Power and data transmission device

Abstract

The invention relates to a power and data transmission device, comprising a first circuit (100), a second circuit (200) and a cable (300) connecting the first circuit and the second circuit and comprising a first pair (301) and a second pair (302) of electrical conductors for transmitting a data signal and a power signal, the data signal being transmitted in differential mode in a first direction on the first pair of electrical conductors and in a second direction on the second pair of electrical conductors; characterized in that the first circuit is designed to transmit, in differential mode, the power signal on a sinusoidal carrier using the common modes of the two pairs of conductors and the second circuit is designed to receive said power signal while maintaining, with respect to the cable, a real impedance equal to an iterative impedance of the cable.

Description

[0001] POWER AND DATA TRANSMISSION DEVICE

[0002] The present invention relates to the field of data transmission between two remote electronic devices, and in particular two electronic devices on board a vehicle, such as an electronic control unit and a sensor.

[0003] BACKGROUND OF THE INVENTION

[0004] In the aeronautical field, the need to ensure the maintenance of aircraft safety and performance has led to increasing the number of sensors present on aircraft and disseminating them throughout the structure and equipment of said aircraft.

[0005] The physical quantities measured by these sensors are of all types and it is necessary to limit as much as possible the intrusive nature of their installation in the aircraft or its equipment in order to facilitate said installation and minimize as much as possible the increase in mass linked to the addition of the sensors.

[0006] Two particularly restrictive aspects of this implementation concern, on the one hand, the transmission of data between the sensors and the electronic unit for processing said data which is generally connected to the electronic control system of the aircraft and, on the other hand, the electrical power supply of said sensors. The means implemented both for the transmission of data and for the electrical power supply of the sensors must be relatively light, minimally intrusive, reliable and also require reduced maintenance. Naturally, data transmission by radio waves and battery power are envisaged but they do not satisfy all the constraints mentioned above.

[0007] In fact, the ARINC 664 (or AFDX) standard was chosen for data transmissions on aircraft. The implementation of this standard is based on a wired link comprising a shielded double differential pair cable capable of carrying two opposing data streams (commonly called Tx and Rx) at a bit rate of 125 Mbit / s.

[0008] Furthermore, a data link system is known, in particular from document FR-A-3049790, which allows power supply by carrier current so that a power signal circulates on the same cable as the data signal.

[0009] One of the difficulties encountered is to prevent the power signal from disturbing the data signal.

[0010] SUBJECT OF THE INVENTION

[0011] The invention particularly aims at providing a connection system between two electronic devices, which allows common transport of a data signal and a power supply signal while limiting the risk of disturbance of the first signal by the second.

[0012] SUMMARY OF THE INVENTION

[0013] For this purpose, a power and data transmission device is provided, comprising a first circuit, a second circuit and a cable connecting the first circuit and the second circuit and comprising a first pair and a second pair of electrical conductors for transmitting a data signal and a power signal, the data signal being transmitted in differential mode in a first direction on the first pair of electrical conductors and in a second direction on the second pair of electrical conductors. According to the invention, the first circuit is arranged to transmit the power signal in differential mode on a sinusoidal carrier using the common modes of the two pairs of conductors and the second circuit is arranged to receive said power signal while maintaining with respect to the cable a real impedance equal to an iterative impedance of the cable.The use of a sinusoidal carrier ensures optimal coexistence of data signals and power signals on the same cable. Such a cable has the characteristic, like a conventional coaxial link, of having an iterative impedance, that is to say that it has a real impedance reproducing itself step by step over its entire length. A line with iterative impedance, when it is loaded by a resistance of value equal to that of its iterative impedance (we often speak of characteristic impedance), presents at its input a real impedance equal to the resistance loading it at its end, whatever the length of the line. When a line with iterative impedance is loaded by its characteristic impedance, the signals progress on the line without causing echoes (local overvoltages and / or overcurrents) which would be conducive to parasitic couplings.Thus, the adaptation of the line on its iterative or characteristic impedance makes it possible to avoid having standing waves on the alternating wave of the power signal: such standing waves would cause antinodes or nodes of currents or voltages, and would be likely to increase the parasitic coupling between the power transmission in common mode and the data transmission in differential mode. There is therefore an effective segregation between the power signals and the data signals. To this end, the second circuit is arranged to load the cable with a constant pure resistance even though the load is variable. The transmission of power in sinusoidal voltage and current makes it possible to limit their bandwidth and therefore limit the couplings at high frequency. More preferably, the carrier of the power signal is centered on a frequency much lower than that of the data binary trains.Segregation by filtering is then facilitated. Preferably, the first circuit comprises a first transformer connected to the first pair of electrical conductors, a second transformer connected to the second pair of electrical conductors, and a third transformer in common mode on the two pairs of electrical conductors; and / or the second circuit comprises a first transformer connected to the first pair of electrical conductors, a second transformer connected to the second pair of electrical conductors, and a third transformer in common mode on the two pairs of electrical conductors.

[0014] This provides galvanic isolation which, in combination with the AC power transmission, protects all or part of the circuit from lightning and bulk current injections (BCI). The device then benefits from resistance to lightning and BCI without requiring specific protection components which are expensive, bulky and difficult to test; while minimizing interface wiring and guaranteeing a maximum bit error rate.

[0015] Advantageously, the first circuit is arranged so that the power signal has an alternating voltage having a high frequency, preferably of the order of one megahertz. According to additional characteristics, used separately or in whole or in part in combination:

[0016] - the second circuit comprises an AC / DC converter receiving the power signal as input and providing as output a DC power signal having a rectified voltage and an electronic load arranged to be proportional to the rectified voltage.

[0017] - the AC / DC converter is associated with a filter designed to attenuate switching noise from the AC / DC converter;

[0018] - the filter includes a common mode mutual inductance;

[0019] - the electronic load includes a current generator following the rectified voltage and connected to the output of the AC / DC converter;

[0020] - a low-pass filter Pi is placed at the output of the current generator and adapted to the iterative impedance of the cable;

[0021] - the second circuit includes a Zener diode voltage regulator;

[0022] - the second circuit includes a low dropout linear voltage regulator.

[0023] The electronic load circuit is an advantageous means of presenting a constant and real load to the power transmission line in order not to create standing waves or current distortions (because this corresponds to a broadening of the frequency spectrum of the current and therefore creates crosstalk with the data transmission).

[0024] The invention also relates to an aircraft equipped with such a remote connection device for connecting an electronic data processing unit to a sensor. Other characteristics and advantages of the invention will emerge from reading the following description of particular and non-limiting embodiments of the invention.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Reference will be made to the attached drawings, including:

[0027] [Fig. 1] Figure 1 is an overall view of the circuit of the transmission device according to the invention; [Fig. 2] Figure 2 is an overall view of the first circuit of the transmission device;

[0028] [Fig. 3] Figure 3 is an overall view of the circuit of the second circuit of the device of this transmission device, according to a first embodiment of the invention;

[0029] [Fig. 4] Figure 4 is a partial view of the second circuit according to a variant of the first embodiment of the invention;

[0030] [Fig. 5] Figure 5 is an overall view of the second circuit of this transmission device, according to a second embodiment of the invention.

[0031] DETAILED DESCRIPTION OF THE INVENTION

[0032] With reference to Figure 1, the transmission device according to the invention comprises a first circuit 100, a second circuit 200 and a cable 300 providing a connection between the first circuit 100 and the second circuit 200. According to a typical application of the invention, the first circuit 100 is arranged to be connected to a first electronic device, for example a data processing computer, and the second circuit 200 is arranged to be connected to a second electronic device, for example a detector providing measurement data of any physical parameter.

[0033] The cable 300, here “QUADRAX”, is standard and comprises a first pair 301 of electrical conductors and a second pair 302 of electrical conductors. In a manner known per se, the pairs are twisted and arranged in quadrature in a shield 303.

[0034] The first circuit comprises an input 101 for the data to be transmitted, an output 102 for the data received, and a power supply 103 receiving a continuous input power signal provided for example by the first device or a power distribution network. The input 101 is connected to the terminals of a primary winding 104.1 of a first transformer 104 having a secondary winding 104.2 to the terminals of which the electrical conductors of the first pair 301 of the cable 300 are connected.

[0035] The output 102 is connected to the terminals of a secondary winding 105.2 of a second transformer 105 having a primary winding 105.1 to the terminals of which the electrical conductors of the second pair 302 of the cable 300 are connected.

[0036] The power supply 103 is connected to the terminals of a primary winding 106.1 of a third transformer 106 having a secondary winding 106.2 having a first terminal connected to the midpoint of the secondary winding 104.2, a second terminal connected to the midpoint of the primary winding 105.1, and a midpoint connected to the mechanical ground of the first circuit 100 and / or the first device and to the shield 303 of the cable 300 (this mechanical ground constitutes the potential reference for the first device and the first circuit 100). The power supply 103 comprises a DC / AC converter arranged to convert the DC input power signal into a sinusoidal AC power signal having a frequency of the order of one megahertz and more particularly equal here to 1 MHz.

[0037] The second circuit comprises an output 201 of the data received from the first device, an input 202 of the data to be transmitted to the first device, and a power supply 203 providing a continuous output power signal to the second device.

[0038] The output 201 is connected to the terminals of a secondary winding 204.2 of a first transformer 204 having a primary winding 204.1 to the terminals of which are connected the electrical conductors of the first pair 301 of the cable 300. A Tx line is thus formed between the input 101 and the output 201. The input 202 is connected to the terminals of a primary winding 205.1 of a second transformer 205 having a secondary winding 205.2 to the terminals of which are connected the electrical conductors of the second pair 302 of the cable 300. An Rx line is thus formed between the input 202 and the output 102.

[0039] The power supply 203 is connected to the terminals of a secondary winding 206.2 of a third transformer 206 having a primary winding 206.1 having a first terminal connected to the midpoint of the primary winding 204.1, a second terminal connected to the midpoint of the secondary winding 205.2, and a midpoint connected to the mechanical ground of the second circuit 200 and / or the second device and to the shielding 303 of the cable 300 (this mechanical ground constitutes the potential reference for the second device and the second circuit 200) via a capacitor 213.1 and a resistor 213.2. The power supply 203 comprises an AC / DC converter arranged to convert the AC power signal received at the input into a DC output power signal suitable for powering the second device.

[0040] It is understood that we thus have a solution of integral galvanic isolation, both in direct current and in high frequency alternating current, which makes it possible to protect the second device from attacks of the type overvoltage and / or massive injection of current (lightning and BCI). It is therefore not necessary to use protection components, such as surge suppressors, which are difficult to monitor both in manufacturing and in operation. The data transmission part is carried out conventionally and will not be described further here. We are therefore interested in the rest of the description only in the power part.

[0041] The power supply 103 preferably comprises a sinusoidal voltage generator having a frequency of approximately 1 MHz and an angular phase shift (cosine PHI) equal to 1. This sinusoidal voltage generator is arranged to transmit each of its phases in common mode on the pair of electrical conductors 301 of the Tx line and on the pair of electrical conductors 302 of the Rx line respectively. An example of a sinusoidal voltage generator 1030 is shown in FIG. 2. With reference to FIG. 2, the sinusoidal voltage generator 1030 comprises a crystal oscillator 1031 having a first terminal connected to a first input of a first exclusive OR gate 1032.1 and a second terminal connected to an output of the first exclusive OR gate 1032.1. The output of the output of the first exclusive OR gate 1032.1 is connected to a first input of a second exclusive OR gate 1032.2 which has an output connected to a first input of an output of the third exclusive OR gate 1032.3 and to the first input of a fourth exclusive OR gate 1032.4. The exclusive OR gates 1032.1, 103.2 and 103.3 have second inputs connected to ground and the fourth exclusive OR gate 1032.4 has a second input receiving the input DC power signal. The fourth exclusive OR gate 1032.4 has an output connected to four amplifiers 1033 each having an output connected via a resistor 1034 to the positive terminal of the primary winding 103.1 and the third exclusive OR gate 1032.3 has an output connected to four amplifiers 1035 each having an output connected via a resistor 1036 to the negative terminal of the primary winding 106.1. The 1032 Exclusive-OR gates are thus integrated into a so-called quartz oscillator and phase shifter assembly.The amplifiers 1033 and 1035 belong, for example, to a digital buffer whose currents are distributed thanks to the resistors 1034, 1036 providing protection against short circuits of the connection between the first circuit 100 and the second circuit 200.

[0042] The connection of the primary winding 105.1 and the secondary winding 104.2 to the secondary winding 106.2 will be detailed. The midpoint of the primary transformer 105.1 is connected to a first terminal of a first capacitor 107.1 having a second terminal connected to the midpoint of the secondary transformer 104.2. The secondary winding 106.2 has a first terminal connected to the first terminal of the capacitor 107.1 by a first line 108.1 and a second terminal connected to the second terminal of the capacitor by a second line 108.2. The first line

[0043] 108.1 comprises two coils 109.1 in series which are polarized in the same manner and the second row 108.2 comprises two coils 109.2 in series which are polarized opposite to the coils 109.1. Each coil 109.1,

[0044] 109.2 therefore has its own inductance and each pair of coils 109.1, 109.2 facing each other has a mutual inductance. A second capacitor 107.2 extends between the connection point of the coils 109.1 to each other and the connection point of the coils 109.2 to each other. The midpoint of the secondary winding 106.2 is connected to the mechanical ground M-Gnd via a third capacitor 107.3 and a resistor 107.4 to achieve online adaptation in common mode. This forms a low-pass LC filter, of the fourth order and with low loss due to the absence of a resistive component, ensuring the elimination of the high-frequency components of the sinusoidal signal which is transmitted with each potential on the common mode of one of the pairs 301, 302 and with the DC component in common mode.

[0045] The second circuit 200, according to a first embodiment, will be described in relation to FIG. 3.

[0046] The first stage comprises a filter 207 and a rectifier bridge 208. The filter 207 is a Pi LC filter which comprises a pair of coils 2071, 2072, of opposite polarizations and facing each other, each having a self-inductance and together a mutual inductance, each having a first terminal connected to one of the terminals of the secondary winding 206.2 and a second terminal connected to one of the input terminals of the rectifier bridge 208. A first capacitor 2073 connects the first terminals of the coils 2071, 2072 to each other and a second capacitor 2074 connects the second terminals of the coils 2071, 2072 to each other. The rectifier bridge 208 is here a full-wave rectifier bridge of the conventional type, here of the GRAETZ type. Filter 207 is an analog circuit that provides pre-filtering to attenuate the switching noise of rectifier bridge 208.It is understood that the first stage ensures a conversion of the alternating power signal into a direct power signal having a full-wave rectified voltage equal to the average of the sinusoidal voltage.

[0047] The second stage is arranged to form a current consumer 209 following the rectified voltage and comprises a first line 209.1 and a second line 209.2 which each extend from one of the output terminals of the rectifier bridge 208 to one of the input terminals of the third stage. The second line comprises in series a resistor 2091 and a transistor 2092, of the NPN type, having an emitter connected to the resistor 2091 and a collector connected as indicated previously to one of the input terminals of the third stage. The second stage also includes an operational amplifier 2090 having a positive input connected to a voltage divider 2093 connecting lines 209.1 and 209.2, a negative input connected to the second line 209.2 between resistor 2091 and transistor 2092, a positive power supply pin connected to the cathode of a diode 2094 having an anode connected to the first line 209.1, a negative power supply pin connected to the second line 209.2, and an output connected via a resistor 2095 to a base of the transistor 2092. A capacitor 2096 further connects the cathode of the diode 2094 to the second line 209.2. The second stage constitutes an electronic load making it possible to simulate a resistive behavior of the load by forming a current-controlled consumer on the waveform of the full-wave rectified voltage. The second stage therefore allows the cable 300 to “see” a constant load.

[0048] The third stage comprises a Pi LC filter 210 similar to the filter 207. The filter 210 comprises a pair of coils 2101, 2102, of opposite polarizations and facing each other, each having a self-inductance and together a mutual inductance. The first coil 2101 has a first terminal connected to the first line 209.1 of the second stage and a second terminal connected to a first line 211.1 of the fourth stage. The second coil 2102 has a first terminal connected to the second line 209.2 of the second stage and a second terminal connected to a second line 211.2 of the fourth stage. A first capacitor 2103 connects the first terminals of the coils 2101, 2102 to each other and a second capacitor 2104 connects the second terminals of the coils 2101, 2102 to each other. It is understood that the filter 210 makes it possible to extract the resulting average voltage.

[0049] The fourth stage forms a load proportional to the rectified voltage received at the input and therefore a current-controlled consumer on the direct voltage received to provide a constant voltage to the second device (i.e. the user load). The fourth stage comprises a current generator 211 similar to the current consumer 209. The first line 211.1 and the second line 211.2 are connected, opposite the third stage, to a voltage regulator 212 which comprises in parallel a Zener diode type component 2121 and a capacitor 2122 and which is connected to the second device. The second line 211.2 comprises in series a resistor 2111 and a transistor 2112, of the NPN type, having an emitter connected to the resistor 2111 and a collector connected as previously indicated to the voltage regulator 212. The fourth stage also comprises an operational amplifier 2110 having a positive input connected to a voltage divider 2113 connecting the lines 211.1 and 211.2, a negative input connected to the second line 211.2 between the resistor 2111 and the transistor 2112, a positive power supply pin connected to the cathode of a diode 2114 having an anode connected to the first line 211.1, a negative power supply pin connected to the second line 211.2, and an output connected via a resistor 2115 to a base of the transistor 2112. A capacitor 2116 further connects the cathode of the diode 2114 to the second line 211.2. The voltage regulator 212 makes it possible to desensitize the device to load variations. The current consumed therefore varies in a small proportion, dependent on the variation of the input voltage received. This current flows through the equivalent of a Zener diode, across which there is a constant voltage regardless of the current flowing through it.

[0050] The second circuit therefore consumes a voltage in the image of the reference voltage to maintain constant the charge "seen" by the cable. The cable is for example loaded by the second circuit to 100 real ohms (i=u / r) for example. We understand that the rectified voltage equal to the average of the sinusoidal voltage received at the input serves as a reference voltage for the current generators.

[0051] Preferably, the transformers and the coupled inductors are produced in PCB technology, that is to say by burying the cores in the PCB plates and by producing the coils by conductive tracks, because this technology guarantees reproducible electrical performances and symmetries such that the rejection of common modes is greatly improved. This technology is for example known from documents FR-A-2201553 and FR-A-3110780.

[0052] In the variant of Figure 4, the voltage regulator 212 is replaced by a low-dropout linear voltage regulator or LDO also connected to ground. The LDO voltage regulator is an analog "series" voltage regulator capable of operating with a very low voltage drop between its input and its output. Furthermore, it outputs a more precise voltage and it is often easier to adjust the output voltage by simply changing resistor values ​​which are not shown in the figure.

[0053] It is then possible to use in the first stage a third-order low-pass LC filter 207 (and no longer the fourth order) because its role is just to limit the reinjection of the switching noise of the diodes of the rectifier bridge 208 into the cable 300.

[0054] The second circuit 200, according to a second embodiment, will be described in relation to FIG. 5. The second circuit 200 also comprises four stages. The first stage and the second stage are identical to those of the above variant.

[0055] The second circuit 200 according to the second embodiment differs from the variant of the first embodiment firstly in that the windings 204.2, 206.2 and 205.1 have midpoints connected via capacitors 2041, 2061 and 2051 to the mechanical ground Sensor housing - Gnd of the second circuit 200 and of the second device.

[0056] The second circuit 200 according to the second embodiment differs from the variant of the first embodiment secondly in that the current generator 211 is removed and is replaced by a voltage recovery circuit 220. The voltage recovery circuit 220 comprises a diode 2201 having an anode connected to the first line 209. 1 and to the collector of the NPN transistor 2092 and a cathode connected to the LDO voltage regulator. The voltage recovery circuit 220 also comprises a capacitor 2202 having a first terminal connected to the cathode of the diode 2021 and to a first branch of the LDO voltage regulator and a second terminal connected to a second branch of the LDO voltage regulator and to mechanical ground.

[0057] The diode 2021, capacitor 2022 and LDO voltage regulator assembly form a variable load stage to provide a constant voltage to the second device. The consumption is variable such that the sum of the current at the emitter of transistor 2092 and the second branch of the LDO is the same as at the positive input of amplifier 2090. Transistor 2092 serves as a variable for adjusting the consumption of the second circuit 200 provided that no voltage is present at the negative input of amplifier 2090. It should be noted that the consumption via diode 2093 is very low, which has very little influence on the overall consumption of the second circuit 200.

[0058] Electromagnetic compatibility with respect to massive current injections resulting from high-frequency radar-type pulses that produce common-mode disturbances is achieved by line symmetry, connection to mechanical ground and connection of the double inductance in differential. Capacitor 2061 also evacuates common-mode disturbances.

[0059] The quadrupole common mode inductance of coils 2071 and 2072 is applied across the entire quadrifilar line in order to present a high impedance to high-frequency common mode parasitic signals. Transformers 204, 205, 206 are responsible for DC and low-frequency isolation. At the series resonance of this assembly (around 100 MHz), the system being very symmetrical due to the PCB technology, the currents are balanced, opposite and flow almost entirely towards the shield 303 of cable 300 via resistor 213.2. The value of the resistor 213.2 is equal to the characteristic impedance value of the cable 300 in common mode, between 50 and 100 ohms, in order not to create standing waves likely to increase the common mode currents or voltages in certain parts of the cable, and therefore to create disturbances on the useful signals by poor common mode rejection.

[0060] The residual common mode voltages are all transmitted to the equipotential of the mechanical mass, itself connected to the structure close to the carrier. Thus, lightning and BCI currents cannot create differential voltages dangerous for the electronics of this sensor. For this, the capacitors 2041, 2051 and 2061 have a low impedance with respect to the high-frequency common mode voltages exacerbated during the resonance of the series LC couples formed by: the common mode inductance of the coils 2071 and 2072 and the transformer 204; the common mode inductance of the coils 2071 and 2072 and the transformer 205; the common mode inductance of the coils 2071 and 2072 and the transformer 206.

[0061] Thus, the high-frequency currents are mainly looped back to the proximity potential reference of the second device. This results in a high-frequency common-mode voltage, applied to the electronics of the second device, which is completely minimized and therefore has no impact on the operation of the second device.

[0062] The invention can be used in particular in an aircraft A comprising a data processing device A1 connected to the first circuit 100 of the device according to the invention and at least one sensor A2 connected to the second circuit 200 of this device.

[0063] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0064] In particular, any sinusoidal signal generator can be used as a current generator. The sinusoidal signal generator can further be arranged to provide a signal having a frequency other than 1 MHz.

[0065] The structure described is particularly simple. In fact, the received sinusoidal signal must be loaded by a "real" resistance equal to the characteristic impedance of the line (around a hundred ohms in the case of the Quadrax cable) and the power to be transmitted is low, of the order of a Watt: to make the system as simple as possible, a purely analog solution is preferred here, despite its low efficiency. However, a solution based on digital components can be considered.

[0066] This solution is also advantageous because many of the components that can be used to implement it are easily found commercially.

[0067] The invention is applicable to any type of installation, fixed or mobile, and to any vehicle.

Claims

CLAIMS 1. Power and data transmission device, comprising a first circuit (100), a second circuit (200) and a cable (300) connecting the first circuit and the second circuit and comprising a first pair (301) and a second pair (302) of electrical conductors for transmitting a data signal and a power signal, the data signal being transmitted in differential mode in a first direction on the first pair of electrical conductors and in a second direction on the second pair of electrical conductors; characterized in that the first circuit is arranged to transmit in differential mode the power signal on a sinusoidal carrier using the common modes of the two pairs of conductors and the second circuit is arranged to receive said power signal while maintaining with respect to the cable a real impedance equal to an iterative impedance of the cable.

2. Device according to claim 1, in which the first circuit (100) comprises a first transformer (104) connected to the first pair (301) of electrical conductors, a second transformer (105) connected to the second pair (302) of electrical conductors, and a third transformer (106) in common mode on the two pairs of electrical conductors.

3. Device according to claim 1 or 2, in which the second circuit (200) comprises a first transformer (204) connected to the first pair (301) of electrical conductors, a second transformer (205) connected to the second pair (302) of electrical conductors, and a third transformer (206) in common mode on both pairs of electrical conductors.

4. Device according to any one of the preceding claims, wherein the first circuit (100) is arranged so that the power signal has an alternating voltage having a high frequency, preferably of the order of megahertz.

5. Device according to any one of the preceding claims, in which the second circuit (200) comprises: - an AC / DC converter (208) receiving the power signal as input and providing a DC power signal having a rectified voltage as output; - an electronic load arranged to be proportional to the rectified voltage.

6. Device according to claim 5, in which the AC / DC converter (208) is associated with a filter (207) arranged to attenuate switching noises of the AC / DC converter.

7. Device according to claim 6, in which the filter (207) comprises a common mode mutual inductance (2071, 2072).

8. Device according to any one of claims 5 to 7, in which the electronic load comprises a current consumer (209) following the rectified voltage and connected to the output of the AC / DC converter (208).

9. Device according to claim 8, comprising a low-pass filter (210) Pi arranged at the output of the current consumer (209) and adapted to the iterative impedance of the cable (300).

10. Device according to any one of claims 5 to 9, in which the second circuit (200) comprises a Zener diode voltage regulator (212).

11. A device according to any one of claims 5 to 9, wherein the second circuit (200) comprises a low dropout linear voltage regulator (LDO).

12. Aircraft comprising a data processing apparatus connected to the first circuit (100) of a device according to any one of the preceding claims and at least one sensor connected to the second circuit (200) of this device.

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