Apparatus for AC-to-DC conversion which provides a signed DC signal
First Claim
1. An apparatus for obtaining phase and amplitude signal information from a displacement transducer that is excited by an AC excitation signal and provides an AC input signal indicative of transducer position, said apparatus comprising:
- a first rectifier circuit that receives and sums the AC excitation signal and the AC input signal, and rectifies the sum to provide a rectified summed excitation and input signal indicative thereof;
a second rectifier circuit that receives and rectifies the AC excitation signal and provides a rectified excitation signal indicative thereof; and
a summing circuit that receives and determines the differences between said rectified summed excitation and input signal and said rectified excitation signal to provide a signed DC signal indicative of displacement transducer position.
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Accused Products
Abstract
An AC-to-DC converter obtains phase and amplitude signal information from a displacement transducer that is excited by an AC excitation signal and provides an AC sensor signal indicative of transducer position. The converter includes a first rectifier circuit that receives and sums the AC excitation signal and the AC sensor signal, and rectifies the sum to provide a rectified summed excitation and input signal indicative thereof. A second rectifier circuit receives and rectifies the AC excitation signal, and provides a rectified excitation signal indicative thereof. A summing circuit computes the difference between the rectified summed excitation and input signal and the rectified excitation signal, and provides a signed DC signal indicative of displacement transducer position. Advantageously, the AC-to-DC converter of the present invention performs summing and difference functions directly and provides a signed DC signal representative of the AC amplitude and phase input of the transducer output, thus eliminating the need for an analog-to-digital converter (ADC) and the support of an associated processor.
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Citations
11 Claims
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1. An apparatus for obtaining phase and amplitude signal information from a displacement transducer that is excited by an AC excitation signal and provides an AC input signal indicative of transducer position, said apparatus comprising:
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a first rectifier circuit that receives and sums the AC excitation signal and the AC input signal, and rectifies the sum to provide a rectified summed excitation and input signal indicative thereof;
a second rectifier circuit that receives and rectifies the AC excitation signal and provides a rectified excitation signal indicative thereof; and
a summing circuit that receives and determines the differences between said rectified summed excitation and input signal and said rectified excitation signal to provide a signed DC signal indicative of displacement transducer position. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An AC-DC converter circuit for obtaining phase and amplitude signal information from a displacement transducer that is excited by an AC excitation signal and provides an AC input signal indicative of transducer position, said converter circuit comprising:
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a first rectifier circuit that receives the AC excitation signal and rectifies said AC excitation signal and provides a rectified excitation signal indicative thereof;
a second rectifier circuit of opposite polarity from said first rectifier circuit, wherein said second rectifier circuit receives and rectifies the AC input signal and provides a rectified sensor position signal indicative thereof;
means for summing the AC excitation signal, the AC signal, said rectified excitation signal and said rectified sensor position signal to provide a signed summed signal; and
means for filtering said signed summed signal to provide a filtered signal indicative of displacement transducer position. - View Dependent Claims (9, 10)
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11. Apparatus for AC-to-DC conversion that receives an AC excitation signal and an AC input signal from a transducer excited by the AC excitation signal, and provides a signed DC signal indicative of transducer position, said apparatus comprising:
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an inverting rectifier circuit that receives the AC excitation signal and the AC input signal and rectifies the sum of the AC excitation signal and the AC input signal to provide a rectified summed excitation and input signal indicative thereof;
a non-inverting rectifier circuit that receives and rectifies the AC excitation signal and provides a rectified excitation signal indicative thereof; and
a current summing circuit that receives and sums said rectified summed excitation and input signal and said rectified excitation signal and provides a summed current signal that is filtered to provide the signed DC signal.
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Specification