Rotary dialwikipedia
A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing.
rotary dialdialrotary telephonetelephone dialrotary phonedialsrotary phonesrotaryrotary telephone dialdial telephone

Telephone

telephonephonetelephones
A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing.
Until approximately the 1970s, most telephones used a rotary dial, which was superseded by the modern dual-tone multi-frequency (DTMF) push-button dial, first introduced to the public by AT&T in 1963.

Push-button telephone

push-button telephonepush-button dialingpushbutton telephones
From the 1980s 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".
The push-button telephone is a telephone that has buttons or keys for dialing a telephone number, in contrast to having a rotary dial as in earlier telephone instruments.

Pulse dialing

pulse dialingdial pulsepulse dialling
A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing.
Historically, the most common device to produce such pulse trains is the rotary dial of the telephone, lending the technology another name, rotary dialing.

Dual-tone multi-frequency signaling

DTMFtouch-tonetouch tone
From the 1980s 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".
The Touch-Tone system using a telephone keypad gradually replaced the use of rotary dial and has become the industry standard for landline and mobile service.

Telephone exchange

telephone exchangeexchangescentral office
It is used when initiating a telephone call to transmit the destination telephone number to a telephone exchange.
When used with a rotary telephone dial, each pair of digits caused the shaft of the central contact "hand" of the stepping switch to first step (ratchet) up one level for each pulse in the first digit and then to swing horizontally in a contact row with one small rotation for each pulse in the next digit.

Signaling (telecommunications)

signalsignalingsignalling
A rotary dial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing.
In the first half of the 20th century, addressing formation is done by using a rotary dial, which rapidly breaks the line current into pulses, with the number of pulses conveying the address.

Telephone call

telephone callcallphone call
It is used when initiating a telephone call to transmit the destination telephone number to a telephone exchange.
The caller then rotary dials or presses buttons for the phone number needed to complete the call, and the call is routed to the phone which has that number.

North American Numbering Plan

Area codeArea codes<span style="white-space:nowrap;">Area code(s)
On rotary dial phones smaller numbers, such as 2, are dialed more rapidly than longer numbers, such as 9 (because the dial turns much further with a 9). In 1947, area codes were introduced in the United States, so as to facilitate direct distance dialing first by operators, then by subscribers.
The codes prefixed with an asterisk symbol are intended for use on Touch-Tone telephones, whereas the four-digit numbers prefixed 11xx are intended for use on rotary dial telephones, where the Touch-Tone * symbol is not available.

999 (emergency telephone number)

9999-9-9999 call
A relic of these differences is found in emergency telephone numbers used in various countries; the United Kingdom selected 999 due to the ease of converting call office dials to make free calls.
The 9-9-9 format was chosen based on the 'button A' and 'button B' design of pre-payment coin-operated public payphones in wide use (first introduced in 1925) which could be easily modified to allow free use of the 9 digit on the rotary dial in addition to the 0 digit (then used to call the operator), without allowing free use of numbers involving other digits; other combinations of free call 9 and 0 were later used for more purposes, including multiples of 9 (to access exchanges before STD came into use) as a fail-safe for attempted emergency calls, e.g. 9 or 99, reaching at least an operator.

Dial tone

dial tonedial-tonestutter dial tone
When he picked up his own household phone his assistant had to explain what the strange noise was, as well as show Eisenhower how to use a rotary dial phone.

Almon Brown Strowger

Almon B. StrowgerStrowger
The first patent for a rotary dial was granted 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.

Single-frequency signaling

single-frequency signalingtonesingle frequency
In the seized state, dial pulses are conveyed by bursts of SF tone, corresponding to the interruptions in dc continuity created by a rotary dial or other DC dialing mechanism.

Panel switch

panel switchpanelPanel system
Hence the first Panel automatic exchanges cutover in 1915 in Newark, New Jersey used "semiautomatic" operation with the local operator keying the number for the caller.
While the Strowger (step-by-step) switch moved under direct control of dial pulses that came from the telephone dial, the more sophisticated Panel switch had senders, which registered and stored the digits that the customer dialed, and then translated the received digits into numbers appropriate to drive the selectors to their desired position: District Brush, District Group, Office Brush, Office Group, Incoming Brush, Incoming Group, Final Brush, Final Tens, Final Units.

All-figure dialling

all-figure diallingall figure dialling01609
Dials outside Canada, the United States, and large cities in Britain (before all-figure dialling) usually did not bear alphabetic characters or an indication of the word "operator" in addition to numbers.
The rotary dial included the corresponding letters next to the appropriate digits.

Stepping switch

stepping switchuniselectoruniselectors
The coils were typically driven by the electrical pulses derived from a rotary telephone dial.

History of the telephone

telephonetelephone historymechanical telephone
The rotary dial in the base interrupted the line current by repeatedly but very briefly disconnecting the line 1 to 10 times for each digit, and the hook switch (in the center of the circuit diagram) permanently disconnected the line and the transmitter battery while the handset was on the cradle.

Voice command device

voice command deviceVoice controlvoice commands
By removing the need to use buttons, dials and switches, consumers can easily operate appliances with their hands full or while doing other tasks.

Dial H for Hero

Robby ReedChris King and Vicki GrantHero dial
Resembling a rotary telephone dial, the device is hand-held with unknown symbols inside the dial's finger- openings and along its outer rim, which Robby deciphers into modern English letters.

Chatter Telephone

The toy has a rotary dial that rings a bell, and was conceived as a way to teach children how to dial a phone.

Clix (miniatures)

Clix
It is characterized by the use of a dial wheel in the base of miniature figurines.

Dialling (telephony)

dialingDiallingredial
Dialling, (dialing in US English), is the action of initiating a telephone call by operating the rotary dial or the telephone keypad of a telephone.

Ericofon

Most Ericofons had mechanical rotary dials, typical of all phones made in the era.