Spark image

The Electric Bell


A simple electric bell is shown in the diagram - it works like this. When the switch S is closed current flows round the circuit, through the electromagnet - along the spring - through the contacts - through the adjusting screw and back to the battery again.

The electromagnet therefore attracts the soft iron armature and the striker hits the gong once.

As soon as the armature is attracted the contacts are opened and so the current stops flowing.

This switches off the electromagnet, the spring pulls the armature away — the contacts meet again and so the current starts flowing again. This is repeated over and over again and so the bell rings.


schoolphysics electric bell animation

To see an animation of the electric bell click on the animation link.


 


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© Keith Gibbs 2020