Invention Grant
- Patent Title: Liquid level sensing device and method
- Patent Title (中): 液位感测装置及方法
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Application No.: US11966103Application Date: 2007-12-28
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Publication No.: US07802471B2Publication Date: 2010-09-28
- Inventor: Philip J. Sieh , Robert L. Johnson , Bryce T. Osoinach
- Applicant: Philip J. Sieh , Robert L. Johnson , Bryce T. Osoinach
- Agent Michael Balconi-Lamica; Ranjeev Singh
- Main IPC: G01F23/26
- IPC: G01F23/26

Abstract:
A liquid level sensor device (10) includes a liquid level sensor element (14), a capacitance-to-voltage converter (16), and a controller (18). The liquid level sensor element (14) comprises (i) at least two sets of N conductive electrodes (22) and (ii) M sense lines (S1-S7), where M is greater than or equal to N within each set of the at least two sets of conductive electrodes. Each of the M sense lines couples to select ones of the N conductive electrodes of the at least two sets of conductive electrodes to form a number of L sets of parallel coupled conductive electrodes, where L equals M. The capacitance-to-voltage converter (16) periodically measures a capacitance of the L sets of parallel coupled conductive electrodes for each of the M sense lines. The controller (18) establishes initial measured baseline capacitance values for each of the L sets of parallel coupled conductive electrodes and an initial liquid level height value. The controller (18) also detects transitions in the measured capacitance of the L sets of parallel coupled conductive electrodes. Responsive to the detected transitions corresponding to incremental changes in measured capacitance values, the controller updates the liquid level height value.
Public/Granted literature
- US20090165552A1 LIQUID LEVEL SENSING DEVICE AND METHOD Public/Granted day:2009-07-02
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