Control unit for LED assembly and lighting system
First Claim
1. A lighting system comprising:
- a LED assembly that comprises a plurality of LED units, said LED units being serial connected;
a switched mode power supply for powering the LED assembly;
a control unit for controlling the LED assembly the control unit being arranged to;
receive an input signal representing a desired output characteristic of the LED assembly,determine a plurality of duty cycles for the respective plurality of LED units associated with a nominal current level of the switched mode power supply, for providing the desired output characteristic,determine the largest of the plurality of duty cycles for respective LED units,determine a current level that is reduced relative to the nominal current level based on at least the largest of the duty cycles,adjust the plurality of duty cycles for respective LED units based on the reduced current level or the largest of the duty cycles, andprovide output data for the LED assembly and the switched mode power supply based on the adjusted plurality of duty cycles and the reduced current level,and wherein the LED assembly further comprises a capacitor connectable in parallel to the plurality of LED units by operating a switch connected in series with the capacitor and wherein the control unit is arranged to control the switch based on at least one of the reduced current and the input signal.
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Accused Products
Abstract
A lighting system comprising an LED assembly that comprises a first and second LED unit said LED units being serial connected is described. The system comprises; □ a switched mode power supply for powering the LED assembly; □ a control unit for controlling the LED assembly the control unit being arranged to: □ receive an input signal representing a desired output characteristic of the LED assembly, □ determine a first and second duty cycle for the respective first and second LED units associated with a nominal current of the switched mode power supply, for providing the desired output characteristic, □ determine the largest of the first and second duty cycles for respective LED units, □ determine a reduced current based on at least the largest of the duty cycles, □ adjust the first and second duty cycle for respective LED units based on the reduced current or the largest of the duty cycles, □ provide output data for the LED assembly and the switched mode power supply based on the adjusted first and second duty cycles and the reduced current. The LED assembly of the system further comprises a capacitor connectable in parallel to the first and second LED units by operating a switch connected in series with the capacitor and wherein the control unit is arranged to control the switch based on at least one of the reduced current and the input signal.
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Citations
16 Claims
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1. A lighting system comprising:
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a LED assembly that comprises a plurality of LED units, said LED units being serial connected; a switched mode power supply for powering the LED assembly; a control unit for controlling the LED assembly the control unit being arranged to; receive an input signal representing a desired output characteristic of the LED assembly, determine a plurality of duty cycles for the respective plurality of LED units associated with a nominal current level of the switched mode power supply, for providing the desired output characteristic, determine the largest of the plurality of duty cycles for respective LED units, determine a current level that is reduced relative to the nominal current level based on at least the largest of the duty cycles, adjust the plurality of duty cycles for respective LED units based on the reduced current level or the largest of the duty cycles, and provide output data for the LED assembly and the switched mode power supply based on the adjusted plurality of duty cycles and the reduced current level, and wherein the LED assembly further comprises a capacitor connectable in parallel to the plurality of LED units by operating a switch connected in series with the capacitor and wherein the control unit is arranged to control the switch based on at least one of the reduced current and the input signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A lighting system comprising:
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an LED assembly comprising a first LED unit and a capacitor connectable in parallel to the first LED unit by operating a switch connected in series with the capacitor; a switched mode power supply for, in use, powering the LED assembly, and a control unit comprising; an input port for receiving an input signal; an output port for providing a control signal to the switched mode power supply and the switch, the control unit being arranged to receive the input signal representing a desired output characteristic of the LED assembly, determine a power supply current for the switched mode power supply from the received input signal, provide, via the output port, the control signal to the switched mode power supply to control the switched mode power supply to provide the power supply current to the LED assembly; and provide, via the output port, a switch control signal to control the switch based on at least one of the power supply current and the input signal, and wherein said control unit further comprises a first LED control switch coupled to said first LED unit for controlling the current in said first LED unit said first LED control switch being operable independently of said switch connected in series with said capacitor. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification