Lighting control system
First Claim
1. A lighting control circuit for controlling illumination and dimming of at least one light in a lighting circuit, said lighting control circuit comprising:
- power supply means for receiving an AC line voltage input and for converting said AC line voltage to selectable rectified Ac and DC power supplies;
timing generator circuit means coupled with said power supply means and responsive to a rectified Ac power supply from said power supply means for generating and shaping an electrical timing signal;
timing comparator circuit means responsive to said electrical timing signal and to a selectable control voltage for generating a variable duty cycle output signal;
switching circuit means coupled with said lighting circuit for gating current therethrough and having a control input coupled in circuit with said timing comparator circuit means for gating said current in accordance with said variable duty cycle output, and current limiting comparator circuit means coupled with said switching circuit means and with said lighting circuit means for comparing the current gated by said switching circuit means with a selectable threshold value, and for controlling said switching circuit means to limit current flow in said lighting circuit in accordance with said comparison.
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Accused Products
Abstract
A lighting control circuit is provided for controlling illumination and dimming of at least one light in a lighting circuit for operation at a selectable one of a plurality of applied voltages. The lighting control circuit includes a power supply circuit for receiving an AC line voltage input and for converting the AC line voltage to selectable rectified AC and DC power for delivery to the lighting control circuit. A timing generator circuit is also coupled with the power supply circuit and is responsive to a rectified AC sample from the power supply for generating and shaping an electrical timing signal. A timing comparator circuit is responsive to the electrical timing signal for generating a variable duty cycle output signal. A switching control circuit is coupled with the lighting circuit for gating current therethrough in accordance with the variable duty cycle output control signal.
56 Citations
12 Claims
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1. A lighting control circuit for controlling illumination and dimming of at least one light in a lighting circuit, said lighting control circuit comprising:
- power supply means for receiving an AC line voltage input and for converting said AC line voltage to selectable rectified Ac and DC power supplies;
timing generator circuit means coupled with said power supply means and responsive to a rectified Ac power supply from said power supply means for generating and shaping an electrical timing signal;
timing comparator circuit means responsive to said electrical timing signal and to a selectable control voltage for generating a variable duty cycle output signal;
switching circuit means coupled with said lighting circuit for gating current therethrough and having a control input coupled in circuit with said timing comparator circuit means for gating said current in accordance with said variable duty cycle output, and current limiting comparator circuit means coupled with said switching circuit means and with said lighting circuit means for comparing the current gated by said switching circuit means with a selectable threshold value, and for controlling said switching circuit means to limit current flow in said lighting circuit in accordance with said comparison. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- power supply means for receiving an AC line voltage input and for converting said AC line voltage to selectable rectified Ac and DC power supplies;
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11. A lighting control circuit for controlling illumination and dimming of at least one light in a lighting circuit, said lighting control circuit comprising:
- power supply means for receiving an AC line voltage input and for converting said AC line voltage to selectable rectified Ac and Dc power supplies;
timing generator circuit means coupled with said power supply means and responsive to a rectified AC power supply from said power supply means for generating and shaping an electrical timing signal;
timing comparator circuit means responsive to said electrical timing signal for generating a variable duty cycle output signal;
switching circuit means coupled with said lighting circuit for gating current therethrough in accordance with said variable duty cycle output signal; and
line voltage isolation circuit means interposed between said timing comparator circuit means and said switching circuit means for isolating AC line-connected circuit portions from low-voltage circuit portions.
- power supply means for receiving an AC line voltage input and for converting said AC line voltage to selectable rectified Ac and Dc power supplies;
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12. A lighting control circuit for controlling illumination and dimming of at least one light in a lighting circuit said lighting control circuit comprising:
- power supply means for receiving an AC line voltage input and for converting said AC line voltage to selectable rectified AC and Dc power supplies;
timing generator circuit means coupled with said power supply means and responsive to a rectified AC power supply from said power supply means for generating and shaping an electrical timing signal;
timing comparator circuit means responsive to said electrical timing signal for generating a variable duty cycle output signal; and
switching circuit means coupled with said lighting circuit for gating current therethrough in accordance with said variable duty cycle output signal;
said switching circuit means including power transistor means coupled for gating current through said lighting circuit and further including waveform shaping circuit means coupled between said timing comparator circuit means and said switching circuits for regulating the switching time of said power transistor means.
- power supply means for receiving an AC line voltage input and for converting said AC line voltage to selectable rectified AC and Dc power supplies;
Specification