output existing versus output voltage for a offered energy source constitutes its static characteristic.

The dynamic characteristic of an arc welding energy source is determined by recording the transient variations occurring more than a brief intervals in the welding existing and the arc voltage. Hence, it describes instantaneous variations occurring more than a brief interval of time say a millisecond. Arc stability is determined by the combined interaction of the static and dynamic colt ampere (V-I) qualities of the welding machine energy source.

The intrinsic transient nature of a welding arc is the principal cause for excellent significance of the dynamic traits of an arc welding energy source. Most welding arcs have constantly altering circumstances which are primarily connected with striking of the arc, metal transfer from the electrode to the weld pool, and arc extinction and reignition in the course of every single half cycle of ac welding.

The transient nature of the welding arc is also due to variation in arc length, arc temperature and electron emission characteristic of the cathode.

The rate of change of voltage and existing in arc welding machine is so speedy that the static volt-ampere characteristic of a energy source can hardly be of any importance in predicting the dynamic characteristic of a welding arc. Having said that, it is only the static volt-ampere traits of a welding energy source which are supplied by the manufacturer. By means of they can not give the nature of behaviour of the energy source with regards to its dynamic response but they are of considerable significance in figuring out the basic all round response in controlling the technique parameters.

For much more information on arc welding machine and welding machine stop by weldingmachineindia.co.in