Practical Audio Electronics

4  |  Mains Electricity and Electrical Safety

Although this book is concerned mainly with circuits running from low voltage power sources (most typically a single nine volt battery), mains power is never very far away. Indeed the place of the battery can just as easily be taken by a mains power adaptor designed to supply the same DC voltage to the circuit but drawing its energy from the mains supply. When circuits with higher power requirements are encountered, most obviously power amplifiers outputting more than a couple of watts, battery powering quickly becomes troublesome and a mains power supply becomes the only viable option. Additionally mains connected bench power supplies are commonly encountered in electronics labs as they are far ...