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:
Nov. 26, 2002
Filed:
Jun. 13, 2000
Dennis Keith Mull, Concord, OH (US);
The North American Manufacturing Company, Cleveland, OH (US);
Abstract
A capacitance measuring circuit having a sensor electrode and a reference electrode that are spaced apart so that a material can be positioned between the two electrodes. A first polarity and a second polarity voltage source are used to charge the sensor electrode and a switch controller controls the charging and discharging of a capacitor by the sensor electrode. The charge on the capacitor after being charged and at least partially discharged by the sensor electrode represents the capacitance between the sensor electrode and the reference electrode. The charge on the capacitor is used to measure the position of the material relative to the sensor and reference electrode. The measuring circuit also has a system parasitic controller to measure and adjust for system parasitic capacitance in the measuring circuit.