Device and method for controlling current to solid state lighting circuit
AssigneeKoninklijke Philips Electronics N.V.
InventorHarald Josef Günther Radermacher
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Abstract
A device for controlling current to a solid state lighting load includes a capacitor (241, 341) and a current source (245, 345). The capacitor is connected in a parallel arrangement with the solid state lighting load (260, 360). The current source is connected in series with the parallel arrangement of the capacitor and the solid state lighting load. The current source is configured to modulate dynamically an amplitude of an input current provided to the parallel arrangement of the capacitor and the solid state lighting load based on an input voltage.
Claims20
A device for controlling current to a solid state lighting load, the device comprising:
- a capacitor connected in a parallel arrangement with the solid state lighting load;
- and
- a current source connected in series with the parallel arrangement of the capacitor and the solid state lighting load, the current source being configured to modulate dynamically an amplitude of an input current provided to the parallel arrangement of the capacitor and the solid state lighting load based on an input voltage.
A device for controlling current to a light emitting diode (LED) load, the device comprising:
- a capacitor connected in parallel with the LED load;
- a transistor connected in series between the capacitor and a bridge rectifier circuit providing a rectified input voltage;
- and
- a modulation control circuit connected in parallel with the capacitor and the transistor and configured to receive the rectified input voltage from the bridge rectifier circuit, the modulation control circuit comprising a current mirror connected to a gate of the transistor, the current mirror being selectively activated and deactivated to downward and upward modulate an amplitude of a current through the capacitor based on an input voltage from the bridge rectifier circuit.
A method for controlling current to a solid state lighting load, the method comprising:
- receiving an input voltage (Urect) having a waveform;
- and
- adjusting an amplitude modulation of a capacitor current of a capacitor connected in parallel with the solid state lighting load, in response to at least one of the waveform of the received input voltage and a time delay in the waveform of the received input voltage, wherein adjusting the amplitude modulation of the capacitor current changes at least one of a power factor and operation efficiency of the solid state lighting load.
The method of claim 20, wherein the input voltage comprises a rectified voltage received from a bridge rectifier circuit.
Dependencies are inferred from the claim text.