Bistable multivibrator controlled oscillating d.-c. motor

Claim 1

IN COMBINATION WITH A D.-C. MACHINE HAVING ALTERNATE NORTH AND SOUTH FIELD POLES AND HAVING ARMATURE WINDINGS WHICH FOR EFFECTING COMMUTATION ARE REQUIRED TO BE SWITCHED IN PAIRS SO AS TO CARRY CURRENT ALTERNATELY IN RHYTHM WITH THEIR PASSAGE PAST THE FIELD POLES OF THE MACHINE, AT LEAST ONE BISTABLE SWITCHING CIRCUIT COMPRISING A PAIR OF ELECTRONIC SWITCHING DEVICES EACH PROVIDING A MAIN CURRENT PATH AND HAVING A CONTROL ELECTRODE ABLE TO CONTROL AT LEAST THE INITIATION OF CONDUCTION OVER SAID PATH, RESPECTIVE LOAD ELEMENTS CONNECTED IN SERIES WITH SAID MAIN CURRENT PATHS OF SAID DEVICES, SAID LOAD ELEMENTS BEING CONSTITUTED BY A PAIR OF SAID ARMATURE WINDINGS AND BEING SUCH AS TO PRESENT A VARYING VOLTAGE DROP, EACH SWITCHING DEVICE HAVING FROM A POINT BETWEEN IT AND ITS SERIES ARMATURE WINDING LOAD ELEMENT TO THE OTHER SWITCHING DEVICE A CROSS-COUPLING CONNECTION EFFECTIVE TO RENDER THE LATTER DEVICE NON-CONDUCTIVE WHEN THE FORMER HAS BEEN INITIATED INTO CONDUCTION, AND UNIDIRECTIONALLY CONDUCTIVE DEVICES CONNECTED BETWEEN THE RESPECTIVE ARMATURE WINDING LOAD ELEMENTS AND SAID POINTS FROM WHICH THE CROSS-COUPLING CONNECTIONS ARE TAKEN, WHEREBY TO TEND TO ELIMINATE ADVERSE EFFECTS OF SAID VARIABLE VOLTAGE DROPS.