Method of controlling a lighting arrangement, a lighting control circuit and a lighting system
AssigneeSignify Holding B.V.
InventorsTheo Gerrit Zijlman, Henricus Marius Joseph Maria Kahlman
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Abstract
A lighting arrangement such as a LED lamp comprises a light source and associated current driver, or a set of at least two parallel light sources and associated current drivers, supplied by a DC voltage from a voltage-regulated power converter. A feedback circuit provides a temperature-dependent control input to a control loop of the power converter, such that the DC voltage is adjusted in dependence on a sensed temperature. In this way, the voltage headroom required can be reduced, and efficiency gains are made.
Claims13
A lighting control circuit for controlling a lighting arrangement, the lighting control circuit comprising:
- a power converter for delivering a DC voltage to a current driver, wherein the current driver is arranged to be connected in series with the lighting arrangement for driving a current through the lighting arrangement, and wherein the power converter has a control loop for controlling the level of the DC voltage;
- a temperature sensing element for sensing a temperature at or near the lighting arrangement and arranged to be used in a feedback circuit;
- and
- the feedback circuit arranged to receive the measured voltage and arranged to provide a temperature-dependent control input to the control loop of the power converter, such that the DC voltage is adjusted in dependence on a sensed temperature, wherein the DC voltage is adjusted inversely with respect to sensed temperature.
A method of controlling a lighting arrangement, comprising:
- delivering a DC voltage to a current driver using a power converter, the power converter having a control loop for controlling the level of the DC voltage;
- sensing a temperature at or near a light source;
- providing a temperature-dependent control input based on the sensed temperature and on a measured voltage over an inductor of the power converter to the control loop of the power converter, such that the DC voltage is adjusted in dependence on a sensed temperature;
- and
- driving the light source using the current driver, and
- adjusting the DC voltage inversely with respect to sensed temperature.
Dependencies are inferred from the claim text.