Moisture-detection device

• US 20020189329A1
• Filed: 06/07/2002
• Published: 12/19/2002
• Est. Priority Date: 06/08/2001
• Status: Active Grant

• Current Assignee: VOGT Electronic AG (Sumida Corporation)
• Original Assignee: VOGT Electronic AG (Sumida Corporation)
• Inventors: Wimmer, Willi
• Granted Patent: US 6,981,405 B2
• Time in Patent Office: Days
• US Class Current: 73/73
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• CPC Class Codes: B60S 1/0829 Oscillator-resonator rain sensor
• CPC Class Codes: B60S 1/0877 at least part of the sensor being positioned between layers of the windshield
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825

Abstract

A device for determining moisture has an LC-oscillating circuit (1) as a transducer and an oscillator (2) for exciting the oscillating circuit (1). Further, the device for determining moisture has a tuning device (3) for frequency-wise tuning the oscillator (2) and a measuring and evaluation circuit (4) to determine an attenuation condition of the oscillator (2) and to provide a signal that is proportional to a degree of moisture at the transducer (1). The transducer (1) and the oscillator (2) are coupled in a contact-free manner.

Claims

1. A device for determining moisture, said device including an LC-oscillating circuit as a transducer (1);

an oscillator (2) for exciting the oscillating circuit (1);

a tuning device (3) for frequency-wise tuning the oscillator (2); and

a measuring and evaluation circuit (4) for recording the moisture condition of the oscillator (2) and for providing a signal that is proportional to a degree of moisture at the transducer (1);

wherein the transducer (1) and the oscillator (2) are coupled by a contact-free energy coupling.

4. The device of claim 1, wherein the transducer is formed of a single conductive lead.

6. The device of claim 1, wherein the transducer (1) is integrated into a support.

7. The device of claim 6, wherein the transducer (1), as seen in a cross section of the support, is arranged closer to a front surface of the support than to an opposite surface of the support.

8. The device of claim 1, wherein the transducer (1) is mounted on an outer surface of a support.

9. The device of claim 6, wherein the support is a window pane.

10. The device of claim 9, wherein the window pane is a pane of a motor vehicle (7).

11. The device of claim 1, wherein is further included at least one additional LC-oscillating circuit as a further transducer.

12. The device of claim 11, wherein the at least one additional LC-oscillating circuit is used for taking a reference measurement.

13. The device of claim 11, wherein the oscillating circuits are so arranged that their natural frequencies do not cross in a range of from 0% to 100% moisture.

14. The device of claim 7, wherein there is at least one additional LC-oscillating circuit as a further transducer, and wherein the at least one additional LC-oscillating circuit is mounted on the opposite surface of the support.

15. The device of claim 10, wherein the oscillator (2) is integrated into one of a mirror (8) and a roof of the motor vehicle (7).

16. The device of claim 1, wherein a spacing between the oscillator (2) and the transducer (1) is in a range of from 1 cm to 1 m.

17. A method of using the device of claim 1, wherein the device is used to measure moisture in an oven.

18. The device of claim 4, wherein the single conductive lead is arranged in one of a planar and coiled manner.

2. A device for determining moisture, said device including:

an LC-oscillating circuit as a transducer (1);

an oscillator (2) for exciting the oscillating circuit (1);

a tuning device (3) for frequency-wise tuning the oscillator (2); and

a measuring and evaluation circuit (4) for recording the moisture condition of the oscillator (2) and for providing a signal that is proportional to a degree of moisture at the transducer (1);

wherein the transducer (1) is formed of a single conductive lead.

3. The device of claim 2, wherein the transducer (1) and the oscillator (2) have a galvanic coupling.

5. The device of claim 2, wherein the single conductive lead is arranged in one of a planar and coiled manner.

19. A method of using the device of claim 2, wherein the device is used to measure moisture in an oven.