US4023071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transient and surge protection apparatus
Assignee: Individual
•
Filing: 1975-06-09
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Granted: 1977-05-10
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Expires: 1995-06-09
Abstract
Abstract Apparatus is disclosed for absorbing and dissipating the electrical energy present in voltage transients and surges occurring in a power distribution system for protecting the system and equipment connected thereto from damage due to such transients and surges. First bilateral nonlinear semiconductors having zener-type voltage breakdown characteristics and capability of essentially instantaneous breakdown for inputs exceeding a selected voltage breakdown are connected in parallel with the circuits to be protected. Such semiconductors have low energy-dissipating capability; therefore, second bilateral nonlinear semiconductors having much greater energy-dissipating capability, similar voltage breakdown characteristics, and slower response time are connected in parallel with the first semiconductors. The breakdown of the second semiconductors occurs in time to prevent the first semiconductors from being damaged from excessive dissipation. A gaseous discharge gap-type arrestor is connected essentially in parallel with the first and second semiconductors and has a selected striking voltage appropriate to the breakdown voltages of the semiconductors.Upon firing of the arrestor, the voltage is dropped to a very low value and the remaining surge energy is dissipated in the arrestor. Firing of the arrestor occurs after the breakdown of the second semiconductor in time to prevent the dissipation capability of the second semiconductor from being exceeded. The cooperative and consecutive breakdown of the three elements serves to limit the peak voltage of a surge to a safe value and dissipate the surge energy without damage to the elements, thereby preventing damage to the power distribution system and associated equipments.
Inventors
- 👤 Gerald W. Fussell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:59
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/04; H02H9/06; H02H9/005
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
336 words
Apparatus for protecting electrical power systems and equipment connected thereto from damage due to voltage transients and surges that exceed the maximum instantaneous peak voltages of the systems, comprising: first electrical energy-dissipation means having a first breakdown voltage slightly greater than the maximum instantaneous peak voltage, said first means responsive essentially instantaneously to a voltage surge exceeding such first breakdown voltage, to dissipate a first portion of energy contained in such surge; second electrical energy-dissipation means having a selected second breakdown voltage slightly less than said first breakdown voltage of said first means, said second means responsive after a selected first delay period to such voltage surge to dissipate a second portion of energy contained in such surge, causing the voltage across said first means to drop below said first breakdown voltage whereby said first means ceases to dissipate energy with said first delay period selected to limit the energy-dissipation in said first means to a value within the dissipation capability of said first means, said second means being electrically connected to said first means; third electrical energy-dissipation means having a selected third breakdown voltage essentially equal to said first breakdown voltage, said third means responsive after a selected second delay period to such voltage surge to dissipate the remaining energy contained in such surge, causing the voltage across said second means to drop below said second breakdown voltage whereby said second means ceases to dissipate energy with said second delay period selected to limit the energy dissipated in said second means to a value within the dissipation capability of said second means, said third means being electrically connected to said second means; and wherein said first, second, and third electrical energy-dissipating means are electrically connected to an electrical power system whereby said first, second, and third means cooperate to dissipate the energy of said voltage surge without damage to said first and second means thereby preventing such voltage surge from exceeding a value slightly greater than the maximum instantaneous peak voltage of such power system.
Claim 2
Dependent Claim
336 words
Apparatus for protecting electrical power systems and equipment connected thereto from damage due to voltage transients and surges that exceed the maximum instantaneous peak voltages of the systems, comprising: first electrical energy-dissipation means having a first breakdown voltage slightly greater than the maximum instantaneous peak voltage, said first means responsive essentially instantaneously to a voltage surge exceeding such first breakdown voltage, to dissipate a first portion of energy contained in such surge; second electrical energy-dissipation means having a selected second breakdown voltage slightly less than said first breakdown voltage of said first means, said second means responsive after a selected first delay period to such voltage surge to dissipate a second portion of energy contained in such surge, causing the voltage across said first means to drop below said first breakdown voltage whereby said first means ceases to dissipate energy with said first delay period selected to limit the energy-dissipation in said first means to a value within the dissipation capability of said first means, said second means being electrically connected to said first means; third electrical energy-dissipation means having a selected third breakdown voltage essentially equal to said first breakdown voltage, said third means responsive after a selected second delay period to such voltage surge to dissipate the remaining energy contained in such surge, causing the voltage across said second means to drop below said second breakdown voltage whereby said second means ceases to dissipate energy with said second delay period selected to limit the energy dissipated in said second means to a value within the dissipation capability of said second means, said third means being electrically connected to said second means; and wherein said first, second, and third electrical energy-dissipating means are electrically connected to an electrical power system whereby said first, second, and third means cooperate to dissipate the energy of said voltage surge without damage to said first and second means thereby preventing such voltage surge from exceeding a value slightly greater than the maximum instantaneous peak voltage of such power system.
Claim 3
Dependent Claim
30 words
The apparatus as defined in claim 1 in which said first, second, and third electrical energy-dissipating means are electrically connected essentially in parallel with a single-phase ac electrical power system.
Claim 4
Dependent Claim
36 words
The apparatus as defined in claim 1 in which a plurality of said first, second, and third electrical energy-dissipating means are electrically connected essentially in parallel with each phase of a multiphase ac electrical power system.
Claim 5
Dependent Claim
55 words
The apparatus as defined in claim 1 in which: the response of said first electrical energy-dissipation means to such surge occurs within approximately one nanosecond after the voltage of such surge exceeds said first breakdown voltage; said selected first delay period is approximately fifty nanoseconds; and said selected second delay period is approximately one microsecond.
Claim 6
Dependent Claim
117 words
The apparatus as defined in claim 1 in which: said first electrical energy-dissipation means includes at least one bilateral nonlinear semiconductor device; said second electrical energy-dissipation means includes at least one bilateral varistor wherein breakdown of said varistor causes a small drop in system voltage to a value resulting in recovery of said first means from its breakdown state; and said third electrical energy-dissipation means includes at least one gaseous means in which breakdown of said gaseous discharge means causes a drop in system voltage to a relatively low value resulting in recovery of said second means from its breakdown state and said gaseous discharge means recovers from its breakdown state shortly after cessation of such surge.
Claim 7
Dependent Claim
89 words
The apparatus as defined in claim 5 in which: said bilateral nonlinear semiconductor device is responsive to such voltage surge within approximately one nanosecond after the voltage of such surge exceeds said first breakdown voltage; said bilateral varistor is responsive to such voltage surge within approximately 50 nanoseconds after the voltage of such surge exceeds said second breakdown voltage; and said gaseous discharge means is responsive to such final portion of such voltage surge within approximately one microsecond after the voltage of such surge exceeds said third breakdown voltage.
Claim 8
Dependent Claim
38 words
The apparatus as defined in claim 5 in which: said bilateral nonlinear semiconductor device comprises two back-to-back zener diodes; said bilateral varistor comprises metallic oxide voltage dependent resistors; and said gaseous discharge means comprises two-electrode gas-filled surge arrestors.
Claim 9
Dependent Claim
38 words
The apparatus as defined in claim 5 in which: said bilateral nonlinear semiconductor device comprises two back-to-back zener diodes; said bilateral varistor comprises metallic oxide voltage dependent resistors; and said gaseous discharge means comprises three-electrode gas-filled surge arrestors.
Claim 10
Dependent Claim
75 words
The apparatus as defined in claim 1 in which: said first and second electrical energy-dissipation means include fusing means arranged to isolate said first and second energy-dissipation means from said electrical power system in the event of failure of said first or second means; and said third electrical energy-dissipation means includes circuit breaker means arranged to isolate said third energy-dissipation means from said electrical power system in the event of failure of said third means.
Claim 11
Dependent Claim
28 words
The apparatus as defined in claim 9 in which said fusing means includes indicator means, said indicator means providing visual indication of the operating condition of said apparatus.
Claim 12
Dependent Claim
272 words
Apparatus for absorbing and dissipating electrical energy present in voltage transients and surges occurring in power distribution systems, comprising: first bilateral nonlinear semiconductor means, said first means electrically connected essentially in parallel with an electrical circuit, and having a breakdown voltage slightly higher than the instantaneous peak voltage in said electrical circuit, said means essentially instantaneously clamping transient and surge voltages to such breakdown voltage, and dissipating energy from first portions of such transient and surge voltages; second bilateral nonlinear semiconductor means, said second means electrically connected in parallel with said first means, and having a breakdown voltage slightly higher than the instantaneous peak voltage in said electrical circuit and slightly lower than the breakdown voltage of said first means, having a first delay in breakdown of said second means causing such breakdown to occur a short time period after the breakdown of said first means, whereby energy from second portions of such transient and surge voltages is dissipated and said first means is protected from damage from such energy in such second portions; and gaseous discharge means, said latter means electrically connected essentially in parallel with said first and second means, and having a striking voltage slightly higher than the instantaneous peak voltage in said electrical circuit, wherein an arc occurs in said gaseous discharge means subsequent to the voltage breakdown of said second means, thereby dissipating energy from final portions of such transient and surge voltages and protecting said second means from damage from such energy in such final portions; whereby said electrical circuit is protected from damage from such transient and surge voltages by such dissipation of electrical energy.
Claim 13
Dependent Claim
272 words
Apparatus for absorbing and dissipating electrical energy present in voltage transients and surges occurring in power distribution systems, comprising: first bilateral nonlinear semiconductor means, said first means electrically connected essentially in parallel with an electrical circuit, and having a breakdown voltage slightly higher than the instantaneous peak voltage in said electrical circuit, said means essentially instantaneously clamping transient and surge voltages to such breakdown voltage, and dissipating energy from first portions of such transient and surge voltages; second bilateral nonlinear semiconductor means, said second means electrically connected in parallel with said first means, and having a breakdown voltage slightly higher than the instantaneous peak voltage in said electrical circuit and slightly lower than the breakdown voltage of said first means, having a first delay in breakdown of said second means causing such breakdown to occur a short time period after the breakdown of said first means, whereby energy from second portions of such transient and surge voltages is dissipated and said first means is protected from damage from such energy in such second portions; and gaseous discharge means, said latter means electrically connected essentially in parallel with said first and second means, and having a striking voltage slightly higher than the instantaneous peak voltage in said electrical circuit, wherein an arc occurs in said gaseous discharge means subsequent to the voltage breakdown of said second means, thereby dissipating energy from final portions of such transient and surge voltages and protecting said second means from damage from such energy in such final portions; whereby said electrical circuit is protected from damage from such transient and surge voltages by such dissipation of electrical energy.
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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) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |