- When the switch closes, current flows through the coils, magnetizing the inner
- The iron armature on the sprung striker arm is attracted by the electromagnet;
the bell sounds.
- The contact points separate; current flow in the coils ceases; the electromagnet
- The spring returns the armature; the contact points close; the coils renervate.
- The cycle repeats and the bell continues to ring while the switch is held down.