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An electric bell is a mechanical or electronic bell that functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing, clanging or ringing sound.
Starting in the 1970s the most frequently used BSPs were bundled in convenient handbooks each covering general subject matters, such as the Station Service Manual. The 9-digit format and numbering system was also used by Nortel and ITT Corporation due to their provenance from the Bell System's manufacturing unit, Western Electric.
A few million reed relays were used from the 1930s to the 1960s for memory functions in Bell System electromechanical telephone exchanges. [2] Often a multiple-reed relay was used, with one of the reeds latching the relay, and the other or others performing logic or memory functions.
Telephone magneto viewed from beneath shows the armature (inset, left) and the horseshoe field magnets, and the gears to drive the rotor. A telephone magneto is a hand-cranked electrical generator that uses permanent magnets to produce alternating current from a rotating armature.
The housing of the bell box may be manufactured from wood, metal, or plastic. The basic core component of a conventional bell box is an electromagnet and a bell or other metal piece, some of which create a repetitive sound. [1] The bell sound is normally created inside the box, although the unit may have bells mounted on the outside of the box.
Western Electric hand telephone set of c. 1930 with its ringer box or subscriber set in the background.. A ringer box is a telephone signaling device, similar to a bell box.It usually contains an electromechanical gong and was used with most early desk stand telephones, such as candlestick telephones and the Western Electric type Western Electric hand telephone sets, which were too small to ...
The Panel Machine Switching System is a type of automatic telephone exchange for urban service that was used in the Bell System in the United States for seven decades. The first semi-mechanical types of this design were installed in 1915 in Newark, New Jersey , and the last were retired in the same city in 1983.
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole in the center of the coil. The magnetic field disappears when the current is turned off.