GB2161659A - Apparatus for protecting against overvoltages having a coarse protection and a fine protection means - Google Patents
Apparatus for protecting against overvoltages having a coarse protection and a fine protection means Download PDFInfo
- Publication number
- GB2161659A GB2161659A GB08511293A GB8511293A GB2161659A GB 2161659 A GB2161659 A GB 2161659A GB 08511293 A GB08511293 A GB 08511293A GB 8511293 A GB8511293 A GB 8511293A GB 2161659 A GB2161659 A GB 2161659A
- Authority
- GB
- United Kingdom
- Prior art keywords
- protection means
- protection
- cable
- coarse
- fine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
- H02H9/06—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage using spark-gap arresters
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The apparatus has a coarse protection means 7 and a fine protection means 8 which are spaced apart and connected together by way of a cable 3. This results in a reduction in the protection factor (ratio of maximum output voltage to nominal limiting voltage of the fire protection means). The protection means 7, 8 may be housed in respective connectors 4, 2 at the ends of the cable 3. The cable 3 may be 1 to 3 meters long and have a screen 5 connected to conductive parts of the housings of connectors 2, 4. <IMAGE>
Description
SPECIFICATION
Apparatus for protecting against overvoltages having a course protection and a fine protection means
The invention relates to an apparatus for protecting against overvoltages, in particular of equipment and apparatuses which are provided with electronic components, having a coarse protection and a fine protection means.
Protective circuits with coarse protection means which is provided for example with varistors and a fine protection means which is provided for example with Z-diodes and which is intended to afford protection against overvoltages are known. In that connection, the coarse protection means is intended to control high transient energies which are above the limit for destruction of the fine protection components, while the essence of the fine protection means lies in the high response speed and the low limiting voltage. The response speed of the fine protection means is substantially higher than that of the coarse protection means. The limiting voltage of the fine protection means is art a few volts, while that of the coarse protection means is some 100 volts.
Now, the essence of such protective circuits lies in particular in the fact that the two kinds of protection are to be matched to each other in such a way as to ensure a certain distribution in terms of operation between coarse protection and fine protection. In particular, the coarse protection means must respond before the fine protection means is overloaded. It is necessary to ensure that, when the circuit is loaded with quick transients, with rise times of a few nanoseconds to microseconds, an effective level of protection is afforded.
The measurement used in respect of protection factors which are to be afforded by protective circuits of that kind is generally the ratio of maximum output voltage in regard to rapid transients, in relation to the nominal limiting voltage of the fine protection components (clamping factor).
That protection factor, in conventional protective circuits, is between 1.5 and 2, the crucial consideration in regard to those high factors being the relatively high inductances of the fine protection components and their feed lines and the high current changes which occur in the direct vicinity, with frequency components in the gigahertz range, which provide for corresponding voltage excesses.
The problem of the invention is to provide a solution which makes it possible to achieve an enduring reduction in the protective factor.
According to the invention, the problem is solved in that the coarse protection means and the fine protection means are arranged separately in terms of space and connected together by way of a cable.
Surprisingly it has been found that, with a 16 V protective circuit, the protective level measured was only 20 V, which corresponds to a protection factor of 1.25. In conventional protective circuits, upon firing of an arrester, within from 1 to 4 nanoseconds, there is a firing jump from 1 kV, to 20 V. In the case of the protective circuit of conventional printed
circuit board type and with a Z-diode voltage of for
example 16 V, there is accordingly a maximum
protective level limit of 32 V.
The invention avoids those unsatisfactory
conditions.
In an embodiment, the invention provides that the
coarse protection means and the fine protection
means are each disposed in a plug and coupling
housing respectively, which are connected together
by way of the cable. The fact that the protection
means are provided directly in plug and coupling
housings quite considerably simplifies handling.
It has been found that it is particularly
advantageous for the length of the connecting cable
to be approximately in the range of from 1 to 3
metres inclusive.
A further feature of the invention provides that at
least portions of the plug and coupling housings are
formed from an electrically conductive material
which serves for screening purposes, wherein said
housing portions are electrically conductively
connected together by way of the cable.
In accordance with the last-mentioned
embodiment, it may also be provided that the
housings are made entirely of electrically - conductive material and the cable is formed as a
screened cable so that then the entire apparatus is
screened.
The cable itself acts as an attenuating member in
respect of high frequencies in the GHz-range so that
in the fine protection means, the large changes in
current which, in the state of the art, result in the
high protection factors, no longer occur at all,
thereby making it possible to achieve an improved
protective effect.
It is also provided in accordance with the
invention, as is known per se, that gas discharge
arresters and/or spark gaps and/or varistors may be
provided for the purposes of coarse protection, as
voltage-limiting elements, and Z-diodes and/or
suppressor diodes and/or transzorbs may be
provided for the purposes of fine protection as
voltage-limiting elements.
An embodiment of the invention will now be
described in greater detail hereinafter by way of
example with reference to the accompanying
drawings, in which: Figure 1 is a perspective view of apparatus for
protection against overvoltages; and
Figure 2 is an explanatory circuit diagram.
As illustrated therein, a plug housing 2 is
connected to a coupling housing 4 by way of a cable
3. Both the plug housing 2 and the coupling housing
4 are made from an electrically conductive material,
while the housings are electrically conductively
connected together, for example by way of the
screening of a cable 3.
Disposed in the interior of each of the housings 2
and 4 are coarse protection means and fine
protection means respectively.
A possible form of such a circuit is shown in
Figure 2, for example, as an overvoltage protection
cable for a V 24-interface.
The protection means shown on the left-hand side
represents the cable input, that is to say, as shown in Figure 1,the cable coupling. Reference numeral 5 denotes the connection of the cable screening while reference numeral 6 denotes the connection to the housing.
The fine protection means is disposed at 2 and forms the end of the cable which is towards the device, for example the plug 2.
It should be noted at this point that, depending on the equipment and layout of the device, the fine protection means may be formed as the coupling and conversely the coarse protection means may be formed as the plug, without the invention being restricted thereto.
It will be appreciated that the above-described embodiment of the invention may also be varied in many ways without thereby departing from the basic concept of the invention. Thus in particular the invention is not restricted to the electronic components shown in the circuit diagram, for example the gas discharge arresters 7 in the coarse protection means and the Z-diodes in the fine protection means 8. Any other components which may be considered may also be provided here, without departing from the basic concept of the invention.
Claims (7)
1. Apparatus for protection against overvoltages, having a coarse projection and a fine projection means, the coarse protection means and the fine protection means being arranged separately in terms of space and connected together by way of a cable.
2. Apparatus according to Claim 1, in which the coarse protection means and fine protection means are respectively disposed in a plug and coupling housing, which are connected together by way of a cable.
3. Apparatus according to Ciaim 1 or Claim 2, in which the length of the connecting cable is in the range between 1 and 3 inclusive.
4. Apparatus according to any one of the preceding claims, in which at least portions of the plug and coupling housings are formed from an electrically conductive material which serves for screening purposes, and said housimg portions are electrically conductively connected together by way of the cable.
5. Apparatus according to any one of the preceding claims, in which gas discharge arresters and/or spark paths and/or varistors are provided for coarse protection as voltage-limiting elements.
6. Apparatus according to any one of the preceding claims, in which Z-diodes and/or diodes andlor transzorbs are provided for fine protection as voltage-limiting elements.
7. Apparatus substantially as hereinafter described with reference to the accompanying drawings.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19843425296 DE3425296A1 (en) | 1984-07-10 | 1984-07-10 | DEVICE FOR PROTECTION AGAINST OVERVOLTAGE WITH A COARSE PROTECTION AND A FINE PROTECTIVE DEVICE |
Publications (3)
Publication Number | Publication Date |
---|---|
GB8511293D0 GB8511293D0 (en) | 1985-06-12 |
GB2161659A true GB2161659A (en) | 1986-01-15 |
GB2161659B GB2161659B (en) | 1987-12-09 |
Family
ID=6240225
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08511293A Expired GB2161659B (en) | 1984-07-10 | 1985-05-03 | Apparatus for protecting against overvoltages having a course protection and a fine protection means |
Country Status (2)
Country | Link |
---|---|
DE (1) | DE3425296A1 (en) |
GB (1) | GB2161659B (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2209893A (en) * | 1987-09-12 | 1989-05-24 | Rainford Racks Limited | Shielded line protection device |
DE9217814U1 (en) * | 1992-12-30 | 1993-02-25 | Dehn + Söhne GmbH + Co KG, 90489 Nürnberg | Surge protection device |
US5953194A (en) * | 1990-09-28 | 1999-09-14 | Raychem Limited | Arrangement for protecting telecommunications equipment from voltage transients |
US8625247B2 (en) | 2007-10-03 | 2014-01-07 | Huber + Suhner Ag | Protective circuit for the input-side protection of an electronic device operating in the maximum frequency range |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3905427C2 (en) * | 1989-02-22 | 1997-10-09 | Dehn & Soehne | Surge protection for the connection of data lines |
DE4106505C2 (en) * | 1990-03-15 | 1994-01-27 | Quante Ag | Surge protection device for cross-house data lines |
DE4107459C2 (en) * | 1990-03-15 | 1993-09-30 | Quante Ag | Device for overvoltage protection of an electrical terminal connected to a cable |
DE4305779A1 (en) * | 1993-02-25 | 1994-09-01 | Gerd Bajog | Compact mains interference suppression filter module |
CN109309378B (en) * | 2018-11-28 | 2024-02-13 | 温州正泰船岸电气有限公司 | Anti-electrification disconnecting device |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB251292A (en) * | 1925-04-23 | 1927-04-07 | Gen Electric | Improvements in and relating to the protection of electric systems against excess voltages |
GB543689A (en) * | 1940-01-03 | 1942-03-09 | Standard Telephones Cables Ltd | Improvements in protective arrangements for high frequency communication systems |
GB836435A (en) * | 1956-09-04 | 1960-06-01 | Gen Railway Signal Co | Protection of electronic apparatus from current and voltage surges |
GB953419A (en) * | 1960-11-17 | 1964-03-25 | Philips Electrical Ind Ltd | Improvements in or relating to excess voltage safety devices |
US3558830A (en) * | 1969-04-09 | 1971-01-26 | Communication Technology Inc | Overvoltage transmission line protector |
GB2046539A (en) * | 1979-03-29 | 1980-11-12 | Staco Werner Stauber Gmbh | Overvoltage protection circuits |
EP0056275A1 (en) * | 1981-01-14 | 1982-07-21 | LES CABLES DE LYON Société anonyme dite: | Device for protecting an electric line from very steep edge disturbances |
GB2102218A (en) * | 1981-07-06 | 1983-01-26 | Herb Joseph John Seguin | Method and apparatus for the protection of electrical equipment from high voltage transients |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH654149A5 (en) * | 1980-11-14 | 1986-01-31 | Zellweger Uster Ag | METHOD AND DEVICE FOR PROTECTING AN ELECTRONIC DEVICE AGAINST DESTRUCTION BY STRONG ELECTROMAGNETIC IMPULSES. |
-
1984
- 1984-07-10 DE DE19843425296 patent/DE3425296A1/en active Granted
-
1985
- 1985-05-03 GB GB08511293A patent/GB2161659B/en not_active Expired
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB251292A (en) * | 1925-04-23 | 1927-04-07 | Gen Electric | Improvements in and relating to the protection of electric systems against excess voltages |
GB543689A (en) * | 1940-01-03 | 1942-03-09 | Standard Telephones Cables Ltd | Improvements in protective arrangements for high frequency communication systems |
GB836435A (en) * | 1956-09-04 | 1960-06-01 | Gen Railway Signal Co | Protection of electronic apparatus from current and voltage surges |
GB953419A (en) * | 1960-11-17 | 1964-03-25 | Philips Electrical Ind Ltd | Improvements in or relating to excess voltage safety devices |
US3558830A (en) * | 1969-04-09 | 1971-01-26 | Communication Technology Inc | Overvoltage transmission line protector |
GB2046539A (en) * | 1979-03-29 | 1980-11-12 | Staco Werner Stauber Gmbh | Overvoltage protection circuits |
EP0056275A1 (en) * | 1981-01-14 | 1982-07-21 | LES CABLES DE LYON Société anonyme dite: | Device for protecting an electric line from very steep edge disturbances |
GB2102218A (en) * | 1981-07-06 | 1983-01-26 | Herb Joseph John Seguin | Method and apparatus for the protection of electrical equipment from high voltage transients |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2209893A (en) * | 1987-09-12 | 1989-05-24 | Rainford Racks Limited | Shielded line protection device |
US5953194A (en) * | 1990-09-28 | 1999-09-14 | Raychem Limited | Arrangement for protecting telecommunications equipment from voltage transients |
DE9217814U1 (en) * | 1992-12-30 | 1993-02-25 | Dehn + Söhne GmbH + Co KG, 90489 Nürnberg | Surge protection device |
US8625247B2 (en) | 2007-10-03 | 2014-01-07 | Huber + Suhner Ag | Protective circuit for the input-side protection of an electronic device operating in the maximum frequency range |
Also Published As
Publication number | Publication date |
---|---|
DE3425296C2 (en) | 1992-10-22 |
GB2161659B (en) | 1987-12-09 |
GB8511293D0 (en) | 1985-06-12 |
DE3425296A1 (en) | 1986-01-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7221550B2 (en) | Surge protection device and method | |
US5966283A (en) | Surge suppression for radio frequency transmission lines | |
US4021759A (en) | EMP line filter using MOV devices | |
US6101080A (en) | EMP-charge eliminator | |
KR100454013B1 (en) | Telephone facility protection circuit | |
GB2161659A (en) | Apparatus for protecting against overvoltages having a coarse protection and a fine protection means | |
US4835650A (en) | Apparatus and method for minimizing the let-through voltage associated with circuits used in conjunction with electronic elements to suppress surges, transients and like electrical disturbances | |
US7035072B2 (en) | Electrostatic discharge apparatus for network devices | |
EP1456921B1 (en) | Overvoltage protection device | |
US5008770A (en) | Filter pin integrated circuit socket kit | |
US5786974A (en) | Apparatus for and method of suppressing power surges utilizing electrical striplines | |
US4438365A (en) | Spark gap for line transient protection | |
US6178078B1 (en) | Discharge gap device and its mounting structure | |
RU2273929C1 (en) | Multipole overvoltage protective system and method ensuring reliable operation of multipole overvoltage protective system | |
DE3111096C2 (en) | Network transient protection arrangement for electrical equipment | |
GB2179214A (en) | Surge voltage protection arrangement | |
US20040169982A1 (en) | Surge protector | |
US4920443A (en) | Electrical protection assemblies | |
JP2000224718A (en) | Lightning protective device and ground terminal board with the device | |
JPH1050453A (en) | Circuit protection instrument and printed substrate | |
EP1746695B1 (en) | Overvoltage arresting device for use in industrial bus bar distribution systems | |
JP2000261957A (en) | Surge absorber and indoor wiring method using the same | |
Carpenter Jr et al. | Protection From Incoming Power Line Voltage Anomalies | |
DD264094A1 (en) | ARRANGEMENT FOR THE PROTECTION OF THE INPUT DEVICES OF A LOW VOLTAGE CONTROL FOR HIGH VOLTAGE CIRCUIT BREAKERS | |
Suryanarayana et al. | Role of transient/surge suppressors in a typical airborne system. A case study |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19920503 |