Patent US4950978A successfully refreshed from Google Patents.
US4950978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Atmospheric potential measurement device
Assignee: Airborne Research Associates
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Filing: 1988-12-08
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Granted: 1990-08-21
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Expires: 2008-12-08
Abstract
Abstract A device to remove the dead band in atmospheric electric potential measurements while maintaining a low leakage path to ground. In one embodiment the device comprises a AC high voltage source connected through a high ohm resistor and capacitor network to a sharp corona point and a means for measuring the current through the corona point.
Inventors
- 👤 Johan A. Govaert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:04
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
76 words
An electrostatic potential measuring device comprising a corona point made of a conductor connected in series with a capacitor which in turn is connected to a terminal of a high voltage power supply, said point also connected in series with a high ohm resistor which in turn is connected to a low pass filter, the output signal of said filter being the input signal to a device for determining the current flow through said corona point.
Claim 2
Dependent Claim
76 words
An electrostatic potential measuring device comprising a corona point made of a conductor connected in series with a capacitor which in turn is connected to a terminal of a high voltage power supply, said point also connected in series with a high ohm resistor which in turn is connected to a low pass filter, the output signal of said filter being the input signal to a device for determining the current flow through said corona point.
Claim 3
Dependent Claim
114 words
An electrostatic potential measuring device comprising a corona point made of a conductor connected in series with a plurality of capacitors which are connected in series and which are in turn connected to a terminal of a high voltage power supply, said point is also connected in series with a plurality of high ohm resistors which are connected in series and which in turn are connected to a low pass filter, the output signal of said filter being the input signal to a device for determining the current flow through said corona point, wherein each of said capacitors and resistors except for the last resistor and capacitor are connected in parallel with each other.
Claim 4
Dependent Claim
114 words
An electrostatic potential measuring device comprising a corona point made of a conductor connected in series with a plurality of capacitors which are connected in series and which are in turn connected to a terminal of a high voltage power supply, said point is also connected in series with a plurality of high ohm resistors which are connected in series and which in turn are connected to a low pass filter, the output signal of said filter being the input signal to a device for determining the current flow through said corona point, wherein each of said capacitors and resistors except for the last resistor and capacitor are connected in parallel with each other.
Claim 5
Independent Claim
16 words
The device of claims 1 or 2 wherein said corona point is made of stainless steel.
Claim 6
Dependent Claim
14 words
The device of claim 3 wherein said corona point is sharpened by chemical etching.
Claim 7
Independent Claim
13 words
The device of claims 1 or 2 wherein said high voltage is AC.
Claim 8
Independent Claim
14 words
The device of claims 1 or 2 wherein said high voltage is pulsed DC.
Claim 9
Independent Claim
16 words
The device of claims 1 or 2 wherein said corona point is located atop a mast.
Claim 10
Dependent Claim
15 words
The device of claim 7 wherein said mast is greater than 5 meters in height.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-20 | 1994-02-19 | 1994-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-20 | 1998-02-19 | 1998-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-20 | 2002-02-19 | 2002-08-21 | $7700.00 | Window Closed / Lapsed |