Which component in a power supply is responsible for isolating the high-voltage AC input?

The transformer is key in isolating the high-voltage AC input in a power supply. Its primary function is to transfer electrical energy through electromagnetic induction between two or more circuits while providing electrical isolation. This isolation is crucial in protecting the low-voltage circuits connected to the power supply from potentially dangerous high-voltage inputs.

Transformers work on the principle of varying magnetic fields, which allows them to adjust the voltage levels while ensuring that the high-voltage and low-voltage sides are electrically separated. This isolation helps in maintaining safety and preventing damage to sensitive electronic components downstream.

The other components in the power supply have different roles; for example, filters smooth out the output voltage, rectifiers convert AC to DC, and regulators ensure a consistent output voltage. However, none of these components provide the same level of high-voltage isolation as the transformer.