a. (context of a telephone English) Activated by rotating the numeric dial instead of activating push buttons. n. 1 (&lit rotary dial English) 2 A telephone with a rotary dial to indicate the number to be called.
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 dial, the digits are arranged in a circular layout so that a finger wheel may be rotated with one finger from the position of each digit to a fixed stop position, implemented by the finger stop, which is a mechanical barrier to prevent further rotation. When released at the finger stop, the wheel returns to its home position by spring action at a speed regulated by a governor device. During this return rotation, the dial interrupts the direct electrical current of the telephone line ( local loop) a specific number of times for each digit and thereby generates electrical pulses which the telephone exchange decodes into each dialed digit. Each of the ten digits are encoded in sequences of up to ten pulses. For this reason, the method is sometimes called decadic dialling.
The first patent for a rotary dial is due to Almon Brown Strowger (November 29, 1892) as , but the commonly known form with holes in the finger wheel was not introduced until ca. 1904. While used in telephone systems of the independent telephone companies, rotary dial service in the Bell System in the United States was not common until the introduction of the Western Electric model 50AL in 1919.
From the 1960s onward, the rotary dial was gradually supplanted by dual-tone multi-frequency push-button dialing, first introduced to the public at the 1962 World's Fair under the trade name "Touch-Tone". Touch-tone technology primarily used a keypad in form of a rectangular array of push-buttons for dialing.
Usage examples of "rotary dial".
It was because she'd seen an old, black rotary dial phone on the floor.
Vexed by the fact that the local operator in his town referred the bereaved to a competing undertaker, he had invented the stepping switch, which enabled people to reach their own phone destinations merely by turning a rotary dial.
He leaned forward and began to pick out the number on the old-fashioned rotary dial.
It was an antique, the kind where the handset was cradled above a rotary dial.
When the telephone in the hall rang (it was Bakelite and black and had an honest-to-goodness rotary dial on the front), Mr.
Our telephone, a Bakelite dinosaur with a rotary dial, was on a table in the front hall.
He thought he must see the pay phone caked with ice, ice that was sweating through the phone's black plastic case, extruding from the holes in the earpiece and the mouthpiece in lines of blue ice as thin as pencil-leads, hanging from the rotary dial and the coin return in icicle beards.