Per"mu*la`tor (?), n. (Elec.) A special form of rotary converter with stationary commutator and rotating brushes, in which the exciting field is induced by the alternating current in a short-circuited magnetic core instead of being produced by an external magnet.

Per"mu*la`tor (?), n. (Elec.) A special form of rotary converter with stationary commutator and rotating brushes, in which the exciting field is induced by the alternating current in a short-circuited magnetic core instead of being produced by an external magnet.