Answer to Question #116950 in Electric Circuits for James

Question

when using DC equipment such as tablets, games consoles and mobile phones, discuss the principles behind ‘charging them up’ from the AC mains supply.

Answer 1

Tablets, game consoles and mobile phones have batteries inside that can only be charged from DC supply. An adapter is used for this purpose. In the simplest version it looks like this

How does it work?

A transformer converts high voltage to low voltage, a "diode bridge" makes alternating voltage pulsate,and an electrolytic capacitor smooths out the ripples. All adapters are arranged similarly, although there are more complex devices.