Driver for providing variable power to a LED array
First Claim
1. A driver for providing variable power to at least one LED array when coupled through a phase-modulating dimmer to an AC power supply, the driver comprising:
- a filtering and rectifying unit for attenuating electromagnetic interference from/to the AC power supply and converting an AC power from the AC power supply into a DC power output;
a switching power unit for receiving the DC power output from the filtering and rectifying unit and providing an output current to the LED array; and
a control unit for determining the output current to the LED array in response to a comparison between a dim reference signal representing phase-modulating information of the AC power when the phase angle of the AC power is cut by the phase-modulating dimmer and a feedback signal representing an average value of the output current to the LED array, wherein the control unit comprises a first sampling sub-unit adapted to sample the dim reference signal and cause the dim reference signal to be in a low frequency range, and a second sampling sub-unit adapted to sample the feedback signal and cause the feedback signal to be in a low frequency range.
3 Assignments
0 Petitions
Accused Products
Abstract
A driver for providing variable power to a LED array, which can be coupled through a dimmer to an AC power supply, comprises a filtering and rectifying unit, a switching power unit, and a control unit. The filtering and rectifying unit is adapted to attenuate EMI and convert an AC power from the AC power supply into a DC power output. The switching power unit is adapted to receive the DC power output and provide an output current to the LED array. The control unit is adapted to determine the output current in response to a comparison between a dim reference signal representing phase-modulating information of the AC power and a feedback signal representing an average value of the output current. The LED array can thus be controlled by a dimmer at the primary side so as to adjust its light output, and can further be utilized in currently existing lighting infrastructures.
-
Citations
14 Claims
-
1. A driver for providing variable power to at least one LED array when coupled through a phase-modulating dimmer to an AC power supply, the driver comprising:
-
a filtering and rectifying unit for attenuating electromagnetic interference from/to the AC power supply and converting an AC power from the AC power supply into a DC power output; a switching power unit for receiving the DC power output from the filtering and rectifying unit and providing an output current to the LED array; and a control unit for determining the output current to the LED array in response to a comparison between a dim reference signal representing phase-modulating information of the AC power when the phase angle of the AC power is cut by the phase-modulating dimmer and a feedback signal representing an average value of the output current to the LED array, wherein the control unit comprises a first sampling sub-unit adapted to sample the dim reference signal and cause the dim reference signal to be in a low frequency range, and a second sampling sub-unit adapted to sample the feedback signal and cause the feedback signal to be in a low frequency range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method of providing variable power to at least one LED array, the method comprising the steps of:
-
supplying current to the LED array by means of a power supply; and adjusting the current in accordance with a dimming demand signal at an input side of the power supply, by performing a comparison between a dim reference signal representing phase-modulating information at the input side of the power supply and a feedback signal representing an average value of the current to the LED array, wherein the adjusting step comprises a first sub-step of sampling and low-pass filtering the dim reference signal, and a second sub-step of sampling and low-pass filtering the feedback signal. - View Dependent Claims (10)
-
-
11. A driver for providing variable power to at least one LED array when coupled through a phase-modulating dimmer to an AC power supply, the driver comprising:
-
a filtering and rectifying unit for attenuating electromagnetic interference from/to the AC power supply and converting an AC power from the AC power supply into a DC power output; a switching power unit for receiving the DC power output from the filtering and rectifying unit and providing an output current to the LED array; and a control unit for determining the output current to the LED array in response to a comparison between a dim reference signal representing phase-modulating information of the AC power when the phase angle of the AC power is cut by the phase-modulating dimmer and a feedback signal representing an average value of the output current to the LED array, wherein the control unit comprises a third sampling sub-unit adapted to sample a voltage signal reflecting a voltage waveform of the AC power, and wherein the control unit is adapted to implement a power factor correction in response to the voltage signal. - View Dependent Claims (12, 13, 14)
-
Specification