Why do some transformers make a humming noise?

You may hear a humming noise when the transformer is operating. This is due to the mechanical vibrations it produces. This is only audible under certain circumstances, for example when a transformer for a lighting system is mounted between a ceiling or wall. Hollow spaces can then act as a sound box, making the humming sound audible.

Why is the power of a transformer indicated by VA?

A transformer is an inductive load through a copper coil. Therefore, the power is stated in volts x amperes (VA) and not in watts.

Can a transformer be dimmed?

In principle, this is possible, as long as the power of the dimmer is specified in VA. These dimmers are suitable for conventional transformers with the coil. If the power is stated in watts, then the dimmer is only suitable for incandescent lamps. Electronic transformers must be dimmed using a trailing edge dimmer. The packaging of these dimmers indicates that they are suitable for electronic transformers.

Can the coils in a transformer connect in parallel or in series?

If a transformer has two identical coils, the coils can be connected in series to increase the voltage. Parallel switching is also possible to increase the current. When connecting the outputs, make sure to make the correct connections.

Why does the iron core of a transformer consist of thin metal plates?

In main transformers, alternator plates (of an iron/silicon alloy) are stacked on top of each other. Thus they form the core of the transformer. The plates are insulated from each other to prevent losses due to eddy currents. Damage to the insulation leads to a warmer working environment.

What is the difference between a primary and secondary coil of a mains transformer?

The primary coil has a thin wire with many turns. The exact thickness of the wire and the number of turns depends on the power that the transformer has to transfer. At the secondary coil, the wire is much thicker, with fewer bends. Here too, the number of revolutions and the thickness of the wire depend on the voltage to be generated in the second instance.