Wireless swimming pool water level system
First Claim
1. A capacitive sensor for determining liquid level, comprising:
- a surface adjacent which the liquid is present, and on which the fluid defines a level;
a reference electrode at a lower part of the surface;
a first sensor electrode arranged above the reference electrode at the surface; and
a second sensor electrode arranged at least in part above the first sensor electrode and at the surface;
wherein each of the first and second sensor electrodes has a greater area at the surface than does the reference electrode.
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Accused Products
Abstract
A wireless (e.g., radio) system and method for automatic water level maintenance of, e.g., a swimming pool utilizing capacitive liquid level sensing. A reference electrode allows water level sensing independent of the water chemistry or temperature. Capacitive electrodes having areas larger than the reference electrode sense various liquid levels when the liquid covers an area of any sensing electrode equal to the area of the reference electrode. Averaging is incorporated to filter out effects of wind or other disturbances. Upon sensing a given condition, the transmitter transmits a sensed condition to a remote receiver for control of valves and pumps for changing the water level in the pool. The receiver includes safety timers for filling and emptying to protect against equipment failure or communications faults. User selectable identification allows identical such radio systems to operate within proximity to each other. Power saving features are used to extend battery life.
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Citations
20 Claims
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1. A capacitive sensor for determining liquid level, comprising:
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a surface adjacent which the liquid is present, and on which the fluid defines a level;
a reference electrode at a lower part of the surface;
a first sensor electrode arranged above the reference electrode at the surface; and
a second sensor electrode arranged at least in part above the first sensor electrode and at the surface;
wherein each of the first and second sensor electrodes has a greater area at the surface than does the reference electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of determining a level of a liquid, comprising the acts of:
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capacitively sensing a reference level of the liquid;
capacitively sensing a first level of the liquid higher than the reference level;
capacitively sensing a second level of the liquid higher than the first level; and
wherein a sensed electrical capacitance at the first and second levels is greater than at the reference level. - View Dependent Claims (14)
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15. A method of sensing a level of water in a swimming pool, comprising the acts of:
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locating a sensor in the swimming pool;
capacitively sensing, using the sensor, a level of the water in the swimming pool; and
transmitting by a wireless link the sensed level to a receiver. - View Dependent Claims (16)
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17. A method of causing an action in a device having a housing, the device having an internal magnetic switch, comprising the acts of:
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at least partially immersing the device in a liquid;
holding a magnet external to the housing in proximity to the switch, thereby activating the switch; and
causing the action in the device by activation of the switch. - View Dependent Claims (18, 19, 20)
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Specification