Magneto Bell

Magneto Bell Points : Magneto Bell, Definition Bell is a way of signal. When the calling party wants to call the called party. He must first give him a bell to draw his attention. For this purpose magneto bell is used in the telephone set of each subscriber.

The magneto bell works on a.c. supplied by the exchange. The constructional detail of the magneto bell is shown in the figure.

It consists of a permanent magnet, two windings on the two legs of the iron yoke and an armature with a hammer. The static flux produced by the permanent magnet complete their path through the two parallel magnetic Circuits. As the static field in each circuit is equal, thus the armature remains stationary. When alternating current flows through the windings, electromagnets are produced. The two fields interact with each other, supporting at one side and weakening at the other alternatively. The armature is attracted by the stronger magnetic field and the hammer strikes the gongs alternatively, thus produce a sound.