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US 2013/0154500 A1Published application
Method and apparatus for led driving and dimming, and illumination system
AssigneeOSRAM GmbH
InventorsYang Hu, LiBo Wu
Life of this patent
Estimating the term…
Abstract
A method for driving an LED connected to a power switch is provided. The method may include: determining a duty cycle of a pulse sequence for controlling the power switch according to a present current and a predetermined operating current of the LED; generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence; and controlling switching operation of the power switch by the pulse sequence, so as to drive the LED.
Claims20
A method for driving a light emitting diode connected to a power switch, the method comprising:
- determining a duty cycle of a pulse sequence for controlling the power switch according to a present current and a predetermined operating current of the light emitting diode;
- generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence;
- and
- controlling switching operation of the power switch by the pulse sequence, so as to drive the light emitting diode.
1 more element
A method for dimming an light emitting diode,
- wherein the light emitting diode is connected to a power switch, the method comprising:
- determining a duty cycle of a pulse sequence for controlling the power switch according to a present current and a desired brightness of the light emitting diode;
- generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence;
- and
- controlling switching operation of the power switch by the pulse sequence, for dimming the light emitting diode to a desired brightness.
2 more elements
An apparatus for driving a light emitting diode, comprising:
- a driving duty cycle determining module for determining a duty cycle according to a present current and a predetermined operating current of the light emitting diode;
- a driving pulse sequence generating module for generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence;
- and
- a driving power switch which is connected to the light emitting diode and is used for switching operation under control of the:
- pulse sequence, so as to drive the light emitting diode.
2 more elements
An apparatus for dimming a light emitting diode, comprising:
- a dimming duty cycle determining module for determining a duty cycle according to a present current and a desired brightness of the light emitting diode;
- a dimming pulse sequence generating module for generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence;
- and
- a dimming power switch which is connected to the light emitting diode, and is used for switching operation under control of the pulse sequence, for dimming the light emitting diode to a desired brightness.
1 more element
An illumination system, comprising:
- a light emitting diode;
- and
- an apparatus, comprising:
- a driving duty cycle determining module for determining a duty cycle according to a present current and a predetermined operating current of the light emitting diode;
- a driving pulse sequence generating module for generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence;
- and
- a driving power switch which is connected to the light emitting diode and is used for switching operation under control of the:
- pulse sequence, so as to drive the light emitting diode;
- wherein the driving duty cycle determining module comprises:
- a driving sampling unit for sampling the present current of the light emitting diode;
- a driving comparing unit for comparing the sampled present current and the predetermined operating current;
- and
- a driving determining unit for determining the duty cycle of the pulse sequence for controlling the power switch according to a comparison result of the driving comparing unit.
10 more elements
An illumination system, comprising:
- a light emitting diode;
- and
- an apparatus, comprising:
- a dimming duty cycle determining module for determining a duty cycle according to a present current and a desired brightness of the light emitting diode;
- a dimming pulse sequence generating module for generating the pulse sequence according to the duty cycle and according to at least one of a randomized period sequence and a randomized pulse position sequence;
- and
- a dimming power switch which is connected to the light emitting diode, and is used for switching operation under control of the pulse sequence, for dimming the light emitting diode to a desired brightness.
4 more elements
Dependencies are inferred from the claim text.