Power supply controller for multiple lighting components
View Patent ↗A power supply controller for a plurality of lighting components in a battery-powered apparatus. The power supply controller comprises a current source common to the lighting components, and a sequencer for coupling the current source sequentially to each of the lighting components with a repetition rate substantially faster than the flicker perception rate. Each of the lighting components comprises a respective array of lighting elements connected in series to receive the same current as the other lighting elements of the same lighting component.
1. A method comprising:
coupling, via a sequence, a current source sequentially to each of multiple groups of light emitting diodes during respective allocated time slots with a repetition rate substantially faster than a flicker perception rate, wherein each of the multiple groups of light emitting diodes include a respective array of light emitting diodes connected in series, wherein the current source is common to the multiple groups of light emitting diodes;
applying, via a pulse width modulator, pulse width modulation during the allocated time slots with a controlled duty cycle, for controlling an average current applied to the corresponding group of light emitting diodes.
2. A power supply controller for a plurality of lighting components, each of said lighting components comprising a respective array of lighting elements connected in series to receive the same current as the other lighting elements of the same lighting component, in a battery-powered apparatus, the power supply controller comprising:
a current source common to said lighting components;
a sequencer for coupling said current source sequentially to first and second ones of said lighting components during respective allocated time slots with a repetition rate substantially faster than a flicker perception rate; and
a pulse width modulator for applying pulse width modulation during said allocated time slots with a controlled duty cycle, for controlling an average current applied to the corresponding lighting components.
3. Battery-powered apparatus including a power supply controller as claimed in claim 2 and said lighting components and said first and second lighting components having different numbers of said elements.
4. A power supply controller as claimed in claim 2 , wherein said current source is arranged to control intensities of current supplied to said lighting components, whereby to control the perceived luminosity of the respective lighting components.
5. Battery-powered apparatus including a power supply controller as claimed in claim 4 and said lighting components and said first and second lighting components having different numbers of said elements.
6. A power supply controller as claimed in claim 2 , wherein said power supply controller comprises voltage controlling means for controlling a voltage applied across said lighting components and said current source.
7. Battery-powered apparatus including a power supply controller as claimed in claim 1 and said lighting components and said first and second lighting components having different numbers of said elements.
8. Battery-powered apparatus including a power supply controller as claimed in claim 6 and said lighting components and said first and second lighting components having different numbers of said elements.
9. A power supply controller as claimed in claim 6 , wherein said sequencer is arranged to control an on-time during said allocated time slots as a proportion of their respective durations, whereby to control the perceived luminosity of the respective lighting components.
10. A power supply controller as claimed in claim 9 , wherein said sequencer is arranged to control respective durations of said allocated time slots, whereby to control the perceived luminosity of the respective lighting components.
11. A power supply controller as claimed in claim 6 , wherein said current source is arranged to control intensities of current supplied to said lighting components, whereby to control the perceived luminosity of the respective lighting components.
12. Battery-powered apparatus including a power supply controller as claimed in claim 11 and said lighting components and said first and second lighting components having different numbers of said elements.
13. A power supply controller as claimed in claim 2 , wherein said sequencer is arranged to control an on-time during said allocated time slots as a proportion of their respective durations, whereby to control the perceived luminosity of the respective lighting components.
14. A power supply controller as claimed in claim 13 , wherein said sequencer is arranged to control respective durations of said allocated time slots, whereby to control the perceived luminosity of the respective lighting components.
15. Battery-powered apparatus including a power supply controller as claimed in claim 13 and said lighting components and said first and second lighting components having different numbers of said elements.
16. A power supply controller as claimed in claim 15 , wherein said sequencer is arranged to control respective durations of said allocated time slots, whereby to control the perceived luminosity of the respective lighting components.
17. A power supply controller as claimed in claim 13 , wherein said current source is arranged to control intensities of current supplied to said lighting components, whereby to control the perceived luminosity of the respective lighting components.
18. A power supply controller as claimed in claim 17 , wherein said sequencer is arranged to control respective durations of said allocated time slots, whereby to control the perceived luminosity of the respective lighting components.
19. Battery-powered apparatus including a power supply controller as claimed in claim 13 and said lighting components and said first and second lighting components having different numbers of said elements.
20. A power supply controller as claimed in claim 19 , wherein said sequencer is arranged to control respective durations of said allocated time slots, whereby to control the perceived luminosity of the respective lighting components.