Freescale Semiconductor,inc.

Other

Philip J Sieh

Bradley C Stewart

Robert L Johnson

Bryce T Osoinach

William DeWitt McWhorter

Michael A Steffen

A liquid level sensor device () includes a liquid level sensor element (), a capacitance-to-voltage converter (), and a controller (). The liquid level sensor element () comprises (i) at least two sets of N conductive electrodes () and (ii) M sense lines (S-S), 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 () periodically measures a capacitance of the L sets of parallel coupled conductive electrodes for each of the M sense lines. The controller () 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 () 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.

Liquid level sensing device and method

'Electrical field ('E-field') sensor systems that sense displacement or change in displacement of one body relative to another.' In general, the bodiesare within an electrical field and displacement of a body causes a change in the E-field. A field sensordetects this change and a processortranslates it to a change in position of the displaced body. The E-fields are generated by electrodes (or an electrode and a ground member) that generate the E-field. The systems include detectorsthat detect changes in the E-field, such as capacitance, and transmit these to the processor

Electric field reciprocal displacement sensors

The present disclosure provides several systems. In general, it provides E-field sensor systems that utilize at least one electrodeadapted for creating an E-field in an areawithin a detection volume where fluid presenceor presence of a solid bodyis to be detected. The electrical field sensor is configured to generate a detected signal responsive to a change in capacitance of the electric field, and is communicatively coupled to the electrode. In addition, a processoris configured to determine a quantitative measure of a fluid or solid body within the detection volume in accordance with a capacitive relationship with the detection volume. Described are examples of the system for fluid presence detection, fluid level measurement and measurement of proximity to a solid object.

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Chandler, AZ, United States of America

Philip J Sieh