DE2349570A1 - Current transformer has core in metallic trough - and start and finish of winding joined to the trough - Google Patents

Abstract

The iron core of the transformer is embedded in resin inside a metallic trough which surrounds it on at least three sides. The end of the secondary winding is attached to one side of the trough. The other end of the remainder of the winding is attached to the opposite side of the trough. In this way the trough forms one turn of the winding and is closely coupled with the core thus helping to eliminate errors due, for example, to leakage. The winding fastened to the trough may equally well be used as a primary if this is desired.

Description

AKIIENGESEILSCHAPT Erlangen., % 8th SEP. Berlin and Munich Werner ~ von-Siemens-Str.

Our reference: VPA 73/3802 Kr / Etz -

Measuring transducer with an iron core housed in a ring-shaped metal trough

The invention "relates to a transducer having a Iron core housed in a ring-shaped metal trough.

For example from the manual of Vacuumschmelze GmbH Hanau "Soft Magnetic Materials", edition 1967, page 55 »it is known to protect soft magnetic iron cores To use metal troughs, in which the iron core is inserted and to lock it with a plastic cover is provided. The ring-shaped metal trough is closed by a plastic cover.

The invention is based on the object of providing a transducer with one housed in an annular metal trough To propose iron core, which is comparatively cheaper Manufacturing is characterized by an advantageously low translation error.

To solve this problem, a transducer of the type described at the outset is attached to the annular metal trough

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one end of the primary or secondary winding in the area of one edge of the transducer and in the area of the other edge of the metal trough the beginning of the adjoining the remaining part of the primary or secondary winding is conductively connected.

In the transducer according to the invention, the metal trough is used as a turn by one end of a Primary or secondary winding on one edge of the metal trough and the remaining part of the primary or secondary winding is conductively connected to the other edge of the metal trough. The transducer of the invention therefore comes with a Wire or foil winding less than the known transducers and is therefore in terms of low material costs advantageous.

It is already known (DT-OS 1 638 548, DT-OS 1 563 435, DT-AS 1 563 448, DT-OS 1 563 449 and DT-GM 7 204 896), the housing of high-voltage current transformers to be used to form a turn of the primary winding, however, the housing surrounds the iron core together Secondary winding.

An essential part of the goal of the fiction like aßen transducer is that the utilization of the ring-shaped Metal trough as a turn of a primary or secondary winding causes a good magnetic coupling that leads to leads to a low leakage inductance. In a transducer designed as a current transformer according to the invention results therefore a clear overcurrent behavior and a lower Translation errors over a large current range.

This advantage is particularly evident when the edges of the ring-shaped metal trough to achieve an almost

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complete covering of the iron core by the metal trough are bent inwards. With such a design of the metal tub, the leakage inductance becomes large kept low, which is beneficial to the transmission accuracy of the transducer 8 according to the invention.

There is a subsequent bending of the edges of the metal trough after the iron core has been introduced, it may cause difficulties in production of the metal trough viewed as advantageous, which consists of two metal rings, preferably with a U-shaped cross section exists, which are electrically conductive and mechanically firmly connected to one another at one edge and to one another face each other at their other edge while maintaining an insulating distance. The electrically conductive connection the two metal rings can preferably be made by welding take place.

Another embodiment of the metal trough which is advantageous in terms of production technology to achieve a transducer with very low leakage inductance looks like the ring-shaped Metal trough is provided with an annular disc-shaped metal cover, which is conductive with its one edge one edge of the metal trough and connected with its other edge insulating to the other edge of the metal trough is.

To explain the invention, a section is shown in FIG reproduced by an embodiment of the transducer according to the invention designed as a current transformer FIG. 2 shows a side view of this exemplary embodiment. In Figures 3 and 4 are in terms of Formation of the metal trough differentiating further embodiments of the transducer according to the invention are shown .

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73/3802

In the embodiment shown in Figures 1 and 2 "example of a measuring transformer designed as a current transformer, an iron core 1 is housed in a metal trough 2. To ensure a firm fit of the iron core 1 in the metal trough 2, the iron core 1 is encased with plastic 3. In the area of an edge 4 of the metal trough 2, one end 5 of a secondary winding is conductively connected while in the area of the other edge 6 of the metal trough 2, the beginning 7 of the remaining part 8 of the secondary winding 9 connected. The metal trough 2 therefore forms one turn of the secondary winding 9. The metal trough 2 and thus The iron core 1 is also penetrated by a primary conductor 10.

With one in view of the lowest possible leakage inductance particularly advantageous embodiment of the invention The transducer is a metal trough 20 composed of two metal rings 21 and 22 with a U-shaped cross section (see Figure 3). The metal rings 21 and 22 are welded to one another at point 23 with one edge each, while they face each other at their other edges while maintaining an insulating distance 24. In the area of one edge 25 of the metal ring 21, one end 26 of a secondary winding 27 is conductively connected; the beginning the remaining part of the secondary winding 27 is connected in the area of one edge of the metal ring 22, bo that the metal trough 20 in turn is one turn of the secondary winding 27 forms. A primary conductor, not shown, is sentric through the iron core 30 with an insulating sheath budding metal trough 20 out.

Bsi tea shown in Figure 4 example of a current transformer executed measuring transducer according to the invention is a © inen iron core 40 with insulating barrel 41 receiving ring-

shaped metal trough 42

Lid 43 closed. The metallic © 1 its one edge 44 is conductively connected to a trough 42, for example welded. To his » other edge 46 is the cover 43 opposite the other Edge 47 of the metal trough 42 is insulated.

To obtain a secondary winding with only a single turn, the cover 43 has one end. 48 of the secondary winding conductively connected, during the beginning of the remaining part of the secondary winding or in the illustrated embodiment another end 49 of the secondary winding is connected in the area of the other edge 47 of the metal trough 42 is. The metal trough 42 therefore forms one turn of the secondary winding. The primary winding is not shown.

With the invention, a transducer is proposed with an iron core housed in an annular metal trough, in which as a result of the use of the metal trough to form a turn of the primary or secondary winding a good magnetic coupling and a low leakage inductance and thus a small translation error is achieved is.

4 Piguren

4 claims

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Claims (4)

-S- YPA. 75/3802 Claims ί 1. JMeßwäufer with an iron core in an annular metal trough under it, characterized in that on the annular metal trough (2) in the region of an edge (4) one end of the primary or secondary winding (9) and in the region of the other edge (6) of the metal trough (2), the beginning (7) of the adjoining remaining part (8) of the primary or secondary winding (9) is conductively connected. 2. A transducer according to claim 1, characterized in that the edges of the annular metal trough to achieve an almost complete covering of the iron core by the metal trough are bent inwards. 3. A transducer according to claim 1 or 2, characterized in that the annular metal trough (20) consists of two metal rings (21, 22) with a preferably U-shaped cross-section, which are electrically conductive and mechanically at one edge are firmly connected to each other and at their other edge (25, 28) while maintaining an insulating distance (24) face. 4. transducer according to claim 1, characterized in that that the annular metal trough (42) is provided with an annular disc-shaped metal cover (43) with its one edge (44) conductively with one edge (45) of the metal trough (42) and with its other edge (46) is connected in an insulating manner to the other edge (47) of the metal trough (42). 5098U / 0653