Water sensor system

• US 5,428,347 A
• Filed: 01/12/1993
• Issued: 06/27/1995
• Est. Priority Date: 01/12/1993
• Status: Expired due to Fees

• Current Assignee: Leakgard, Inc.
• Original Assignee: Leakgard, Inc.
• Inventors: Barron, Robert C.
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Lefkowitz, Edward
• Application Number:
  US08/003,139
• Time in Patent Office: 896 Days
• Field of Search: 340/604, 340/605, 340/618, 340/620, 200/61.04
• US Class Current: 340/604
• CPC Class Codes: G01F 23/243 Schematic arrangements of probes combined with measuring circuits
• CPC Class Codes: G01M 3/16 using electric detection means G01M3/045, G01M3/06, G01M3/12, G01M3/20, G01M3/24, G01M3/26 take precedence
• CPC Class Codes: G08B 25/14 Central alarm receiver or annunciator arrangements

Abstract

An improved water sensor unit wherein a plurality of water-related appliances or equipment can be simultaneously monitored and, in the event of sensing water with respect to any one of the several items being monitored, appropriate action is taken, such as shutting off the power to the unit and simultaneously shutting off the water supply to that particular unit. The sensor unit comprises a plurality of electronic circuits which include thermal circuit breakers acting as a "fault memory." When a fault occurs, the circuit breakers are tripped. Thus, the fault condition will be "remembered" indefinitely until human intervention.

Claims

1. A water detector system for the detection of standing water indicative of an abnormal condition in a building or other habitable structure, said system comprising:

(a) a power circuit having an input to be connected to a source of alternating current, and an output to which is connected an electrical appliance to be protected, said power circuit having at least two electrically conducting leads, said electrically conducting leads connected at one end to said input, and at their respective other ends to said output, said electrical appliance receiving its electrical power through said leads of said power circuit;

(b) a lower circuit board connected to said power circuit comprising

(i) means for interrupting the electrical circuit between said input and said output of said power circuit when a fault is detected by said system thus disconnecting the electrical appliance from the source of alternating current;

(ii) means for controlling said means for interrupting;

(iii) means for electrically isolating said means for interrupting from said means for controlling;

(iv) means for sounding an alarm in response to conditions that would engage said means for interrupting;

(c) an upper circuit board comprising

(i) means for connecting said upper circuit board to said lower circuit board, said means for connecting electrically isolating said upper circuit board from said lower circuit board;

(ii) means for initiating alarm signals responsive to the detection of standing water, said alarm signals being passed to said means for sounding an alarm on said lower circuit board through said means for connecting said upper circuit board to said lower circuit board;

(iii) means for initiating control signals responsive to the detection of standing water, said control signals being passed to said means for controlling said means for interrupting through said means for connecting said upper circuit board to said lower circuit board;

(iv) means for passing said control signals from said upper circuit board to external control devices, whereby the external control devices, in response to said control signals, perform functions responsive to the detection of standing water, including disconnecting said electrical appliance from said source of alternating current;

(d) means for sensing water connected to said upper circuit board for generating water detection signals for initiating said alarm signals and said control signals;

(e) means for preventing said electrical appliance from reconnecting to said source of alternating current until said means for preventing is manually reset thus resetting said means for interrupting; and

(f) means for initiating alarm signals and control signals in response to a blown fuse.

2. A water detector system as claimed in claim 1, wherein said means for interrupting the electrical circuit between said input and said output of said power circuit includes a triac switch means connected between said input and said output, said triac switch means controlled by said means for controlling said means for interrupting.

3. A water detector system as claimed in claim 1, wherein said means for electrically isolating said means for interrupting from said means for controlling includes light emitting diodes and associated photo transistors placed between said power circuit and said means for controlling said means for interrupting.

4. A water detector system as claimed in claim 1, in which said means for sensing water include:

(a) means for converting alternating current provided from said means for electrically isolating to direct current;

(b) means for providing a continuous electrical current path only in the presence of standing water, whereby said standing water becomes an integral, electrically conducting element of said continuous electrical current path, said standing water thereby electrically completing said continuous electrical current path; and

(c) means for communicating the presence of said continuous electrical current path to each of said means for initiating alarm signals and control signals.

5. A water detector system as claimed in claim 4, in which said means for providing a continuous electrical current patch includes two spaced apart water probes;

wherein said means for converting alternating current to direct current includes a full wave diode rectifier positioned across the drain and source of a field effect transistor, said full wave diode rectifier electrically connected to said means for electrically isolating; and

wherein said means for providing a continuous electrical current path also includes two resistors operating as a voltage divider biasing the gate of said field effect transistor, causing said field effect transistor to conduct electrical current from said drain to said source in the absence of water between said water probes, each of said water probes respectively electrically connected to each side of said resistor positioned between said gate and said source of said field effect transistor so that an electrical circuit containing said water probes is in parallel with said resistor positioned between said gate and said source, whereby the presence of water between said water probes dissipates the bias of said gate of said field effect transistor, thereby shutting off said field effect transistor, whereby in the presence of water between said water probes, the only electrical current flowing through said water sensor flows through said resistor positioned between said drain and said gate and through said water probes and the water therebetween, which electrical current flows in a reduced amount in comparison to the electrical current flowing through said water sensor means in the absence of water between said water probes.

6. A water detector system as claimed in claim 5, wherein said means for communicating the presence of said continuous electrical current path to said means for initiating alarm signals and control signals includes means for detecting the reduction in electrical current flowing through said water sensors in response to water present between said water probes.

7. A water detector system as claimed in claim 2, which includes means for sensing a ground fault in said power circuit or said electrical appliance and activating said means for interrupting the electrical circuit between said input and said output of said power circuit, thereby disconnecting said protected appliance from said source of alternating current.

8. A water detector system as claimed in claim 1, wherein said means for preventing is a circuit breaker.

9. A water detector system for the detection of standing water indicative of an abnormal condition in a building or other habitable structure, said system comprising:

(a) a power circuit having an input connected to a source of alternating current and an output to which is connected an electrical appliance to be protected, said power circuit having at least two electrically conducting leads, said electrically conducting leads connected at one end to said input, and at their respective other ends to said output, said electrical appliance receiving its electrical power through said leads of said power circuit, said power circuit having a triac switch means connected to each of said electrically conducting leads, whereby the flow of electrical current through said electrically conducting leads is controlled by the operation of said triac switch means;

(b) a lower circuit board connected to said triac switch means and said output, said lower circuit board including optical isolator control means for controlling each of said triac switch means, a low voltage power supply connected between said electrically conducting leads of said power circuit, an alarm enable circuit, said alarm enable circuit including optical isolator control means for controlling said alarm enable circuit and for electrically isolating said alarm circuit from said power circuit;

(c) an upper circuit board powered by said low voltage power supply on said lower circuit board, said upper circuit board including a plurality of water sensors and associated circuitry for detecting standing water and generating a control signal at said sensors, whereby said control signal enables said alarm circuit, activates said alarm circuit optical isolator means, causes a circuit breaker connected to said alarm circuit optical isolator means to blow, whereby when said circuit breaker blows, it causes said triac switch means to discontinue the flow of electrical current through said leads, thereby protecting said electrical appliance from electrically-related damage and alerting persons near said electrically protected device to the presence of the standing water condition, whereby when said circuit breaker blows the electrical appliance is disconnected from the source of alternating current until said circuit breaker is manually reset thus resetting said triac switch means; and

(d) means for initiating alarm signals and control signals in response to a blown fuse.

10. A water detector system as claimed in claim 9, further comprising means for disconnecting the water supply to said electrical appliance in response to said control signal.

11. A water detector system as claimed in claim 9, which includes means for sensing a ground fault in said power circuit or said electrical appliance and initiating a control signal which causes said triac switch means to electrically disconnect said appliance from said source of alternating current.

12. A water detector system as claimed in claim 11, in which, once a ground fault has been sensed and alarm and control action has been taken, normal operation of said water detector system may not be restored except by manual resetting of the control circuits involved.

13. A water detector and cutoff system for detecting the presence of moisture in the immediate vicinity of a water consuming appliance and cutting off the supply of power and water thereto, said system comprising:

(a) a power circuit having an input to be connected to a source of alternating current, and an output to which is connected an electrical appliance to be protected, said power circuit having at least two electrically conducting leads, said electrically conducting leads connected at one end to said input, and at their respective other ends to said output, said electrical appliance receiving its electrical power through said leads of said power circuit;

(b) a lower circuit board connected to said power circuit comprising

(i) means for interrupting the electrical circuit between said input and said output of said power circuit when a fault is detected by said system thus disconnecting the electrical appliance from the source of alternating current;

(ii) means for controlling said means for interrupting;

(iii) means for electrically isolating said means for interrupting from said means for controlling; and

(iv) means for sounding an alarm in response to conditions that would engage said means for interrupting;

(c) an upper circuit board comprising

(i) means for connecting said upper circuit board to said lower circuit board, said means for connecting electrically isolating said upper circuit board from said lower circuit board;

(ii) means for initiating alarm signals responsive to the presence of moisture, said alarm signals being passed to said means for sounding an alarm on said lower circuit board through said means for connecting said upper circuit board to said lower circuit board;

(iii) means for initiating control signals responsive to the presence of moisture, said control signals being passed to said means for controlling said means for interrupting through said means for connecting said upper circuit board to said lower circuit board;

(iv) means for passing said control signals from said upper circuit board to external control devices, whereby the external control devices, in response to said control signals, perform functions responsive to the presence of moisture, including the closing of a solenoid to shut off a water supply; and

(v) means for turning off the supply of water to the appliance in response to said control signals;

(d) a plurality of water sensors connected to said upper circuit board for generating water defection signals for initiating said alarm signals and said control signals;

(e) means for preventing said electrical appliance from reconnecting to said source of alternating current until said means for preventing is manually reset thus resetting said means for interrupting; and

(f) means for initiating alarm signals and control signals in response to a blown fuse.

14. A water detector and cutoff system as claimed in claim 13, wherein said means for controlling said means for interrupting includes isolating means for electrically isolating said means for interrupting from said means for controlling for protection of personnel from said source of alternating current.

15. A water detector and cutoff system as claimed in claim 13, wherein the connection to said lower circuit board for passing alarm signals and control signals initiated on said upper circuit board is through said isolating means.

16. A water detector and cutoff system as claimed in claim 13, wherein said water detection signal activates an audible alarm.

17. A water detector and cutoff system as claimed in claim 13, wherein said water detection signal activates an audible and visual alarm.

18. A water detector and cutoff system as claimed in claim 13, wherein said means for preventing is a circuit breaker.

19. A water detection device for turning off the supply of water to a water consuming appliance comprising:

means for sensing water, said means for sensing water electrically connected between a transformer and a solenoid valve, said means for sensing water including two spaced apart water probes, a full wave diode rectifier positioned across the drain and source of a field effect transistor, said full wave diode rectifier electrically connected between said transformer and said solenoid valve, wherein said means for sensing water also includes two resistors positioned so as to bias the gate of said field effect transistor between the drain and gate of said field effect transistor, to turn on said field effect transistor in the event of the presence of water between said water probes, said water probes electrically connected in series with said resistor, positioned between said gate and said drain, said water probes and the water therebetween being integral electrically conducting elements of the circuit between said gate and said drain of said field effect transistor, said means for sensing water further including a circuit breaker, said circuit breaker electrically connected between said transformer and said solenoid valve, and a resistor electrically connected between said circuit breaker and said rectifier, whereby the sensing of water by said probes closes the drain to gate connection, causing said field effect transistor to turn on, thereby shorting out said full wave diode rectifier, causing said circuit breaker to blow whereby when said circuit breaker blows electrical communication between said transformer and said solenoid valve is disconnected thus cutting off the supply of water to the water consuming appliance until said circuit breaker is manually reset, said means for sensing water acting as a normally open switch.