The very simplest working telephone would look like this inside:
 | It consists of 3 parts: A switch to connect and disconnect the phone from the network. This switch is generally called the hook switch. It connects when you lift the handset. A speaker, which is generally a little 50 cent 8-ohm speaker of some sort. A microphone. In the past, telephone microphones have been as simple as carbon granules compressed between two thin metal plates. Sound waves from your voice compress and decompress the granules, changing the resistance of the granules and modulating the current flowing through the microphone. |
