Mechanical Engineering - Workshop Technology - Discussion

Because spot welding does not have any secondary transformer.

The correct answer is any one of the above.

The current in electric resistance welding (ERW) can be regulated by:

- Varying the input supply: Adjusting the voltage of the input power supply can change the current flowing through the welding circuit.
- Changing the primary turns of the transformer: Increasing or decreasing the number of turns in the primary coil of the transformer can change the current output.
- Changing the secondary turns of the transformer: Increasing or decreasing the number of turns in the secondary coil of the transformer can also change the current output.

All of these methods can be used to regulate the current in ERW, and the choice of method depends on the specific welding application and equipment being used.

ERW machines often have controls that allow the operator to adjust the current output to suit the specific welding task. This may involve adjusting the input voltage, transformer turns, or other parameters to achieve the desired current output.

Then, The exact method of current regulation may vary depending on the type of ERW machine and its design.