This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Rotary dial" – news · newspapers · books · scholar · JSTOR(February 2015) (Learn how and when to remove this message)
A traditional North American rotary telephone dial. The associative lettering was originally used for dialing named exchanges but was kept because it facilitated memorization of telephone numbers.
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, with one finger hole in the finger wheel for each digit. For dialing a digit, the wheel is rotated against spring tension with one finger positioned in the corresponding hole, pulling the wheel with the finger to a stop position given by a mechanical barrier, the finger stop. When released at the finger stop, the wheel returns to its home position driven by the spring at a speed regulated by a governor device. During this return rotation, an electrical switch interrupts the direct current (DC) 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. Thus, each of the ten digits is encoded in sequences to correspond to the number of pulses; thus, the method is sometimes called decadic dialing. Pulse count dialing is a digital addressing system which uses decimal pulse count modulation. The typical average baud rate is 10 bits per second, though the system will usually accept from about 9 through 13 pulses per second, a requirement due to variations in the rotary dial mechanism governor speed.
This dialing method is the world's first mass scale digital addressing system. It is sometimes erroneously referred to as an analog system due to some individuals' beliefs that mechanical and old are synonyms for analog. However, like the telegraph, which is also mechanical and digital, and which uses both pulse count and pulse width modulation for communicating, pulse dialing is a digital communication method used for addressing telephone subscribers.
The first patent for a rotary dial was granted to Almon Brown Strowger on November 29, 1892, but the commonly known form with holes in the finger wheel was not introduced until about 1904.[citation needed] 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 early 1920s.[1]
From the 1960s onward, the rotary dial was gradually supplanted by push-button telephones, first introduced to the public at the 1962 World's Fair under the trade name Touch-Tone (DTMF). Touch-tone technology primarily used a keypad in the form of a rectangular array of push-buttons. Although no longer in common use, the rotary dial's legacy remains in the verb "to dial (a telephone number)".
^Roberts, William Lee. "A look at the evolution of the Dial Telephone". Retrieved 15 January 2016.
A rotarydial is a component of a telephone or a telephone switchboard that implements a signaling technology in telecommunications known as pulse dialing...
right-hand quadrant of the test pattern while the second hand swept around the dial for one minute. The first TV ad broadcast in the U.K. was on ITV on 22 September...
that replaced rotarydialing originally developed in electromechanical switching systems. Because of the installed abundance of rotarydial equipment well...
produce such pulse trains is the rotarydial of the telephone, lending the technology another name, rotarydialing. The pulse repetition rate was historically...
When subscribers could dial themselves, the initial letters of the names were converted to digits as displayed on the rotarydial. Thus, telephone numbers...
October 1914. Dial tone was an essential feature, because the 7A Rotary system was a common control switching system. It used the dial tone to indicate...
Look up rotary in Wiktionary, the free dictionary. Rotary may refer to: Rotary motion Rotarydial, a rotating telephone dialRotary engine (disambiguation)...
Look up dial, dialed, or dials in Wiktionary, the free dictionary. Dial may refer to: Rotarydial, a device for the input of number(s) in telephones and...
rotation, and the individual rotary position of each wheel can be manipulated by turning the dial left and right. The dial is mechanically connected via...
standard telephone dial, and speed dial calls are placed by dialing simply the digit and waiting a few seconds on a standard rotarydial phone and an older...
and, after the rotarydial was added, the instrument itself changed little until Touch-Tone signaling started replacing the rotarydial in the 1960s. The...
including dSLR and SLR-like cameras, support modes, selectable either by a rotarydial or from a menu. On point-and-shoot cameras which support modes a range...
In automotive engineering, a manettino dial is a rotary switch part of some modern Ferrari cars first designed by Frank Stephenson, beginning with the...
also known in the UK as MF4. Touch-Tone dialing with a telephone keypad gradually replaced the use of rotarydials and has become the industry standard in...
by intervals of roughly one second, the caller can dial numbers as if they were using the rotarydial. The pulse counter in the exchange counts the pulses...
pound/hash (#) dialed on a telephone keypad or rotarydial to access certain telephone service features. Some vertical service codes require dialing of a telephone...
whereas the four-digit numbers prefixed 11xx are used on rotarydial telephones which cannot dial the * symbol. Not all NANP countries use the same codes...
obviating a separate ringer box. The rotarydial becoming commonplace in the 1930s in many areas enabled customer-dialed service, but some magneto systems...
while dialing, so an optional lead weight was added to fill the space intended for the ringer. Later models included the M1A ringer. The rotarydial version...
were pressed, simulating the pulses produced by a rotarydial. Ericsson continued to produce rotary-dial Ericofons until about 1980. Wild and Wolf produces...
changed the rotarydial for a push-button version with lights in an effort to modernize the toy, but consumers complained and the rotary version returned...
centre; thus dialing 0+0, plus another 0 would call (at least) an operator. Zero is closest to the finger stall on Australian rotarydial phones, so it...
Global Information
