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. 26, 1986
Filed:
Apr. 29, 1985
Nobuyoshi Yokobori, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
An output circuit to drive a current into a load. Collector voltage of a current controlling transistor is automatically adjusted to maintain h.sub.FE of the transistor constant, whereby saturation of the transistor and excessive power consumption are avoided. A brushless motor using the output circuit. Current detectors detect emitter current and base current of output transistors and h.sub.FE of the transistors are kept constant, whereby excessive torque loss and harmful vibration are avoided. A limiter limits excessive torque control to prevent power transistor saturation. A switching mode power supply adjusts the collector voltage of the transistor in a feedback loop to keep h.sub.FE constant.