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. 24, 2012
Filed:
Jul. 01, 2009
Peter Muerset, Milpitas, CA (US);
Peter Muerset, Milpitas, CA (US);
Tecan Trading AG, Mannedorf, CH;
Abstract
Method and corresponding apparatus for liquid level detection with a liquid level detection unit () with a capacitive liquid level detector () with a input capacitance (C) changing if the capacitive liquid level detector () contacts a liquid, the method comprising the steps of: generating a clock signal (CLK), with a predetermined on-time (t) corresponding to a predetermined sensitivity of the capacitive liquid level detector (), being fed both to a reference generator () and to the capacitive liquid level detector (); said reference generator () generating a control value (CV), derived from an on/off ratio of said clock signal (CLK) and feeding it into a control input () of a comparator (); feeding a liquid detection response signal (RS), of said capacitive liquid level detector () in response to said clock signal (CLK), into a signal input () of the comparator (); said comparator () triggering an output signal at an output () when said liquid detection response signal (RS) exceeds a threshold value (TV) in response to a change of the input capacitance (C).