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:
Dec. 01, 1987
Filed:
Oct. 12, 1984
Nippon Kogaku K.K., Tokyo, JP;
Abstract
A drive circuit for a brushless DC motor capable of generating a torque in the acceleration and deceleration directions, respectively, and effective when used in a portable device such as an electronic still picture camera. In the drive circuit, a power amplifier having an output stage composed of a pair of complementarily connected tansistors is connected to each end of each of the stator coils. Thus, the drive circuit controls the input potentials of the power amplifiers so as to produce a potential difference across the terminals of each of the stator coils and thereby control the magnitude and direction of current flow through the stator coils. Also, all the transistors of the power amplifier output stages are cut off to prevent the flow of current through the stator coils.