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:
Jul. 08, 1997
Filed:
Aug. 31, 1995
George Codina, North Hollywood, CA (US);
Chandrasekar Ramamoorthy, Normal, IL (US);
Donna J Murr, Dunlap, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
An apparatus for sensing two parameters of a hydraulic system having a hydraulic line includes a pair of electrodes contained within the line and oppositely spaced, forming a capacitor. The apparatus alternately produces first and second charging currents having first and second constant magnitudes, respectively, and charges the capacitor to respective first and second predetermined voltages. The apparatus detects the time needed to charge to the first and second predetermined voltages and produces a pulse width modulated signal having a series of alternating first and second pulses. The first and second pulses are indicative of the first and second parameters, respectively. The first pulse is defined by the time required to charge the capacitor to the first predetermined voltage. The second pulse is defined by the time required to charge the capacitor to the second predetermined voltage. The apparatus determines the two parameters as a function of the pulse width modulated signal.