1. vibrator, electro-magnetic The make and break mechanism used on induction coils, or other similar apparatus in which by alternate attractions by and releases from an electro-magnet an arm or spring is kept in motion. In most cases the work is done by a single magnet, whose armature is attracted to the magnet, when the latter is excited, but against the action of a spring which tends to pull it away from the magnet. In its motions a make and break action is produced, to give the requisite alternations of attraction and release. Two electro-magnets may be connected so as alternately to be excited and keep an arm carrying a mutual armature in vibration, or the same result may be attained by a polarized relay. The make and break is illustrated under Bell, Electric--Coil, Induction-- Anvil.