Menu

A history of the telephone

06/06/2008 - 00:00 AM

- + Text size
Print

Many types of telephone have come and gone between the end of the nineteenth century and the present day. New styles have been introduced following the development of new technologies, resulting in a very broad range of different devices.
The process of evolution may be divided into five main stages:

  • A shift from local battery-powered to central-powered battery devices;
  • The introduction of the dial and automatic switching;
  • Introduction of a keypad and the shift to digital systems;
  • Introduction of a display;
  • Cordless phones.

In the beginning: the hand-crank

In the very beginning, wall-mounted and table-top telephones were of the "local battery" type: each individual device had to be powered by its own battery. Telephones consisted of two boxes: one housed the battery used to power the mouthpiece; the other housed the mouthpiece, receiver, hand-cranked AC generator (to send the call signal to the exchange), ringer and circuits. Table-top phones generally had a separate mouthpiece joined to the receiver by a cord.
Telephone exchanges began to incorporate a large battery into their operations during the first two decades of the 20th century. This battery powered the mouthpiece, eliminated the need for a hand-cranked generator, and made it possible to build simplified "one-box" telephones for wall- or table-mounted devices. A signal was sent to the exchange on lifting the handset; the signal ceased transmission when the mouthpiece was hung up.

From the dial to the digital keypad

In the 1910s and 1920s, the introduction of automatic switching led to the appearance of the dial on telephones. Dials enabled callers directly to input the phone number they wanted to call on their own device. Once dials became standardized, they quickly established themselves as the most immediate and recognizable symbol of the telephone.
The dial telephone benefitted from a major new development at the end of the 50s, when Italy's telephone concessionary companies (STIPEL, TELVE, TIMO, TETI and SET) teamed up with the Siemens and Face manufacturers to design a new telephone. The “Unificato” model could be transformed into a table-top or wall model simply by changing the top part of the device. Furthermore, telephones made by the two manufacturers came with fully interchangeable top parts, bases, handsets, microphones, receivers, dials and cords. The name “Unificato” was particularly apt. As a side benefit, maintenance became much easier too.
This model of phone changed very little in shape and colour in Italian homes right through to the late 70s, when it finally began to be replaced; some remained in service into the 90s.
During the 80s, the introduction of circuits capable of generating wholly electronic tones paved the way for phones with digital keypads, and the entire telephone system converted to digital. A great many new automatic telephone services became available to users thanks to the adoption of digital keypads.

Displays and cordless phones

Displays began appearing on telephones in the late 80s, once again as a benefit from evolving digital technology. Telephone display showed the caller's number, stored telephone numbers, and listed numbers to be called. More recently, displays on fixed-line telephones have made it possible to send SMS and MMS messages (just like mobile phones) and be used for video calls (videophones).
Technological progress in the 90s also led to the widespread take-up of cordless phones, which were at last liberated from the handset base connection to the telephone network.