Method and apparatus for controlling a lighting device

• US 9,220,136 B2
• Filed: 05/21/2013
• Issued: 12/22/2015
• Est. Priority Date: 05/21/2012
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Zhang, Wanfeng, Sutardja, Pantas, Song, Yonghua
• Primary Examiner(s): Wells, Kenneth B
• Application Number:
  US13/899,121
• Publication Number:
  US 20130307434A1
• Time in Patent Office: 945 Days
• Field of Search: 315/141, 315/212, 315/219, 315/254, 315/276
• US Class Current: 1/1
• CPC Class Codes: H05B 41/3924 by phase control, e.g. using a triac H05B41/3922 takes precedence
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/382 with galvanic isolation between input and output
• CPC Class Codes: H05B 45/385 using flyback topology
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Aspects of the disclosure provide a method. The method includes detecting a dimming characteristic in an energy source that provides energy to be transferred to a load via a magnetic component, receiving a dimming control signal, and controlling a switch in connection with the magnetic component based on the dimming characteristic and the dimming control signal to transfer energy to the load via the magnetic component.

Claims

1. A method, comprising:

detecting a dimming characteristic in an energy source that provides energy to be transferred to a load via a magnetic component;

receiving a dimming control signal;

entering a control mode to control a switch in connection with the magnetic component; and

determining control parameters for the control mode to transfer energy to the load via the magnetic component, wherein determining the control parameters further comprises;

detecting whether the dimming control signal is compatible with the dimming characteristic;

ignoring the dimming control signal when the dimming control signal is not compatible with the dimming characteristic; and

adjusting values of the control parameters based on the dimming control signal when the dimming control signal is compatible with the dimming characteristic.

2. The method of claim 1, wherein detecting the dimming characteristic in the energy source that provides the energy to be transferred to the load via the magnetic component further comprises:

detecting at least one of a conduction angle, a phase-cut angle and a dimming percentage of the energy source.

3. The method of claim 1, wherein receiving the dimming control signal further comprises at least one of:

receiving the dimming control signal from a wired control component; and

receiving the dimming control signal from a wireless control component.

4. The method of claim 1, further comprising:

prioritizing the dimming characteristic over the dimming control signal; and

controlling the switch in connection with the magnetic component based on the prioritized dimming characteristic and the dimming control signal.

5. The method of claim 2, wherein the control mode is a first control mode, further comprising:

entering a second control mode to control the switch with a substantially constant turn-on time when the phase-cut angle is about zero; and

determining control parameters for the second control mode based on the dimming control signal.

6. A circuit, comprising:

a detecting circuit configured to detect a dimming characteristic in an energy source that provides energy to be transferred to a load via a magnetic component;

an interface circuit configured to receive a dimming control signal; and

a controller configured to enter a control mode to control a switch in connection with the magnetic component, and to determine control parameters for the control mode to transfer energy to the load via the magnetic component, the controller being further configured to detect whether the dimming control signal is compatible with the dimming characteristic, ignore the dimming control signal when the dimming control signal is not compatible with the dimming characteristic, and adjust values of the control parameters based on the dimming control signal when the dimming control signal is compatible with the dimming characteristic.

7. The circuit of claim 6, wherein the detecting circuit is configured to detect at least one of a conduction angle, a phase-cut angle and a dimming percentage of the energy source.

8. The circuit of claim 6, wherein the controller is a first controller, and the circuit further comprises:

a second controller configured to receive the dimming control input from a wired control component or receive the dimming control signal from a wireless control component, and provide the dimming control signal to the interface circuit.

9. The circuit of claim 8, wherein the first controller and the second controller are on the same integrated circuit (IC) chip.

10. The circuit of claim 8, wherein the first controller and the second controller are on separate integrated circuit (IC) chips.

11. The circuit of claim 6, wherein the controller is configured to prioritize the dimming characteristic over the dimming control signal, and control the switch in connection with the magnetic component based on the prioritized dimming characteristic and the dimming control signal.

12. The circuit of claim 7, wherein the control mode is a first control mode and the controller is further configured to enter a second control mode to control the switch with a substantially constant turn-on time when the phase-cut angle is about zero, and determine control parameters for the second control mode based on the dimming control signal.

13. An apparatus, comprising:

an energy transfer module configured to transfer electric energy from an energy source to an output device;

a detecting circuit configured to detect a dimming characteristic in the energy source;

an interface circuit configured to receive a dimming control signal; and

a controller configured to enter a first control mode to control a switch in connection with the energy transfer module with a substantially constant turn-on time when a phase-cut angle of the dimming characteristic is about zero, and determine control parameters for the control mode to transfer energy to the output device, the controller being further configured to enter a second control mode to control the switch based on a current flowing through the switch when the phase-cut angle is not zero, detect whether the dimming control signal is compatible with the dimming characteristic, ignore the dimming control signal when the dimming control signal is not compatible with the dimming characteristic, and adjust values of control parameters for the second control mode based on the dimming control signal when the dimming control signal is compatible with the dimming characteristic.

14. The apparatus of claim 13, wherein the controller is configured to prioritize the dimming characteristic over the dimming control signal, and control the switch in connection with a magnetic component based on the prioritized dimming characteristic and the dimming control signal.