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. 30, 1995
Filed:
Apr. 09, 1993
Malcolm P Varnham, Plymouth, GB;
Huw D Thomas, Plymouth, GB;
British Aerospace Public Limited Company, Hampshire, GB;
Abstract
A single axis rate sensor comprising a cylinder positioned about an axis and having primary and secondary drive and pick-off transducers and primary and secondary control loops. The primary control loop is provided for maintaining resonance of the cylinder by generating a ninety-degree phase shift between the primary drive transducer and the primary pick-off transducer. The secondary control loop is provided for receiving a signal from the secondary pick-off transducer indicative of rotation of the cylinder and for nulling the secondary drive transducer to zero. The primary control loop includes a phase-locked loop having a phase detector configured to operate at quadrature. By operating the demodulator in quadrature the demodulator and loop filter combination are a linear device which will not mix the microphonic baseband signal with the carrier. There will therefore be a reduction and possibly an elimination of the modulation of the voltage controlled oscillator by microphonic noise.