Lighting control circuit for vehicle lighting fixture
First Claim
1. A lighting control circuit for a vehicle lighting fixture, comprising:
- an energy supply control section which receives power from a power supply, and supplies light emission energy to a plurality of semiconductor light sources connected in series with each other as well as controls a current and a voltage for the plurality of semiconductor light sources; and
a fault detection section which makes relative comparison between a voltage applied to all of the semiconductor light sources and a voltage applied to a part of the semiconductor light sources to detect a fault in any one of the semiconductor light sources.
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Accused Products
Abstract
Relative comparison is made between a voltage applied to the whole of the first through eighth LEDs and a voltage applied to the first LED by a comparator. When the voltage applied to the whole of the LEDs has relatively dropped with respect to the voltage applied to part of the LEDs, the comparator outputs a Low Level signal, assumes an abnormality that accompanies a short-circuit fault in any one of the LEDs and causes a ninth LED to illuminate. Meanwhile, relative comparison is made between a voltage applied to the whole of the first through eighth LEDs and a voltage applied to the first LED by another comparator. When the voltage applied to the whole of the LEDs has relatively dropped with respect to the voltage applied to part of the LEDs, the comparator outputs a Low Level signal, assumes an abnormality that accompanies a short-circuit fault in the first LED and causes a ninth LED to illuminate.
44 Citations
9 Claims
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1. A lighting control circuit for a vehicle lighting fixture, comprising:
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an energy supply control section which receives power from a power supply, and supplies light emission energy to a plurality of semiconductor light sources connected in series with each other as well as controls a current and a voltage for the plurality of semiconductor light sources; and
a fault detection section which makes relative comparison between a voltage applied to all of the semiconductor light sources and a voltage applied to a part of the semiconductor light sources to detect a fault in any one of the semiconductor light sources. - View Dependent Claims (2, 7)
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3. A lighting control circuit for a vehicle lighting fixture, comprising:
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an energy supply control section which receives power from a power supply, and supplies light emission energy to a plurality of semiconductor light sources connected in series with each other as well as controls a current and a voltage for the plurality of semiconductor light sources; and
a fault detection section which makes relative comparison between a voltage applied to all of the semiconductor light sources and a voltage applied to a part of the semiconductor light sources as well as makes relative comparison between the voltage applied to the part of the semiconductor light sources and a voltage applied to another part of the semiconductor light sources other than the part of the semiconductor light sources to detect a fault in any one of the semiconductor light sources. - View Dependent Claims (4, 8)
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5. A lighting control circuit for a vehicle lighting fixture, comprising:
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an energy supply control section which receives power from a power supply, and supplies light emission energy to a plurality of semiconductor light sources connected in series with each other as well as controls a current and a voltage for the plurality of semiconductor light sources; and
a fault detection section which makes relative comparison between a voltage applied to all of the semiconductor light sources and a voltage applied to a part of the semiconductor light sources as well as makes relative comparison between the voltage applied to the part of the semiconductor light sources and a set voltage to detect a fault in any one of the semiconductor light sources. - View Dependent Claims (6, 9)
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Specification