Electro-magnetic pick-off device

Claim 1

AN ELECTROMAGNETIC TRANSDUCER COMPRISING A STATIONARY MAGNETIC CORE STRUCTURE INCLUDING A CIRCULAR YOKE AND A RETURN RING CONCENTRIC WITH SAID YOKE AND RADIALLY SPACED APART THEREFROM, SAID YOKE BEING PROVIDED WITH AT LEAST FOUR EQUALLY CIRCUMFERENTIALLY SPACED POLES COMPRISING CIRCUMFERENTIALLY-ALTERNATED PRIMARY AND SECONDARY POLES AND FORMING EQUAL AIR GAPS WITH SAID CORE STRUCTURE, A PAIR OF WINDINGS ON SAID PRIMARY POLES INTERCONNECTED IN SERIES OPPOSITION AND A PAIR OF WINDINGS ON SAID SECONDARY POLES INTERCONNECTED IN SERIES OPPOSITION, AND A NON-MAGNETIC CONDUCTIVE SHORTED-TURN ARMATURE OF ANNULAR CYLINDRICAL FORM HAVING LEGS DISPOSED IN SAID AIR GAPS ADJACENT CIRCUMFERENTIALLY-ALTERNATE ONE OF SAID POLES, SAID ARMATURE HAVING A NULL POSITION IN WHICH EQUAL AND OPPOSITE VOLTAGES ARE INDUCED IN SAID SECONDARY WINDINGS IN RESPONSE TO A VOLTAGE APPLIED ACROSS SAID PRIMARY WINDINGS, SAID ARMATURE BEING ANGULARLY MOVABLE WITH RESPECT TO SAID CORE TO REDUCE THE VOLTAGE INDUCED IN ONE OF SAID SECONDARY POLE WINDINGS AND INCREASE THE VOLTAGE INDUCED IN THE OTHER.