DE102008049470A1 - Overcurrent protection device for use in high voltage overvoltage arresters - Google Patents

Abstract

The invention relates to an overcurrent protection unit for use in overvoltage protection devices having higher rated voltages in combination with a mechanical trip for a display and fusible elements for overload protection. According to the invention, a series circuit has a plurality of fusible elements forming a geometrically prescribed mechanical and electrical combination. The series circuit comprises a mechanical and electrical parallel combination of fusible elements, wherein at least one of the fusible elements of the parallel combination comprises a striker as a mechanical trip.

Description

The The invention relates to an overcurrent protection device for use in surge protection devices with high rated voltages in combination with a mechanical release for a display and fusible elements for overload protection according to the preamble of claim 1.

Overvoltage Protection Devices are used in electrical and information technology networks for protection used by equipment, consumers and terminals. Limit such overvoltage protection devices especially in transient overvoltage events, z. B. lightning events, the voltage to uncritical values. The Limitation occurs at overvoltage events by the Derivation of pulse currents in the transverse path and thus generally parallel to consumer connections. As overvoltage protection elements be z. B. spark gaps, varistors, gas arresters, non-linear Resistors and their combinations used.

Of the Need for overvoltage protection devices with higher Rated voltages is limited. The effort, for each rated voltage level a special geometry of overvoltage protection elements, in particular spark gaps, as well as appropriate ignition devices and to develop and manufacture housing parts is very high. In addition, the requirements regarding the protection and display devices of Hilfszündkreisen Very large for arresters with higher rated voltages. This applies in addition to the separation distances, d. H. the air and creepage distances, also the level of rated voltage and the switching capacity of the protective devices of the Hilfszündkreises, So the corresponding electrical circuit.

Next the protective function for the overvoltage protection elements The response of a fuse is often used as a display criterion for overloading and disconnecting the overvoltage protection element used. For this purpose, the power interruption or the increased Voltage drop across the fuse evaluated. In addition to the Optical display is also the electrical signal for audible indicators or opening and closing used by switches for remote signaling.

From the DE 199 14 313 A1 is the hedge of a starting aid a spark gap previously known. In this case, fuses or reversible fuses are used. The melting of the fuse is used with the aid of electronic circuits for optical, acoustic and / or electronic display.

After the fuse has responded, the spark gap should be able to exert a redundant protective function with an increased protection level without an ignition aid. Derivation of a display function from the shutdown behavior of fuses is beyond the DE 38 31 935 A1 , of the DE 197 51 470 A1 or the DE 32 28 471 A1 previously known.

The U.S. Patent 6,157,529 discloses the interruption of a circuit by means of the disconnection of a fuse and a holding coil of a switch.

Ignition aids, as in the DE 199 14 313 A1 described, are also used in combination arresters. With these arresters, the starting aid itself can be designed as an independent overvoltage protection device, which activates the short-circuit element, generally a spark gap, only at the risk of its own overload via a trigger function. A combination arrester is for example in the DE 198 38 776 C2 shown.

Out The above, it is therefore an object of the invention, an advanced overcurrent protection device for use in surge protection devices with higher rated voltages in the range of 440 V to 760 Specify V and more, in combination with a mechanical one Trigger for a display and fuses for overload protection. This should be the possibility be created using geometrically identical Housing, display and mounting parts at different Voltage levels an economical and functional sense Design the active parts, allowing easy customization given to different uses and applications is.

The Solution of the object of the invention is achieved by the feature combination according to claim 1, wherein the dependent claims at least expedient Represent refinements and developments.

Of the The basic idea of the invention is accordingly the fuse elements, in particular fusible elements, in a series circuit to split several fuses, in addition to the electrical connection partly in a mechanical series and partly on the other hand in a mechanical parallel connection. By doing so Splitting the fuse arrangement creates different possibilities the geometric design and thus for optimal space utilization in otherwise used standard housings.

The division also allows a large variance in terms of residual voltage behavior, rollover protection, current limitation, the actual performance and the necessary Ab to endangered further components, in particular a trigger circuit.

As already stated, according to the invention is a series circuit provided by a plurality of fusible elements, which is a geometric form predetermined, mechanical and electrical composite.

These Series connection in one embodiment has a mechanical and electrical parallel composite of fusible elements, wherein at least one of the fusible elements of the parallel compound a Striker as a mechanical trigger to operate includes a function display.

One the first part of the series is on one side of a wiring substrate, in particular a printed circuit board, and a second part of the series composite on a second, the first opposite side located the wiring substrate.

Of the first part of the series compound comprises at least two cylindrical Individual fuses, which by a conductive cylinder on the front sides and there existing connection caps mechanically and are electrically connected. This mechanical and electrical Connection takes place with the help of the conductive cylinder only in the area of the mechanical connection caps so that the insulation and separation distances are maintained.

Of the Composite of the cylindrical individual fuses with the conductive Connecting cylinder can of an insulating material, in particular of be covered by a shrink tube.

Of the second part of the series compound includes the already mentioned Parallel network, the parallel network predominantly surrounded by a protective housing, the others, below yet described functions can be assigned.

The Connection caps of the fusible elements of the parallel connection are electrical and mechanically connected and go into a terminal extension, which each have a mounting on the wiring carrier allows.

The free ends of the individual fuses of the first part of the series compound also have connection caps with solder flags or tab-like extensions.

to Adaptation to the nominal voltage ranges it is possible one or more of the individual fuses or fuses by a conductive, in particular metallic, geometric to replace diameter-adapted cylinder. It can the Cylinder also have a predetermined impedance.

Of the Wiring carrier has in a preferred embodiment an elongated, rectangular shape with on the narrow sides attached screw connection tabs on.

Of the first part of the series composite is at a longitudinal outer edge, with this substantially laterally terminating, on the wiring carrier located.

Of the second part of the series network, containing the parallel network, is substantially perpendicular to the longitudinal axis of the first Part of the series assembly arranged on the wiring substrate.

The Protective housing is to the longitudinal edge of the wiring substrate open to a discharge of the firing pin and an operative connection the firing pin towards a spring-biased indicator slide to allow.

The Protective housing has at its from the wiring carrier facing away from a color indicator surface or an indicator surface extension attached to the housing is formed. In this way, based on a viewing window in an end cap or an outer casing that has a view of the Top of the protective housing releases, a functional state be displayed by a slide either the view of the Top unlocks or blocks that look.

It Thus, the protective housing on the one hand has the function of Isolation of the parallel compound and serves the purpose of retention of elements in case of triggering this fuse. Farther the housing serves the aforementioned formation of a Indicator surface or the inclusion of an indicator surface extension.

Of the Wiring carrier is preferably on top of a Housing mountable, with the housing in his Inside an array of surge arresters, in particular Spark gaps takes up. This arrangement of surge arresters, in particular spark gaps is in series connection.

A the spark gaps of the arrangement may be triggerable, in In this case, the trigger circuit is on the wiring carrier located.

The housing for receiving the spark gaps has on its upper side over a longitudinal edge a trough-like recess into which the first part of the series compound dives, in order to provide a protective and insulating function of the first Part of the series composite effect.

The Overall arrangement of spark gaps mounted in the housing, on the top of the housing located wiring carrier with electrical elements and the series connection of several Melting elements is umber of an insulating cap, wherein the cap the already mentioned window for recognition the functional state with respect to the indicator surfaces having.

The inventive overcurrent protection device is by a modular design with selected fusible elements marked for series connection to a slight To effect adaptation to different nominal voltages.

Of the Display slide, which is spring-biased and the firing pin of the parallel network can be released, has a display area, which a color-deviating indicator surface, in particular the indicator surface of the top of the protective housing releases or obscures.

Farther the display slider has an extension which extends in the longitudinal direction extending the narrow side of the wiring substrate, There to interact with a telecommunications contact in operative connection.

The can be used in the series connection of the overcurrent protection device Fusible elements consist of inexpensive to manufacture individual fuses, each z. B. for a voltage level of 250 V.

For the first part of the series connection will be at least two of the fuses connected by a precisely fitting cylinder. The cylinder may preferably be a metal cylinder, in addition to the electrical Connection also the mechanical fixing and the necessary mechanical stabilization the corresponding part of the series connection takes over. The number of connection elements is through this type of connection less than a simple series connection of electrical Individual fuses, each z. B. by soldering with a PCB are connected.

Of the Distance between the remaining connection elements or end caps the fuses is significant, ensuring compliance with the separation distances is facilitated and the bridging danger clearly sinks.

The preferred arrangement of the above-described series circuit on the Bottom of the wiring substrate creates sufficient Separation distances on the wiring substrate also space on the component side, d. H. the opposite Page, on the one hand about the volume saving and on the other hand by avoiding critical approximations between the overload endangered ones Elements and the protective device. The series connection of the fuses provides a further advantage, which is that two connecting legs or Connection feet are saved in the board, due to the connection of the incremental fuses to a conductive, in particular brass sleeve.

Of the first part of the series connection is at the top through the board separated from the components of the ignition circuit and on the Bottom through the trough-like expression of the housing. It this results in a quasi-complete isolation Enclosing the protective device. This prevents in case of error a manifestation that may occur, and it become the parting lines of the ignition circuit when it becomes free of gas or plasma from the fuse from flashovers protected.

The parallel part arrangement representing the second part of the series combination is preferably designed as in the German patent application DE 10 2006 026 711.7 described. The content of this patent application is herewith fully explained as the subject of the present invention.

The used fuses as fuses of the parallel connection and also of the series composite are preferred at maximum rated voltage the same fusible link. This ensures at adiabatic loads and at loads in which the axial heat output opposite the radial heat dissipation dominates, an almost simultaneous Response of all fuses.

The Characteristic of the series connection of the fuses thus corresponds to one Up fuse. The dimensions of such a series connection are considerably smaller with comparable switching capacity as of individual backups, z. B. for a nominal voltage from 690 V.

Next the mentioned space saving allows the distribution of Fuse in several subunits also a very flexible arrangement of the individual functional units in relation to the position and position with regard to the wiring substrate.

At desired lower rated voltages, one or more fuses of the series assembly can be replaced by a simple metallic cylinder. In addition to the cost reduction, this also leads to a reduction of the residual voltage and thus supports the desired basic function of the arrester. By a two-sided arrangement of metal cylinders in addition to a real fuse in the series network also allows the power be reduced effect on the fusible conductor, whereby higher pulse currents can be worn.

By the use of the previously mentioned impedance cylinder can also meet the requirements in terms of switching capacity The actual backup can be reduced because of the prospective Short-circuit current is limited by the impedance.

Further Advantages of the modular construction of the overcurrent protection device according to the invention for ignition aids of arresters with identical geometrical Arrangements are described in the following embodiment.

in this connection demonstrate:

1 and 2 a representation of the first part of the series of fused elements;

3 a plan view of the housing with enclosed spark gaps and recognizable trough-like recess at the top of the housing;

4 a side view of an arrangement with housing and wiring support, which inter alia, the trigger circuit and the overcurrent protection device receives, and

5 a representation similar to that after 4 but in a perspective form.

The inventive overcurrent protection device comprises a series connection of a plurality of fuse elements, which a geometrically predetermined, mechanical and electrical composite form.

A first part of the series composite comprises two individual cylindrical fuses 1 and 2 , These two cylindrical individual fuses 1 and 2 be through a conductive, preferably metallic cylinder 3 on the front sides 4 and existing connection caps 5 mechanically and electrically, z. B. connected by clamping or soldering.

The resulting composite of cylindrical individual fuses 1 and 2 with the connecting cylinder 3 is with an insulating shrink tube 6 coated (see 2 ).

The free ends of the individual fuses 1 and 2 also have connection caps 5 , but with solder flags 5a , which are used for electrical connection and mechanical fixing on a circuit board, on.

The Series connection according to the invention comprises above addition, a mechanical and electrical parallel composite of fusible elements, wherein at least one of the fusible elements of the parallel compound a Having a firing pin as a mechanical trigger. The mechanical Trigger can as a wire-shaped trigger part be executed, preferably this wire of the triggering part over a Part of the entire overcurrent protection device connected in parallel which has the advantage of tuning the current commutation and the switching capacity is limited to this part of the fuse.

at a parallel connection to the entire fuse arrangement, d. H. parallel to all incremental fuses, the fuselage would have to the indicator fuse has the full switching capacity, which is possible, but at a higher cost leads.

In In one embodiment, the fusible conductor of the fuse, to which the indicator is connected in parallel, with a minimal lower melting integral to provide a secure indication, too to ensure at low overloads.

There the complete outgassing of the indicator fuse or the Spinning away parts of the indicator avoided only with great effort In principle, there is a risk of external rollover the fuse arrangement at high voltages.

To counteract this danger, the indicator part, ie the parallel connection, with an additional housing 7 (please refer 4 and 5 ) Mistake.

This case 7 blocks the external flashover and considerably reduces the danger that can arise from released indicator parts (firing pins).

Like from the 4 can be seen, is the case 7 preferably at right angles with respect to the longitudinal axis of the wiring substrate 8th arranged.

The first part of the series 9 comprising the individual fuses with connecting cylinder and protective cover, is on the underside of the wiring substrate 8th located, the second part of the series, located in the housing 7 located on top of the wiring harness 8th is arranged.

From the illustration to 4 it can be seen that the wiring carrier 8th an elongated, rectangular shape with attached on the narrow sides Schraubanschlusslaschen 10 , wherein the first part of the series composite 9 at a longitudinal outer edge, with this substantially laterally, is located.

The protective housing 7 is to the longitudinal edge of the wiring substrate 8th open, to an outlet of the firing pin therein and an operative connection to a spring-biased indicator slide 11 to enable.

The protective housing 7 owns at its from the wiring carrier 8th facing away from a color indicator surface 18 , z. B. red, or has an indicator surface extension, extending from the housing 7 starting out.

The wiring carrier 8th is on top of a case 12 mountable, being in the housing 12 there may be a series spark gap arrangement.

At least one spark gap of the spark gap arrangement can be triggered and the trigger circuit can be located on the wiring carrier. The contacting between the wiring carrier and the spark gap to be triggered can take place via a contact spring extending through a recess 13 in the case 12 extends.

Furthermore, the spark gap housing has 12 on its upper side a trough-like recess 14 into which the first part 9 of the series compound immersed to effect a protective and insulating function (see 3 and 4 ).

The overall assembly may be surrounded by an insulating cap, the cap having a viewing window for a view of the top of the housing 7 or the display slider 11 to allow.

The indicator slider 11 has a display area 15 on. This display area can, for. B. have a green color, which signals the state "OK".

If the display slider moves as shown in the illustration 5 to the left, the underlying top of the case becomes 7 , which is designed differently colored, released and signaled an error condition.

The indicator slider 11 also has an extension 16 extending longitudinally across the narrow side of the wiring substrate 8th extends to having a telecommunications contact 17 to come into operative connection.

In the area of the extension 16 has the indicator slide 11 a mandrel-like formation which receives a helical compression spring which faces the spark gap housing 12 supported to produce the necessary bias.

1; 2

cylindrical Single fuse

3

connecting cylinder

4

front

5

connection cap

5a

Lötfähnchen

6

coating

7

casing for parallel connection

8th

wiring support

9

first Part of the series network

10

Schraubanschlusslasche

11

display slide

12

Spark gap housing

13

recess for trigger contact

14

trough-like recess

15

display area

16

extension

17

telecomm

18

indicating surface

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 19914313 A1 [0005, 0008]
• - DE 3831935 A1 [0006]
• - DE 19751470 A1 [0006]
• - DE 3228471 A1 [0006]
• US 6157529 [0007]
• - DE 19838776 C2 [0008]
• - DE 102006026711 [0040]

Claims (21)

Overcurrent protection means for use in over-voltage protection devices with higher rated voltages in combination with a mechanical shutter for a display as well as fuse elements for overload protection, characterized in that a series circuit is provided from several fuse elements which form a geometrically predefined mechanical and electrical bond. Overcurrent protection device according to claim 1, characterized in that the series connection is a mechanical and electrical parallel composite of fusible elements, wherein at least one of the fusible elements of the parallel compound a Having a firing pin as a mechanical trigger. Overcurrent protection device according to claim 1 and 2, characterized in that a first part ( 9 ) of the series combination on one side of a wiring substrate ( 8th ) and a second part of the series combination on a second, the first opposite side of the wiring substrate ( 8th ) is located. Overcurrent protection device according to claim 3, characterized in that the first part of the series compound at least two cylindrical individual fuses ( 1 ; 2 ), which by a conductive cylinder ( 3 ) on the front sides ( 4 ) and there existing connection caps ( 5 ) are mechanically and electrically connected. Overcurrent protection device according to claim 4, characterized in that the composite of cylindrical individual fuses ( 1 ; 2 ) of an insulating shrink tube or the like material ( 6 ) is coated. Overcurrent protection device according to one of claims 3 to 5, characterized in that the second part of the series compound comprises the parallel connection, wherein the parallel connection predominantly of a protective housing ( 7 ) is surrounded. Overcurrent protection device according to claim 6, characterized in that the connection caps of the fusible elements of the parallel connection connected electrically and mechanically connected in each case in a terminal extension, which mounting on the wiring substrate ( 8th ), in particular a printed circuit board. Overcurrent protection device according to claim 4 or 5, characterized in that the free ends of the individual fuses ( 1 ; 2 ) Connection caps ( 5 ) with solder flags ( 5a ) exhibit. Overcurrent protection device according to one of claims 4 to 8, characterized in that one or more of the individual fuses ( 1 ; 2 ) or fusible elements can be replaced by a conductive, in particular metallic, geometrically adapted cylinder. Overcurrent protection device according to one of claims 3 to 9, characterized in that the wiring substrate ( 8th ) an elongated, rectangular shape with attached on the narrow sides Schraubanschlusslaschen ( 10 ), the first part ( 9 ) of the series composite at a longitudinal outer edge, with this substantially laterally terminating, is arranged. Overcurrent protection device according to claim 10, characterized in that the second part of the series compound, containing the parallel connection, substantially at right angles to the longitudinal axis of the first part ( 9 ) of the series combination on the wiring carrier ( 8th ) is arranged. Overcurrent protection device according to one of claims 6 to 11, characterized in that the protective housing ( 7 ) to the longitudinal edge of the wiring substrate ( 8th ) is open, to an outlet of the firing pin and an operative connection to a spring-biased indicator slide ( 11 ). Overcurrent protection device according to claim 12, characterized in that the protective housing ( 7 ) at its from the wiring carrier ( 8th ) facing away from the top has a color-coded indicator surface or has an indicator surface extension. Overcurrent protection device according to at least one of claims 3 to 13, characterized in that the wiring carrier ( 8th ) on top of a housing ( 12 ) is mountable, wherein in the housing ( 12 ) a spark gap arrangement is providable. Overcurrent protection device according to claim 14, characterized in that the spark gap arrangement in series is present. Overcurrent protection device according to claim 15, characterized in that one of the spark gaps of the arrangement can be triggered and the trigger circuit can be triggered on the wiring carrier ( 8th ) is located. Overcurrent protection device according to one of claims 3 to 13 and 14 to 16, characterized in that the spark gap housing ( 12 ) on its upper side a trough-like recess ( 14 ) into which the first part of the series ver bunds dips to effect a protection and isolation function. Overcurrent protection device according to one of the claims 14 to 17, characterized in that the overall arrangement of surrounded by an insulating cap. Overcurrent protection device according to one of the claims 1 to 14, characterized by a modular construction with selected Melting elements for series connection to a light To effect adaptation to different nominal voltages. Overcurrent protection device according to claim 12 or 13, characterized in that the indicator slide ( 11 ) a display area ( 15 ), which releases or obscures a color-deviating indicator surface. Overcurrent protection device according to claim 20, characterized in that the indicator slide ( 11 ) an extension ( 16 ), which extends in the longitudinal direction over the narrow side of the wiring substrate ( 8th ) to communicate there with a telecommunications contact ( 17 ) enter into operative connection.