Variable synchronous motors which rotate at a self-determined rotational speed

Claim 1

A VARIABLE SYNCHRONOUS MOTOR WHEREIN DRIVING FIELD COILS ARE COMPOSED OF COILS OF A SWITCHING CIRCUIT HAVING SWITCHING ELEMENTS THEREIN, AND A ROTOR OF A PERMANENT MAGNET IS PROVIDED SO THAT SAID PERMANENT MAGNET ROTOR IS CONTINUOUSLY ROTATED BY AN ELECTROMAGNETIC FORCE BETWEEN SAID ROTOR AND A MAGNETIC FIELD INDUCED IN SAID DRIVING FIELD COILS BY THE ACTION OF THE SWITCHING CIRCUIT, AND WHEREIN AN EXTERNAL SYNCHRONIZING SIGNAL IS APPLIED TO SAID SWITCHING CIRCUIT TO ROTATE SAID PARMANENT MAGNET ROTOR IN SYNCHRONISM WITH A FREQUENCY OF SAID EXTERNAL SYNCHRONIZING SIGNAL, SAID PERMANENT MAGNET ROTOR BEING SUBSEQUENTLY CAPABLE OF MAKING SYNCHRONOUS ROTATION RELATIVE TO THE FREQUENCY OF SAID EXTERNAL SYNCHRONIZING SIGNAL IRRESPECTIVE OF A VARIATION OF A LOAD APPLIED TO SAID MOTOR; SAID MOTOR COMPRISING PICK-UP COILS IN WHICH A VOLTAGE IS INDUCED BY THE ROTATION OF SAID PERMANENT MAGNET ROTOR, AND A COUPLING TRANSFORMER FOR IMPRESSING SAID EXTERNAL SYNCHRONIZING SIGNAL ON CONTROL TERMINALS OF SAID SWITCHING CIRCUIT, SAID PICK-UP COILS BEING CONNECTED IN SERIES WITH SECONDARY COILS OF SAID COUPLING TRANSFORMER.