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 PDF

Info

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
Application number
GB08511293A
Other versions
GB2161659B (en
GB8511293D0 (en
Inventor
Wolf-Dieter Oels
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
OELS WOLF DIETER
Original Assignee
OELS WOLF DIETER
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by OELS WOLF DIETER filed Critical OELS WOLF DIETER
Publication of GB8511293D0 publication Critical patent/GB8511293D0/en
Publication of GB2161659A publication Critical patent/GB2161659A/en
Application granted granted Critical
Publication of GB2161659B publication Critical patent/GB2161659B/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
    • H02H9/06Emergency 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.
GB08511293A 1984-07-10 1985-05-03 Apparatus for protecting against overvoltages having a course protection and a fine protection means Expired GB2161659B (en)

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)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
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.

Patent Citations (8)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
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