i have learnt from engineers that welding transformer is different from power transformer. welding transformer's current will be high.but its load will be low.my actual doubt is current is always proportional to load.then how we can justify this logic that welding transformer's current rating is high and its load is less.
the main difference of the two transformer are the manner of how they deliver their output. Welding transformers are capable of delivering huge amount of current. This is due to the fact that huge amount of current facilitates the melting and welding of metals. On the other hand, power transformers are mainly used for power supplies and therefore requires a stable amount of current to avoid current surges and voltage has to be regulated such that it can be used for consumer electronics.
The power transformer is used for transformation of electrical power from one circuit to another but welding transformer is used for obtaining the very high current at secondary windind for melting the metals of different types for welding INZMAM SIDDIQUI
Its not to do with load. There is no reason you couldn't have the same load on a power transformer. Its the impedance that is different. A welding arc is started by short circuiting the output of the transformer. Doing this to a power transformer would damage it, or at least, operate the protection. The impedance is higher on a welding transformer so it can withstand the shorts.
A welding transformer is generally a Step-Down transformer with variable secondary taps and very high secondary current rating (on the order of hundreds of amps) that will drive through what's essentially a shorted secondary without translating that back to the primary and tripping the supply side breaker. The frame and windings are designed to withstand large magnetic forces produced by the high current impulses. They're designed to withstand a lot of heat for short periods of time, and are almost always air cooled. Welding transormers are generally physically sized so they can be moved easily. Power transformers as a group adjust line voltage depending on the application. They are designed to continuously handle high voltages (thousands of volts) and large amounts of current that doesn't vary much over short periods of time. In commercial and utility applications they are oil cooled. Most power transmission transformers are very large.
