Multi-layer windshield moisture detector
First Claim
1. A moisture detection system comprising:
- a moisture detector including a first electrical conductor disposed on a surface of a first substrate and having a resonant frequency that varies as a function of an amount of moisture present adjacent the first electrical conductor, an electrically conductive layer disposed on the surface of a second substrate, and a spacing layer disposed between the first and second substrates for maintaining at least portions of the first electrical conductor and the electrically conductive layer in spaced relation;
an oscillator which outputs an oscillator signal at a predetermined frequency;
a resonator circuit coupled to the first electrical conductor and responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the first electrical conductor and the predetermined frequency;
a filter circuit responsive to the resonator signal for outputting a rectified and filtered signal;
an analog-to-digital converter responsive to the rectified and filtered signal for outputting a digital signal related to the rectified and filtered signal; and
a controller responsive to the digital signal for causing another system to operate in accordance with the digital signal.
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Accused Products
Abstract
A moisture detection system includes a moisture detector having a first electrical conductor, a first substrate having the first electrical conductor disposed on one surface thereof, a spacing layer coupled to the other surface of the first substrate, a second substrate having one surface thereof coupled to a surface of the spacing layer opposite the first substrate, and an electrically conductive layer disposed on a surface of a substrate opposite the spacing layer. A second electrical conductor can be disposed on the same surface of the first substrate as the first electrical conductor. The first and second electrical conductors can define interdigitated fingers. Circuitry is provided for stimulating the first electrical conductor with a predetermined frequency oscillator signal and for outputting a control signal that is responsive to the response of the first electrical conductor to the oscillator signal and an amount of moisture adjacent the first electrical conductor.
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Citations
21 Claims
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1. A moisture detection system comprising:
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a moisture detector including a first electrical conductor disposed on a surface of a first substrate and having a resonant frequency that varies as a function of an amount of moisture present adjacent the first electrical conductor, an electrically conductive layer disposed on the surface of a second substrate, and a spacing layer disposed between the first and second substrates for maintaining at least portions of the first electrical conductor and the electrically conductive layer in spaced relation;
an oscillator which outputs an oscillator signal at a predetermined frequency;
a resonator circuit coupled to the first electrical conductor and responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the first electrical conductor and the predetermined frequency;
a filter circuit responsive to the resonator signal for outputting a rectified and filtered signal;
an analog-to-digital converter responsive to the rectified and filtered signal for outputting a digital signal related to the rectified and filtered signal; and
a controller responsive to the digital signal for causing another system to operate in accordance with the digital signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A moisture detection system comprising:
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a moisture detector including a spacing layer disposed between a first printed circuit layer having a first electrical conductor disposed on a surface of a substrate thereof and a second printed circuit layer having an electrically conductive layer disposed on the surface of a substrate thereof, the spacing layer maintaining at least a portion of the first electrical conductor and at least a portion of the electrically conductive layer in spaced relation;
an oscillator for outputting to the first electrical conductor an oscillator signal at a predetermined frequency;
circuitry responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the first electrical conductor; and
circuitry responsive to the resonator signal for outputting a control signal related to an amplitude of the resonator signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A moisture detection system comprising a moisture detector including:
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a first electrical conductor;
a first substrate having the first electrical conductor disposed on one surface thereof;
a spacing layer coupled to the other surface of the first substrate;
a second substrate having one surface thereof coupled to a surface of the spacing layer opposite the first substrate; and
an electrically conductive layer disposed on a surface of a substrate opposite the spacing layer. - View Dependent Claims (20, 21)
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Specification