Solid state fluid level sensor
First Claim
1. A fluid level sensor apparatus for detecting a moving fluid level and capable of activating a controlled device, said fluid level sensor apparatus comprising:
- a fluid-proof barrier of substantially uniform thickness having first and second opposite surfaces, wherein said first barrier surface is exposed to the fluid;
a dielectric substrate of substantially uniform thickness having first and second opposite surfaces, wherein said substrate is proximate said barrier second surface;
a first thin, conductive electrode pad disposed on said substrate in a closed, continuous geometric form having an area which affords substantial coverage by fluid contact with said barrier;
a second thin, conductive electrode disposed on said substrate in a spaced, coplanar and substantially surrounding relationship to said first electrode pad; and
an active electrical component disposed on said substrate proximate said first and second electrodes and electrically coupled to said first and second electrodes, such that fluid contact with said barrier activates the controlled device.
3 Assignments
0 Petitions
Accused Products
Abstract
A sensor system for sensing liquid level in a bilge, for use in automatic bilge pump actuation. First and second field effect sensors are potted or sealed within a container or the bilge wall and are aligned in a vertical array and each comprise a substantially planar pattern of “electrodes” or conductive traces disposed on a printed circuit board (PCB) along with integrated circuits used to create a loop or arc-shaped electric field. As bilge liquid rises to the proximity or level of the field effect sensors, a change in the arc-shaped electric field is sensed and, in response, a bilge pump is automatically actuated to pump liquid out of the bilge. Optionally, the pump control can be programmed by use of a microprocessor to permit control of on-off timing and prevent undesirable effects of “sloshing.”
31 Citations
30 Claims
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1. A fluid level sensor apparatus for detecting a moving fluid level and capable of activating a controlled device, said fluid level sensor apparatus comprising:
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a fluid-proof barrier of substantially uniform thickness having first and second opposite surfaces, wherein said first barrier surface is exposed to the fluid;
a dielectric substrate of substantially uniform thickness having first and second opposite surfaces, wherein said substrate is proximate said barrier second surface;
a first thin, conductive electrode pad disposed on said substrate in a closed, continuous geometric form having an area which affords substantial coverage by fluid contact with said barrier;
a second thin, conductive electrode disposed on said substrate in a spaced, coplanar and substantially surrounding relationship to said first electrode pad; and
an active electrical component disposed on said substrate proximate said first and second electrodes and electrically coupled to said first and second electrodes, such that fluid contact with said barrier activates the controlled device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A low impedance fluid level sensor apparatus for detecting contact by a fluid and capable of activating a controlled device, said fluid level sensor apparatus comprising:
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a dielectric carrier;
a first thin, conductive electrode pad disposed on said carrier in a closed, continuous geometric form having an area which affords substantial coverage by a region of fluid contact;
a second thin, conductive electrode disposed on said carrier in a spaced and substantially surrounding relationship to said first electrode;
an active electrical component disposed on said carrier proximate said first and second electrodes and electrically coupled to said first and second electrodes; and
a dielectric substrate having first and second opposite surfaces, said dielectric carrier disposed on said first surface of said dielectric substrate, such that fluid contact of said substrate activates the controlled device. - View Dependent Claims (14)
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15. A low impedance fluid proximity sensor apparatus for detecting fluid contact and capable of activating a controlled device, said fluid proximity sensor apparatus comprising:
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a dielectric substrate having first and second opposite surfaces;
a first thin, conductive electrode pad disposed on said substrate in a closed, continuous geometric form having an area which affords substantial coverage by an area of fluid contact;
a second thin, conductive electrode disposed on said substrate in a spaced, coplanar and substantially surrounding relationship to said first electrode pad; and
an active device disposed on said first surface of said substrate proximate said first and second electrodes and electrically coupled to said first and second electrodes, such that fluid contact with said substrate activates the controlled device. - View Dependent Claims (16, 17, 18, 19)
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20. A plurality of fluid sensing pads for detecting fluid contact and capable of activating a controlled device, each fluid sensing pad comprising:
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a dielectric carrier;
a first thin, conductive electrode pad having a peripheral edge and disposed on said carrier in a closed, continuous geometric form having an area which affords substantial coverage by a fluid contact area;
a second thin, conductive electrode disposed on said carrier in a spaced relationship to said first electrode, said second electrode surrounding said first electrode on peripheral edges having an adjacent fluid sensing pad; and
a dielectric substrate having first and second opposite surfaces, said carrier disposed on said first surface of said substrate, such that fluid contact with said substrate activates the controlled device.
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21. A fluid proximity sensor for detecting a moving fluid and capable of generating a fluid presence detected signal or activating a controlled device, said fluid proximity sensor apparatus comprising:
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a fluid-proof dielectric substrate of substantially uniform thickness having first and second opposite surfaces;
a first thin, conductive electrode pad disposed on said first surface of said substrate in a closed, continuous geometric form having an area which affords substantial coverage by fluid contact with said substrate second surface;
a second thin, conductive electrode disposed on said first surface of said substrate in a spaced, coplanar and substantially surrounding relationship to said first electrode pad; and
an active electrical component disposed on said substrate proximate said first and second electrodes and electrically coupled to said first and second electrodes, such that fluid contact with said substrate second surface activates the controlled device. - View Dependent Claims (22, 23, 24, 25)
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26. A method of operating a bilge pump, comprising the steps of:
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a) positioning within a bilge a sealed housing having therein at least a first field effect sensor;
b)generating an electromagnetic field with the sensor; and
c) sensing the presence of fluid proximate the sensor by detecting variations in the electromagnetic field. - View Dependent Claims (27, 28, 29, 30)
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Specification