Moisture detection system and method of use thereof
First Claim
1. A moisture detection system comprising:
- an electrical conductor disposed on a surface of a substrate and having a resonant frequency that varies as a function of an amount of moisture present adjacent the electrical conductor;
an oscillator which outputs an oscillator signal at a predetermined amplitude and a predetermined frequency;
a resonator circuit coupled to the electrical conductor and responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the electrical conductor;
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 an electrical conductor disposed on a surface of a substrate. The electrical conductor has a resonant frequency that varies as a function of an amount of moisture present adjacent the electrical conductor. An oscillator outputs an oscillator signal at a predetermined amplitude and a predetermined frequency. A resonator circuit is coupled to the electrical conductor and is responsive to the oscillator signal and the resonant frequency of the electrical conductor for outputting a resonator signal having an amplitude related to the resonant frequency of the electrical conductor. A filter circuit rectifies and filters the resonator signal and provides it to an analog-to-digital converter which outputs a digital signal related to the rectified and filtered resonator signal. A controller is responsive to the digital signal for causing a system associated with the substrate to operate in accordance with the digital signal.
68 Citations
38 Claims
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1. A moisture detection system comprising:
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an electrical conductor disposed on a surface of a substrate and having a resonant frequency that varies as a function of an amount of moisture present adjacent the electrical conductor;
an oscillator which outputs an oscillator signal at a predetermined amplitude and a predetermined frequency;
a resonator circuit coupled to the electrical conductor and responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the electrical conductor;
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, 5, 6, 7, 8, 9, 11)
the wiper system includes a means for wiping; and
the wiper system is responsive to the digital signal for causing the wiping means to remove moisture from a surface.
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5. The system as set forth in claim 1, wherein:
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the substrate is a vehicle windshield having a plurality of transparent sheets laminated together, and the electrical conductor is sandwiched between the sheets.
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6. The system as set forth in claim 1, wherein the substrate is a flexible substrate.
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7. The system as set forth in claim 6, further including a vehicle windshield having a plurality of transparent sheets laminated together with the flexible substrate sandwiched between the transparent sheets.
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8. The system as set forth in claim 7, further including an electrically conductive coating disposed on a surface of at least one transparent sheet.
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9. The system as set forth in claim 8, wherein said surface is positioned on a side of the flexible substrate opposite the electrical conductor.
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11. The system as set forth in claim 1, wherein the resonator circuit includes:
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a tank circuit having a capacitor and an inductor connected in parallel between the electrical conductor and a reference voltage; and
a resistor connected between the oscillator and the electrical conductor side of the tank circuit.
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4. A moisture detection system comprising:
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an electrical conductor disposed on a surface of a substrate and having a resonant frequency that varies as a function of an amount of moisture present adjacent the electrical conductor;
an oscillator which outputs an oscillator signal at a predetermined amplitude and a predetermined frequency;
a resonator circuit coupled to the electrical conductor and responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the electrical conductor;
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, wherein the predetermined frequency is between one of (i) 300 and 700 kHz and (ii) 400 and 600 kHz.
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10. A moisture detection system comprising:
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an electrical conductor disposed on a surface of a substrate and having a resonant frequency that varies as a function of an amount of moisture present adjacent the electrical conductor;
an oscillator which outputs an oscillator signal at a predetermined amplitude and a predetermined frequency;
a resonator circuit coupled to the electrical conductor and responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the electrical conductor;
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, wherein;
the substrate is a flexible substrate; and
the flexible substrate further includes at least one of (i) a ground conductor disposed on the flexible substrate at least partially surrounding the electrical conductor and (ii) a conductive material disposed on a surface of the flexible substrate opposite the electrical conductor, said conductive material having a form that defines a faraday shield.
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12. A moisture detection system comprising:
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an electrical conductor disposed on a surface of a substrate and having a resonant frequency that varies as a function of an amount of moisture present adjacent the electrical conductor;
an oscillator which outputs an oscillator signal at a predetermined amplitude and a predetermined frequency;
a resonator circuit coupled to the electrical conductor and responsive to the oscillator signal for outputting a resonator signal having an amplitude related to the resonant frequency of the electrical conductor;
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, wherein the filter circuit includes;
a diode connected to conduct current from the resonator toward the analog-to-digital converter; and
a capacitor connected between an end of the diode adjacent the analog-to-digital converter and a reference voltage.
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13. A moisture detector system comprising:
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means disposed on a substrate for conducting electrical current, the conducting means having a resonant frequency that changes as a function of moisture adjacent the conducting means;
an oscillator for outputting to the conducting means an oscillator signal having a predetermined frequency and a first amplitude;
means responsive to the oscillator signal for outputting a resonator signal having a second amplitude related to the resonant frequency of the conducting means, wherein the second amplitude is different than the first amplitude; and
means responsive to the resonator signal for outputting a control signal having a value related to the second amplitude of the resonator signal. - View Dependent Claims (14)
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15. A moisture detector system comprising:
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means disposed on a substrate for conducting electrical current, the conducting means having a resonant frequency that changes as a function of moisture adjacent the conducting means;
an oscillator for outputting to the conducting means an oscillator signal having a predetermined frequency and a first amplitude;
means responsive to the oscillator signal for outputting a resonator signal having a second amplitude related to the resonant frequency of the conducting means, wherein the second amplitude is different than the first amplitude; and
means responsive to the resonator signal for outputting a control signal having a value related to the second amplitude of the resonator signal, wherein the conducting means includes at least one of (i) one or more lines of conductive material, (ii) one or more sheets of conductive material, and (iii) a dispersion of conductive particles in the form of one or more lines and/or sheets.
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16. A moisture detector system comprising:
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means disposed on a substrate for conducting electrical current, the conducting means having a resonant frequency that changes as a function of moisture adjacent the conducting means;
an oscillator for outputting to the conducting means an oscillator signal having a predetermined frequency and a first amplitude;
means responsive to the oscillator signal for outputting a resonator signal having a second amplitude related to the resonant frequency of the conducting means, wherein the second amplitude is different than the first amplitude; and
means responsive to the resonator signal for outputting a control signal having a value related to the second amplitude of the resonator signal, wherein the substrate is a windshield that includes plural sheets of glass laminated together. - View Dependent Claims (17)
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18. A moisture detector system comprising:
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means disposed on a substrate for conducting electrical current, the conducting means having a resonant frequency that changes as a function of moisture adjacent the conducting means;
an oscillator for outputting to the conducting means an oscillator signal having a predetermined frequency and a first amplitude;
means responsive to the oscillator signal for outputting a resonator signal having a second amplitude related to the resonant frequency of the conducting means, wherein the second amplitude is different than the first amplitude; and
means responsive to the resonator signal for outputting a control signal having a value related to the second amplitude of the resonator signal, wherein;
the substrate is a flexible substrate that is coupled to a sheet; and
the conducting means has a resonant frequency that changes as a function of moisture on the sheet. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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26. A method of moisture detection comprising:
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(a) providing a substrate having an electrical conductor disposed thereon;
(b) stimulating the electrical conductor with an oscillator signal in the absence of moisture adjacent the electrical conductor;
(c) determining a first amplitude of the electrical conductor to the stimulation in step (b);
(d) stimulating the electrical conductor with the oscillator signal when moisture is present adjacent the electrical conductor;
(e) determining a second amplitude of the electrical conductor to the stimulation in step (d), wherein the second amplitude is different than the first amplitude due to a change in resonant frequency of the electrical conductor in response to the presence of moisture adjacent the electrical conductor; and
(f) determining a difference between the first amplitude and the second amplitude, wherein the difference is related to the amount of moisture present adjacent the electrical conductor. - View Dependent Claims (27, 28, 29, 30)
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31. A moisture detection system comprising:
- a substrate;
an electrical conductor disposed on the substrate;
means for stimulating the electrical conductor with an oscillator signal operating at a predetermined frequency;
means responsive to the oscillator signal and the electrical conductor for detecting changes in resonant frequency of the electrical conductor in response to changes in an amount of moisture disposed adjacent the electrical conductor; and
a controller responsive to the frequency changes for causing another system to operate in accordance with the changes. - View Dependent Claims (32)
- a substrate;
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33. A moisture detection system comprising:
- a substrate;
an electrical conductor disposed on the substrate;
means for stimulating the electrical conductor with an oscillator signal;
means responsive to the oscillator signal and the electrical conductor for detecting changes in a resonant frequency of the electrical conductor in response to changes in an amount of moisture disposed adjacent the electrical conductor;
a controller responsive to the frequency changes for causing another system to operate in accordance with the changes; and
a sheet in contact with the substrate. - View Dependent Claims (34, 35, 36)
- a substrate;
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37. A moisture detection system comprising:
- a fluid reservoir, an electrical conductor disposed on the fluid reservoir;
means for stimulating the electrical conductor with an oscillator signal;
means for stimulating the electrical conductor with an oscillator signal;
means responsive to the oscillator signal and the electrical conductor for detecting a change in a resonant frequency of the electrical conductor responsive to a change in a level of fluid in the fluid reservoir and for outputting a control signal when the detected change in the resonant frequency of the electrical conductor corresponds to less than a desired level of fluid in the fluid reservoir; and
a controller responsive to the frequency changes for causing another system to operate in accordance with the changes. - View Dependent Claims (38)
- a fluid reservoir, an electrical conductor disposed on the fluid reservoir;
Specification