Line voltage detection circuit
First Claim
1. A system comprising:
- a first filter configured tooutput a first signal in response to receiving an input signal,wherein the first signal has a first state in response to the input signal reaching a first threshold voltage on a leading edge of the input signal, andwherein the first signal has a second state in response to the input signal reaching the first threshold voltage on a trailing edge of the input signal;
a second filter configured tooutput a second signal in response to receiving the input signal,wherein the second signal has the first state in response to the input signal reaching a second threshold voltage on the leading edge of the input signal, andwherein the second signal has the second state in response to the input signal reaching the second threshold voltage on the trailing edge of the input signal; and
a detection circuit configured to determine, based on times at which the first threshold and the second threshold are reached on the leading edge of the input signal or the trailing edge of the input signal, whether the input signal is received from a triac.
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Accused Products
Abstract
A first filter outputs a first signal in response to receiving an input signal. The first signal has a first state in response to the input signal reaching a first threshold voltage on a leading edge of the input signal, and a second state in response to the input signal reaching the first threshold voltage on a trailing edge of the input signal. A second filter outputs a second signal in response to receiving the input signal. The second signal has the first state in response to the input signal reaching a second threshold voltage on the leading edge of the input signal, and the second state in response to the input signal reaching the second threshold voltage on the trailing edge of the input signal. A detection circuit determines, based on times when the first and second thresholds are reached, whether the input signal is received from a triac.
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Citations
13 Claims
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1. A system comprising:
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a first filter configured to output a first signal in response to receiving an input signal, wherein the first signal has a first state in response to the input signal reaching a first threshold voltage on a leading edge of the input signal, and wherein the first signal has a second state in response to the input signal reaching the first threshold voltage on a trailing edge of the input signal; a second filter configured to output a second signal in response to receiving the input signal, wherein the second signal has the first state in response to the input signal reaching a second threshold voltage on the leading edge of the input signal, and wherein the second signal has the second state in response to the input signal reaching the second threshold voltage on the trailing edge of the input signal; and a detection circuit configured to determine, based on times at which the first threshold and the second threshold are reached on the leading edge of the input signal or the trailing edge of the input signal, whether the input signal is received from a triac. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method comprising:
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generating, using a first filter, a first signal having (i) a first state in response to an input signal reaching a first threshold voltage on a leading edge of the input signal, and (ii) a second state in response to the input signal reaching the first threshold voltage on a trailing edge of the input signal; generating, using a second filter, a second signal having (i) the first state in response to the input signal reaching a second threshold voltage on the leading edge of the input signal, and (ii) the second state in response to the input signal reaching the second threshold voltage on the trailing edge of the input signal; and determining, based on times at which the first threshold and the second threshold are reached on the leading edge of the input signal or the trailing edge of the input signal, whether the input signal is received from a triac. - View Dependent Claims (10, 11, 12, 13)
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Specification