阅读说明：本技术 具有简化几何形状的无源电流传感器 (Passive current sensor with simplified geometry ) 是由 C.克雷默 G.里德尔 T.保罗斯 S.法斯 M.皮希勒 于 2020-03-16 设计创作，主要内容包括：一种无源电流传感器(1),包括一对导电汇流排(5)、电连接汇流排(5)的分流电阻器(7)和具有第一对电压降测量触头(23)的载体(9)。至少一个电压降测量触头(23)附接到汇流排(5)中的每一个并且在所述至少一个电压降测量触头(23)与汇流排(5)之间形成直接电接触。(A passive current sensor (1) comprises a pair of electrically conductive busbars (5), a shunt resistor (7) electrically connecting the busbars (5) and a carrier (9) having a first pair of voltage drop measuring contacts (23). At least one voltage drop measuring contact (23) is attached to each of the busbars (5) and forms a direct electrical contact between the at least one voltage drop measuring contact (23) and the busbar (5).)

1. A passive current sensor (1) comprising:

a pair of electrically conductive busbars (5);

a shunt resistor (7) electrically connected to the bus bar (5); and

a carrier (9) having a first pair (19) of voltage drop measuring contacts (23), at least one voltage drop measuring contact (23) being attached to each of said busbars (5) and forming a direct electrical contact between said at least one voltage drop measuring contact (23) and said busbar (5).

2. The passive current sensor (1) according to claim 1, further comprising a second pair (19) of voltage drop measurement contacts (23), one of the second pair (19) of voltage drop measurement contacts (23) being directly electrically and mechanically connected to a first one (5a) of the busbars (5), and the other one of the second pair (19) of voltage drop measurement contacts (23) being directly electrically and mechanically connected to a second one (5a) of the busbars (5).

3. The passive current sensor (1) according to claim 1, wherein the carrier (9) has a receiving rod (37), the bus bar (5) and the shunt resistor (7) being inserted in the receiving rod (37).

4. The passive current sensor (1) according to claim 3, wherein one of the busbars (5) has a recess (5c), the carrier (9) engaging in the recess (5 c).

5. The passive current sensor (1) according to claim 1, further comprising a pair of temperature measurement contacts (21), each of the temperature measurement contacts (21) being electrically insulated from the busbar (5) and the shunt resistor (7).

6. The passive current sensor (1) of claim 5 further comprising a temperature sensor (35) electrically connected to the temperature measurement contact (21) and positioned near the shunt resistor (7).

7. The passive current sensor (1) according to claim 1, wherein the voltage drop measuring contacts (23) are each directly electrically and mechanically connected to the busbar (5) at a connection section (25).

8. The passive current sensor (1) as claimed in claim 1, wherein the voltage drop measuring contacts (23) each have a bending region (65) which connects together a busbar contact region (67) of the voltage drop measuring contact (23) and a plug connection region (69) of the voltage drop measuring contact (23).

9. The passive current sensor (1) according to claim 1, wherein the voltage drop measuring contacts (23) are each held and/or fixed in a pin receiving opening (79) of the carrier (9).

10. The passive current sensor (1) according to claim 1, further comprising a blind pin (73) mechanically fixing the position of the carrier (9), the blind pin (73) being connected to the carrier (9) and at least one of the busbars (5).

11. The passive current sensor (1) according to claim 1, wherein the carrier (9) is connected to at least one of the busbars (5) by means of undercut elements (85) and/or snap elements (97).

12. The passive current sensor (1) according to claim 7, wherein the connection section (25) of each voltage drop measuring contact (23) is accessible via an access recess (43) of the carrier (9).

13. The passive current sensor (1) according to claim 6, wherein an electrical temperature contact section (45) of the temperature measurement contact (21) and/or temperature sensor (35) is accessible via an access recess (43) of the carrier (9).

14. The passive current sensor (1) according to claim 13, wherein the carrier (9) has an entry protection device (39) which is designed to at least partially enclose the entry recess (43).

15. An assembly (61) for a passive current sensor (1), comprising:

providing a carrier (9), a pair of voltage drop measuring contacts (23) and a pair of temperature measuring contacts (21);

inserting the pair of voltage drop measurement contacts (23) and the pair of temperature measurement contacts (21) into a plurality of pin receiving openings (79) of the carrier (9); and

a temperature sensor (35) is electrically and mechanically connected to the temperature measuring contact (21).

16. An assembly (61) according to claim 15, further comprising a shunt element (63) having a pair of electrically conductive busbars (5) and shunt resistors (7) electrically connecting the busbars (5).

Technical Field

The present invention relates to current sensors, and more particularly to passive current sensors.

Background

A passive current sensor is used to measure the voltage drop at the shunt resistor. These current sensors are used, for example, in automotive engineering in the field of electric vehicles. In these vehicles, such passive current sensors are used to measure the flowing current, i.e. the current intensity. A shunt resistor is interposed between the two conductive buses. The shunt resistor has a very low resistance value, but the resistance value is high enough to enable the voltage drop across the shunt resistor to be measured. Typically, the resistance value of the shunt resistor is in the range of several tens of microohms.

Contacts of a Printed Circuit Board (PCB) soldered to the busbars contact the busbars which are interconnected by shunt resistors. On such PCBs, there are corresponding conductor tracks and connection points to which plug-in contacts can be soldered to tap the measured voltage signal (voltage drop across shunt resistance). The electrical plug contacts are indirectly connected via the PCB by soldering to one or more busbars. Such solder connections are not high strength and have little resistance to ageing and the quality of the solder connections cannot be easily tested due to the presence of the PCB.

Disclosure of Invention

A passive current sensor includes a pair of conductive busbars, a shunt resistor electrically connecting the busbars, and a carrier having a first pair of voltage drop measurement contacts. At least one voltage drop measurement contact is attached to each of the busbars and forms a direct electrical contact between the at least one voltage drop measurement contact and the busbars.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a passive current sensor according to one embodiment;

FIG. 2 is a perspective view of the case-less current sensor of FIG. 1;

FIG. 3 is an exploded perspective view of components for assembling a passive current sensor according to an embodiment;

FIG. 4 is a plan view of a stamped grid according to one embodiment;

FIG. 5 is a perspective view of a stamped grid according to another embodiment;

FIG. 6 is a perspective view of a stamped grid according to another embodiment;

FIG. 7 is a perspective view of a passive current sensor according to another embodiment;

FIG. 8 is a schematic diagram of a method for assembling a passive current sensor;

FIG. 9 is a perspective view of a first step of assembling a passive current sensor according to one embodiment;

FIG. 10 is a perspective view of a second step of assembling a passive current sensor according to one embodiment;

FIG. 11 is a perspective view of a third step of assembling a passive current sensor according to one embodiment;

FIG. 12 is a plan view of a fourth step of assembling a passive current sensor according to one embodiment;

FIG. 13 is a perspective view of a passive current sensor according to another embodiment;

FIG. 14 is a perspective view of a passive current sensor according to another embodiment, wherein the foldable element is in an open state;

FIG. 15 is a perspective view of the passive current sensor of FIG. 14 with a folded foldable element;

FIG. 16 is a perspective view of the passive current sensor of FIG. 14 with the cover member in an open state; and

fig. 17 is a perspective view of the passive current sensor of fig. 16 with the cover element in a covered state.

Detailed Description

The passive current sensor 1 according to one embodiment is shown in a preassembly position 3 in fig. 1. The passive current sensor 1 comprises a pair of electrically conductive busbars 5, which pair of electrically conductive busbars 5 is electrically and mechanically interconnected by a shunt resistor 7. The shunt resistor 7 is shown, for example, in fig. 2 and can be seen in particular in fig. 3, 7 and 8. The passive current sensor 1 has a carrier 9, which carrier 9 is designed as a housing 11 in the exemplary embodiment shown.

For the sake of clarity, fig. 2 does not show the carrier 9 or the housing 11. A plurality of contact pins 13 can be seen, which are arranged in a punching grid 15 and are spaced apart from one another and oriented towards one another. During the insertion into the housing 11, only the entire punched grid 15 is inserted, and there is no need to insert the individual contact pins 13 into the housing 11 separately. In one embodiment, the contact pins 13 are pins that may be received and securely fixed in the housing 11 via a press-fit or barb-like capture mechanism. The stamped grid 15 has connecting struts 17; in the embodiment shown, only four connecting struts 17 are denoted by reference numerals for the sake of clarity.

As shown in fig. 1 and 2, the contact pins 13 are provided in pairs with one pair 19 of temperature measuring contacts 21 and two pairs 19 of voltage drop measuring contacts 23.

The voltage drop measuring contacts 23 are connected to the busbar 5 at least one connection section 25 of the respective voltage drop measuring contact 23. The connection 27 at the connection section 25 is a direct electrical and mechanical connection 29, i.e. the voltage drop measuring contact 23 is fastened directly and immediately to the corresponding busbar 5 without an intervening element. This is achieved, for example, by means of solder or soldered connections 31, for example, by means of cold solder points. Alternatively, the connection 27 may be an integrally bonded, frictionally engaged, or any type of electrical or mechanical connection.

The connecting section 25 can be aligned in a defined manner away from the voltage drop measuring contact 23 in the direction of the busbar 5. If the voltage drop measuring contact 23 is a stamped part, such a connection section 25 can be produced by bending a section of the voltage drop measuring contact 23. The connection section 25 may be located at the free end of the voltage drop measuring contact 23 or in the central region. In the latter case, the voltage drop measuring contact 23 therefore has a projection which is deflected convexly in the direction of the busbar 5. Such a connection section 25 may be formed by a welding point accessible from the outside of the housing 11. The temperature measuring contacts 21 can form a temperature contact section which alternatively or additionally has at least one weld point.

The voltage potential applied at the voltage drop measuring contacts 23 can be tapped off on both sides of the shunt resistor 7 and the voltage difference between the voltage drop measuring contacts 23 can be determined. The voltage tapped on both sides of the shunt resistor 7 is present at each point of the corresponding bus bar 5. In the circuit diagram, the falling voltage across this resistor 7 is tapped by a voltage drop measuring contact 23 in parallel with the shunt resistor 7 and can be used via ohm's law for further processing to determine the current flowing through the resistor 7. Which is available via contact pins 13 received in the housing 11. The contact pins 13 are attached to the busbar 5 near the shunt resistor 7, since the voltage drop occurring at the shunt resistor 7 is the desired measurement variable to be tapped.

In addition to the connecting section 25, the elements of the voltage drop measuring contact 23 can in one embodiment be arranged in particular in a plane arranged parallel to the busbar 5. This distance can be ensured by the carrier or, in another embodiment, by a housing which holds the received voltage drop measuring contact 23 at precisely this distance from the busbar 5. Only the connecting section 25 can extend exactly this distance in the direction of the busbar 5 and be in mechanical contact with the busbar 5. Thus, the connection section 25 may already contact the busbar 5 before the connection section 25 is directly electrically and mechanically fastened to the busbar 5. The connecting section 25 can be produced in a simple manner by bending or stamping in a stamping process for producing a stamped grid.

For redundancy reasons, two pairs 19 of voltage drop measuring contacts 23 may be provided. The voltage drop determined via the first pair of contact pins 13 can thus be checked and/or verified. Defects in the contact pins 13 or the connection to the busbar 5 can thus be detected. In this case, pairs 19 may be distinguishable or indistinguishable.

Furthermore, one or more connection posts 17 can be held, which are located between the voltage drop measuring contacts 23 of one of the busbars 5. According to the method of the invention, the connection legs 17 connecting the voltage drop measuring contacts fastened to different busbars 5 are disconnected before the use of the passive current sensor 1. The same applies to the connecting column 17 which is present between the temperature measuring contacts 21 or between the temperature measuring contacts 21 and the voltage drop measuring contacts 23.

The temperature measuring contacts 21 may be assigned to the shunt resistors 7 and may be located closer to the shunt resistors 7 than the busbar 5. An insulating material bridge, for example comprising air, may be provided between the shunt resistor 7 and the temperature measurement contacts 21. The temperature sensor 35 is electrically connected to the temperature measurement contact 21 and is located in the vicinity of the shunt resistor 7. Neither the temperature measuring contacts 21 nor the temperature sensor 35 itself is allowed to make electrical contact with the busbar 5 or the shunt resistor 7. The temperature measuring contacts 21 are spaced apart from the busbar 5 and the shunt resistor 7 or are provided with an electrical insulator.

As shown in fig. 1, the bus bar 5 may be referred to as a first bus bar 5a and a second bus bar 5b, wherein the specified order is arbitrarily selected. The busbar 5 may have a fastening opening 55 for fastening the busbar 5. The options for fastening the busbar 5 are known from the prior art and will not be described further here. In each pair 19 of voltage drop measuring contacts 23, one contact 23 may be directly electrically and mechanically connected to the first busbar 5a, while the second contact 23 may be directly electrically and mechanically connected to the second busbar 5 b.

In one embodiment, the busbar 5 is a flat elongated cuboid having a thickness less than its width and also having a width less than its length. In one embodiment, the cross-section of the busbar 5 is rectangular. For low loss power lines, the busbar 5 is typically made of a material with high electrical conductivity, such as metal. For example, but not limiting of, the bus bar 5 may be made of copper.

The housing 11 of the embodiment of the passive current sensor 1 shown in fig. 1 also has an insertion face 33, in which insertion face 33 the contact pins 13 are received and/or fastened. The voltage drop occurring at the shunt resistor 7 and the resistance value of the temperature sensor 35 can thus be tapped in a simple manner via the insertion surface 33. Since the voltage drop across the shunt resistor 7 depends not only on the current flowing through it, but also appears to depend on the temperature of the shunt resistor 7, the temperature of the shunt resistor 7 is determined to correctly determine the flowing current.

The temperature sensor 35 is arranged at a distance from the bus bar 5 at a certain voltage level and prevents electrical cross-talk. In particular, the distance is greater than the creepage distance. Furthermore, an electrically insulating material, for example in the form of an air gap, a membrane or a liquid, can be provided between the busbar 5 and the temperature sensor 35 and the temperature measuring contact 21. In one embodiment, an insulating material with a higher thermal conductivity than air is used, which ensures that the temperature is efficiently transferred from the shunt resistor 7 to the temperature sensor 35, wherein sufficient insulation is still provided and thus electrical cross-talk and/or spurious measurements are prevented.

The housing 11 of the passive current sensor 1 shown in fig. 1 also has a receiving rod 37, as shown in fig. 3, 8 and 9-11. The bus bar 5 is received in the housing 11 by the receiving rod 37.

The housing 11 further comprises an access protection 39 shown in fig. 1, which in the embodiment shown is configured as a cover element 41. With the access protection 39, it is possible to at least partially cover the access recess 43 and prevent access to elements accessible through the access recess 43, such as the connection section 25, the direct electrical and mechanical connection 29 and the temperature sensor 35.

The connection 27 of the temperature sensor 35 to the temperature contact section 45 is also covered by the entry protection 39. The temperature contact sections 45 differ from the connection sections 25 of the voltage drop measuring contacts 23 in that they are electrically insulated from the busbar 5 and the shunt resistor 7. It is also possible to provide a direct electrical and mechanical connection 29 at the temperature contact section 45, but in this case between the temperature sensor 35 and the associated temperature contact section 45 of the corresponding temperature measurement contact 21.

The cover element 41 of the illustrated embodiment is connected to the rest of the housing 11 by a connecting element 49 configured as a membrane hinge 47, as shown in fig. 1. In some configurations of the passive current sensor 1, the membrane hinge 47 may have a flexibility that allows the cover element 41 with the attached membrane hinge 47 to fold towards the entry groove 43 in a rotational movement 51 and close the entry groove 43. However, in other constructions, the material of the housing 11 may be too brittle for such movement and requires the connecting element 49 to be separated before the access groove 43 is closed by the cover element 41.

In the embodiment shown in fig. 1, the entry groove 43 is a sensor entry groove 53, i.e. the connection section 25 as well as the temperature contact section 45 and the temperature sensor 35 themselves are accessible via a single groove.

The stamped grid 15 of fig. 2 also shows the fixing eyelets 57; for the sake of clarity, only a few are indicated with reference signs. As shown in fig. 9, the fixing holes 57 are used to securely fasten and/or position the punching grid 15 in the housing 11 by fixing pins 59 protruding through the fixing holes 57.

Fig. 3 shows an assembly 61 for assembling the passive current sensor 1. The assembly 61 comprises a housing 11, a stamped grid 15, the temperature sensor 35 and a shunt element 63, the stamped grid 15 comprising, in the embodiment shown, four voltage drop measuring contacts 23 and two temperature measuring contacts 21. In the embodiment shown, the shunt element 63 is to be understood as a one-piece element, comprising the two busbars 5 and the shunt resistor 7. In other configurations of the assembly 61 according to the invention, such a diverting element 63 may not be present.

Fig. 3 further shows a recess 5c in the shunt element 63 for engaging the shunt element 63 in the housing 11 without play. For safety reasons, the locking mechanism is of redundant design; functionally, one notch 5c is sufficient. The punch grid 15 has a bending region 65, which bending region 65 connects the busbar contact region 67 to the plug connection region 69. In the embodiment shown, the two regions 67, 69 are arranged at an angle of 90 ° to each other, but may be aligned at any angle to each other.

The bending region 65 can be produced after the contact pins 13, i.e. for example the voltage drop measuring contacts 23 and the temperature measuring contacts 21, have been punched out. In one embodiment, the entire stamped grid is curved. In this case, the busbar contact area 67 may be aligned substantially parallel to the busbar 5, and in one embodiment, the busbar contact area 67 and the plug connection area may enclose an angle of about or exactly 90 °. The connecting section 25 can therefore be arranged in the busbar contact region 67, wherein the pin-like free ends of the voltage drop measuring contact 23 and/or the temperature measuring contact 21 can be arranged in the plug connection region. The busbar contact area 67 and the plug connection area 69 may be at any angle to each other. The bending region 65 can be understood as the knee of the respective contact pin 13 located in this region.

The passive current sensor 1 according to the invention can have differently designed stamped grids 15; three further possible embodiments are shown in fig. 4-6. The stamped grids 15 each have four voltage drop measuring contacts 23, two temperature measuring contacts 21 and corresponding connecting sections 25 and temperature contact sections 45.

In the embodiment of the stamped grid 15 of fig. 4 and 5, each temperature sensor 35 is connected to a temperature contact section 45 of the corresponding temperature measurement contact 21. In one embodiment, the depicted temperature sensor 35 is an NTC temperature sensor 71, but may be any temperature sensor, such as a PTC resistor, an SMD component, or a wired temperature sensor. In addition, the embodiment of the punching grid 15 shown in fig. 4 and 5 has fixing eyelets 57. In this case, any geometry, position and number of fixation holes 57 may be chosen.

In fig. 5 and 6, the punching grid 15 also has two blind pins 73. They also have a connection section 25, but do not lead to the contact pins 13; instead, they lead into a fastening pin 75 which is not provided for the electrical contact but merely ensures the mechanical stability of the housing 11 relative to the shunt element 63.

A blind pin 73 may be provided to mechanically fix the position of the housing 11, the blind pin 73 being mechanically connected to the busbar 5 and the carrier 11. To mechanically connect the blind pin 73 to the busbar 5, it is attached to the busbar 5, for example, by welding. In another embodiment, the blind pin 73 engages in a hole configured in the busbar 5 and is held in the hole by a frictional connection or catch mechanism. The contact or the fixing of position by the connection to the housing 11 can take place, for example, in the form of a plug contact or a snap-in element. The voltage drop measuring contact 23 and/or the temperature measuring contact 21 and the blind pin 73 are therefore received in the housing 11 or are fastened firmly in the housing 11 or on the housing 11. The housing 11 is then positioned and fastened on at least one busbar 5 and, in a subsequent step, the contact pins 13 provided in the corresponding embodiment, i.e. the voltage drop measuring contacts 23, the temperature measuring contacts 21 or the blind pins 73, are fastened to the busbar 5. According to the invention, this takes place directly, i.e. without additional interposed elements.

A passive current sensor 1 according to another embodiment is shown in fig. 7. In addition to the four voltage drop measuring contacts 23, the passive current sensor 1 of fig. 7 also has an SMD temperature sensor 77, which SMD temperature sensor 77 is fastened to the temperature measuring contact 21, but is at the same time positioned electrically insulated from the shunt resistor 7. In the simplest case, this is ensured by spacing the SMD temperature sensor 77 from the shunt resistor 7. Also shown is the insertion face 33, in which insertion face 33 the contact pins 13 are received in the pin receiving openings 79 of the housing 11. In the embodiment shown, the contact pins 13 are designed as plug contacts 81, which has the advantage that the contact pins 13 can be received in a guided manner in the housing 11 and additionally are securely fastened in their position by the housing 11. The pin receiving openings 79 may also be referred to as contact chambers, and the housing 11 may also be referred to as a pin contact housing.

The assembly of the passive current sensor 1 is shown in fig. 8. The method starts from the first method step at the upper left of the figure and follows the arrow shown.

First, as shown in fig. 8, the contact pins 13 comprising at least two voltage drop measuring contacts 23, or more precisely the plug connection areas 69 of the contact pins 13, are received in the housing 11. For this purpose, the contact pins 13 can be inserted firmly into the housing 11 and can additionally be fastened to the housing 11 by means of fixing eyelets 57.

As shown in fig. 8, the temperature sensor 35, which is designed as an SMD temperature sensor 77, is then attached with the temperature measuring contact 21 to the temperature contact section 45 via the access groove 43.

The shunt element 63 is then inserted laterally into the receiving rod 37 of the housing 11 until the temperature sensor 35 is positioned above the shunt resistor 7, as shown in fig. 8. In this case, the four voltage drop measuring contacts 23 in the embodiment shown are directly electrically and mechanically connected to the two busbars 5 by their connecting sections 25. Subsequently, a thermally conductive material 83 may be additionally installed between the temperature sensor 35 and the shunt resistor 7. Such a thermally conductive material 83 has high thermal conductivity, while it has an electrical insulating effect.

Fig. 9 to 12 show bottom views of the passive current sensor 1 in different method steps. In fig. 9, a stamped grid 15 is inserted into the housing 11. Fastening the stamped grid 15 against movement in the housing 11 may be accomplished by inserting the voltage drop measurement contacts 23 and the temperature measurement contacts 21 into the corresponding pin receiving openings 79 of the housing 11. Furthermore, the fixing of the punching grid 15 is supported by the above-mentioned fixing holes 57 and the fixing pins 59 of the housing 11 received therein.

As shown in fig. 8 and 9, the housing 11 shown has an undercut element 85, which undercut element 85 completely surrounds the busbar 5 to be received. The undercut elements 85 are at least partially designed complementary to the busbars 5 and in which the busbars 5 can be guided. The undercut element 85 may thus have an L-shaped cross section, extend along a side surface of the busbar 5 and engage behind in the busbar 5, with an undercut section on the side of the busbar 5 opposite the carrier or housing 11. Another embodiment of the undercut element 85 is a closed receiving opening which surrounds the busbar 5 both partially and completely and engages the busbar 5 from behind at its side surfaces. In one embodiment, the undercut elements 85 are arranged in pairs facing each other. In order to fix the housing 11 with one or more undercut elements 85 to the busbar 5, it is necessary to move it into a receiving opening or receiving rod formed by the undercut elements 85.

In a further method step in fig. 10, the temperature sensor 35 is inserted into the housing, wherein the positioning pin 93 assists in the positioning of the temperature sensor 35. Finally, the temperature sensor 35 is fastened to the temperature contact section 45 of the temperature measurement contact 21 by a direct electrical and mechanical connection 29.

When the shunt element 63 is mounted, its front edge may hit the very sensitive voltage drop measuring contact 23. For this purpose, as shown in fig. 11, a lateral opening 11a may be provided in the housing 11. These openings 11a allow the measuring contacts 21, 23 to be raised using a tool, such as a wedge plate, before the shunt element 63 is mounted. The raising of the measuring contacts 21, 23 takes place in the plane of the drawing. After installation, the wedge plate can be removed, so that the measuring contacts 21, 23 spring back to the starting position and contact the inserted shunt element 63. Subsequently, the welding process may be started.

Fig. 12 shows the housing 11 of fig. 11 after the lateral introduction of the shunt element 63 into the receiving rod 37 of the housing 11. The connection sections 25 of the four voltage drop measuring contacts 23 provided can be accessed through the access recess 43. The temperature contact section 45 is accessible via a separately configured sensor access recess 53.

The passive current sensor 1 according to the invention can also have a further embodiment of an entry protection 39, as shown in fig. 13, in the form of a secondary snap element 95. As shown in fig. 12, the secondary catch element 95 and the catch element 97 together engage with the housing 11 and also have a foldable element 99, which foldable element 99 can be folded over the access groove 43 and prevents counting into the connecting section 25. The secondary catch element 95 shown in fig. 13 covers the sensor entry groove 53 by means of the rear side 101. The folding movement 103 is schematically shown in fig. 15.

Fig. 14 and 15 show a further embodiment of a passive current sensor 1, which differs from the previous embodiments in that the housing 11 is joined to the shunt element 63 by a second embodiment of a foldable element 99. This is also connected to the housing 11 by a membrane hinge 47. The foldable element 99 has stop elements 105, which stop elements 105 each bear against one busbar 5 and are pressed against the busbar 5 when a folding movement 103 is carried out about the film hinge 47. This is shown in fig. 15, where the housing 11 also has a further snap element 107, which snap element 107 engages the foldable element 99 from behind, thereby keeping the stop element 105 pressed against the busbar 5 and preventing the foldable element 99 from opening.

Fig. 16 and 17 show different perspective views of the passive current sensor 1 according to the invention of fig. 14 and 15. The accessible entry groove 43 in fig. 16 can be seen. In order to close the access recess 43, the passive current sensor 1 has a second example of an access protection 39 which is designed as a cover element 41. Its function substantially corresponds to the cover element 41 of the embodiment of the passive current sensor 1 shown in fig. 1. The cover element 41 is also connected via a membrane hinge 47, but in other configurations it may be achieved by a differently configured hinge. In the covering state 109, the foldable element 99 is engaged from behind by means of a snap strip 111, which snap strip 111 correspondingly engages in a complementarily configured snap hook 113.

In the passive current sensor 1 and the assembly 61, no PCB is required; the contact pins 13 are directly connected to the bus bar 5. Due to the direct contact of the contact pins 13 with the busbar 5 and the electrical connection 29, a soldering process can be carried out, wherein soldered connections can generally have a low error rate. Furthermore, since no PCB is required anymore, components are saved and instead of using two connections, i.e. from the contact pins 13 to the PCB and from the PCB to the busbar 5, only one electrical and mechanical connection 29 is required for connecting the contact pins 13. The current sensor 1 thus has a simpler structure than prior art solutions, is more cost-effective and can increase the service life of the passive current sensor 1 due to the more durable connection.