Electricity: electrical systems and devices – Safety and protection of systems and devices – Transient responsive
Patent
1997-05-28
1999-11-30
Sherry, Michael J.
Electricity: electrical systems and devices
Safety and protection of systems and devices
Transient responsive
361 56, 361 91, 361118, H02H 322
Patent
active
059953527
DESCRIPTION:
BRIEF SUMMARY
FIELD
The present application relates to the technology of igniting spark gaps, particularly lightning type arrestors. The application also relates to lightning protection and transient protection.
One invention relates particularly to an apparatus and method adapted to ignite the spark gap when line overvoltage is detected. Another invention relates to alleviating excess line voltage caused by transients or the passage of relatively high currents.
The present invention has application in many industries, particularly but not exclusively electrical transmission lines and telecommunications.
BACKGROUND
Spark gap type lightning arrestors have been used in order to protect electrical equipment. In operation they conduct excess line voltage delivered by lightning strikes to ground. The arrestors, by virtue of their configuration, have a spark gap which provided by an air gap dimensioned to not break down at system working voltages (line voltages), but to breakdown by arcing at an overvoltage well in excess of line voltage, such as an overvoltage consequential upon a lightning strike. The arc formed conducts the transient current, inherent in an overvoltage condition, to ground.
In order to ensure that the arc formed upon a lightning strike will extinguish after the overvoltage has been conducted to ground, the spark gap is dimensioned relatively wide. As a consequence, it typically requires approximately 3 kV to 4 kV across the gap to initiate the breakdown arc on a 220-240 V, 50 Hz system.
Thus, before the breakdown arc is initiated, a situation can arise where a line voltage of up to 4 kV is transmitted to equipment which is sensitive to such excess voltage. This problem has to date been left unaddressed.
Other arrestors incorporate a third electrode proximate one of the main electrodes. When activated, the third electrode creates a spark between it and one of the main electrodes. This spark forces the main gap between the main electrodes to avalanche. The problem in reducing the gap width is power follow-on current and formation of metal fingers from gasified metal. These can short circuit the gap. Also, the enormous temperatures (typically 5000.degree.-8000.degree. C.) and pressures in the triggered arc cause severe burning of the trigger electrode (with virtually whatever material is used). Further, these type of arrestors are specially constructed, relatively expensive, or have internal gas pressure reduced to control spark overvoltage.
Yet a further type of arrestor is the gas arrestor which has a spark gap encapsulated in a gas environment, the gas environment providing a relatively selected strike voltage. The gases typically used are neon, with a strike voltage of approximately 75V to 90V, and argon, with a strike voltage of approximately 230V. However, for example in the telecommunications industry there is a need for over voltage protection with a strike voltage of approximately 60V, and to date this need has also been unaddressed.
Other problems related to prior art devices is that where the arrestor is configured to a set trigger voltage, it has been found that after several operations, the trigger electrode can burn or deteriorate to such an extent that the original characteristics of break down voltage are partially or totally lost.
SUMMARY OF INVENTION
It is an object of the present invention to alleviate the problem of low voltage triggering of a spark gap type arrestor.
The present invention overcomes problems associated with the prior art by increasing the voltage across the spark gap.
This invention provides, in one form, an apparatus and method of initiating the firing of a spark gap, including: the voltage means provides an additive voltage to the spark gap.
The present invention is predicated on the concept of increasing or amplifying the voltage across the spark gap in order to ignite the gap when required thus enabling ignition of the spark gap when required. The incremental voltage to obtain gap ignition is additive to any voltage already across the gap, and is additive irresp
REFERENCES:
patent: 3154718 (1964-10-01), Yonkers et al.
patent: 3626237 (1971-12-01), Bolton et al.
patent: 3657594 (1972-04-01), Latal
patent: 3877864 (1975-04-01), Carlson
patent: 4112330 (1978-09-01), Stimson et al.
patent: 4187524 (1980-02-01), Peterson
patent: 4366523 (1982-12-01), Hasse et al.
patent: 4486805 (1984-12-01), Cline
patent: 4628398 (1986-12-01), Cook
patent: 4631453 (1986-12-01), DeSouza et al.
patent: 4665357 (1987-05-01), Herbert
patent: 4683514 (1987-07-01), Cook
patent: 4760213 (1988-07-01), Gumley
patent: 4760486 (1988-07-01), Beeken et al.
patent: 4860156 (1989-08-01), Stenstrom et al.
patent: 5233498 (1993-08-01), Kansala
Derwent Abstract Accession No. J1154 D/35, class X13, SU,A,777771 (Kuzbass Poly) Nov. 7, 1980.
Derwent Abstract Accession No. B4247A/07, class R51,SU,A,502443 (Energosetproekt Ele) Jul. 26, 1977.
Derwent Abstract Accession No. 84-236382/38, class X13,SU,A,1069064 (Lukkonen V D) Jan. 23, 1984.
Erico Lightning Technologies Pty. Ltd.
Sherry Michael J.
LandOfFree
Ignition apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ignition apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ignition apparatus and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1681217