Methods and apparatus for providing a controllably variable power to a load

• US 7,659,673 B2
• Filed: 03/14/2005
• Issued: 02/09/2010
• Est. Priority Date: 03/15/2004
• Status: Active Grant

• Current Assignee: Signify North America Corporation (Signify N.V.)
• Original Assignee: Philips Solid-State Lighting Solutions (Koninklijke Philips N.V.)
• Inventors: Lys, Ihor A.
• Primary Examiner(s): VO, TUYET THI
• Application Number:
  US11/079,448
• Publication Number:
  US 20050218870A1
• Time in Patent Office: 1,793 Days
• Field of Search: 315/247, 315/246, 315/224, 315/225, 315/200.A, 315/185.S, 315/312, 315/324, 315/291, 315307-311
• US Class Current: 315/247
• CPC Class Codes: H02M 1/0012 Control circuits using digital or numerical techniques in DC/DC converters H02M3/157, H02M3/33515; in DC-AC converters H02M7/53873
• CPC Class Codes: H02M 1/0019 the disturbance parameters being load current fluctuations
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H02M 1/425 using a single converter stage both for correction of AC input power factor and generation of a high frequency AC output voltage
• CPC Class Codes: H02M 1/4291 by using a Buck converter to switch the input current
• CPC Class Codes: H02M 3/155 using semiconductor devices only
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/157 with digital control
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/305 Frequency-control circuits
• CPC Class Codes: H05B 45/355 Power factor correction [PFC]; Reactive power compensation
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

Methods and apparatus for providing and controlling power to at least some types of loads. In one example, a controlled predetermined power is provided to a load without requiring any feedback information from the load (i.e., without monitoring a load voltage and/or load current). In another example, a “feed-forward” power driver for an LED-based light source combines the functionality of a DC-DC converter and a light source controller, and is configured to control the intensity of light generated by the light source based on modulating the average power delivered to the light source in a given time period, without monitoring and/or regulating the voltage or current provided to the light source. In various examples, significantly streamlined circuits having fewer components, higher overall power efficiencies, and smaller space requirements are realized. Based on various power driver configurations, lighting apparatus incorporating one or more power drivers for one or more LED-based loads may be implemented, and multiple such lighting apparatus may be coupled together to form a lighting network in which operating power is efficiently provided throughout the network.

Claims

1. An apparatus, comprising:

at least one energy transfer element to store input energy derived from a power source and to provide output energy to at least one LED;

at least one switch coupled to the at least one energy transfer element to control at least the input energy stored to the at least one energy transfer element; and

at least one switch controller controlling the at least one switch using a discontinuous mode switching technique to perform multiple switching operations in at least one time period, each switching operation transferring a predetermined quantum of the input energy to the at least one energy transfer element,

wherein the at least one switch controller comprises a processor to receive at least one control signal representing a desired power to the at least one LED, the processor controlling, based on a relative range of the desired power to the at least one LED, the multiple switching operations to vary at least one of;

the predetermined quantum of the input energy for at least two switching operations in the at least one time period; and

a number of the multiple switching operations in the at least one time period,

so as to provide a controllably variable power to the at least one LED.

2. The apparatus of claim 1, wherein the at least one switch controller does not receive any feedback information relating to the load.

3. The apparatus of claim 1, wherein the apparatus neither monitors nor regulates a load voltage and neither monitors nor regulates a load current.

4. The apparatus of claim 1, wherein:

the at least one switch includes only one single switch;

a DC supply voltage provides the power source;

the at least one switch controller applies a first converted DC voltage across the at least one LED; and

the at least one switch controller further controls the one single switch to facilitate a first conversion of the DC supply voltage to the first converted DC voltage and concurrently provides the controllably variable power to the load at least one LED.

5. The apparatus of claim 1, wherein the processor further controls at least one power factor correction apparatus based on the at least one control signal representing the desired power to the at least one LED.

6. The apparatus of claim 1, wherein the processor is an addressable device controlled via a network.

7. The apparatus of claim 1, wherein the at least one control signal representing the desired power to the at least one LED is formatted using a DMX protocol.

8. The apparatus of claim 1, wherein the at least one energy transfer element includes at least one of a tapped inductor and a transformer with a non-unity turns ratio.

9. The apparatus of claim 8, further comprising an energy transfer arrangement that includes the at least one energy transfer element, the at least one switch, and at least one diode, wherein the energy transfer arrangement comprises one of a buck converter, a boost converter, a buck-boost converter, a CUK converter, a flyback converter and a forward converter.

10. The apparatus of claim 1, wherein the at least one switch controller controls the at least one switch based on at least one of the voltage output by the power source and a current drawn from the power source, and the at least one control signal representing a desired power.

11. The apparatus of claim 10, wherein the at least one switch controller controls at least one power factor correction apparatus based on the at least one control signal representing the desired power to the load.

12. The apparatus of claim 10, wherein the at least one switch controller is an addressable device controlled via a network.

13. The apparatus of claim 12, wherein the at least one control signal representing the desired power to the load is formatted using a DMX protocol.

14. The apparatus of claim 10, further comprising an energy transfer arrangement that includes the at least one energy transfer element, the at least one switch, and at least one diode, wherein the energy transfer arrangement comprises one of a buck converter, a boost converter, a buck-boost converter, a CUK converter, a flyback converter and a forward converter.

15. The apparatus of claim 14, wherein the at least one switch controller controls both of a frequency and a duty cycle of the multiple switching operations of the at least one switch, based on the at least one control signal representing the desired power to the load.

16. The apparatus of claim 15, wherein the processor controls at least one of the frequency and the duty cycle of the multiple switching operations based on a relative range of the desired power to the load.

17. The apparatus of claim 16, wherein the desired power to the load includes at least a first range and a second range, wherein the processor controls only one of the frequency and the duty cycle of the multiple switching operations in the first range, and wherein the processor controls both of the frequency and the duty cycle of the multiple switching operations in the second range.

18. The apparatus of claim 16, wherein the desired power to the load includes at least a first range, a second range, and a third range, and wherein the processor controls only the frequency of the multiple switching operations in the first range, only the duty cycle of the multiple switching operations in the second range, and both of the frequency and the duty cycle of the multiple switching operations in the third range.

19. The apparatus of claim 16, further comprising the load, wherein the load includes at least one LED.

20. The apparatus of claim 16, wherein the processor is an addressable device controlled via a network.

21. The apparatus of claim 20, wherein the at least one control signal representing the desired power to the load is formatted using a DMX protocol.

22. A method, comprising acts of:

A) storing input energy derived from a power source to at least one energy transfer element;

B) providing output energy from the at least one energy transfer element to a load;

C) controlling at least the input energy stored to the at least one energy transfer element via at least one switch coupled to the at least one energy transfer element; and

D) controlling the at least one switch using a discontinuous mode switching technique to perform multiple switching operations in at least one time period, each switching operation transferring a controllably variable predetermined quantum of the input energy to the at least one energy transfer element,

wherein the act D) comprises acts of;

receiving at least one control signal representing a desired power to the load as at least one addressed control signal; and

controlling the multiple switching operations to vary, based on a relative range of the desired power to the load, at least one of;

the predetermined quantum of the input energy for at least two switching operations in the at least one time period; and

a number of the multiple switching operations in the at least one time period,

so as to provide a controllably variable power to the load.

23. The method of claim 22, wherein the act D) comprises an act of:

controlling the at least one switch without receiving any feedback information relating to the load.

24. The method of claim 22, wherein the act B) comprises an act of:

providing the output energy without regulating either a load voltage or a load current.

25. The method of claim 22, further comprising the load, wherein the load includes at least one LED.

26. The method of claim 22, wherein the at least one switch includes only one single switch, wherein a DC supply voltage provides the power source, wherein a first converted DC voltage is applied across the load, and wherein the act D) further comprises an act of controlling the one single switch to facilitate a first conversion of the DC supply voltage to the first converted DC voltage and concurrently provide a controllably variable power to the load.

27. The method of claim 22, wherein the at least one energy transfer element includes at least one of a tapped inductor and a transformer with a non-unity turns ratio.

28. The method of claim 22, further comprising an act of:

controlling at least one power factor correction apparatus based on the controllably variable power to the load.

29. The method of claim 22, further comprising an act of formatting the at least one control signal representing the desired power to the load using a DMX protocol.

30. The method of claim 22, wherein the act D) comprises an act of:

controlling the at least one switch without monitoring either a load voltage or a load current.

31. The method of claim 30, wherein the act B) comprises an act of:

providing the output energy without regulating either a load voltage or a load current.

32. The method of claim 22, further comprising an energy transfer arrangement that includes the at least one energy transfer element, the at least one switch, and at least one diode, wherein the energy transfer arrangement comprises one of a buck converter, a boost converter, a buck-boost converter, a CUK converter, a flyback converter and a forward converter.

33. The method of claim 32, further comprising the load, wherein the load includes at least one LED.

34. The method of claim 22, wherein the act D) comprises an act of:

D1) controlling the at least one switch based on at least one of a voltage output of the power source and a current drawn from the power source, and at least one control signal representing a desired power to the load.

35. The method of claim 34, further comprising an act of:

controlling at least one power factor correction apparatus based at least in part on the at least one control signal representing the desired power to the load.

36. The method of claim 34, further comprising an act of transmitting the at least one control signal representing the desired power to the load as at least one addressed control signal.

37. The method of claim 36, further comprising an act of formatting the at least one control signal representing the desired power to the load using a DMX protocol.

38. The method of claim 34, further comprising an energy transfer arrangement that includes the at least one energy transfer element, the at least one switch, and at least one diode, wherein the energy transfer arrangement comprises one of a buck converter, a boost converter, a buck-boost converter, a CUK converter, a flyback converter and a forward converter.

39. The method of claim 38, wherein the act D1) comprises an act of:

D2) controlling both of a frequency and a duty cycle of multiple switching operations of the at least one switch, based on the at least one control signal representing the desired power to the load.

40. The method of claim 39, wherein the act D2) comprises an act of:

D3) controlling at least one of the frequency and the duty cycle of the multiple switching operations based on a relative range of the desired power to the load.

41. The method of claim 40, wherein the desired power to the load includes at least a first range and a second range, and wherein the act D3) comprises acts of:

controlling only one of the frequency and the duty cycle of the multiple switching operations in the first range; and

controlling both of the frequency and the duty cycle of the multiple switching operations in the second range.

42. The method of claim 40, wherein the desired power to the load includes at least a first range, a second range, and a third range, and wherein the act D3) comprises acts of:

controlling only the frequency of the multiple switching operations in the first range;

controlling only the duty cycle of the multiple switching operations in the second range; and

controlling both of the frequency and the duty cycle of the multiple switching operations in the third range.

43. The method of claim 40, further comprising the load, wherein the load includes at least one LED.

44. The method of claim 40, further comprising an act of transmitting the at least one control signal representing the desired power to the load as at least one addressed control signal.

45. The method of claim 44, further comprising an act of formatting the at least one control signal representing the desired power to the load using a DMX protocol.