Abstract: A reciprocating motor compressor assembly includes a pair of opposed pistons or diaphragms actuated by a reciprocating armature. The armature is fabricated from laminations of ferromagnetic material and includes a pair of electrically conductive induction rings disposed about the ends of the laminations in coaxial relationship with a longitudinal axis of the armature. A two coil stator is disposed in coaxial relationship with the armature and the coils are alternately energized by a multivibrator or a pair of oppositely poled half wave rectifiers connected to a source of alternating current voltage. In order to increase the duty cycle of the energizing current, each stator coil is provided with two coaxially wound parallel connected windings and a phase shifting capacitor connected in series with one of the windings.