Rotary dial phone

A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing. It is used when initiating a telephone call to transmit the destination telephone number to a telephone exchange.

On the rotary phone dial, the digits are arranged in a circular layout so that a finger wheel may be rotated against spring tension with one finger. Starting from the position of each digit and rotating to the fixed finger stop position, the angle through which the dial is rotated corresponds to the desired digit. Compact telephones with the dial in the handset had all holes equally spaced in the dial, and a spring-loaded finger stop with limited travel.

When released at the finger stop, the wheel returns to its home position driven by the spring at a speed regulated by a centrifugal governor device. During this return rotation, the dial interrupts the direct electrical current of the telephone line (local loop) the specific number of times associated with each digit and thereby generates electrical pulses which the telephone exchange decodes into each dialed digit. Each of the ten digits is encoded in sequences to correspond to the number of pulses, so the method is sometimes called decadic dialing.

Ingredients: Rotary dial phone | 2 remixes