Power source sensing dimming circuits and methods of operating same
AssigneeCree, Inc.
InventorsJoseph Paul Chobot, Michael James Harris, Paul Arthur Beck
Life of this patent
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Abstract
Lighting is controlled by receiving an input signal, determining whether the input signal is an AC signal or a DC signal and generating a dimming command signal based on the determination of whether the input signal is an AC signal or a DC signal. For example, determining whether the input signal is an AC signal or a DC signal may include generating an average signal indicative of an average duty cycle of the input signal and determining whether the average signal meets a predetermined criterion.
Claims33
A lighting control circuit comprising:
- a dimming command signal generation circuit configured to receive an input signal and to responsively generate a dimming command signal to apply a dimming that varies over a range between a minimum dimming and a maximum dimming responsive to variation of a dimming control signal when the input signal is an AC signal and to apply a fixed dimming greater than the minimum dimming when the input signal is a DC signal.
A lighting control circuit, comprising:
- a sense signal input;
- a dimming control signal generation circuit configured to generate a dimming control signal;
- and
- a variable gain circuit configured to apply a first gain to the dimming control signal responsive to a first state of a signal at the sense signal input to generate a dimming command signal and to apply a second gain to the dimming control signal responsive to a second state of the signal at the sense signal input to generate the dimming command signal.
A method of controlling lighting, comprising:
- generating a dimming command signal responsive to an input signal to apply a dimming that varies over a range between a minimum dimming and a maximum dimming responsive to a dimming control signal when the input signal is an AC signal and to apply a fixed dimming greater than the minimum dimming when the input signal is a DC signal.
A lighting control circuit comprising:
- a dimming command signal generation circuit configured to receive an input signal, to determine whether the input signal is an AC signal or a DC signal, and to responsively generate a dimming command signal based on the determination of whether the input signal is an AC signal or a DC signal.
A method of controlling lighting, comprising:
- receiving an input signal;
- determining whether the input signal is an AC signal or a DC signal;
- and
- generating a dimming command signal based on the determination of whether the input signal is an AC signal or a DC signal.
Dependencies are inferred from the claim text.