TIMING CIRCUITS AND DRIVING CIRCUITS USED IN LIGHTING SYSTEMS
First Claim
1. A timing circuit, comprising:
- a first logic circuit having an input terminal, a first output terminal and a second output terminal, wherein the input terminal is configured to receive a detecting signal, and wherein based on a falling edge of the detecting signal, the first logic circuit provides a first logic signal and a second logic signal at the first output terminal and the second output terminal respectively;
a first counter having a control terminal, a first output terminal and a second output terminal, wherein the control terminal is coupled to the second output terminal of the first logic circuit for receiving the second logic signal, and wherein based on the second logic signal, the first counter generates a first counting signal at the first output terminal and a second counting signal at the second output terminal, and wherein a counting period of the first counting signal is longer than a counting period of the second counting signal;
a latching circuit having a control terminal, an input terminal and an output terminal, wherein the control terminal is coupled to the first output terminal of the first logic circuit for receiving the first logic signal, and wherein the input terminal is coupled to the first output terminal of the first counter for receiving the first counting signal, and wherein based on the first logic signal, the latching circuit samples and holds the first counting signal and provides a third counting signal at the output terminal; and
a judging circuit having a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the second output terminal of the first counter for receiving the second counting signal, the second input terminal is coupled to the output terminal of the latching circuit for receiving the third counting signal, and wherein the judging circuit detects whether the second counting signal is equal to the third counting signal and provides a timing signal at the output terminal accordingly.
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Accused Products
Abstract
A timing circuit used in lighting systems includes a first logic circuit, a first counter, a latching circuit and a judging circuit. The first logic circuit generates a first logic signal and a second logic signal based on a falling edge of a detecting signal. The first counter generates a first counting signal and a second counting signal based on the second logic signal, wherein the counting period of the first counting signal is longer than that of the second counting signal. The latching circuit samples and holds the first counting signal based on the first logic signal and provides a third counting signal. The judging circuit detects whether the second counting signal is equal to the third counting signal and provides a timing signal.
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Citations
20 Claims
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1. A timing circuit, comprising:
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a first logic circuit having an input terminal, a first output terminal and a second output terminal, wherein the input terminal is configured to receive a detecting signal, and wherein based on a falling edge of the detecting signal, the first logic circuit provides a first logic signal and a second logic signal at the first output terminal and the second output terminal respectively; a first counter having a control terminal, a first output terminal and a second output terminal, wherein the control terminal is coupled to the second output terminal of the first logic circuit for receiving the second logic signal, and wherein based on the second logic signal, the first counter generates a first counting signal at the first output terminal and a second counting signal at the second output terminal, and wherein a counting period of the first counting signal is longer than a counting period of the second counting signal; a latching circuit having a control terminal, an input terminal and an output terminal, wherein the control terminal is coupled to the first output terminal of the first logic circuit for receiving the first logic signal, and wherein the input terminal is coupled to the first output terminal of the first counter for receiving the first counting signal, and wherein based on the first logic signal, the latching circuit samples and holds the first counting signal and provides a third counting signal at the output terminal; and a judging circuit having a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the second output terminal of the first counter for receiving the second counting signal, the second input terminal is coupled to the output terminal of the latching circuit for receiving the third counting signal, and wherein the judging circuit detects whether the second counting signal is equal to the third counting signal and provides a timing signal at the output terminal accordingly. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A driving circuit for a lighting system, wherein the lighting system comprises a dimmer, a bridge rectifier and a light emission device, and wherein the driving circuit comprises:
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a detecting circuit having an input terminal coupled to an output terminal of the bridge rectifier and an output terminal configured to provide a detecting signal; a compensating circuit having an input terminal coupled to the output terminal of the detecting circuit and an output terminal configured to provide a compensated detecting signal; and a control circuit configured to adjust voltage or current of the light emission device based on the compensated detecting signal; wherein the compensating circuit comprises; a timing circuit, comprising; a first logic circuit having an input terminal, a first output terminal and a second output terminal, wherein the input terminal is coupled to the output terminal of the detecting circuit for receiving the detecting signal, and wherein based on a falling edge of the detecting signal, the first logic circuit provides a first logic signal and a second logic signal at the first output terminal and the second output terminal respectively; a first counter having a control terminal, a first output terminal and a second output terminal, wherein the control terminal is coupled to the second output terminal of the first logic circuit for receiving the second logic signal, and wherein based on the second logic signal, the first counter generates a first counting signal at the first output terminal and a second counting signal at the second output terminal, and wherein a counting period of the first counting signal is longer than a counting period of the second counting signal; a latching circuit having a control terminal, an input terminal and an output terminal, wherein the control terminal is coupled to the first output terminal of the first logic circuit for receiving the first logic signal, and wherein the input terminal is coupled to the first output terminal of the first counter for receiving the first counting signal, and wherein based on the first logic signal, the latching circuit samples and holds the first counting signal and provides a third counting signal at the output terminal; a judging circuit having a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the second output terminal of the first counter for receiving the second counting signal, the second input terminal is coupled to the output terminal of the latching circuit for receiving the third counting signal, and wherein the judging circuit detects whether the second counting signal is equal to the third counting signal and provides a timing signal at the output terminal; and an operating circuit having a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the output terminal of the detecting circuit for receiving the detecting signal, and wherein the second input terminal is coupled to the output terminal of the timing circuit for receiving the timing signal, and wherein based on the detecting signal and the timing signal, the operating circuit provides the compensated detecting signal at the output terminal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification