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:
Oct. 01, 1996
Filed:
Oct. 04, 1995
Yutaka Iguchi, Chita-gun, JP;
Kazuo Sato, Toyota, JP;
Toshihiro Kobayashi, Nagoya, JP;
Masayuki Sato, Nagoya, JP;
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
An electrical circuit for reliably starting the oscillation of an oscillator comprising a cylindrical piezoelectric body on which an exciting electrode, a feedback electrode which causes an oscillation, and an electrode for detecting an angular rate are mounted. The electrical circuit includes an exclusive OR gate for detecting a phase difference between an exciting voltage and a voltage developed at the feedback electrode, a circuit for integrating an output voltage from the gate and a band pass filter having its resonant frequency shifted in proportion to a voltage from the integrating circuit. The band pass filter is effective to provide an automatic adjustment of a phase difference of a voltage, which is actually fed back to the exciting electrode, with respect to a voltage developed at the feedback electrode. In this manner, if the natural frequency of the oscillator is offset from a reference value, it is assured that a phase difference between the exciting voltage and the voltage which is actually fed back to the exciting electrode be equal to 360.degree.. The electrical circuit also includes an oscillation starter circuit which increases the gain of a positive feedback loop including the filter for a given time interval immediately after the turn-on of the power.