System for controlling the supply of power to and for thermal management of light sources
AssigneeValeo Vision
InventorPatrick Wacheux
Life of this patent
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Abstract
A device and method for controlling the supply of power to light sources, in which a DC/DC converter is capable of delivering a voltage VMAX to the light sources. The forward voltage of the light sources depends on temperature and may temporarily exceed VMAX at low temperatures. The invention proposes means that allow the required forward voltage to be decreased automatically depending on a measurement of ambient temperature.
Claims19
A device for controlling the supply of power to light sources, comprising:
- a DC/DC converter capable of converting an input electrical voltage into an output electrical voltage;
- a circuit mounted to load said converter comprising a plurality of light sources mounted in series;
- wherein said device furthermore comprises at least one switching circuit comprising switching means intended to short-circuit at least one of said plurality of light sources depending on a temperature measurement obtained by means for measuring ambient temperature;
- wherein said at least one switching circuit comprises:
- an electrical circuit comprising a thermistor, said electrical circuit being able to deliver two electrical voltage levels, said two electrical voltage levels being substantially equal when the ambient temperature is above said temperature threshold, and said two electrical voltage levels being different when the ambient temperature is below said temperature threshold.
A method for controlling the supply of power to light sources, comprising steps of:
- providing a DC/DC converter capable of converting an input electrical voltage into an output electrical voltage;
- providing a circuit mounted to load said converter comprising a plurality of light sources mounted in series;
- selectively short-circuiting at least one of said plurality of light sources via at least one switching circuit depending on a temperature measurement obtained by means for measuring ambient temperature;
- providing said at least one switching circuit with an electrical circuit comprising a thermistor;
- and
- delivering two electrical voltage levels by said electrical circuit, said two electrical voltage levels being substantially equal when the ambient temperature is above said temperature threshold, and said two electrical voltage levels being different when the ambient temperature is below said temperature threshold.
A device for controlling the supply of power to light sources, comprising:
- a DC/DC converter capable of converting an input electrical voltage into an output electrical voltage;
- a circuit mounted to load said converter comprising a plurality of light sources mounted in series;
- wherein said device furthermore comprises at least one switching circuit comprising a switch intended to short-circuit at least one of said plurality of light sources depending on a measurement of an ambient temperature;
- wherein said at least one switching circuit comprises:
- an electrical circuit comprising a thermistor, said electrical circuit being able to deliver two electrical voltage levels, said two electrical voltage levels being substantially equal when the ambient temperature is above said temperature threshold, and said two electrical voltage levels being different when the ambient temperature is below said temperature threshold.
Dependencies are inferred from the claim text.