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:
Sep. 25, 1990
Filed:
Apr. 05, 1989
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An electric power steering device having a clutch 25 for connecting and disconnecting the motor 14 to and from the steering shaft is disclosed, the control circuit of which comprises, in addition to a microcomputer 3, an additional analog direction determiner circuit 17, and a first and a second logical circuit. The first logical circuit consists of a pair of AND gates 20A, 20B generates a final right or left direction signal supplied to the motor driver circuit. The second logical circuit consists of a pair of exclusive OR gates 21A, 21B and an AND gate 22 and supplies a deenergization signal to the clutch driver when the directions determined by the microcomputer and the analog direction determiner circuit disagree. The direction determiner circuit includes: a first comparator 31 which outputs a right direction signal when the output voltage of the torque sensor exceeds a first reference level; and a second comparator 32 which outputs a left direction signal when the output voltage of the torque sensor is below a second reference level which is lower than the first level. These reference voltages, selected at upper and lower ends of the non-sensitive region, may be obtained by a voltage divider.