Electric Bell


Also found in: Dictionary, Thesaurus, Wikipedia.

Electric Bell

 

a device consisting of an electromagnet, an armature with a hammer, and a cup (bell). When a button connected to the electric bell is pressed, thereby closing a DC supply circuit to the electromagnet, the armature is attracted and its hammer strikes the bell cup. Upon being attracted to the electromagnet the armature opens the contacts of a circuit breaker in the supply circuit and is returned to its position by the action of a spring. A basic drawback is the sparking at the contacts, which creates considerable radio interference. When supplied from a 127–220 V AC system, an electric bell is supplied through a transformer built into the bell’s housing, so that the voltage at the button does not exceed 12 V (to meet safety specifications). The AC electric bell, which operates on the principle of a polar relay, has no contacts and utilizes the change in the direction of the magnetic field to move the hammer. There are also resonant polar types, which are employed in selective signaling systems (for example, in telephone systems).

References in periodicals archive ?
July 16, 2013 /PRNewswire/ -- Since the invention of the electric bell ringer in 1831, Americans have relished the benefits of the ever-present doorbell to let them know someone's calling.
The electric bell sounded and all the girls in the playground formed lines.
Providing of Electric bell (good quality) (including cost of item and labour)
1874: The Bothnia featured |no fewer than three firsts - the first library at sea, the first lounge for women, and the first system of electric bells.
There is also fine French porcelain, Chinese ceramics and other oriental ware, paintings, jewellery, clocks, English furniture of all periods, tribal clubs, swords, fishing rods, even a child's brass cot complete with horsehair mattress and an Edwardian telephone exchange with Bakelite phones and electric bells.
The former invited the viewer to press a switch, which trig-gered twenty electric bells lining the perimeter of the gallery to ring in quick succession.
100 YEARS AGO: Frank and Lawrence Pendergest, aged respectively 19 and 17, living at 568 Icknield Street, pleaded guilty to stealing a quantity of electric bells and fittings from Wood Road Handsworth, belonging to William Kirbey, and also from houses in Wood Road Handsworth belonging to the Far Croft Estate Company.
featured no fewer than three firsts - the first library at sea, the first lounge for women, and the first electric bells 1881: When Servia was .
22 - automatic switches for a voltage not exceeding 1000 V (switches, electric bells, auxiliary contacts, connectors, sockets, control buttons, auxiliary contacts, boxes, milliammeters, switches, Posts push-button, relay sockets LED lamps, Alarm, push buttons); Lot 3 - 27.