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:
Oct. 26, 1976
Filed:
Apr. 09, 1975
Kabushiki Kaisha Suwa Seikosha, Tokyo, JA;
Shinshu Seiki Kabushiki Kaisha, BOTH OF, JA;
Abstract
A brushless motor drive circuit including at least one hall effect element and a drive transistor circuit adapted to produce a signal to energize at least two drive coils, which coils operate to drive the brushless motor. The amplitude of the signal applied to said drive coils is determined by the current supplied to the drive transistor circuit. A control circuit is provided for controlling said supplied current in response to the speed of the motor. The control circuit includes a single transistor coupled to said drive transistor circuit, the series connection of a constant voltage produced by a voltage limiting device and a voltage representative of motor speed being coupled to the base of the transistor to bias the control transistor to maintain a constant motor speed.