Charge transfer capacitance sensing and control system for an integrated venting system

• US 6,367,092 B2
• Filed: 04/04/2001
• Issued: 04/09/2002
• Est. Priority Date: 04/07/2000
• Status: Expired due to Fees

• Current Assignee: Casey Cardwell, Cory Cardwell, Troy Cardwell
• Original Assignee: Casey Cardwell, Cory Cardwell, Troy Cardwell
• Inventors: Cardwell, Troy, Cardwell, Casey, Cardwell, Cory
• Primary Examiner(s): Eloshway, Charles R.
• Application Number:
  US09/827,039
• Publication Number:
  US 20010034899A1
• Time in Patent Office: 370 Days
• Field of Search: 421/3, 421/6, 462/3, 421/7
• US Class Current: 4/216
• CPC Class Codes: E03D 9/05 ventilating the bowl

Abstract

A capacitance charge transfer sensing and control system for a venting system. Preferably the sensing and control system is used with a toilet having an integrated venting system which includes ducting communicating with an exhaust air passageway located in the toilet bowl and an exhaust fan to draw air from the bowl and exhaust it outside. A sensing electrode, such as a wire antenna, is located in a covered location adjacent the toilet bowl, preferably in the exhaust air passageway located in the bowl of an integrated toilet venting system. The wire antenna is connected to a detection and motor control circuit which can detect a change in capacitance of the wire antenna upon a person entering into close proximity thereto. A micro-controller in the detection and motor control circuit is programmed to generate a circuit closing signal to an electric switch located in the circuit between a power source and the exhaust fan in response to a minimum pre-selected increase in the capacitance of the wire antenna. The micro-controller is programmed to open the circuit between the power source and the exhaust fan when there is a pre-selected decrease in the capacitance of the wire antenna and a pre-selected period of time has elapsed after such decrease.

Claims

1. A toilet having a base, a bowl having an interior and a rim, and an air exhaust system for removing air from the interior of said bowl and exhausting it in a region remote from said bowl, said air exhaust system including an air exhaust duct integral with said bowl and extending around said rim of said bowl, said air exhaust duct having an interior in communication with the interior of said bowl, ductwork communicating said air exhaust duct and said region remote from said bowl, and an electric exhaust fan motor connected to a power source through an exhaust fan motor switch, said exhaust fan motor adapted to drive an exhaust fan in communication with said ductwork;

a sensing electrode located within the interior of said exhaust air duct of said bowl; and

a detection and exhaust fan motor control circuit in electrical communication with said exhaust fan switch and with said sensing electrode, said detection and motor control circuit adapted to charge said sensing electrode and to detect changes in the capacitance of said sensing electrode;

said detection and exhaust fan motor control circuit adapted to generate an actuating signal to said exhaust fan motor switch upon detection that the capacitance of said sensing electrode has increased to a minimum triggering level, thereby opening electrical communication between said power source and said electric exhaust fan motor;

said detection and exhaust fan motor control circuit adapted to terminate said actuating signal to said fan motor switch to thereby terminate electrical communication between said power source and said electric exhaust fan motor when said minimum triggering level of capacitance of said sensing electrode is not present.

2. The device of claim 1 wherein said sensing electrode is a conductive, non-magnetic wire antenna.

3. The device of claim 2 wherein said sensing electrode is copper wire.

4. The device of claim 1 wherein said sensing electrode extends partially around the interior of said exhaust air duct.

5. The device of claim 1 wherein said power source is a DC power source.

6. A toilet having a base, a bowl having a rim, and an air exhaust system for removing air from the vicinity of said bowl and exhausting it in a region remote from said bowl, said air exhaust system including an air exhaust duct integral with said bowl and extending around said rim of said bowl, said air exhaust duct having an interior in communication with the interior of said bowl, ductwork communicating said air exhaust duct and said region remote from said bowl, and an electric exhaust fan motor connected to a power source through an exhaust fan motor switch, said exhaust fan motor adapted to drive an exhaust fan in communication with said ductwork;

a sensing electrode located within the interior of said exhaust air duct of said bowl; and

a detection and exhaust fan motor control circuit in electrical communication with said exhaust fan switch and with said sensing electrode, said detection and motor control circuit adapted to charge said sensing electrode and to detect changes in the capacitance of said sensing electrode;

said detection and exhaust fan motor control circuit adapted to generate an actuating signal to said exhaust fan motor switch upon detection that the capacitance of said sensing electrode has increased to a minimum triggering level and has remained at said minimum triggering level for a fixed period of time, thereby opening electrical communication between said power source and said electric exhaust fan motor;

said detection and exhaust fan motor control circuit adapted to terminate electrical communication between said power source and said electric exhaust fan motor when said minimum triggering level of capacitance of said sensing electrode is not detected for a fixed period of time.

7. The device of claim 6 wherein said minimum triggering level of capacitance is set to correspond to user content with said toilet.

8. The device of claim 6 wherein said sensing electrode is a conductive, non-magnetic wire antenna.

9. The device of claim 6 wherein said sensing electrode is copper wire.

10. The device of claim 6, wherein said sensing electrode extends partially around the interior of said exhaust air duct.

11. The device of claim 6 wherein said power source is a DC power source.

12. The method of operating an integrated exhaust system for a toilet wherein said toilet includes a bowl having a rim, and an air exhaust system for removing air from the vicinity of said bowl and exhausting it in a region remote from said bowl, said air exhaust system including an air exhaust duct integral with said bowl and extending around said rim of said bowl, said air exhaust duct having an interior in communication with the interior of said bowl, ductwork communicating said air exhaust duct and said region remote from said bowl, and an electric exhaust fan motor connected to a power source through an exhaust fan motor switch, said exhaust fan motor adapted to drive an exhaust fan in communication with said ductwork, the steps comprising:

locating a sensing electrode within the interior of said exhaust air duct of said bowl;

locating a charge transfer sensing integrated circuit in electrical communication with said sensing electrode;

locating a micro-controller integrated circuit in electrical communication with said charge transfer sensing integrated circuit and with said power source and said switch means;

causing said micro-controller to send a setup null command to said charge sensing integrated circuit;

causing said micro-controller to send a command to said charge sensing integrated circuit to set the detection sensitivity to a minimum triggering charge value level;

causing the micro-controller to periodically interrogate the charge sensing integrated circuit to determine the current charge value level;

causing a filter timer to be set for a fixed period of time upon said minimum triggering charge value level being detected by said micro-controller;

causing said micro-controller to generate a fan motor actuation signal upon expiration of said fixed period of time with the charge value remaining above the minimum triggering charge value level;

causing said micro-controller to send a null command to said charge sensing integrated circuit;

causing said micro-controller to send a command to said charge sensing integrated circuit to set the detection sensitivity to a system datum level charge value and setting a presence threshold charge value level that is less than said datum level charge value;

causing the micro-controller to periodically interrogate the charge sensing integrated circuit to determine the current charge detection value;

causing a filter timer to be set for a fixed period of time upon said threshold charge value level or lower charge level being detected by said micro-controller; and

causing said micro-controller to terminate the fan actuation signal upon expiration of said fixed period of time with the charge value remaining at or below said threshold charge value level.

13. The process of claim 12 in which said minimum triggering charge value level is set at a value that requires a user to come into contact with said toilet.