Power frequency welding transformer

Resistance welding transformer welding efficiency is high, fast speed, welding parts are firm, reduce welding costs, suitable for a variety of materials of welding, such as aluminum alloys and aluminum and other hot conductivity, poor weldability of materials can also be welded. In addition, for the welding of galvanized sheet and ordinary multilayer board, the welding quality is also much higher than the welding quality of the power frequency welding machine

Characteristics of transformers:

1, large current, low voltage Resistance welding is the use of resistance heat as a heat source, because the resistance is very small (generally less than 100μΩ), so there must be a large enough current to obtain the due heat, the commonly used welding current is 2000 ~ 40000A. Because the weldment and welding circuit resistance are in the order of micro-euro range, the secondary voltage of the transformer is not high. Fixed welding machines are usually within 10V, and suspension welding machines have a secondary voltage of about 24V due to the long welding circuit and wide range. Since resistance welding requires large welding current and low voltage, the secondary winding of the resistance welding transformer is only one turn (suspension or long-arm welding machine uses two turns), so the welding circuit conductor of the resistance welding machine is relatively large and requires forced cooling.

2, large power, adjustable Due to the large welding current, the capacity of the resistance welding transformer is greater than 50kVA. Since the transformer winding is only one or two turns, the number of winding turns can only be changed once to change the welding power.

3, the work is not continuous, no-load operation In general, the switch of the resistance welding transformer is placed between the primary winding and the power line, and before the primary winding is connected to the network, the weldment has been pressed in the weldment, the welding circuit has been closed, and once the power supply is turned on, the transformer will run under load, so there is generally no no-load state (flash butt welding exception). When welding, welding fittings loading and unloading, clamping, welding position movement and pre-pressure, forging, resting and other procedures in the welding cycle generally do not need to be connected to the power supply. Therefore, the power-on working time of the resistance welding transformer is intermittent.