DE2329418A1 - LC filter and interference suppression - capacitor electrodes and coil windings are of strips facilitating construction and saving space - Google Patents

Abstract

The strips, together with insulating layers, are combined into a single element with separate inductance and capacitance zones; strip windings of the two chokes are placed on both sides of capacitor strip electrodes. The number of turns in the capacitor and in the chokes is the same. The choke strip windings are near each other, and the capacitor(s) electrodes consist of parts of strips forming also the choke windings, and of an opposite electrode, made in one piece near an end of the choke windings strip.

Description

DR. MÜLLER-BORt DIPL-PH ^V S. D ». MANITZ DIPL-CHEM. DR. DEUFEL DiPL-ING. FINSTERWALD DlPL-ING. GRÄMKOW

PATENT LAWYERS

Munich, "the" I JüHI töS

Fi / Sv - H 1112

S30Ü Landshut / Bavaria, Ludmillastraße 23/25

Electrical filter, especially LC filter for

Radio interference suppression

The invention never relates to electrical filters, particularly LC filters for radio interference suppression. In general, the invention encompasses all of them Types of LC members, such as Larsen members, Mehrxach-Larsen limbs, combinations of chokes and XY capacities as well as chain connections of chokes and arbitrarily distributed X and Y capacities.

As is well known, chokes are used to suppress interference voltages, Capacitors and combinations of these two components are used. Some form of a combination of the two The so-called Larsen circuit represents components, which consists of two inductors and one with respect to the interferer there is transverse capacitance downstream of the choke coils. This Larsen circuit representing a four-pole filter is

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Dr. Müller-Bof * Or. Manitz · Or. OeuM ■ Dipl.-Ing. Finsterwald Dipl.-Ing. Qrfcnkow Brtfunschweig. Am Bürgwpark · a MOndten 22. Rbbert-Koch-StraB · 1 7 Stuttgart-Bad Cannstatt. MarkMraB 3 Taielon (0531) 7 »« 7 T ·! * »| W1)» 3β «. Telex 5-22050 mbpat Telephone J0711) 567261

: Zaiilialfcaeaa Bayer. Votatanfcan. Munich. Toilet no. 9622 Poetscheck: Manchen 95466

preferably used for interference suppression of switches but also for the interference suppression of the power supply of devices.

The main disadvantages of this Larsen circuit, as well as the others ■ known filters and filter combinations used for radio interference suppression purposes "consist in the fact that their production is relatively complex and costly and, moreover, that of installing them Filters required space in the respective device is not always available stands.

Wound capacitors which have been expanded to LC elements have also become known, in which the capacitive and inductive components are used to suppress interference in electrical devices. They essentially consist of two band-shaped or wire-shaped electrodes that are rolled up into a coil with the interposition of a dielectric (German patent specification • 959 659).

The main disadvantage of these known choke capacitors is that their interference suppression leaves something to be desired and measures are taken to improve the interference suppression, e.g. a subdivision Each capacitor electrode of the same polarity in a predetermined, from the geometric shape of the finished Winding dependent ratio, leads to the fact that the interconnection is complicated and thus in turn the production of such Choke capacitors made difficult and automatic production is practically prevented.

The object of the invention is to provide an electrical LG filter, in particular To create radio interference suppression that is simple, essentially fully automatic and particularly economical can be manufactured, built compact and thus space-saving and in a simple manner to the respective requirements is adaptable with regard to the radio interference suppression.

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According to the invention, this object is achieved in that both the capacitance coverings and the windings of the chokes ribbon-shaped and with the interposition of insulating layers to form a single, separate inductance and winding containing capacitance areas are.

In contrast to previously known filters, in which capacitors and coils are manufactured separately, in a support structure had to be combined and interconnected or where capacitive and inductive components had to be one Windings have been exploited, the invention makes a particularly simple one, essentially relying on one with conventional ones Capacitor winding machines feasible operation allows limiting manufacturing and thus practical any assembly and switching work avoided. By combining all the components of the noise filter in one A single V / ickel can also be achieved a space saving, the use of such a filter even then made possible if only a relatively small installation space is available in the respective device.

According to an expedient embodiment of the invention, in the case of a Larsen circuit, the windings are ribbon-shaped of the two DiOsseln in the winding viewed in the axial direction arranged on both sides of the band-shaped coverings of the capacity.

This embodiment is particularly suitable for combined line filters and Larsen links for relatively large, E.g. nominal currents above 1.6 amps.

An advantageous embodiment of the invention is distinguished characterized in that the band-shaped throttle windings in the coil run side by side and the coverings of the capacity or Capacities of sub-areas of the inductor windings

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forming bands and at least one of these partial areas opposite mating surface are formed.

This embodiment is particularly favorable in terms of winding technology. Also, due to the side by side running inductor windings compensations of symmetrical disturbance voltage components avoided.

The counter-facing is preferably designed in one piece and arranged in the region of one end of the bands forming the throttle windings, this counter-facing, for example can be vapor-deposited on an intermediate layer.

A particularly advantageous embodiment of the invention is characterized in that the counter-layer is subdivided and a separate partial counter-layer is assigned to each of the bands which also form the throttle windings in a predeterminable area, and that the partial capacitances thus formed are connected in series.

This embodiment leads to electrically optimal properties, because when using such partial counter-coverings practically any unfavorable mutual influence of Capacities and inductances can be switched off.

The partial counter-linings are preferably arranged next to one another and connected to one another by at least one contact element. What is important here is that the electrical properties of the filter can be influenced by choosing the position of the contact element and in this way extensive influence can be exerted on the respective radio interference suppression effect.

The contact element is preferably arranged in the region of the connection points of the throttle windings, which are expediently located approximately at the outer end of the counter-linings.

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According to a further expedient embodiment, the chokes in the winding formed by ribbon-shaped windings inside, and in this case the winding preferably has a soft magnetic core. By using a soft magnetic core, the inductance can be increased by the factor 3 ^ is 5 in the case of internal chokes, which has an advantageous effect in particular with rated currents from around 1 ampere or inductance values greater than around 250 uH, as this results in smaller dimensions and a lower cost of materials. In addition to rod-shaped cores closed cores can also be used, especially when relatively large inductance values are required which are composed, for example, of two U-shaped sections. The cores can consist of dynamo sheet or from powder cores made from orarbonyl iron. In case of The use of powder cores has the advantage that the shape of these cores corresponds to the respective needs can be selected and, for example, in the case of using a round core, a direct winding of this core is possible.

According to a further embodiment of the invention, the chokes formed by ribbon-shaped windings can be in the winding also lie outside. This leads to the advantage of better heat dissipation and also facilitates production, since with external chokes, the capacitors are inevitably internal and the intermediate layers required to build the capacitors in the course of the wrapping process at the end of each Capacitor layer only need to be separated so that additional intermediate layers are inserted in the course of the winding process can be circumvented. The external throttles also have the advantage that due to the in comparison to internal choke with larger winding diameters obtained a certain desired inductance with fewer windings can be.

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Another feature of the invention is that the insulating layers between the band-shaped throttle windings have less strength than the dielectric of the capacitance or capacities.

An intermediate layer that is as thin as possible in the area of the inductor winding leads to a desired, favorable fill factor.

A further advantageous embodiment of the subject matter of the invention is characterized in that the Conductive strips forming choke turns within the area between the choke contacting points Area are more heavily dimensioned. In this way the fact can be taken into account that the coverings only in the area forming the throttle, from the operating current are flowed through. As already mentioned, however, in * this part the insulating intermediate layer can be used against the Dielectric required in the capacitor area be reduced in terms of strength.

According to a further advantageous embodiment, at least one discharge resistor in the form of a is in the winding thin resistor or a resistor layer attached to a carrier film.

An advantageous option for the formation of the band-shaped coverings and turns is to use them in the form of Apply metal layers to plastic films.

Copper and / or aluminum are preferably used as the material for the strip-shaped coverings and windings, with im In the case of the use of aluminum, a larger volume of the total winding is obtained, but in comparison to copper when using Eein-Aluminum the advantage is

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would keep that cutting burrs do not occur in a disruptive manner, which is just in the area of the inductor winding will prove advantageous, since in this area the thinnest possible intermediate layers must be used, to achieve a favorable fill factor.

Furthermore, it can be expedient to have copper or aluminum tracks without intermediate layers that are insulated at least in the throttle part to use, because in this way not only a smaller volume but also better heat dissipation is achieved can be. Aluminum sheets oxidized on both sides are suitable for this purpose. With such aluminum tracks it is enough the oxidation layer in the choke area as insulation, and it produces a desired one in the condenser area additional mechanical protection due to their hardness.

The connections, housings and casings for the winding constructed according to the invention can be carried out in the usual way will. The housings can be made of plastic or metal, especially aluminum and steel, but it It is also possible, instead of such a housing, to use a wrapping film that is encapsulated at the end.

The width of the counter-layers is preferably somewhat greater than the width of the opposing layers assigned to them, since in this way it can be ensured in a particularly simple manner that small mutual dislocations of the two Tracks do not have a disadvantageous effect during winding, i.e. do not lead to undesired changes in capacitance.

If a discharge resistor has to be wrapped in the winding at the same time, a band-shaped one is preferred Resistance layer in the form of a bridge between the two throttle plates in the area of the outer end of the winding.

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In the manufacture of the filter or LC elements according to the invention For example, the capacitor plates and the chokes consisting of ribbon-shaped conductors can be used simultaneously wound next to each other and contacted during the winding process and interconnected inside. The capacitor can also be designed as a series circuit and / or contain X and Y capacitances. To set up chains for radio interference suppression or network wiring, it is only necessary to remove the capacitor backing to interrupt and make a new contact. When building the lap, it is essential that that the conductor tracks and insulating layers are matched to one another in width and thickness.

The invention is explained in more detail below on the basis of exemplary embodiments with reference to the drawing; in the drawing shows:

Fig. 1 is a basic circuit diagram of the known Larsen circuit,

FIG. 2 is a schematic cross-sectional view to explain the winding structure of a first embodiment of FIG Invention,

3 is a schematic plan view and a longitudinal sectional view the winding webs of a further embodiment of the invention before winding,

Fig. 4- is a schematic plan view of part of the winding webs for a Larsen link according to a further embodiment the invention,

5 shows a schematic cross-sectional view of the embodiment according to FIG. 2 and a modification of this embodiment, and the

6 and 7 are schematic longitudinal sectional views of the winding webs of embodiments with Y capacitances, wherein for the embodiment according to FIG. 7, the associated electrical circuit diagram is also given. 409881/0625

The well-known Larsen circuit according to Pig. 1 consists of two chokes L with capacitance C lying across them. The purpose of the chokes is to provide internal resistance of the switching contact S and to support the effectiveness of the interference suppression capacitor.

This is mainly used to suppress interference from switches, but also for interference suppression of the mains supply Larsen links suitable for devices were previously interconnected in the form of separate components, wherein the chokes are designed as separate inductances or as double inductances on a common core could be.

Fig. 2 shows in a schematic sketch the basic winding structure of a according to the invention in the form Larsen link made of a single coil.

The two layers 1, 2 of the capacitor run in the middle of the total tape to be wound, with the dielectric being used 5 paper, plastic or a mixed dielectric can be used. On either side of the condenser Forming bands 1, 2 run the band-shaped windings 3 »4 of the chokes with reduced intermediate layers. the the bands forming the throttles 3 »4- are made

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for example made of copper or aluminum with a thickness ranging from 40 to 60 ai.

At the beginning of the winding, a capacitor plate 1 or 2 is in common contact with a throttle 3 or 4, respectively and led out of the coil in the form of a connector 7 ″ or 8. Accordingly, only the throttle connections have to be led out at the end of the winding, with this possibly being the case the conductive tracks themselves can serve if they protrude by a small amount over the termination of the coil.

When producing the roll, a sufficiently large mandrel hole can also be provided to allow the introduction of a To enable core made of dynamo sheets, but it is also possible to manufacture the tracks directly be wound on the respective core.

Tests have shown that about 100 turns are required to achieve a sufficiently large inductance, The coverings and dielectric of the capacitor must be chosen so that the capacitance is achieved with the same number of turns the desired value, which is, for example, 0.03 to 0.07 AiF is reached.

Such a roll can of course be used in a known manner installed in plastic pipes or rectangular cups and, if necessary, potted. This embodiment a Larsen coil according to the invention is particularly suitable for relatively high rated currents, the can be greater than 1.6 amps, for example, and also this type of construction is more composite Line filter suitable.

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Fig. 3 shows an embodiment of a Larsen circuit in Winding form, which is particularly advantageous in terms of winding technology, since it practically only has two adjacent has continuous coverings, which simultaneously act as band-shaped inductor windings and as capacitor coverings to serve.

According to Fig. 3, two made of copper or aluminum run Tracks 10, 11 side by side and thus become with the interposition of an insulating layer 9 Chokes wound, with compensations of symmetrical interference voltage components due to this arrangement can be avoided.

In the area of one end, preferably in the area of the start of winding, the conductor track areas 10 ', 11 * a counter-facing 12 is provided opposite, so that the required capacity is obtained. Advantageously this counter-facing is implemented using a metallized plastic film. In such an embodiment, especially when the capacitance in the winding is inside, the use of a soft magnetic core can be dispensed with, since such a core only has one produces a slight increase in the effective inductance and, moreover, there is a risk that it will deteriorate of the properties of the capacitance.

This is important in the embodiment according to FIG. 3 Contacting the individual coverings, as this contacting has an influence on the interference suppression effect of the Larsen * link.

Instead of contacting at the beginning and at the end of the linings 10, 11, as shown at A, A ¹ and ^ O, it is advisable to make contact at a point on the roll that is determined experimentally, depending on the respective required suppression properties. One possible contact is

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given for example at B, B ¹ . Appropriate contact can be made in the area of the middle of the counter-facing. Although the operating current then flows through part of the capacitor area in this embodiment, this choice of contacting is advantageous for certain applications. When choosing the contact, it must be ensured that the capacitance has a sufficiently low self-inductance and that the chokes are not attenuated too much.

The advantage of the embodiment according to FIG. 3 is that the winding time can be minimized and without particular difficulties the contacting of the individual conductive strips can be integrated into the winding process.

4- shows a particularly advantageous embodiment of Invention in which a Larsen limb is made up of two adjacent continuous conductor tracks 10, 11 and these conductor tracks in areas 10 ', 11' opposite separate Counter-coverings 13, 14- is constructed, the in this way partial capacities obtained by a metallic connecting link 15 are connected in series.

The separate counter-linings and the series connection of the capacitors formed in this way have a particularly high-frequency effect advantageous, it should generally be pointed out that the series connection provided in accordance with the invention is the Capacity has the advantage that a high ionization threshold voltage even with a non-impregnated plastic dielectric is ensured.

The connection of the counter-linings is preferably made via the contact element 15 in the area of contacting the main linings 10, 11, as indicated by the contacts B, B ¹ in Pig. 4.

An essential feature of the invention is that the electrical properties of the built-up Larsen roll due to the special arrangement of the two opposing coverings

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COPY

connecting contact element there are 15 adjustable. It v / uräe already he vj civ nt, aa-i / preferred verbinaun ^ cpuri'.it in Tereicli: he l.or / taktierunrjsst eilen eier Hauptbel'lge lies, but a ■ / r_ ε c: \ iebur = j der junction of the Ge ^ enbelc.ge ka_m je : -. ': S ~ the required filter properties are advantageous and necessary, in which case the exact location of the junction can be determined experimentally, for example.

As shown in FIG. A at 9, can consist, for example, of Hostaphan, the thickness of the intermediate layer in the throttle openings being able to be reduced, for example, to 5 ×. Such a reduction is made possible by the division of a dielectric and accordingly does not lead to any difficulties in production.

Since the continuous main coatings 10, 11 are only traversed by the operating current in the part that forms the throttles, If necessary, these can be strengthened in this area.

Instead of bare conductor tracks and insulating intermediate layers, it is also possible to use insulated, e.g. lacquered or to use anodized sheets with and without intermediate layers. In the throttle part, it is possible to install pads made of insulated copper orb. Use aluminum webs that are entangled without intermediate layers, with advantages in terms of heat dissipation result.

In Fig. 5 is a first cross-sectional view in pore again shown the embodiment of FIG. 2, and in a second representation schematically shows a variant in which a series connection of capacities 1 ·, 16 and 16 " is provided. xline such series connection affects very advantageous with regard to the ionization voltage from, and it can be seen from the representation of FIG. 5 that such a variant without difficulties can be wrapped.

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COPY

Fig. Ξ> shows an LC combination according to the invention, in which the basic structure, consisting of inductors 10, 11 and a counter-facing 12, a Y-capacitance 17 is wrapped. It can be seen that this capacity 17 requires additional insulating coverings, but this does not cause any difficulties in terms of production technology.

A particularly advantageous embodiment of a filter according to FIG the. The invention is shown schematically in FIG. 7 on the one hand in the form of not yet wound layers' and on the other hand shown in the form of an electrical circuit diagram. In this embodiment, the series connection is desired the partial capacities reached so that a reinforcement of the dielectric is not necessary and especially with unimpregnated Plastic / electric can be worked, which in turn is particularly important in terms of manufacturing technology has a beneficial effect.

It is essential that in all embodiments according to the invention the capacitor plates and the strip-shaped conductors existing chokes can be wound side by side at the same time and that there is the possibility of contacting to be carried out during the winding process and to carry out the interconnection inside.

The structure of derailleur circuits, in which sections with opposing linings that act as capacitors and those that act as chokes Alternating sections without opposing surfaces several times does not cause any problems, where X and Y capacities can be distributed and combined as required. When building such derailleurs only the capacitor layers have to be interrupted and reconnected. A coordination in strength and breadth is required for the conductor tracks and insulating layers.

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When manufacturing a filter constructed according to the invention, it is also possible to use an inductance to begin the forming topping and after the appropriate length the second topping, which has a capacity with the first topping forms, add and cut off the first layer after reaching the desired capacity. The ongoing one The second coating then forms the second inductance. In this case, too, there is a series connection via a counter-facing just as possible as XY combinations and several in one Wrap combined LC combinations.

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Claims (24)

Claims M / electrical filter, especially LC filter for radio interference suppression, characterized in that both the capacitance layers (C) and the windings of the chokes (L) in the form of a band and with the interposition of insulating layers to form a single, separate inductance and winding containing capacitance areas are combined. 2. Filter according to claim 1, characterized in that the band-shaped windings (3, 4; 10, 11) of the two throttles in the winding viewed in the axial direction on both sides of the band-shaped linings (1,2; 10 ¹ , 11 ', 12, 13, 14) are arranged. 3. Filter according to claim 2, characterized in that that the number of turns of capacitance and chokes is the same. 4-. Filter according to claim 1, characterized in that the band-shaped throttle windings (10, 11) run side by side in the Wicisl and the capacities of the capacitance or capacities of sub-areas (10 ·, 1Ί ¹ ) of the bands which also form the throttle windings, and of one of them Opposite sub-areas (12) are formed. 5. Filter according to claim 4-, characterized in that the counter-covering (12) is formed in one piece and in the area one end of the bands (10, 11) forming the throttle windings is arranged. 409881/0625 6. Filter according to claim 4-, characterized in that the Cregen covering is divided and each of the bands (10, 11) forming the throttle turns in predeterminable areas (10 ¹ , 11 ') is assigned a separate partial counter-covering (13 »14 ·) and that the partial capacitances thus formed are connected in series. 7- filter according to claim 6, characterized in that that the partial counter-coverings (13 »14-) at least partially arranged side by side and connected to one another by at least one contact element '(15). 8. Filter according to claim 7 »characterized in that the contact element (15) is arranged in the region of the connection points (B, B ¹ ) of the throttle windings (10, 11) which are preferably located approximately at the outer end of the counter-linings. 9. filter according to any one of the preceding claims, characterized characterized in that the chokes formed by ribbon-shaped windings lie inside the winding. 10. Filter according to claim 9 »characterized in that that the winding has a soft magnetic core. 11. Udder according to claim 10, characterized in that that a rod core is used as the core. 12. Udder according to claim 10, characterized in that that a closed core, preferably consisting of two U-shaped parts, is used as the core. 409881/0625 13. Filter according to claim 11 or 12, characterized in that the core made of dynamo sheets or
consists of a powder core made of carbonyl iron. 14. Filter according to one of claims 1 to 8, characterized in that the band-shaped turns formed chokes in the coil are outside. 15 · Filter according to one of the preceding claims, characterized characterized in that the insulating layers between the band-shaped throttle windings are less thick have as the dielectric of the capacitance or capacities. 16. Filter according to one of the preceding claims, characterized in that the conductive strips (10, 11) forming the inductor windings are inside
between the throttle contact points (A, A ¹ ,
B, B ¹ ) are more heavily dimensioned. Filter according to one of the preceding claims, characterized in that at least one discharge resistor in the form of a thin resistor or one mounted on a carrier film in the winding
Resistance layer is wrapped. 18. Filter according to one of the preceding claims, characterized in that the band-shaped coverings and turns in the form of metal layers are applied to plastic films. 19. Filter according to one of the preceding claims, characterized characterized in that the band-shaped coverings and turns are made of copper and / or aluminum. 409881/0625 20. Filter according to one of the preceding claims, characterized characterized in that at least in the throttle part insulated copper or aluminum tracks without intermediate layers are involved. 21. Filter according to claim 6 or 7i, characterized in that the partial coverings with one another connecting contact elements are welded to these partial coverings. 22. Filter according to one of the preceding claims, characterized in that the width of the counter-layers is slightly larger than the width of the opposing layers assigned to them in each case. 23. Filter according to claim 17, characterized that the band-shaped resistance layer in the form of a bridge between the two throttle plates in the area of the outer Vickel end is arranged. 24. Filter according to one or more of the preceding claims, characterized in that at least one of the ribbon-shaped conductors (1,2,3 »4; 10,11) extends from the beginning of the cradle extends to the end of the winding. 409881/0625