US3761803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic field strength measuring apparatus
Assignee: Texaco Inc
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Filing: 1971-12-23
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Granted: 1973-09-25
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Expires: 1991-12-23
Abstract
Abstract A transmitter, including a crystal controlled oscillator, has a pair of three-sided plates mounted on diagonally opposite corners of a rectangular dielectric body. When placed in an electrostatic field, a static voltage is developed across the plates corresponding to the strength of the electrostatic field. The developed voltage is used to change the amount of capacitance of a tank circuit in the oscillator causing the frequency of a signal provided by the oscillator to change. The signal from the oscillator is transmitted to a receiver which may be remotely located from the electrostatic field. The receiver includes a beat oscillator providing a reference signal having the same frequency as the signal induced by the crystal. A detector compares the frequencies of the reference signal and the received signal to provide a signal having a frequency which is the difference in frequency between the received signal and the reference signal. The frequency of the signal from the detector corresponds to the strength of the electrostatic field. The signal from the detector is applied to an output device, such as a loudspeaker or a meter.
Inventors
- 👤 C Slough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:25
CPC Classifications
H; H03; H03B; H03B7/00; H03B7/02; H03B7/06; H03B7/08; G; G01; G01R; G01R5/00; G01R5/28
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
206 words
Apparatus for providing an output corresponding to the strength of an electrostatic field in a gaseous environment, comprising a transmitter placed in the gaseous enviroment, said transmitter includes a pair of conductive plates, a body of dielectric material, said plates being mounted on said body so that a voltage is developed across said plates corresponding to the strength of the electrostatic field, a pair of variable cpacitance diodes connected back to back across said plates, oscillator circuit means connected to said diodes in such a manner that the oscillator provides an output having a frequency which is affected by the diodes responding to said voltage, and means connected to said oscillator for transmitting the output from said oscillator; and a receiver which may be located outside of the gaseous environment and which comprises means for receiving the transmitted output, signal means connected to the receiving means for providing a signal having the same frequency as the received signal, means for providing a reference signal having a frequency corresponding to an unaffected frequency of the oscillator output, and means connected to the signal means and to the reference signal means for providing the output in accordance with the signal from the signal means and the reference signal.
Claim 2
Dependent Claim
206 words
Apparatus for providing an output corresponding to the strength of an electrostatic field in a gaseous environment, comprising a transmitter placed in the gaseous enviroment, said transmitter includes a pair of conductive plates, a body of dielectric material, said plates being mounted on said body so that a voltage is developed across said plates corresponding to the strength of the electrostatic field, a pair of variable cpacitance diodes connected back to back across said plates, oscillator circuit means connected to said diodes in such a manner that the oscillator provides an output having a frequency which is affected by the diodes responding to said voltage, and means connected to said oscillator for transmitting the output from said oscillator; and a receiver which may be located outside of the gaseous environment and which comprises means for receiving the transmitted output, signal means connected to the receiving means for providing a signal having the same frequency as the received signal, means for providing a reference signal having a frequency corresponding to an unaffected frequency of the oscillator output, and means connected to the signal means and to the reference signal means for providing the output in accordance with the signal from the signal means and the reference signal.
Claim 3
Dependent Claim
31 words
Apparatus as described in claim 1 in which each diode is of the type whOse capacitance varies proportionally to the amplitude of a voltage of proper polarity applied across the diode.
Claim 4
Dependent Claim
31 words
Apparatus as described in claim 1 in which the body of dielectric material is rectangular body and the plates are mounted at opposite corners of the body of the dielectric material.
Claim 5
Dependent Claim
29 words
Apparatus as described in claim 3 in which each plate is a single piece of conductive material formed to have three surface planes at right angles to each other.
Claim 6
Dependent Claim
129 words
A transmitter for transmitting a signal corresponding to the strength of an electrostatic field in a gaseous environment when placed in the gaseous environment, comprising a pair of conductive plates, a body of dielectric material, said plates being mounted on said body s0 that a voltage is developed across said plates corresponding to the strength of the electrostatic field when said plates are in the presence of an electrostatic field, a pair of variable capacitance diodes connected back to back across said plates, oscillator circuit means connected to said diodes in such a manner that the oscillator provides an output having a frequency which is affected by the diodes responding to said voltage, and means connected to said oscillator for transmitting the output from said oscillator as the signal.
Claim 7
Dependent Claim
129 words
A transmitter for transmitting a signal corresponding to the strength of an electrostatic field in a gaseous environment when placed in the gaseous environment, comprising a pair of conductive plates, a body of dielectric material, said plates being mounted on said body s0 that a voltage is developed across said plates corresponding to the strength of the electrostatic field when said plates are in the presence of an electrostatic field, a pair of variable capacitance diodes connected back to back across said plates, oscillator circuit means connected to said diodes in such a manner that the oscillator provides an output having a frequency which is affected by the diodes responding to said voltage, and means connected to said oscillator for transmitting the output from said oscillator as the signal.
Claim 8
Dependent Claim
32 words
A transmitter as described in claim 5 in which each diode is of the type whose capacitance varies proportionally to the amplitude of a voltage of proper polarity applied across the diode.
Claim 9
Dependent Claim
32 words
A transmitter as described in claim 6 in which the body of dielectric material is rectangular body and the plates are mounted at opposite corners of the body of the dielectric material.
Claim 10
Dependent Claim
30 words
A transmitter as described in claim 7 in which each plate is a single piece of conductive material formed to have three surface planes at right angles to each other.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |