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:
Jul. 21, 1987
Filed:
Oct. 11, 1985
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02P / ;
U.S. Cl.
CPC ...
318808 ; 318812 ; 307313 ; 307315 ;
Abstract
A motor driving circuit includes an equivalent power PNP transistor constituted by a Darlington connection of a small-current PNP transistor and a large-current NPN transistor, and a switching regulator of a step-down and variable type is provided between the collector of the NPN transistor and the emitter of the PNP transistor. Electric power loss in the motor driving circuit can be reduced, and the electric power required to operate the motor driving circuit can be saved.