Device and method for detecting a current of a first conductor of an electrical circuit, in particular mounted at least

Abstract

The invention relates to a device and a method for detecting a current of a first electrical conductor, in particular of an electrical circuit mounted at least partially on a printed circuit board. The invention relates to a device and a method for detecting a current directly or indirectly by means of a change in current of a first electrical conductor of an electrical circuit, in particular at least partially mounted on a printed circuit board, wherein a short-circuit current proportional to a change in the current in the first conductor is generated in combination with a connected transimpedance amplifier in combination with a change in the magnetic flux given in the first conductor by a change in the current, said sensor sensitive element being embodied according to the invention and placed around the first conductor.

Description

Technical Field

[0001] The invention relates to a device for detecting the current of a first conductor of a circuit, in particular mounted at least partially on a printed circuit board, according to the preamble of claim 1, and a method for detecting the current of a first conductor of a circuit, in particular mounted at least partially on a printed circuit board, according to the preamble of claim 9. Background Art

[0002] Methods and devices for current detection are known. These solutions generally differ in that they involve measurement methods based on different physical effects. Examples of this are so-called shunt measurements, magnetic field measurements, for example using the so-called "giant magnetoresistance" GMR effect, measurements based on Rogowski coils or measurements based on current transformer solutions.

[0003] However, the aforementioned measuring methods and devices have the disadvantage that they are usually frequency-limited due to various factors, for example due to the core material to be used, winding capacitances and / or compensation devices. Summary of the invention

[0004] The object of the present invention is therefore to specify a solution that overcomes the disadvantages of the prior art; in particular, the object of the present invention is to specify a method and a device that enable simple implementation, in particular when the measuring method is integrated in a printed circuit board.

[0005] This object is achieved by a device method for detecting a current in a first conductor of a circuit, in particular mounted at least partially on a printed circuit board, according to the preamble of claim 1, by means of its characterizing features, and by a method for detecting a current in a first conductor of a circuit, in particular mounted at least partially on a printed circuit board, according to the preamble of claim 9, by means of its characterizing features.

[0006] Further advantageous embodiments and developments of the invention are described in the dependent claims.

[0007] In the case of the method according to the invention for detecting the current of a first electrical conductor of an electrical circuit, in particular one at least partially mounted on a printed circuit board, a first body which is placed in a plane forming a closed loop and conducting current around the first electrical conductor and a second body which forms a closed loop and conducts current in the plane, such that the constructed loop of the body is arranged and operated concentrically, in particular circularly, in the plane around the first electrical conductor which is placed in its geometric center point, extends perpendicularly through the plane and conducts the current to be detected, wherein the bodies are shaped and / or functionally connected to each other and operated such that the bodies are electrically conductively connected via at least one second electrical conductor which forms a U-shaped profile perpendicularly to the plane in cross section, wherein the two legs of the U-shaped profile in cross section are located in the corresponding cross-sectional planes. On, and the first leg of the U-shaped profile is connected to the first body via a first connection point, and the second leg of the U-shaped profile is connected to the second body via a second connection point, in particular the first connection point and the second connection point of the corresponding U-shaped profile are located on a straight line with the center point, in addition, the first body is connected to the first input end of a transimpedance amplifier, in particular, designed by an operational amplifier, and the second body is connected to the second input end of the transimpedance amplifier and is operated so that a short circuit can be caused by the transimpedance amplifier, wherein a short-circuit current flowing from the transimpedance amplifier through the first body, the second body and at least one second conductor formed and / or functionally connected in the case of the caused short circuit generates a voltage at the output end of the transimpedance amplifier (transimpedance converter) as an input parameter of the transimpedance amplifier.

[0008] Since the first and second bodies and at least one second conductor that is functionally connected and / or formed are functionally connected and operated in the manner according to the invention, when a current flows through the first conductor, a current is induced in the AC loop thus provided, and since the transimpedance amplifier is functionally connected and operated, the transimpedance amplifier in this case short-circuits the first and second bodies and at least one second conductor. The induction is obtained because the alternating current of the first conductor generates a magnetic field H, which in turn flows perpendicularly through the mesh of the second conductor. The value of the current changes according to the change in the value of the current flowing through the first conductor, and due to the course of the method according to the invention, it is applied to the transimpedance amplifier so that a voltage proportional to the change in the short-circuit current is applied at its output. By evaluating this voltage, the current change can therefore be detected in an inventive and advantageous manner.

[0009] The method according to the invention makes it possible in particular to implement a current detection method on a printed circuit board, preferably in contrast to the sensor-based measurement method based on the Rogowski coil concept known from the prior art, because the process according to the invention generates a strong signal, so that a very well evaluable signal proportional to the current change is generated even with a small number of second electrical conductors, in particular by operating the transimpedance amplifier according to the invention. Compared to the experiments known from the prior art to implement the Rogowski coil concept, according to the invention, not only 100 or even a multiple of 100 loops are required to detect the current, but only a few loops resulting from the U-shape through the second electrical conductors are required. The method according to the invention thus significantly reduces the very large number of holes in the printed circuit board that would otherwise be required according to the prior art, and in particular also reduces the cost and results in significantly more degrees of freedom in the design of the printed circuit board.

[0010] Furthermore, the process according to the invention enables current detection in a galvanically isolated manner. All this is true in particular when the transimpedance amplifier is realized by an operational amplifier, so that this results in a very good implementation variant among the possible implementation variants.

[0011] The elements functionally connected and operated according to the invention furthermore allow flexible adaptation to the magnitude of the current to be expected in the first electrical conductor, ie the current to be detected according to the invention.

[0012] Although it is a possible design option, conceivable, for example when symmetry is desired, to align the connection point with the conductor as the center point, it is not necessary for the current detection according to the invention, because the signal generated by the invention for the current detection is given by the expanded surface of the measuring sensor (Messnehmer), through which the H field of the current change to be detected passes.

[0013] These advantages also apply to a refinement of the method according to the invention, in which the first body and the second body are functionally connected and operated so that each point of the first closed loop is connected to a parallel point of the second loop via an electrically conductive connection forming a U-shaped profile in cross section, so that the cross section surrounding the center point always has a U-shaped profile, so that the at least one second electrical conductor is constructed together with the first body and the second body as a hollow body forming a circumferential U-shaped profile.

[0014] By means of this solution, at least one second electrical conductor is thus formed from the first body and the second body into a three-dimensional integral shape. These bodies can also be regarded as the result of an infinite number of mutually fused second electrical conductors arranged radially around the first electrical conductor, which are arranged in a row, completely surround the first electrical conductor, and in which the magnetic field generated by the alternating current of the first electrical conductor is penetrated to a greater extent. It can also be regarded as a single formed second electrical conductor, which is penetrated by the magnetic field differently than the second electrical conductor given by the single winding, and has different properties only because of this, which can meet the corresponding implementation requirements. Other advantages of this arrangement may be, in particular, greater robustness, a complete lack of holes in the printed circuit board and / or alternative design options.

[0015] According to another embodiment of the method according to the invention, the first body, the second body and / or the at least one second electrical conductor are at least partially operated as conductor tracks of a printed circuit board. This makes it possible to reduce the outlay for providing the method according to the invention, since at least some of the connections and functional units required according to the invention are already produced during the production of the conductor track structure of the printed circuit board and only a few components have to be installed at most.

[0016] Preferably, the method according to the invention is developed in such a way that the first electrical conductor, the at least one second electrical conductor and / or the functional connection are operated as a so-called "vertical interconnect access" (Via) through-hole connection. As a result, the horizontal elements required for the method according to the invention for current detection according to the inventive design can also be produced during the production of the printed circuit board structure, so that the equipment expenditure is further reduced.

[0017] According to a further development of the method according to the invention, the first body, the second body and / or the at least one second electrical conductor are shaped and / or functionally connected in such a way that the first body, the second body and / or the at least one second electrical conductor are run in an inner layer of the printed circuit board. On the one hand, this process advantageously exploits one of the potentials of the method according to the invention, which is the improved minimization possibilities, and allows the method according to the invention to be run to a certain extent at least partially in a concealed manner, or in such a way that, for example, space for shielding is still available on the so-called outer layer, or additional degrees of freedom are provided for the conductor track structures on the outer layer, for example, the current branches whose currents are to be detected.

[0018] In the case of this development of the method according to the invention, in which the voltage at the output of the transimpedance amplifier is fed as an input signal to the first module that performs the integration, the value of the detected current can be determined in an advantageous manner, rather than just its change. The invention can thus be operated in accordance with the desired variable to be measured and make the variable detectable.

[0019] Here, this development of the method according to the invention can be advantageously designed according to the requirements of the circuit or in principle according to the desired design, so that the first module is functionally connected to the transimpedance amplifier and operated so that the module acts as an integrator circuit. An integrator circuit is a simple analog design for converting a detected current change into a current value caused by integration.

[0020] If it is desired to save components and / or to obtain a digitally processable signal as a result of the method according to the invention for current detection, the method according to the invention can be designed so that the second module is functionally connected to the transimpedance amplifier and operated so that the second module acts as an analog / digital converter, in which the analog value of the voltage at the output of the transimpedance amplifier is converted into a digital representation of the value of the voltage, and is functionally connected to a calculation unit and operated so that integration is carried out by the calculation unit, which is in particular designed as a "digital signal processor" DSP, a so-called "central programming unit" CPU or a so-called "application-specific integrated circuit" circuit ASIC.

[0021] In the case of a device according to the invention for detecting the current of a first conductor of a circuit, in particular, at least partially mounted on a printed circuit board, a first body formed around the conductor in a plane to form a closed loop and to conduct current and a second body formed in the plane to conduct current, so that the constructed loop of the body is arranged concentrically, in particular circularly, in the plane around the first conductor, which is placed in its geometric center point, extends perpendicularly through the plane and conducts the current to be detected, wherein the bodies are shaped and / or functionally connected to each other so that the bodies are electrically conductively connected via at least one second conductor, which forms a U-shaped profile perpendicular to the plane in cross section, wherein the two legs of the U-shaped profile in cross section are located on the corresponding cross-sectional planes, and the The first leg of the U-shaped profile is connected to the first body via a first connection point, and the second leg of the U-shaped profile is connected to the second body via a second connection point, and the first connection point and the second connection point of the U-shaped profile are located on a straight line with the center point; in addition, the first body is designed and connected to the first input end of a transimpedance amplifier, in particular, designed by an operational amplifier, and the second body is designed and connected to the second input end of the transimpedance amplifier so that a short circuit can be induced by the transimpedance amplifier, wherein a short-circuit current flowing from the transimpedance amplifier through the first body, the second body and at least one second conductor formed and / or functionally connected in the event of the induced short circuit generates a voltage at the output end of the transimpedance amplifier as an input parameter of the transimpedance amplifier.

[0022] The advantages and preferred embodiments and improvements listed with respect to the method according to the invention can be transferred to the device according to the invention to the same extent and also consist in the fact that their implementation allows the method to be carried out.

[0023] The same also applies to the preferred embodiments and improvements of the device according to the invention described below, which correspond in meaning to the embodiments and improvements of the method. These advantages can also be transferred here mutatis mutandis, so that they have at least these advantages, unless other advantages are specified, and they also each provide at least the additional advantage of enabling the implementation of the corresponding embodiments and improvements of the method according to the invention.

[0024] In one embodiment of the device according to the invention, the first body and the second body are functionally connected and designed so that each point of the first closed loop is connected to the parallel points of the second loop via an electrically conductive connection forming a U-shaped profile in cross section, so that the cross section surrounding the center point always has a U-shaped profile, so that the one conductor is constructed together with the first body and the second body as a hollow body forming a surrounding U-shaped profile. As a result, a short-circuit current proportional to the current change in the conductor is induced in the one-piece molded part. Such a molded part has the advantage, in particular, that it reduces the cost when equipping a circuit with the device according to the invention for detecting current.

[0025] In a further development of the device according to the invention according to one of the preceding claims, the first body, the second body and / or the at least one second electrical conductor are at least partially designed as conductor tracks of a printed circuit board. This represents or enables the device according to the invention to be integrated on a printed circuit board provided for the circuit to be measured.

[0026] Preferably, the device according to the invention can be improved so that the first electrical conductor, the at least one second electrical conductor and / or the functional connection are designed to be connected via so-called "vertical interconnection vias" of the printed circuit board, thereby also supporting integration on the printed circuit board and advantageously using the thickness of the printed circuit board for realizing the legs of the second electrical conductor, which thickness can also be produced almost exclusively when coating the printed conductor structure of the printed circuit board.

[0027] In another embodiment of the device according to the present invention, the first body, the second body and / or the at least one second electrical conductor are formed and / or functionally connected such that the first body, the second body and / or the at least one second electrical conductor are arranged in an inner layer of the printed circuit board.

[0028] According to this development of the device according to the invention, in which the voltage at the output of the transimpedance amplifier is applied as an input signal to a module that performs integration, the signal generated by the method according to the invention, which represents the value of the voltage proportional to the change in the current, is converted into another signal, which is likewise a voltage, but which is proportional to the value of the current actually flowing through the conductor. The invention thus passes beyond the pure detection of the presence of a current in the first electrical conductor based on the change to - indirectly via proportionality - the detection of the value of the actual current, which can then also be used for evaluation, state change and / or control purposes or other actions that can be derived based on the current.

[0029] Preferably, the device according to the invention is developed in this case so that the first module is functionally connected to the transimpedance amplifier and is designed so that the first module acts as an integrator circuit. This will generally mean a solution that can output a voltage given as an analog signal as an analog signal, so that this can be used when designing a circuit that uses the device according to the invention and requires an analog signal for further processing.

[0030] Alternatively, the device according to the invention is developed so that the second module is functionally connected to the transimpedance amplifier and is designed so that the second module acts as an analog / digital converter, wherein the analog value of the voltage at the output of the transimpedance amplifier is converted into a digital representation of the value of the voltage and is functionally applied as an input signal to a calculation unit so that integration is performed by the calculation unit, which is especially designed as a "digital signal processor" DSP, a so-called "central programming unit" CPU or a so-called "application-specific integrated circuit" ASIC circuit. This can also be used when designing circuits that use the device according to the invention and require digital signals for further processing.

[0031] In other words, the sensor-transimpedance amplifier combination can therefore directly give the analog current change signal to the analog input of a computing unit, such as an existing DSP or CPU, without an integrating component, and can generate the integral of the signal about the current signal in a digital manner. In addition to the advantage of reduced circuit expenditure, this has the effect that the digital integration can prevent the integration result from drifting by periodic or strategic zeroing of the integrator. Another advantage is the significantly higher dynamic range or high resolution given by the digitization, which is obtained by the integration according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] According to Figures 1 to 3 The embodiments of the present invention shown here are used to explain other advantages and details of the present invention.

[0033] Figure 1 An exemplary embodiment of the device according to the invention is schematically shown, which has three windings as sensitive elements of the variable value sensor.

[0034] Figure 2 An alternative embodiment of the device according to the invention is schematically shown, which has a cylindrical molding with a U-shaped cross section as a sensitive element of the variable value sensor,

[0035] Figure 3 A transimpedance amplifier is schematically shown as an embodiment of a transimpedance amplifier of the device according to the invention.

[0036] Below Figures 1 to 3 The embodiments explained in the accompanying drawings are preferred embodiments and improvements of the present invention. DETAILED DESCRIPTION

[0037] Since it is not possible to name all these realization possibilities and it is also not convenient or necessary for understanding the invention, in particular the following embodiments only show exemplary realization possibilities: in particular how such a realization according to the teaching of the invention might look like.

[0038] In particular, for the (relevant) person skilled in the art, all possibilities for realizing the invention which are common in the prior art are of course known within the knowledge of a device claim / multiple device claims and / or a method claim / multiple method claims, so that in particular they do not need to be disclosed separately in the description.

[0039] In the case of the exemplary embodiments, the described components of the embodiments each represent individual features of the invention to be considered independently of one another, which also each improve the invention independently of one another and can therefore also be considered as components of the invention individually or in combinations other than those shown.

[0040] Furthermore, the described embodiments may be supplemented by further features of the invention which have already been described.

[0041] In the different figures, the same reference numerals have the same meaning.

[0042] exist Figure 1 In the case of the exemplary embodiment shown in , design variants of the device according to the invention are schematically shown and explained in more detail below together with their function and therefore exemplary embodiments of the method according to the invention.

[0043] exist Figure 1 The exemplary embodiment shown in the embodiment is based in principle on the short-circuit current measurement according to the invention, as opposed to the Roche measurement method, like the solution according to the invention itself, which has a lower inductance and lower parasitic capacitance due to the faster removal of charge carriers and due to the significantly smaller number of sensor windings. As a result, the circuit has a significantly better cutoff frequency and a lower capacitive coupling (dU / dt) to the measuring circuit. The embodiment is therefore particularly suitable for resonant circuits.

[0044] These and other advantages will become more apparent from the following description of the embodiments.

[0045] exist Figure 1The embodiment of the invention can be seen in the case of the embodiment shown in FIG. 1 , wherein according to the invention, at least one second electrical conductor can in principle be designed as one or even a plurality of windings L1 . . . L n The winding is composed of a first conductor L1, a second conductor L2 and a third conductor L3.

[0046] As can be seen, these conductors form a U-shaped winding which is arranged around two electrically conductive first and second bodies K1, K2 and is connected to the first and second bodies which are likewise designed as two concentric circles around the conductor ML to be measured.

[0047] It can also be seen in this illustration that the electrical conductors L1 . . . L3 each electrically conductively connect the first body K1 and the second body K2 and are therefore positioned in parallel and concentrically around the first electrical conductor ML to be measured, in particular distributed evenly.

[0048] exist Figure 1 In addition, it is schematically shown that the legs of the three windings L1 ... L3 extend vertically from the concentrically arranged first body K1 and the second body K2 to the opposite second outer layer (also not shown), where the short printed conductor connections are designed as legs of the vertical through-contact parts and thus form a U shape, wherein the first body K1 and the second body K2 - at Figure 1 Not shown - placed on the first outer layer of the printed circuit board.

[0049] Therefore, the winding can be as in Figure 1 As shown in the greatly simplified diagram in FIG. 1 , it is implemented as a combination of through-holes and printed conductors in a printed circuit board.

[0050] In the exemplary embodiment shown, the electrical conductor ML to be measured can be guided through a hole in a printed circuit board or can also be embodied as a conductor track with an arrangement of through-holes.

[0051] In the first electrical conductor ML to be measured, an alternating current IM to be measured flows at least temporarily. This alternating current in turn generates an alternating magnetic field H which runs in a circle around the electrical conductor ML to be measured and Figure 1 , which is indicated by arrows symbolically representing magnetic fields. This magnetic field H in turn flows through the second electrical conductor L1 ... L3, which is designed as a winding in this embodiment. Therefore, if the winding according to the invention is short-circuited by the transimpedance amplifier TIA according to the invention according to the method according to the invention, a short-circuit current IS flows. The windings L1 ... L3 therefore represent sensitive elements of the magnitude sensor. Therefore, according to the method according to the invention, the short-circuit is achieved by the transimpedance amplifier TIA provided according to the embodiment of the device according to the invention.

[0052] According to the invention, the loop induced by the alternating magnetic field can therefore only be closed by means of a transimpedance amplifier.

[0053] The transimpedance amplifier converts the short-circuit current into a measurement voltage that is proportional to the change in current dI / dt.

[0054] If the absolute current is required, then according to a development of the device according to the invention the measurement signal is integrated by an integrator, which results in a measurement signal that is proportional to the current.

[0055] Instead of separate windings L1 . . . 3 connected in parallel with one another, it is also conceivable to Figure 2 The configuration shown in FIG. 1 is an exemplary embodiment of the device according to the invention.

[0056] In this exemplary embodiment, the magnitude sensor sensitive element consists of an electrically conductive U-shaped molding L which surrounds an electrical conductor ML to be measured and which carries the current IM to be measured.

[0057] exist Figure 2 As can be seen from the sectional view of , the molded part L is a cylindrically shaped body with a cylindrical recess extending around the axis of symmetry of the body, i.e., it forms a tube to a certain extent, the edge of which has a U-shaped cross section running around the axis of symmetry. The ratio of the diameter of the tube to its length is usually designed here so that the diameter is greater than the length of the tube, which is therefore more likely to be like a disk with a circular recess.

[0058] At one tube end, two concentric circles are thus shown in a top view, which correspond to the first body K1 and the second body K2 .

[0059] On the other hand, at the opposite tube end, a circle is formed extending about the axis of symmetry in top view, which circle is formed by the base of the legs forming the U.

[0060] It is also possible to regard the molded part L as an infinite number of fused U-shaped windings.

[0061] In this example, a transimpedance amplifier TIA is also used to convert the short-circuit current IS into a voltage proportional to the current change. For this purpose, a first input of the transimpedance amplifier TIA is connected to one of the circles of the tube end similar to the first body K1, and a second input of the transimpedance amplifier TIA is conductively connected to another circle similar to the second body K2.

[0062] In the case of this example, the integrator may also convert the output signal of the transimpedance amplifier TIA into a voltage proportional to the measurement current change of the measurement current IM.

[0063] The shown solution with a quantity sensor element formed as a U-shaped molding L, with which the circuit is equipped, may be advantageous, for example, if a quantity sensor sensor is required for carrying out the method according to the invention.

[0064] exist Figure 3 The basic structure of an embodiment of a transimpedance amplifier TIA according to the invention is now schematically shown in FIG. In this example, possible windings according to an embodiment of the device according to the invention are circuit symbols for coils, which according to the invention can each be realized by a loop / winding.

[0065] Therefore, in Figure 3 The coils L1...L shown in n represents a number n of loops, the loops being as in Figure 1 and its two terminals are respectively connected to one of the two input terminals of the transimpedance amplifier TIA - and are therefore also connected in parallel. According to an embodiment, the transimpedance amplifier is designed as an operational amplifier, the - and + input terminals of the operational amplifier are used as input terminals of the transimpedance amplifier TIA, and the operational amplifier is further connected according to the present invention so that the feedback resistor RF leads from the output terminal of the operational amplifier to the - input terminal of the operational amplifier.

[0066] Here, the short-circuit current I in the loop is reduced by the feedback resistor RF. S Injection winding L1...L n , the short-circuit current is distributed to each winding according to the number of windings n according to Kirchhoff's law. S The sum of the currents I and n corresponds in value to the injected short-circuit current I generated by the alternating magnetic field H. S The total short-circuit current is composed of the sum of the possible branch currents and corresponds to the injected short-circuit current I flowing to the input of the transimpedance amplifier. S According to the invention, this applies all the time and thus also in Figure 1 and Figure 2 In the embodiment shown in FIG. 1 , the branch currents in the conductors are shown as arrows. Since the − / + inputs of the operational amplifier thus have the same potential, a virtual short circuit VS can be mentioned here. However, from the perspective of the windings L1 ... L n It is therefore operated in a true short circuit.

[0067] The advantages of the invention compared to solutions known from the prior art are in particular that the measuring method can be easily integrated into a printed circuit board, since only a few through-hole conductor tracks are required to realize the sensor, ie the magnitude sensor sensitive element.

[0068] In the experimental setup according to the invention, three conductor loops were sufficient to realize the measured value acquisition according to the invention, wherein the conductor loops L1 . . . L n Furthermore, the parallel connection can be implemented very simply.

[0069] In particular, the device and method according to the invention therefore have considerable advantages compared to attempts from the prior art to integrate Rogowski coils into printed circuit boards.

[0070] According to the solutions known from the prior art with Rogowski coils, each conductor loop only provides a signal in the single-digit millivolt range. Therefore, according to the prior art, 100 to several hundred loops need to be arranged, which results in a large perforated structure on the printed circuit board.

[0071] In contrast thereto, the solution according to the invention provides a relatively strong current signal, in particular compared to the prior art, which can be easily converted into a voltage signal by a transimpedance amplifier TIA and evaluated.

[0072] The strong signal also makes it possible to use small loop structures in the inner layers of the printed circuit board in order to achieve, for example, shielding of coupling capacitors or current branching for the current IM to be measured in the outer layers.

[0073] The integrator that can be used when necessary can conventionally be provided by a substantially analog circuit or preferably also digitally after AD conversion by means of a computing unit (DSP / CPU). This is particularly advantageous if such a computing unit is already part of the circuit to be measured and therefore only performs another function. This saves space and eliminates additional component costs.

[0074] In the case of the solution according to the invention, it is also advantageous if the branch to be measured is galvanically isolated from the measuring branch. This overcomes disadvantages which occur during current measurement by means of shunt measurement, for example.

[0075] Compared to the solutions for current measurement known from the prior art, which, in contrast to the present invention, are based on current transformers, magnetic field sensors and solutions with Rogowski coils known from the prior art, the advantage is furthermore that the measuring principle has no frequency-limiting factors, such as core material, winding capacitance, series inductance and limitations caused by compensation devices.

[0076] Measurements of experimental pick-up configurations show that the solution according to the invention has a resonance frequency in the mid-double-digit MHz range.

[0077] In contrast to commercially available components such as shunts, magnetic sensors and current transformers, the measuring device can also be flexibly adapted to the current I to be measured. M In particular, since the printed circuit board is already present, no or almost no costs are incurred for the sensor when the invention is integrated on the printed circuit board. In particular, when using VIA connections and printed conductors for the windings, only the transimpedance amplifier and / or integrator involve costs.

Claims

1. A method for detecting a current in a first electrical conductor of a circuit, in particular one at least partially mounted on a printed circuit board, characterized in that: a) a first body placed in a plane around a conductor forming a closed loop and conducting an electric current and a second body forming a closed loop and conducting an electric current in the plane, so that the constructed loop of the body is arranged and operated concentrically, in particular circularly, in the plane around a first electrical conductor placed in its geometric center point, extending perpendicularly through the plane and conducting an electric current to be detected, wherein the bodies are shaped and / or functionally connected to each other and operated so that the bodies are electrically conductively connected via at least one second electrical conductor, which forms a U-shaped profile perpendicular to the plane in cross section, wherein in cross section, two legs of the U-shaped profile are respectively located on corresponding cross-sectional planes, and the first leg of the U-shaped profile is connected to the first body via a first connection point, and the second leg of the U-shaped profile is connected to the second body via a second connection point, in particular the first connection point and the second connection point of the U-shaped profile are located on a straight line with the center point, b) The first body is connected to a first input of a transimpedance amplifier, in particular designed as an operational amplifier, and the second body is connected to a second input of the transimpedance amplifier and operated so that a short circuit can be induced through the transimpedance amplifier, wherein a short-circuit current flowing from the transimpedance amplifier through the first body, the second body and at least one second conductor that is formed and / or functionally connected in the event of the induced short circuit generates a voltage at the output of the transimpedance amplifier as an input variable of the transimpedance amplifier.

2. The method according to the preceding claim, characterized in that The first body and the second body are functionally connected and operated so that each point of the first closed loop is connected to the parallel points of the second loop through an electrically conductive connection forming a U-shaped profile in cross section, so that the cross section surrounding the center point always has a U-shaped profile, so that the at least one second electrical conductor is constructed together with the first body and the second body as a hollow body forming a surrounding U-shaped profile.

3. The method according to any one of the preceding claims, characterized in that The first body, the second body and / or the at least one second electrical conductor are at least partially run as conductor tracks of a printed circuit board.

4. The method according to the preceding claim, characterized in that The first electrical conductor, the at least one second electrical conductor and / or the functional connection are run as so-called "vertical interconnect vias" through the printed circuit board.

5. The method according to any one of claims 3 to 4, characterized in that The first body, the second body and / or the at least one second electrical conductor are shaped and / or functionally connected such that the first body, the second body and / or the at least one second electrical conductor are run in an inner layer of the printed circuit board.

6. The method according to any one of the preceding claims, characterized in that The voltage at the output of the transimpedance amplifier is fed as input signal to a first module which performs integration.

7. The method according to claim 6, characterized in that The module is functionally connected to the transimpedance amplifier and is operated such that the first module functions as an integrator circuit.

8. The method according to any one of claims 1 to 5, characterized in that The second module is functionally connected to the transimpedance amplifier and operated so that it acts as an analog / digital converter, in which the analog value of the voltage at the output of the transimpedance amplifier is converted into a digital representation of the value of the voltage, and is functionally connected to a computing unit and operated so that integration is performed by the computing unit, which is in particular designed as a "digital signal processor" DSP, a so-called "central programming unit" CPU or a so-called "application-specific integrated circuit" circuit ASIC.

9. A device for detecting the current of a first electrical conductor of an electrical circuit, in particular one at least partially mounted on a printed circuit board, characterized in that a) a first body formed in a plane around a conductor and conducting a current to form a closed loop and a second body formed in the plane and conducting a current to form a closed loop, so that the constructed loop of the body is arranged concentrically, in particular circularly, in the plane around a first electrical conductor which is placed in its geometric center point, extends perpendicularly through the plane and conducts the current to be detected, wherein the bodies are shaped and / or functionally connected to each other so that the bodies are electrically conductively connected via at least one second electrical conductor, which forms a U-shaped profile perpendicular to the plane in cross section, wherein in cross section, two legs of the U-shaped profile are respectively located on corresponding cross-sectional planes, and the first leg of the U-shaped profile is connected to the first body via a first connection point, and the second leg of the U-shaped profile is connected to the second body via a second connection point, in particular the first connection point and the second connection point of the U-shaped profile are located on a straight line with the center point, b) The first body is designed and connected to a first input of a transimpedance amplifier, in particular designed as an operational amplifier, and the second body is designed and connected to a second input of the transimpedance amplifier so that a short circuit can be induced by the transimpedance amplifier, wherein a short-circuit current flowing from the transimpedance amplifier through the first body, the second body and at least one second conductor that is formed and / or functionally connected in the event of the induced short circuit generates a voltage at the output of the transimpedance amplifier as an input variable of the transimpedance amplifier.

10. Device according to the preceding claim, characterized in that The first body and the second body are functionally connected and designed so that each point of the first closed loop is connected to the parallel points of the second loop through an electrically conductive connection forming a U-shaped profile in cross section, so that the cross section surrounding the center point always has a U-shaped profile, so that the at least one second electrical conductor is constructed together with the first body and the second body as a hollow body forming a surrounding U-shaped profile.

11. The device according to any of the preceding claims, characterized in that The first body, the second body and / or the at least one second electrical conductor are at least partially designed as conductor tracks of a printed circuit board.

12. Device according to the preceding claim, characterized in that The first electrical conductor, the at least one second electrical conductor and / or the functional connection are designed to be connected via so-called “vertical interconnect vias” of the printed circuit board.

13. The device according to any one of claims 11 to 12, characterized in that The first body, the second body and / or the at least one second electrical conductor are shaped and / or functionally connected such that the first body, the second body and / or the at least one second electrical conductor are arranged in an inner layer of the printed circuit board.

14. The device according to any one of claims 9 to 13, characterized in that The voltage at the output of the transimpedance amplifier is applied as an input signal to a first module that performs integration.

15. The device according to claim 14, characterized in that The first module is functionally connected to the transimpedance amplifier and is designed such that the first module functions as an integrator circuit.

16. The device according to any one of claims 9 to 13, characterized in that The second module is functionally connected to the transimpedance amplifier and is designed so that it acts as an analog / digital converter, wherein the analog value of the voltage at the output of the transimpedance amplifier is converted into a digital representation of the value of the voltage and functionally applied as an input signal to a calculation unit so that integration is performed by the calculation unit, which is in particular designed as a "digital signal processor" DSP, a so-called "central programming unit" CPU or a so-called "application-specific integrated circuit" ASIC circuit.

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