The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 04, 1981
Filed:
Mar. 24, 1980
Mitsuo Uzuka, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A brushless DC motor includes a rotor adapted to rotate about an axis and having a plurality of magnets for generating a magnetic flux; a stator having at least two coils through which an alternating signal is applied for rotating the rotor about its axis; and a reversible drive circuit for regulating the alternating signal through the coils and which includes first and second switching transistors for energizing the coils with the alternating signal, a rotational position sensing circuit for generating a position signal corresponding to the rotational position of the rotor, a rotational direction selecting circuit for producing a control signal corresponding to a desired rotational direction of the rotor, an NPN switch control transistor responsive to the position signal and control signal for alternately switching the first and second switching transistors so as to rotate the rotor in the forward direction, and a PNP switch control transistor in parallel with the NPN switch control transistor and responsive to the position signal, the control signal and an output from the NPN switch control transistor for alternately switching the first and second switching transistors so as to rotate the rotor in the reverse direction.