Abstract: A bistable electromechanical transducer is disclosed having an armature reciprocable between first and second positions, a permanent magnet latching arrangement for maintaining the armature in the respective positions, and an electromagnetic repulsion arrangement operable when energized to dislodge the armature from the position in which the armature was maintained and causing it to move to the other of the positions. In a preferred embodiment, the transducer takes the form of an electronically controllable valve mechanism for use in an internal combustion engine and has an engine valve with an elongated valve stem along with the electromagnetic repulsion arrangement for causing the valve to move in the direction of stem elongation between valve-open and valve-closed positions.