| In industrial context, welding refers to a fabrication | | | | from a set of taps on the transformer. |
| process that joins materials such as metals and | | | | Some welding machines use an internal combustion |
| thermoplastics, by causing coalescence. This is | | | | engine or an electric motor to drive the alternator or |
| typically done by softening the work pieces and | | | | generator present in these machines. The process |
| adding a filler material, which is often a welding rod, | | | | used is similar to transformer based welding machines |
| to form a pool of molten material that cools to | | | | as power is first converted into mechanical and back |
| become a strong joint. Various processes and energy | | | | to electrical energy to achieve the step-down affect. |
| sources are used for welding, such as gas flame, | | | | Inverter based welding machines use high-power |
| electric arc, laser, electric beam, friction, and ultra | | | | semiconductors such as the IGBT for building a |
| sound. | | | | switching power supply capable of handling high loads |
| Welding machines can be broadly classified into | | | | of arc welding. These machines convert utility |
| different categories depending on the type of | | | | electricity into high voltage and store it in a capacitor |
| welding processes and equipment used during the | | | | bank. The stored energy is then transferred to a |
| process. Some welding machines use transformers | | | | secondary transformer for producing the desired |
| for converting high voltage, low current electricity | | | | welding current. |
| into high current low voltage, often between 17 to | | | | Welding machines have simplified different types of |
| 45 volts and 190 to 590 amperes. These types of | | | | machining jobs undertaken in small and large |
| welding machines are the least expensive and allow | | | | manufacturing companies. Automated welding |
| welders to select the output current by either | | | | machines are also in use and have helped in increasing |
| moving the core of the transformer in and out of | | | | the effectiveness of welding processes. |
| the magnetic field or by allowing the welder to select | | | | |