Automatic dialing device

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Transfer element of a rotary dial according to Strowger

In telecommunications, a self-dialing device is a mechanism with which a user can establish a dial-up connection without this being manually switched by a "lady from the office" .

The participants dial was the late 19th century through the automation of mediation allows. At first, dials were used, later buttons became popular .

The first automatic dialing device was patented by Almon B. Strowger in 1889, who also set up the first automatic exchange in La Porte , Indiana in 1892 .

Development in Germany

The first self-dialing device in Germany was put into operation on July 10, 1908 in Hildesheim for local traffic with 900 participants. The national telephone traffic was automated in 1923 (in Weilheim / Obb. Was on May 16, 1923 the first Selbstwählfernsprechamt the world with five local networks put into operation), while the first cross-border Selbstwählverbindung only on September 3, 1955 between Loerrach and Basel put into operation has been. It was not until 1966 that self-voting was introduced across the board in the Federal Republic and the last manual switching in Uetze near Hanover was abolished in April 1966. It took another six years until uniform dialing codes and the traffic elimination codes "0" for domestic and "00" for foreign countries were introduced in the Federal Republic of Germany, which also created an international automated remote dialing option. Nevertheless, the simplified direct dialing service ( traffic elimination code  “9”), which was set up in some metropolitan areas of the Federal Republic (e.g. in the Ruhr area) after the Second World War (approx. 1949), was operated in parallel until the 1980s.

After reunification , Deutsche Bundespost Telekom set up an ISDN- based telephone network in the five new federal states . Since July 6, 1991, direct voting has been possible in all parts of the world.


  • Ernst Hettwig, Walter Mai: Self-dialing long-distance traffic in railway telephone systems. Second expanded edition, Springer Verlag, Berlin 1944.

Web links

Individual evidence

  1. Augsburger Allgemeine from July 6, 2011, section Das Datum .