System for interconnecting electrical wiring, corresponding electrical installation and method

Abstract

The present invention relates to an electrical wiring interconnection system comprising: - at least one electrical cable (10) comprising at least one electrical wire, and for each electrical cable: - a rear connection (12); - a connector (14) suitable for being connected to an electrical potential reference; - at least one shielding element (26, 34) of said electrical cable; said at least one electrical cable being connected to said connector via said rear connection, and a protection device (28, 36), located between said rear connection and said at least one shielding element of each electrical cable, and configured to apply a predetermined electronic function of electrical connection between the rear connection and said at least one shielding element, substantially established over the entire circumference of said at least one shielding element.

Description

[0001] The present invention relates to an electrical wiring interconnection system comprising at least one electrical cable comprising at least one electrical wire, and for each electrical cable of said electrical wiring interconnection system: a rear connection; a connector suitable for being connected to an electrical potential reference; at least one shielding element of said electrical cable; said at least one electrical cable being connected to said associated connector via said rear connection.

[0002] The present invention also relates to an electrical installation comprising a plurality of sensors and said interconnection system used for wiring said plurality of sensors.

[0003] The present invention also relates to a method for improving an electrical wiring interconnection system at least one electrical cable comprising at least one electrical wire, and for each electrical cable of said electrical wiring interconnection system: a rear connection; a connector suitable for being connected to an electrical potential reference; at least one shielding element of said electrical cable; said at least one electrical cable being connected to said associated connector via said rear connection.

[0004] The present invention therefore falls within the field of electrical wiring and relates more specifically to the electromagnetic compatibility of electrical wiring, for example for an application of establishing an electrical connection between sensors, in particular so-called low-level sensors. By "low-level sensor" is meant a sensor capable of generating a signal whose value is comparable to or lower than that of the disturbance induced by its environment, for example a signal of a few millivolts at low frequency in an industrial environment.

[0005] For example, such sensors correspond to temperature sensors, such as thermocouples, pressure sensors, temperature and pressure sensors, strain gauges, piezoelectric sensors, sensors dedicated to acquisition electronics.

[0006] From an electromagnetic compatibility point of view, these sensors must be sufficiently protected against disturbances from their environment.

[0007] Such protection is generally provided, at least in part, by the electrical wiring interconnection system used to establish an electrical connection between these sensors. Such an electrical wiring interconnection system conventionally comprises at least one electrical cable comprising at least one electrical wire.

[0008] Document FR 2 651 618 A1 discloses in particular a method and a device for connecting the screen of a cable with a high impedance at low frequencies and a very low transfer impedance at high frequencies.

[0009] Document EP 1 460 730 A1 relates to an audio cable connector intended to avoid potential equalization currents.

[0010] An example of an electrical cable used is illustrated by the figure 1 corresponding to an exploded view extracted from the prior art disclosed in US patent 3,465,092 published in 1969. More precisely, each electrical cable 10 of the electrical wiring interconnection system corresponds, in this example, to a set of individually shielded electrical wires, and for each electrical cable 10, the interconnection system comprises a rear connector 12 (from the English backshell ), a connector 14 (from English connector ) suitable for being connected to an electrical potential reference.

[0011] On the example of the figure 1 of the prior art, the connector 14 is formed of two elements, namely a connection plug 16 and a base 18 arranged concentrically, the base 18 being connected from the rear to the electrical potential reference.

[0012] On the figure 1 , the rear connection 12 (from English backshell ) ,known rear fitting from Glenair ®< called "tag ring ®<" comprises at one end a plurality of teeth arranged in a notch extending along the axis of the cable in the direction of the labeling ring nut 20 (from the English Tag Ring Nut) illustrated on the figure 1 . Each individual shield is conventionally intended to be inserted into the voids between said teeth arranged in a notched manner on said rear connector 12 and to be held there by the corresponding radial notches on said nut labeling ring 20 (from the English Tag Ring Nut). In other words, the nut labeling ring 20 is a part of the rear connector 12, detachable so as to place the individual shields in the voids between said slotted teeth, and engaging the rear connector 12 to hold said individual shields.

[0013] The electrical cable 10 is connected to said associated connector 14 via said rear connector 12 once all of the elements 20, 12, 14 have been assembled.

[0014] Further on the example of the figure 1 each electrical cable is suitable for including optional elements, a 22 adapter (from English Adapter ), and a stress relief element 24 (from English Strain Relief ) .

[0015] According to other classic examples not shown, the individual shielding of each electrical wire is replaced and / or supplemented by an overall shielding of all the electrical wires of the cable at once.

[0016] To protect against high-frequency interference, it is usually necessary to connect the shielding on both sides of the cable. The recommendations for connecting the shielding are listed in particular in the document by Michel Mardiguian entitled "Practical Manual of Electromagnetic Compatibility" second edition of 2003, particularly on page 257.

[0017] However, this type of connection allows low-frequency current to flow along the cable, which distorts the aforementioned "low-level" measurements. The very many rear connection references (from the English backshell ) currently available on the market, such as, for example, the Glenair ®< products called "tag ring ®<" or "starshield ®<", do not provide protection against low-frequency parasitic currents and at the same time (i.e. simultaneously) against high-frequency disturbances. In other words, with reference to the aforementioned manual by Michel Mardiguian, the implementation of an electrostatic or anti-crosstalk screen acceptable at low frequency as a compromise is not simultaneously compatible with the concept of a continuous barrier which attenuates field couplings.

[0018] Thus, in the current state, experimenters connect the shields or not, but these two solutions have the aforementioned advantages and disadvantages, and it is unfortunately currently necessary to choose between, on the one hand, connecting the cable shields to the acquisition electronics to protect against the microwave environment at the risk of disturbing the useful signal of the low-level sensor, and on the other hand not connecting the shields to the acquisition electronics with the risk of disturbing or even destroying these electronics due to the microwave environment.

[0019] In other words, currently no industrial solution can address the aforementioned problem, namely providing comprehensive protection, regardless of the frequency of electromagnetic disturbances in the environment.

[0020] The aim of the invention is therefore to propose an electrical wiring interconnection system making it possible to simultaneously provide effective protection against disturbances induced by the environment, whether at high or low frequency.

[0021] To this end, the invention relates to an electrical wiring interconnection system comprising: at least one electric cable comprising at least one electric wire, and for each electrical cable of said electrical wiring interconnection system: a rear connection; a connector suitable for being connected to an electrical potential reference; at least one shielding element of said electrical cable; said at least one electrical cable being connected to said associated connector via said rear connection, said interconnection system comprising a protection device located between said rear connection and said at least one shielding element of each electrical cable, said protection device being configured to apply a predetermined electronic electrical connection function between the rear connection and said at least one shielding element, said electrical connection being substantially established over the entire circumference of said at least one shielding element.

[0022] The present invention thus aims to take advantage of a predetermined electrical function implemented between the rear connection and said at least one shielding element of each electrical cable of the electrical wiring interconnection system to obtain both electrical continuity at high frequencies, over 360° around the shielding (i.e. the entire circumference), and insulation at low frequencies.

[0023] According to other advantageous aspects of the invention, the electrical wiring interconnection system comprises one or more of the following features, taken individually or in all technically possible combinations: said predetermined electronic function ensures both low-frequency isolation and high-frequency electrical continuity of said electrical wiring; said electronic function is a filtering function; said filtering belongs to the group comprising at least: high-pass filtering, low-pass filtering, band-pass filtering; said filtering function is implemented using at least one element belonging to the group comprising: a capacitor; an assembly formed via the superposition of a conductor, an insulator and another conductor; a capacitive material: an inductive element; a resistive element; said capacitor is a surface-mounted component; said predetermined electronic function comprises at least one on-off control of the implementation of said electrical connection;said at least one shielding element of said electrical cable is at least one general shielding element configured to globally shield said electrical cable and / or is a set of individual shields of each wire of said electrical cable; said general shielding element is a shielding braid or foil arranged around and along said electrical cable, said electrical cable and said shielding braid or foil being concentric; each individual shield of each wire of said electrical cable is a shielding braid or foil arranged around and along said associated electrical wire, said electrical wire and said shielding braid or foil being concentric.;

[0024] The invention also relates to an electrical installation comprising a plurality of sensors and said interconnection system as described previously used for the wiring of said plurality of sensors.

[0025] The invention also relates to a method for improving an electrical wiring interconnection system comprising: at least one electric cable comprising at least one electric wire, and for each electrical cable of said electrical wiring interconnection system: a rear connection; a connector suitable for being connected to an electrical potential reference; at least one shielding element of said electrical cable; said at least one electrical cable being connected to said associated connector via said rear connector, said method comprising a step of inserting a protection device between said rear connector and said at least one shielding element of each electrical cable, said protection device being configured to apply a predetermined electronic electrical connection function between the rear connector and said at least one shielding element of each electrical cable, said electrical connection being substantially established over the entire circumference of said at least one shielding element of said electrical cable.

[0026] These characteristics and advantages of the invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example, and made with reference to the appended drawings, in which: [ Fig 1 ] there figure 1 is a schematic representation of an electrical cable of an existing prior art interconnection system as previously described; [ Fig 2 ] there figure 2 illustrates an example of an electrical cable of an interconnection system according to a first variant of the present invention; [ Fig 3 ] [ Fig 4 ] THE figures 3 And 4 illustrate by means of several separate views a comparison between an electrical cable of an existing interconnection system, and an electrical cable of an interconnection system according to a second variant of the present invention.

[0027] It should be noted that the electrical wiring interconnection system according to the present invention firstly comprises the set of conventional elements previously cited in relation to the figure 1 relating to the prior art, namely: at least one electric cable 10 comprising at least one electric wire (also called electric strand), and for each electrical cable 10 of said electrical wiring interconnection system: a rear connection 12; a connector 14 suitable for being connected to an electrical potential reference; at least one shielding element of said electrical cable; said at least one electrical cable 10 being connected to said associated connector 14 via said rear connection 12.

[0028] Specifically according to the present invention, said interconnection system further comprises a protection device located between said rear connection 12 and said at least one shielding element of each electrical cable, said protection device being configured to apply a predetermined electronic function of electrical connection between the rear connection and said at least one shielding element, said electrical connection being substantially established over the entire circumference of said at least one shielding element.

[0029] In particular, said predetermined electronic function ensures both low-frequency isolation and high-frequency electrical continuity of said electrical wiring.

[0030] According to a first example, said electronic function is a filtering function.

[0031] More specifically, said filtering belongs to the group comprising at least: high-pass filtering, low-pass filtering, band-pass filtering.

[0032] As an optional addition, said filtering function is implemented using at least one element belonging to the group comprising: a capacitor; an assembly formed by the superposition of a conductor, an insulator and another conductor (i.e. a concentric juxtaposition of materials); a capacitive material: an inductive element; a resistive element.

[0033] As an optional addition, the capacitor is a surface mounted component (SMD). surface mounted device ) smaller and lighter, which allows for faster, less expensive assembly of the product, an increase in component density and the complexity of the predetermined electronic function. In addition, parasitic electrical resistances and inductances are reduced via such SMD components, thus increasing high-frequency performance, due to the reduction in the length of inter-component connections.

[0034] As an optional addition, said predetermined electronic function includes at least one all-or-nothing control of the implementation of said electrical connection.

[0035] THE figures 2 à 4 respectively represent a first variant illustrated by the figure 2 and a second variant illustrated by the views of the figures 3 And 4 .

[0036] According to the first variant illustrated by the figure 2 with a view A in section along the axis of the cable and a view B of the section of the cable seen from the end with the rear connection 12, said at least one shielding element of said electric cable is at least one general shielding element 26 (i.e. global) configured to globally shield said electric cable, said electric cable being covered accordingly on the figure 2 by the general shielding 26 and not visible.

[0037] As an optional addition, such a general shielding element is a braid 26 or a shielding foil arranged around and along said electrical cable, said electrical cable and said braid or said shielding foil being concentric.

[0038] According to an implementation of this variant not shown, a plurality of general shielding elements are suitable for use in concentric superposition.

[0039] According to the first variant embodiment of the present invention illustrated by the figure 2 , the protection device located between the rear connection 12 and the general shielding element 26 comprises, according to the example of the figure 2 , a plurality of capacitors 28 arranged all around the rear connection 12 so as to be located between the connection 12 and the general shielding element 26 corresponding for example to a braid.

[0040] In other words, one end of each capacitor 28 is connected to the rear connection 12 while the other end of each capacitor 28 is to the general shielding element 26.

[0041] This involves making the electrical connection between the shielding 26 and the ground of the equipment by means of a capacitance (i.e. a capacitor) 28 or possibly other electronic functions not shown and such as those mentioned previously. It should indeed be noted that any other predetermined electronic function, capable of ensuring both low-frequency isolation and high-frequency electrical continuity, can be used according to the present invention instead of the plurality of capacitors 28 illustrated schematically (i.e. according to an electrical diagram) as an example.

[0042] The present invention therefore proposes to integrate, between the rear connection 12 and the shielding element 26, this predetermined electronic function which makes it possible to ensure both low-frequency insulation and high-frequency electrical continuity of said electrical wiring.

[0043] An example of integrating this function into the rear connection is given by the diagram below.

[0044] In the example of integrating the figure 2 , the “high-frequency shield connection” and “low-frequency shield cut-off” are carried out simultaneously via the protection device corresponding to the plurality of capacitors 28.

[0045] According to the present invention, we speak by misuse of language of “rear filter connection” or even “rear filter connection”.

[0046] It should be noted that the capacitors 28 illustrated by the figure 2 are coupled to a resistance not shown corresponding to the resistance of the rear connection 12 to which is added the resistance of the plug 16 of the figure 1 , the resistance of the base 18, and the resistance between the base 18 and the electrical potential reference plate to which the base 18 of the connector 14 is suitable for being connected.

[0047] The sum of these four resistance values, when the connection is of good quality and the connection between the base and the potential reference plate is carefully made, is typically around 3 milliohms.

[0048] Thus, by calculating a classic RC filter for a cutoff at 100 MHz and to have very good conduction at 1 GHz, a 28 capacitor with a value of 530 nF is suitable, for example. If for another application, it is required to have a cutoff frequency at 10 MHz, a 28 capacitor with a value of 5.30 uF is then suitable, for example.

[0049] As illustrated by the different views of the figures 3 And 4 , according to a second variant, said at least one shielding element of said electric cable is a set of individual shields of each wire (i.e. strand) of said electric cable.

[0050] This second variant based on the use of individual shields, is according to a particular implementation, suitable for being combined with the first variant of implementation of at least one general shielding element 26.

[0051] As an optional addition, each individual shield of each wire of said electrical cable is a shielding braid or foil disposed around and along said associated electrical wire, said electrical wire and said shielding braid or foil being concentric.

[0052] More specifically, on the figures 3 And 4 , the protection device according to the present invention, is for example presented in combination 30 with the known rear connection from Glenair ®< called “tag ring ®<” covered by the aforementioned patent US 3,465,092 and illustrated on the figures 3 And 4 by view C.

[0053] As illustrated in view C, the known Glenair ®< rear fitting called a “tag ring ®<”, previously described in connection with the figure 1 relating to the prior art, comprises at one end a plurality of teeth arranged in a notch extending along the axis of the cable in the direction of the nut labeling ring 20 (from the English Tag Ring Nut ) . Each individual shield is conventionally intended to be inserted into the voids between said teeth arranged in a notched pattern and to be held there by the corresponding radial notches (i.e. radial tabs) of said nut labeling ring 20 (from the English Tag Ring Nut ) . Note that on the figure 3 these radial slots of the nut labeling ring 20 have a substantially T shape.

[0054] According to the present invention, the protection device consists first of all of a plurality of insulators 32 arranged on each vertical of the notches formed by the plurality of teeth. Each individual shield 34 is conventionally intended to be inserted into the voids between said teeth arranged in notches, and advantageously the protection device comprises a plurality of elements 36 capable of implementing said electronic function of electrical connection between the rear connection 12 and said at least one shielding element 34. On the figures 3 And 4 these elements 36 are represented by capacitors both arranged on the lower horizontals of the slots and on the faces of the radial slots (i.e. radial tabs) of the nut labeling ring 20 intended to hold the shielding elements 34 in the voids of the slots. In other words, once the rear connection 12 and its nut labeling ring 20.

[0055] There figure 4illustrates in perspective such an arrangement according to the invention in view D, compared to the conventional arrangement according to view C.

[0056] The present invention thus further makes it possible to propose a method for improving an electrical wiring interconnection system comprising: at least one electric cable comprising at least one electric wire, and for each electrical cable of said electrical wiring interconnection system: a rear connection; a connector suitable for being connected to an electrical potential reference; at least one shielding element of said electrical cable; said at least one electrical cable being connected to said associated connector via said rear connector, said method comprising a step of inserting a protection device between said rear connector and said at least one shielding element of each electrical cable, said protection device being configured to apply a predetermined electronic electrical connection function between the rear connector and said at least one shielding element of each electrical cable, said electrical connection being substantially established over the entire circumference of said at least one shielding element of said electrical cable.

[0057] Those skilled in the art will understand that the invention is not limited to the embodiments described, nor to the particular examples of the description, the embodiments and variants mentioned above being suitable for being combined with each other to generate new embodiments of the invention.

[0058] The present invention thus makes it possible to propose an effective solution to respond to two problems of protection against high-frequency HF and low-frequency LF disturbances simultaneously, by directly integrating, by abuse of language, into the rear connection of a cable the protection device implementing the predetermined electronic function making it possible to respond to these two problems.

[0059] The electrical wiring interconnection system proposed according to the present invention further enables a "standard" wireman to quickly, robustly and repetitively perform such a predetermined electronic function.

[0060] An electrical installation comprising a plurality of sensors and said interconnection system used for the wiring of said plurality of sensors is thus improved compared to existing electrical installations suffering from surrounding electromagnetic disturbances, in particular electrical installations with a plurality of “low-level” sensors as defined above, namely generating a signal whose value is lower than that of the disturbance induced by the environment.

Claims

1. Electrical wiring interconnection system comprising: - at least one electrical cable (10) comprising at least one electrical wire, and for each electrical cable (10) of said electrical wiring interconnection system: - a rear connection (12); - a connector (14) suitable for being connected to an electrical potential reference; - at least one shielding element (26, 34) of said electrical cable; said at least one electrical cable (10) being connected to said associated connector (14) via said rear connection (12), said interconnection system being characterized in thatit comprises a protection device (28, 36) located between said rear connection and said at least one shielding element of each electrical cable, said protection device being configured to apply a predetermined electronic function of electrical connection between the rear connection and said at least one shielding element, said electrical connection being substantially established over the entire circumference of said at least one shielding element, said predetermined electronic function ensures both low-frequency insulation and high-frequency electrical continuity of said electrical wiring. said at least one shielding element of said electrical cable is a set of individual shields (34) of each wire of said electrical cable.

2. An electrical wiring interconnection system according to claim 1, wherein said electronic function is a filtering function.

3. Electrical wiring interconnection system according to claim 2 wherein said filtering belongs to the group comprising at least: - high-pass filtering, - low-pass filtering, - band-pass filtering.

4. Electrical wiring interconnection system according to claim 2 or 3, wherein said filtering function is implemented by using at least one element belonging to the group comprising: - a capacitor (28); - an assembly formed via the superposition of a conductor, an insulator and another conductor; - a capacitive material; - an inductive element; - a resistive element.

5. An electrical wiring interconnection system according to claim 4, wherein said capacitor (28) is a surface mounted component.

6. Electrical wiring interconnection system according to any one of the preceding claims, wherein said predetermined electronic function comprises at least one on / off control of the implementation of said electrical connection.

7. An electrical wiring interconnection system according to any preceding claim, further comprising at least one other general shielding element (26) of said electrical cable configured to generally shield said electrical cable.

8. An electrical wiring interconnection system according to claim 7, wherein said general shielding element (26) is a shielding braid or foil disposed around and along said electrical cable, said electrical cable and said shielding braid or foil being concentric.

9. An electrical wiring interconnection system according to any preceding claim, wherein each individual shield of each wire of said electrical cable is a shielding braid or foil disposed around and along said associated electrical wire, said electrical wire and said shielding braid or foil being concentric.

10. Electrical installation comprising a plurality of sensors and said interconnection system according to any one of the preceding claims used for the wiring of said plurality of sensors.

11. Method for improving an electrical wiring interconnection system comprising: - at least one electrical cable comprising at least one electrical wire, and for each electrical cable of said electrical wiring interconnection system: - a rear connection; - a connector suitable for being connected to an electrical potential reference; - at least one shielding element of said electrical cable;said at least one electrical cable being connected to said associated connector via said rear connector, said method comprising a step of inserting a protection device between said rear connector and said at least one shielding element of each electrical cable, said protection device being configured to apply a predetermined electronic function of electrical connection between the rear connector and said at least one shielding element of each electrical cable, said electrical connection being substantially established over the entire circumference of said at least one shielding element of said electrical cable, said predetermined electronic function ensures both low-frequency insulation and high-frequency electrical continuity of said electrical wiring. said at least one shielding element of said electrical cable is a set of individual shields (34) of each wire of said electrical cable.;

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