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:
Dec. 25, 2012
Filed:
Nov. 16, 2009
Calvin Cox, West Yorkshire, GB;
Thomas W. Bach, Brighton, GB;
Calvin Cox, West Yorkshire, GB;
Thomas W. Bach, Brighton, GB;
Cummins Turbo Technologies Limited, Huddersfield, GB;
Abstract
A speed sensor for use in measuring the speed of rotation of a rotationally salient rotating member The speed sensor comprises an electrode and a sensor circuit. The sensor circuit comprises a constant voltage source for supplying a voltage to the electrode to generate an electric field in a dielectric medium. A current detector detects current flow between the constant voltage source and the electrode due to perturbation of the electric field by passage of at least one salient feature of the rotating member through the electric field as the rotating member rotates. The current detector outputs a first signal modulated at a frequency corresponding to the frequency of perturbation of the electric field. The first signal is amplified to produce an amplified signal modulated at a frequency corresponding to the frequency of perturbation of the electric field. The electrode voltage, the amplifier gain and the electrode position relative to the rotating member are selected such that modulation of the second signal is predominantly caused by perturbation of the electric field within the dielectric medium by the creation and/or movement of ions within the field.