A control circuit for electronic appliances and devices is shown - Leaving Cert Engineering - Question c - 2019

The function of the transformer in this circuit is to step down the voltage from a high level, typically 240 V from the mains supply, to a lower level suitable for electronic devices. In this case, it reduces the voltage to the 6-12 V range required by many electronic appliances. This process involves electromagnetic induction, where the voltage reduction is achieved while helping to isolate the electronic devices from the high-voltage input.