Multi-mode waterflow detector with electronic timer

• US 6,275,160 B1
• Filed: 03/22/2000
• Issued: 08/14/2001
• Est. Priority Date: 04/13/1998
• Status: Expired due to Term

• Current Assignee: Pittway Corporation (Honeywell International Inc.)
• Original Assignee: Pittway Corporation (Honeywell International Inc.)
• Inventors: Ha, Simon
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Goins, Davetta W.
• Application Number:
  US09/532,913
• Time in Patent Office: 510 Days
• Field of Search: 340/606, 340/609, 340/615, 340/618, 340/506, 340/644, 738/617.7, 738/617.8, 200/181, 200/182, 200/186, 200/187, 200/190
• US Class Current: 340/606
• CPC Class Codes: G08B 29/16 Security signalling or alarm systems, e.g. redundant systems
• CPC Class Codes: G08B 29/185 Signal analysis techniques for reducing or preventing false alarms or for enhancing the reliability of the system

Abstract

A flow detector includes solid state delay circuitry coupled to a flow indicating device. In response to flow being indicated, the delay circuitry is enabled. After a preset delay interval, if flow is still being indicated, an output signal can be generated. The flow indicating device can be a two-state mechanical switch. A mode setting element can be used to configure the detector for different types of installations.

Claims

1. A multi-mode flow detection system comprising:

first and second power supplying terminals;

a first switching element with first and second states responsive to fluid flow to go from the first, no flow state, to the second, flow state;

a second, manually settable, switching element having third and forth sates connected in series with at least a portion of the first switching element;

a third switching element having fifth and sixth states, wherein a portion of the third element is coupled to one side of the second switching element wherein the first switching element is coupled to the other side thereof;

a control element coupled to the first and third switching elements whereby in response to the first switching element going from the first to the second state and remaining there for a pre-determined interval the third switching element goes from the fifth to the sixth state, whereupon a short circuit connects the two terminals, until flow ceases provided that the second switching element exhibits the third state.

2. A system as in claim 1 wherein the control element incorporates a digital circuit which establishes the predetermined time interval.

3. A system as in claim 1 wherein despite the third switching element going from the fifth to the sixth states, where the second switching element exhibits the fourth state, the two terminals exhibit a non-short circuit condition.

4. A system as in claim 3 wherein the third switching element includes an isolated, switchable, signal path and wherein that path exhibits a short circuit when the third switching element is in the sixth state.

5. A system as in claim 1 wherein the first switching element includes a double pole switch coupled in part between one terminal and the second switching element.

6. A system as in claim 1 wherein the third switching element includes a latching switch.

7. A system as in claim 6 wherein the control element includes first and second outputs wherein the outputs are coupled to the latching switch.

8. A system as in claim 7 wherein the control element generates a signal on one output to place the latching switch into one state and generates a different signal on another output to place the latching switch into a second, different state.

9. A system as in claim 6 wherein the control element includes a digital timer for establishing the predetermined interval.

10. A system as in claim 1 wherein the control element includes a programmed processor for establishing the predetermined interval.

11. A system as in claim 1 wherein the first switching element includes a double pole switch and the third includes a latching relay wherein one pole is coupled between one terminal and the latching relay and wherein another pole is coupled between the one terminal and the control element whereby as the first switching element goes from a no flow to a flow state the control element initiates the predetermined interval whereupon, when the interval terminates, the control element includes circuits for short circuiting the latching relay in response to the first switching element going to a flow state and staying therein for the predetermined interval.

12. A detector comprising:

a sensor of fluid flow;

a first switch having first and second states, coupled to the sensor;

a digital time delay establishing element, coupled to the first switch, wherein the element is activated each time the first switch goes from the first state to the second state in response to flow having been detected by the sensor and wherein the element generates an output after a selected delay, in response thereto;

a second switch having third and fourth states wherein the second switch goes from the third state to the fourth state in response to the output provided that the first switch is still in the second state; and

a mode setting switch element coupled in series with the second switch.

13. A detector as in claim 12 wherein the switches are coupled in series and wherein the second and fourth states correspond in each instance to a closed circuit.

14. A detector as in claim 12 wherein the delay establishing element comprises an electronic timer.

15. A detector as in claim 12 wherein in the absence of flow the first switch goes from the second state to the first state and thereupon resets the delay establishing element.

16. A detector as in claim 12 wherein the second switch incorporates a mechanical latch.

17. A detector as in claim 14 wherein the timer comprises a digital, programmable timer circuit.

18. A detector as in claim 16 wherein the second switch is forced to the third, open circuit, state on power up.

19. A detector as in claim 12 which includes a source of pulses coupled to the element.

20. A detector as in claim 19 wherein the element includes a solid state counter.

21. A detector as in claim 12 which includes first and second terminals and wherein when the first switch is in the second state and the second switch is in the fourth state, the terminals are short circuited.

22. A flow detector comprising:

a first switch element wherein the element exhibits at least an open circuit and a closed circuit state;

a multi-state latching switch element coupled in series with a portion of the first switch element;

a second element in series with the latching switch wherein the second element has an open circuit state and a closed circuit state;

a digital element for establishing a delay interval and with an output coupled to the latching element wherein in response to the first element changing state the digital element initiates the delay interval and in response to detecting an interval end, causes the latching element to enter a selected output state, provided, that the latching element will not enter the selected output state if during the delay interval the first element changes state again.

23. A flow detector as in claim 22 which included a flow responsive member coupled to the first element whereby the flow responsive member causes the first element to go from the open circuit state to the short circuit state in response to fluid flow.

24. A flow detector as in claim 22 wherein the first switch element comprises a double pole switch wherein one pole is coupled to at least the latching switch element and another pole is coupled to the digital element.

25. A flow detector as in claim 24 wherein if the first element changes state and initiates the delay interval, and changes state again during the delay interval, the digital element is, at least in part, reset.

26. A flow detector as in claim 24 wherein the latching switch element comprises a double pole, latching relay wherein one pole is coupled to the first switch.

27. A flow detector as in claim 22 wherein the second element is manually settable to a selected mode specifying state.

28. A flow detector as in claim 22 wherein the first switch element comprises at least one solid state switch.

29. A flow detector as in claim 22 wherein the latching switch element comprises at least one solid state switch.

30. A flow detector comprising:

a first switch element wherein the element exhibits at least first state and a second state;

a multi-state latching switch element coupled in series with a portion of the switch element;

a second element in series with the latching switch wherein the second element has a third state and a fourth state;

a digital timing element for establishing a delay interval and with an output coupled to the latching element wherein in response to the first element going from one state to another state the digital element initiates the delay interval and in response to detecting an interval end, causes the latching element to enter a selected state, provided, that the latching element will not enter the selected state, if during the delay interval, the first element again changes state.

31. A detector as in claim 30, wherein in response to applied power, the latching switch element is reset.

32. A detector as in claim 30 wherein in response to the first switch entering a selected state, the timing element is reset.

33. A detector comprising:

a sensor of fluid flow;

a first switch having first and second states, coupled to the sensor, wherein when in the second state, the first switch exhibits a low electrical impedance;

an electronic time interval establishing circuit coupled to the first switch, wherein the circuit is activated to establish a predetermined delay interval each time the first switch goes from the first sate to the second state in response to flow having been detected by the sensor;

a second switch having third and fourth states, wherein when in the fourth state, the second switch exhibits a low electrical impedance, and wherein the second switch goes from the third state to the fourth state in response to an end of the delay interval provided that the first switch is still in the second state; and

wherein the second switch is in parallel with at least a portion of the first switch.

34. A detector as in claim 33 wherein the second switch incorporates a mechanical latch.

35. A detector comprising:

a sensor of fluid flow;

a first electrical switch having first and second states, coupled to the sensor, wherein when in the second state, a current can flow through at least part of the first switch;

an electronic timer circuit coupled to the first switch, wherein the timer circuit is activated each time the first switch goes from the first state to the second state in response to flow having been detected by the sensor and wherein the timer circuit generates a selected delay, in response thereto; and

a second electrical switch having third and fourth states, wherein when in the fourth state, a different current can flow through the second switch, and wherein the second switch goes from the third state to the fourth state, provided that the first switch is still in the second state after the selected delay.

36. A detector as in claim 35 wherein the timer circuit comprises a programmed processor.

37. A detector as in claim 35 wherein a part of the first switch is series coupled to a part of the second switch.

38. A detector as in claim 35 wherein each of the switches, when in the current flow state, exhibits substantially a short circuit.

39. A detector as in claim 35 wherein each of the switches comprises a closable mechanical contact.

40. A detector as in claim 35 wherein the timer circuit exhibits a minimize power drawing quiescent state when the first switch is in the first state.

41. A detector as in claim 35 wherein the second switch latches in its fourth state.

42. A detector as in claim 37 wherein a short circuit exists across the switches in response to both switches being in the closed state.

43. A system comprising at least one flow detector having

a sensor of fluid flow;

a first electrical switch having first and second states, coupled to the sensor, wherein when in the second state, a current can flow through at least part of the first switch;

an electronic timer circuit coupled to the first switch, wherein the timer circuit is activated each time the first switch goes for the first state to the second state in response to flow having been detected by the sensor and wherein the timer circuit generates a selected delay, in response thereto;

a second electrical switch having third and fourth states, wherein when in the fourth state, a current can flow through the second switch, and wherein the second switch goes from the third state to the fourth state, provided that the first switch is still in the second state afier the selected delay; and

a third, manually settable mode switch.

44. A system as in claim 43 wherein when in the fourth state, a different current can flow through the second switch.

45. A system as in claim 43 wherein the timer circuit comprises a programmed processor.

47. A system as in claim 43 wherein each of the switches, when in the current flow state, exhibits substantially a short circuit.

48. A detector as in claim 43 wherein each of the switches comprises a closable mechanical contact.

49. A system as in claim 43 wherein the timer circuit exhibits a minimal power drawing quiescent state when the first switch is in the first state.

50. A system as in claim 43 wherein the second switch latches in its fourth state.

52. A system as in claim 44 wherein the second switch comprises a latching relay having at least one pair of isolated, closable contacts wherein a contact closure can provide a flow indicating signal to another electrical unit.

53. A system as in claim 43 comprising:

a control element;

a switchable power supply coupled to the control element; and

a plurality of ambient condition detectors from a class which includes smoke detectors, gas detectors, heat detectors, and intrusion detectors.

54. A system as in claim 53 wherein the flow detector includes first and second terminals with one of the terminals coupled to the power supply and with the other couplable to a load wherein the second switch, when in the fourth state, short circuits the terminals.

55. A system as in claim 53 wherein the flow detector in response to energy being applied thereto assumes a minimal power dissipating quiescent state.

56. A system as in claim 53 wherein said at least one flow detector includes a plurality of flow detectors coupled in parallel, wherein when energy is applied to the plurality of flow detectors and the flow detectors are in a quiescent state, the aggregate current flow through the plurality of flow detectors is below a minimum detectable threshold.

46. A system as in clam 43 wherein a part of the first switch is series coupled to a part of the second switch.

51. A system as in claim 46 wherein a short circuit exists across the switches in response to both switches being in the closed state.