Electronics is the science of how to control electric energy, energy in which the electrons have a fundamental role. Most modern appliances use a combination of electronic and electrical circuitry. A washing machine has an electrical circuit comprising a plug socket, fuse, on/off switch, heater and motor, which rotates the drum. The desired wash cycle and temperature are inputted by the user via the control panel. These instructions are interpreted by electronic circuits, which have been designed and programmed to understand what the user would like based on what buttons have been pressed. When the electronic circuit has interpreted these commands, it sends signals to the electrical circuit to operate the heater and motor, to heat and rotate the drum, for the time required.Most electronic components are very small, and require small direct current (DC) voltages. Electrical components tend to be larger, and use alternating current (AC) voltages. Whilst most electronic components operate on 3-12 volts DC, electrical appliances require 230 volts AC. This textbook provides a comprehensive introduction to electricity and electronics for students at school or college and other institutions of education and training.
