US4594543A
Expired / Lapsed
US
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Lightning warning system
Assignee: South African Inventions Development Corp
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Filing: 1983-11-07
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Granted: 1986-06-10
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Expires: 2003-11-07
Abstract
Abstract An apparatus and method for warning against lightning strikes, in which the rate of occurrence of ground flashes is determined and used as a criterion. The rate of occurrence of ground flashes in 0 to 5 kilometers, 5 to 10 kilometers and 10 to 20 kilometers is determined. In addition, the field intensity is used as a criterion. A series of time windows is generated, each time window starting when a ground flash occurs, and the number of flashes occurring in each time window is counted to determine the rate of occurrence. A criterion selection matrix is provided to select various criteria in different combinations to provide different alarm levels.
Inventors
- 👤 Andrew J. Eriksson
- 👤 Patrick C. Kuhn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:32
CPC Classifications
G; G01; G01W; G01W1/00; G01W1/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
208 words
An apparatus for warning against lightning strikes, which includes a plurality of lightning ground flash sensing means each for sensing the occurrence of a ground flash at a distance that is within a predetermined range therefrom, and each for supplying a flash signal if the flash occurred within the predetermined range for that sensing means; a number of rate determining means each for determining the rate of occurrence of the rate signals of an associated flash sensing means; and a number of level detecting means, each for detecting if the rate of occurrence as determined by an associated rate determining means exceeds a predetermined value and for providing a level signal if it does, there being twice as many rate determining means and level detecting means as there are flash sensing means, with a pair of rate determining means and level detecting means associated with each flash sensing means and with one of the level detecting means of each pair for supplying a low level signal if the rate determined by its associated rate determining means exceeds a first low value and the other of each pair for supplying a high level signal if the rate determined by its associated rate determining means exceeds a second, high value.
Claim 2
Independent Claim
208 words
An apparatus for warning against lightning strikes, which includes a plurality of lightning ground flash sensing means each for sensing the occurrence of a ground flash at a distance that is within a predetermined range therefrom, and each for supplying a flash signal if the flash occurred within the predetermined range for that sensing means; a number of rate determining means each for determining the rate of occurrence of the rate signals of an associated flash sensing means; and a number of level detecting means, each for detecting if the rate of occurrence as determined by an associated rate determining means exceeds a predetermined value and for providing a level signal if it does, there being twice as many rate determining means and level detecting means as there are flash sensing means, with a pair of rate determining means and level detecting means associated with each flash sensing means and with one of the level detecting means of each pair for supplying a low level signal if the rate determined by its associated rate determining means exceeds a first low value and the other of each pair for supplying a high level signal if the rate determined by its associated rate determining means exceeds a second, high value.
Claim 3
Dependent Claim
44 words
An apparatus as claimed in claim 1, in which each rate determining means includes a time window generating means for generating a time window of a predetermined duration and a counting means for counting the number of ground flashes occurring during the time window.
Claim 4
Dependent Claim
46 words
An apparatus as claimed in claim 2, in which each level detecting means includes a comparator for comparing the number of counts counted by the counting means with a predetermined number and for supplying a level signal if the number of counts equals the predetermined number.
Claim 5
Dependent Claim
24 words
An apparatus as claimed in claim 2, in which the time window generating means generates a new time window after a predetermined time interval.
Claim 6
Dependent Claim
46 words
An apparatus as claimed in claim 3, in which each time window generating means generates a new time window each time its associated flash sensing means senses the occurence of a ground flash and which includes a plurality of counting means, one for each time window.
Claim 7
Dependent Claim
27 words
An apparatus as claimed in claim 1, which includes a field intensity detecting means for supplying a field signal when the field intensity exceeds a predetermined value.
Claim 8
Dependent Claim
59 words
An apparatus as claimed in claim 1, which includes a plurality of field intensity monitoring means for location at different selected positions and for supplying signals indicative of the field strengths at their locations and a threshold detecting means for detecting if the signal supplied by any one of the field intensity monitoring means exceeds a predetermined threshold value.
Claim 9
Dependent Claim
40 words
An apparatus as claimed in claim 1, which includes a selection means for selecting various desired combinations of the level detecting means and for supplying activating signals if all the level detecting means of the selected combinations supply a signal.
Claim 10
Dependent Claim
34 words
An apparatus as claimed in claim 8, which includes a plurality of alarm anunciating means, responsive to the selection means, for supplying alarm signals upon receipt of an activating signal from the selection means.
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) | 1989-06-09 | 1989-12-09 | 1990-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-09 | 1993-12-09 | 1994-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-09 | 1997-12-09 | 1998-06-10 | $7700.00 | Window Closed / Lapsed |