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. 22, 2008
Filed:
May. 05, 2006
Augustin Braun, Karlsdorf-Neuthard, DE;
Friedrich Bohnmüller, Karlsruhe, DE;
Augustin Braun, Karlsdorf-Neuthard, DE;
Friedrich Bohnmüller, Karlsruhe, DE;
acam-messelectronic GmbH, Stutensee-Blankenloch, DE;
Abstract
For measuring unknown capacitances, which exist in capacitive sensors, such as pressure, moisture, inclination sensors and the like, the invention proposes a capacitance measurement method, in which a capacitance to be measured is charged and discharged across a resistor and the charging or discharging time up to a preset voltage value is measured and in which the charging/discharging times of a known reference capacitance and stray capacitances are measured across a resistor. The invention also proposes a circuit for measuring an unknown capacitance to be measured and having a voltage source, a resistor for charging or discharging at least the measuring capacitor, at least one switch for connecting and disconnecting the measuring capacitor with respect to the voltage supply and a time measuring device, in which switches are provided for connecting and disconnecting the measuring capacitor and at least one reference capacitor with respect to the circuit.