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:
May. 28, 1991
Filed:
Mar. 02, 1990
Fuji Jukogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
There are disclosed a device and method for saving power supply of a steering sensor for a vehicle having a conventional circuit for detecting a steering angle and a supplementary circuit for detecting an amount of steering angle change when an ignition switch is turned off. The conventional circuit comprises a rotary encoder for generating two signals of sine waveform-like having a phase discrepancy of 90 degrees responsive to a rotation of a steering shaft, and a microcomputer for calculating an absolute angle from the sine waveform-like signals. The supplementary circuit comprises a waveform shaping circuit for converting the sine signals into two rectangular wave pulse signals. While the switch is turned on, the circuit continues to detect the absolute angle based on the sine waves. When the switch is turned off, the supplementary circuit counts and hold the change amount of the angle as the pulse signals while the circuit maintains the storage of the last absolute angle. The microcomputer reads numbers of the pulse signals to set the initial absolute angle and to start operation for detecting the absolute angle.