What is the role of a power supply transformer?

The role of a power supply transformer is primarily to convert alternating current (AC) from one voltage to another. This function is critical in many electrical and electronic systems, as it allows for the adjustment of voltage levels to ensure that devices operate safely and efficiently. For example, a transformer can step down high voltage electricity from power lines to a lower voltage suitable for household use or can step up voltage for transmission over longer distances.

Transformers operate on the principle of electromagnetic induction, where an alternating current in one coil creates a changing magnetic field that induces a voltage in a second coil. This process allows for the efficient transfer of energy while adjusting the voltage in accordance with the turns ratio of the coils involved.

While some of the other choices — such as regulating output voltage or filtering noise — can be functions of different components in a power supply system, the primary role of a transformer is distinctly tied to voltage conversion. Storing energy, which is mentioned in another choice, is a function typically associated with capacitors or batteries, not transformers.