What is the primary function of a transformer in a regulated power supply?

The primary function of a transformer in a regulated power supply is to adjust the voltage level of alternating current (AC) to the desired level required by the connected load. This process involves either stepping up (increasing) or stepping down (decreasing) the incoming voltage as necessary.

While the transformer itself does not convert AC to direct current (which is the role of a rectifier), it plays a crucial part in the power supply by preparing the voltage that will then be rectified. Additionally, it's important to note that while transformers can provide electrical isolation and can be part of the circuitry that connects to external sources, they do not serve the primary purpose of connecting directly to those sources. Filtering out electrical noise is typically handled by capacitors and other components after the voltage has been adjusted by the transformer.

Overall, the transformer's vital role in adjusting voltage ensures that the power supply can deliver the correct voltage to the components it powers, which is essential for the effective operation of electronic devices.