This circuit generates a dual-tone bells ringing similar to most door-bell units. It can be used in many applications other than door-bell. In the Notes below several options will be given in order to ...

For electricity to flow, everything needs to be connected in a big ring. It’s called a circuit. For example, the lights in most houses and flats are part of a circuit controlled by the consumer unit, ...

The wiring in a house connects all appliances together in parallel. This is so that each appliance has the mains supply of 230 volts across it, and also so that they can all be switched on and off ...