Spa heater system

• US 20060115248A1
• Filed: 12/01/2004
• Published: 06/01/2006
• Est. Priority Date: 12/01/2004
• Status: Active Grant

• Current Assignee: Balboa Water Group LLC (Helios Technologies, Inc.)
• Original Assignee: Dymas Funding Company Llc
• Inventors: Tran, Trong
• Granted Patent: US 7,236,692 B2
• Time in Patent Office: Days
• US Class Current: 392/488
• CPC Class Codes: H05B 1/0269 For heating of fluids
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A spa system comprises an electrically powered heater. The electrically powered heater comprises a heating element capable of drawing a rated current when switched on to an AC line voltage. An electronic control system is programmed to control the heating element to draw less than the rated current.

Claims

1. A method of controlling a spa heater, comprising:

providing AC voltage to a heater;

preventing the heater from drawing current during a first non-zero portion of each of a plurality of consecutive cycles of the AC voltage; and

permitting the heater to draw current during a second non-zero portion of each of the plurality of consecutive cycles.

2. The method of claim 1, wherein the first portion of each of the plurality of consecutive cycles begins at a time corresponding to a zero crossing occurring at the beginning of a first half-cycle of each of the plurality of consecutive cycles and ending prior to the end of the first half cycle of each of the plurality of cycles.

3. The method of claim 1, comprising:

preventing the heater from drawing current during first portions of each of first and second half-cycles of each of the plurality of consecutive cycles of the AC voltage; and

permitting the heater to draw current during second portions of each of the first and second half-cycles of each of the plurality of consecutive cycles.

4. The method of claim 1, further comprising sending a signal to a switch, wherein the signal ends the first portion and starts the second portion.

5. The method of claim 1, further comprising sensing a beginning of a first half-cycle of each of the plurality of cycles and controlling the duration of the first portion with reference to the start of the first half-cycle.

6. The method of claim 2, further comprising sensing the zero crossing and controlling the duration of the first portion with reference to the zero crossing.

7. The method of claim 3, further comprising sensing a zero crossing corresponding to a beginning of each of the first and second half-cycles of each of the plurality of cycles and controlling the duration of the respective first portions of each of the first and second half-cycles with reference to the respective start of each of the first and second half-cycles of each of the plurality of cycles.

8. A method of controlling a spa heater, comprising:

providing an AC line voltage source for energizing the heater, wherein the AC line voltage source comprises a plurality of consecutive cycles;

controlling the flow of current from the AC voltage source to the heater with a current control circuit;

controlling the current control circuit to prevent the heater from drawing current during a first non-zero portion of each of a plurality of consecutive cycles and to permit the heater to draw current during a second non-zero portion of each of the plurality of consecutive cycles.

9. The method of claim 8, wherein the current control circuit comprises a triac.

10. The method of claim 9, wherein controlling the current control circuit comprises maintaining a gate voltage for the triac at zero during the first portion of each of the plurality of consecutive cycles and sending a short gate voltage pulse to the triac to start the second portion of each of the plurality of consecutive cycles.

11. The method of claim 10, comprising determining the available current capacity for the heater and adjusting the duration of the first portion of each of the plurality of consecutive cycles responsive to the available current capacity.

12. The method of claim 11, wherein determining the available current capacity for the heater comprises sensing the current being drawn by non-heater components of the spa.

13. The method of claim 11, wherein determining the available current capacity for the heater comprises calculating the current being drawn by non-heater components using nominal current usage values for the non-heater components.

14. A method of controlling a spa heater, comprising:

determining a current drawn by non-heater components of the spa;

calculating an available current capacity for the heater;

controlling a current drawn by the heater to equal approximately the available current capacity for the heater.

15. The method of claim 14, wherein controlling the current drawn by the heater comprises setting the timing of a plurality of consecutive voltage gate pulses to a triac to control the time during each of a plurality of consecutive AC cycles during which the heater can draw current.

16. The method of claim 14, further comprising:

receiving a signal to change the state of one of the non-heater components;

de-energizing the heater prior to changing the state of the one of the non-heater components;

changing the state of the one of the non-heater components; and

determining the current drawn by the non-heater components after changing the state of the one of the non-heater components.

17. The method of claim 16, wherein controlling the current drawn by the heater comprises setting the timing of a plurality of consecutive voltage gate pulses to a triac to control the time during each of a plurality of consecutive AC cycles during which the heater draws current.

18. The method of claim 14, further comprising:

receiving a start heating signal; and

determining the current drawn by the non-heater components prior to energizing the heater.

19. A spa heater controller, comprising:

means for providing a heating element with an alternating current power supply having a plurality of consecutive cycles, each with a period;

means for controlling a duty cycle of the heating element during the period of each of a plurality of consecutive cycles to be less than a full period.

20. The spa heater controller of claim 19, wherein the means for providing a heating element with an alternating current power supply comprises a triac, and the means for controlling comprises providing the triac with at least one gate voltage pulse during each of the plurality of consecutive cycles.

21. The spa heater controller of claim 20, further comprising means for determining the current drawn by non-heater components, wherein a controller sets a phase for the at least one gate voltage pulse during each of the plurality of consecutive cycles responsive, at least in part, to the current drawn by non-heater components.

22. The spa heater controller of claim 21, wherein the means for determining the current drawn by non-heater components comprises a current sensor.

23. The spa heater controller of claim 21, wherein the means for determining the current drawn by non-heater components comprises means for calculating the current drawn by non-heater components responsive, at least in part, to a table of nominal current usage values stored in a memory.

24. A spa heater controller, comprising:

means for providing a heating element with an AC line voltage supply having a plurality of consecutive cycles, each with a period;

means for controlling a duty cycle of the heating element during the period of each of a plurality of consecutive cycles to be less than a full period.

25. The spa heater controller of claim 24, wherein the means for providing a heating element with an AC line voltage supply comprises a triac, and the means for controlling comprises providing the triac with at least one gate voltage pulse during each of the plurality of consecutive cycles.

26. The spa heater controller of claim 25, further comprising means for determining the current drawn by non-heater components, wherein a controller sets a phase for the at least one gate voltage pulse during each of the plurality of consecutive cycles responsive, at least in part, to the current drawn by non-heater components.

27. The spa heater controller of claim 26, wherein the means for determining the current drawn by non-heater components comprises a current sensor.

28. The spa heater controller of claim 26, wherein the means for determining the current drawn by non-heater components comprises calculating the current drawn by non-heater components responsive, at least in part, to a stored set of nominal current usage values.

29. A spa heater controller, comprising:

a triac arranged to switch an AC voltage source to the heater;

a means for controlling the triac to switch the AC voltage source to the heater, wherein the means for controlling the triac provides at least one gate voltage pulse to the triac during each of a plurality of AC voltage cycles, wherein the current drawn by the heater can be varied by adjusting the timing of the at least one gate voltage pulses to each of the plurality of AC voltage cycles.

30. The spa heater controller of claim 29, wherein the triac is mounted on an outer surface of a heater shell.

31. The spa heater controller of claim 29, wherein the means for controlling the triac comprises a microcomputer.

32. The spa heater controller of claim 29, wherein the means for controlling the triac provides a gate voltage of zero from the start of each of the plurality of AC voltage cycles, provides the at least one gate voltage pulse to each of the plurality of AC voltage cycles during a first half-cycle of each of the plurality of AC voltage cycles, and provides a gate voltage of zero from the end of each of the short pulses until at least the end of the first half-cycle of each of the plurality of AC voltage cycles.

33. The spa heater controller of claim 32, wherein the triac prevents the heater from drawing current during each of the plurality of AC voltage cycles from the beginning of each of the plurality of AC voltage cycles until the at least one gate voltage pulse is provided during the first half-cycle of each of the plurality of AC voltage cycles, wherein the triac permits the heater to draw current from when the at least one gate voltage is provided until about the end of the first half-cycle of each of the plurality of AC voltage cycles.

34. The spa heater controller of claim 29, wherein the means for controlling the triac provides a gate voltage of zero from the start of both a first and second half-cycle of each of the plurality of AC voltage cycles, provides a short gate voltage pulse during each of the first and second half-cycles of each of the plurality of AC voltage cycles, and provides a gate voltage of zero from the end of each of the short pulses until the end of each of first and second half-cycles of each of the plurality of AC voltage cycles.

35. The spa heater controller of claim 34, wherein the triac prevents the heater from drawing current during each of the first and second half-cycles of each of the plurality of AC voltage cycles from the beginning of each of the first and second half-cycles of each of the plurality of AC voltage cycles until the at least one gate voltage pulse is provided during each of the first and second half-cycles of each of the plurality of AC voltage cycles, wherein the triac permits the heater to draw current from when the at least one gate voltage is provided during each of the first and second half-cycles of the plurality of AC voltage cycles until about the end of each of the first and second half-cycles of each of the plurality of AC voltage cycles.

36. A spa heater controller, comprising:

a triac for controlling current to an electrical heating element;

a microprocessor for providing a gate voltage signal to the triac;

wherein the microprocessor provides a gate voltage of zero from the start of a half-cycle to time D during the half-cycle, provides a short gate voltage pulse at time D during the half-cycle and provides a gate voltage of zero from the end of the short pulse until the end of the half-cycle.

37. The spa heater controller of claim 36, wherein the triac is mounted on an outer surface of a heater shell.

38. The spa heater controller of claim 36, wherein the microprocessor modulates the current provided to the heating element by adjusting the duration of time D.

39. The spa heater controller of claim 36, further comprising a means for determining the current drawn by non-heater components.

40. The spa heater of claim 39, wherein the non-heater components comprise at least one of a pump, a blower or a light.

41. The spa heater of claim 39, wherein the microprocessor determines the time D responsive to the means for determining the current drawn by non-heater components.

42. The spa heater of claim 39, wherein the means for determining the current drawn by non-heater components comprises a current sensor.

43. The spa heater of claim 39, wherein the means for determining the current drawn by non-heater components comprises calculating the current drawn based a nominal current table stored in a memory.

44. The spa heater of claim 43, wherein the nominal current table includes nominal current values for a plurality of non-heater components.

45. The spa heater of claim 36, further comprising a zero-crossing sensor operatively connected to the microprocessor.

46. The spa heater of claim 45, wherein the microprocessor times the gate voltage pulse with reference to a signal from the zero-crossing sensor.

47. The spa heater controller of claim 36, wherein the means for providing a gate voltage signal to the triac provides a gate voltage of zero from the start of each of a plurality of consecutive half-cycles to time D during each of the respective consecutive half-cycles, provides a short gate voltage pulse at time D during each of the respective consecutive half-cycles and provides a gate voltage of zero from the end of each of the short pulses until the end of each of the respective, consecutive half-cycles.

48. The spa heater controller of claim 36, wherein the means for providing a gate voltage signal to the triac provides a gate voltage of zero from the start of every other one of a plurality of consecutive half-cycles to time D during each of the respective every other one of the consecutive half-cycles, provides a short gate voltage pulse at time D during each of the respective every other one of the consecutive half-cycles and provides a gate voltage of zero from the end of each of the short pulses until the end of each of the respective, every other one of the consecutive half-cycles.

49. A spa heater controller, comprising:

a triac for controlling current to an electrical heating element;

an electronic control system for providing a gate voltage signal to the triac;

wherein the electronic control system provides a gate voltage of zero from the start of a half-cycle to time D during the half-cycle, provides a short gate voltage pulse at time D during the half-cycle and provides a gate voltage of zero from the end of the short pulse until the end of the half-cycle.

50. The spa heater controller of claim 49, wherein the triac is mounted on an outer surface of a heater shell.

51. The spa heater controller of claim 49, wherein the electronic control system modulates the current provided to the heating element by adjusting the duration of time D.

52. The spa heater controller of claim 49, further comprising a means for determining the current drawn by non-heater components.

53. The spa heater of claim 52, wherein the non-heater components comprise at least one of a pump, a blower or a light.

54. The spa heater of claim 52, wherein the electronic control system determines the time D responsive to the means for determining the current drawn by non-heater components.

55. The spa heater of claim 52, wherein the means for determining the current drawn by non-heater components comprises a current sensor.

56. The spa heater of claim 52, wherein the means for determining the current drawn by non-heater components comprises calculating the current drawn based a nominal current table stored in a memory.

57. The spa heater of claim 56, wherein the nominal current table includes nominal current values for a plurality of non-heater components.

58. The spa heater of claim 49, further comprising a zero-crossing sensor operatively connected to the electronic control system.

59. The spa heater of claim 58, wherein the electronic control system times the gate voltage pulse with reference to a signal from the zero-crossing sensor.

60. The spa heater controller of claim 49, wherein the means for providing a gate voltage signal to the triac provides a gate voltage of zero from the start of each of a plurality of consecutive half-cycles to time D during each of the respective consecutive half-cycles, provides a short gate voltage pulse at time D during each of the respective consecutive half-cycles and provides a gate voltage of zero from the end of each of the short pulses until the end of each of the respective, consecutive half-cycles.

61. The spa heater controller of claim 49, wherein the means for providing a gate voltage signal to the triac provides a gate voltage of zero from the start of every other one of a plurality of consecutive half-cycles to time D during each of the respective every other one of the consecutive half-cycles, provides a short gate voltage pulse at time D during each of the respective every other one of the consecutive half-cycles and provides a gate voltage of zero from the end of each of the short pulses until the end of each of the respective, every other one of the consecutive half-cycles.

62. A method of manufacturing a spa heater controller assembly, comprising:

providing a spa heater with a maximum heater current rating;

providing a controller arranged to modulate the current drawn by the heater to maintain a total system current at or below a maximum system current limit, wherein the maximum system current limit can be pre-programmed into the controller for any of a range of current limits.

63. The spa heater controller assembly of claim 62, further comprising pre-programming the controller with the maximum system current limit for a particular application.

64. The spa heater controller assembly of claim 63, wherein the controller modulates the current drawn by preventing current from flowing through the heater during at least a portion of each of a plurality of successive cycles of an AC live voltage.

65. A spa heater controller system, comprising:

an electrically powered heater comprising a heating element capable of drawing a rated current when switched on to an AC line voltage;

an electronic control system, arranged to selectively prevent current flow through the heating element during a non-zero portion of each of a series of sequential cycles of the AC line voltage.

66. A spa heater system, comprising:

an electrically powered heater comprising a heating element capable of drawing a rated current when switched on to an AC line voltage;

an electronic control system programmed to control the heating element to draw less than the rated current.

67. A spa system, comprising:

an electrically powered heater comprising a wet heating element capable of drawing a rated current when switched on to an AC line voltage;

an electronic control system programmed to control the heating element to draw less than the rated current to maintain total system current close at less than a total system current rating.