sensors, protection switches, charging cables and charging stations

Abstract

The invention relates to a sensor (100) which, in comparison with the prior art, has a higher sensitivity to the measurement of differential currents, in particular to the measurement of the AC and DC components of differential currents, on the one hand, due to the inner width of the through-opening of the shield (50) being in the range from 25.2 to 32 mm, and on the other hand, has a lower probability of erroneously detecting a differential current which is falsely assumed to exceed a limit current when the monitored circuit is switched on. The invention also relates to a protective switch, a charging cable and a charging station, respectively, which have such a sensor.

Description

[0001] This invention relates to a sensor, a protective switch, a charging cable, and a charging station.

[0002] Differential currents, in particular, can pose a danger to humans and cause fires. Therefore, sensors with different structures and for different applications are known for measuring differential currents.

[0003] Differential current is generated when there is a fault in the power grid, especially in the circuits within the power grid, causing the fault current within the power grid to flow to the ground. Depending on the specific type and structure of the power grid, the differential current may have AC and / or DC components.

[0004] The significant increase in the use of renewable energy, electric vehicles, variable speed motors, and / or similar technologies has led to a rise in the number of electrical systems with AC and DC grids coupled together. Consequently, the DC component of differential current has become increasingly important.

[0005] Generally, especially during indoor electrical installations, only Type A FI protection switches are installed. These can monitor the differential current containing AC components in the indoor power grid, but cannot detect or disconnect DC faults. However, in indoor electrical installations, such as when charging electric vehicles or due to the operation of solar energy equipment, the use of DC components is also increasing.

[0006] Therefore, especially in charging infrastructure or solar inverters or similar applications, there is a need for AC / DC sensitive monitoring of differential current. This monitoring includes a differential current sensor, whose measured value, if exceeding a limit, causes the relevant infrastructure to be disconnected.

[0007] Type B FI protection switches are known for use with charging infrastructure, solar inverters, or similar applications, and can also detect and monitor the DC component of the differential current. However, Type B FI protection switches are relatively expensive.

[0008] The AC / DC sensitive differential current sensor simultaneously monitors all currents flowing into the phase and neutral lines and detects potential DC and AC faults. Depending on the application, this sensor can automatically control the system to shut down in the event of a fault, or report to the higher-level control unit that the on / off threshold has been exceeded. Due to the extremely small allowable fault current, very high measurement accuracy is required. Furthermore, exceptionally rapid detection and subsequent disconnection of the entire system are necessary to ensure human safety.

[0009] Known differential current sensors are based on a configuration in which a magnetic core is arranged around the conductor to be monitored with an air gap. When current flows, a magnetic field is induced, which passes through the core. In this configuration, a Hall element is arranged in the air gap, generating an output voltage based on the magnetic field. A compensation winding can be incorporated into the core to improve measurement accuracy. This is achieved by electrically compensating for the magnetic field generated by the monitored current and adjusting the zero point of the Hall sensor. The actual output signal of this sensor is the current required in the compensation winding.

[0010] Furthermore, a so-called fluxgate sensor is known for measuring the magnetic field generated by an electric current. In this method, a primary coil is wound around a magnetic core and controlled by an alternating current. The output signal related to the differential current is extracted using a secondary probe coil.

[0011] The purpose of this invention is to improve existing technology or provide alternatives.

[0012] According to a first aspect of the invention, the solution for achieving the above-mentioned objective is a sensor for measuring differential current, particularly for measuring differential current sensitively in both AC and DC modes.

[0013] The sensor described herein includes a magnetic field sensing element, a first main winding, a test winding, and a shield.

[0014] -The magnetic field sensing element has a through hole, wherein the cross-section of the through hole of the magnetic field sensing element is constructed as an ellipse with two axes of symmetry.

[0015] - wherein the first main winding and the test winding are respectively surrounded by multiple turns of wire around the magnetic field sensing element.

[0016] -The shielding component has a receiving cavity adapted to house the magnetic field sensing element, the first main winding, and the test winding.

[0017] -The accommodating cavity of the shielding component is radially limited by the outer wall and the inner wall of the shielding component.

[0018] -The inner wall of the shielding component defines a through-hole in the shielding component, wherein the through-hole in the shielding component is constructed as an ellipse having two axes of symmetry.

[0019] -The shielding element has a circumferential gap in the area of ​​the inner wall of the shielding element.

[0020] -The sensor is adapted to be arranged around at least two electrical wires.

[0021] -The through-hole of the magnetic sensing element has at least one inner width along the axis of symmetry.

[0022] The at least one inner width is in the range of 25.2 to 32 mm, preferably in the range of 25.5 to 29 mm, and particularly preferably in the range of 25.8 to 27 mm.

[0023] The terminology is explained as follows:

[0024] First, it should be clearly pointed out that within the scope of this patent application, if the corresponding context does not explicitly state, or is obvious to a person skilled in the art, or is technically required to be "exactly one...", "exactly two...", etc., then indefinite articles such as "one" and "two" and numerical data should generally be understood as "at least" data, that is, "at least one...", "at least two...", etc.

[0025] Within the scope of this patent application, the expression "in particular" always means that optional, preferred features are introduced by this expression. This expression should not be construed as "exactly" or "that is to say".

[0026] A sensor, or detector, is a technological component that can qualitatively detect specific physical or chemical properties and / or material properties of its surrounding environment, or quantitatively detect them as a "quantitative variable." These quantities are detected through physical or chemical effects and converted into analog or digital electrical signals. These signals are also called "sensor signals."

[0027] Preferably, the sensor signal is proportional to the current consumption, particularly proportional to the current consumption of the test winding and / or the first main winding and / or the second main winding. Preferably, the sensor signal, especially the sensor signal of the test winding and / or the first main winding and / or the second main winding, can be converted into current consumption according to mathematical rules.

[0028] "Current consumption" refers to the current intensity flowing through a circuit, particularly through the test winding and / or the first main winding and / or the second main winding, under a defined voltage. It should be clearly noted that the term "current consumption" does not require specifying the sign of the current. Current consumption can specifically correspond to either positive or negative current.

[0029] Preferably, the sensor signal refers to the current consumption of the first main winding. Preferably, the current consumption of the first main winding can be converted into a differential current of the circuit monitored by the sensor using mathematical rules. Preferably, this mathematical rule is determined through the calibration curve of the sensor.

[0030] "Differential current" refers to the vector sum of all electrical wires around the sensor.

[0031] Differential current can have AC and / or DC components.

[0032] "AC / DC sensitive measurement" of differential current means that the sensor is suitable for measuring both AC and DC components.

[0033] A "magnetic field sensitive element" is an element that responds to a magnetic field by a change in at least one of its state variables.

[0034] Preferably, the magnetic field sensing element refers to a material with magnetic properties.

[0035] Particularly preferred is that the magnetic field sensing element is a soft magnetic material.

[0036] "Soft magnetic material" refers to a material that is easily magnetized in a magnetic field. Preferably, the soft magnetic material has a coercive field strength of less than or equal to 1000 A / m.

[0037] "Coercivity field strength" refers to the magnetic field strength required to completely demagnetize a magnetic field sensitive element that has been pre-charged to saturation magnetic flux density.

[0038] Preferably, soft magnetic materials refer to materials made of amorphous metals and having a nanocrystalline structure.

[0039] Soft magnetic materials, in particular, have alloys containing iron, nickel, and cobalt.

[0040] "Winding" refers to a coil of solid conductive material that extends around a magnetic field-sensitive element, especially in the form of wires.

[0041] The "main winding" refers to a winding suitable for being actively powered by a current source. Alternatively, the main winding can also be connected to a voltage source. The main winding can also be called the "first main winding".

[0042] Preferably, the main winding, particularly the first main winding, is adapted to provide sensor signals, particularly indirectly through the current consumption of the main winding, and especially indirectly through the current consumption of the first main winding and / or the second main winding.

[0043] Preferably, the differential current of the circuit to be monitored by the sensor can be determined by means of mathematical rules based on the current consumption of the main winding, particularly the first main winding and / or the second main winding, preferably by means of mathematical rules derived from the calibration of the sensor.

[0044] A "test winding" refers to a winding suitable for use as a purely passive element, through which current flows due to induction from a magnetic field-sensitive element. Preferably, the test winding can be adapted to provide a test winding signal, which can be used for sensor calibration. Compared to the main winding, the test winding particularly has a different number of turns.

[0045] Preferably, the sensor is calibrated before each measurement operation.

[0046] "Shielding" refers to a component that is adapted to isolate electric and / or magnetic fields from magnetic field sensitive elements, and / or to protect the sensor's surrounding environment from the influence of electric and / or magnetic fields originating from the sensor.

[0047] Preferably, the shielding element is made of an alloy having ≥20 WT of nickel, more preferably ≥30 WT of nickel, and particularly preferably ≥50 WT of nickel. More preferably, the shielding element is made of an alloy having ≥60 WT of nickel, more preferably ≥70 WT of nickel, and particularly preferably ≥80 WT of nickel.

[0048] Preferably, the shielding element is made of an alloy having ≥0.5 WT of molybdenum, preferably ≥1 WT of molybdenum, and particularly preferably ≥3 WT of molybdenum. More preferably, the shielding element is made of an alloy having ≥4 WT of molybdenum, more preferably ≥5 WT of molybdenum, and particularly preferably ≥5.5 WT of molybdenum.

[0049] Preferably, the shielding component is made of an alloy having ≥10 WT of iron, more preferably ≥20 WT of iron, and particularly preferably ≥30 WT of iron. More preferably, the shielding component is made of an alloy having ≥40 WT of iron, more preferably ≥50 WT of iron, and particularly preferably ≥55 WT of iron.

[0050] It should be clearly pointed out that the above values ​​for the alloy composition of the shielding component should not be interpreted as strict limits. Rather, on an engineering scale, values ​​may be exceeded or fallen below these values ​​without departing from the aspects described herein. In short, these values ​​are used to provide a basis for the variables in the alloy composition of the shielding component presented herein.

[0051] Preferably, the shielding component adopts a split construction scheme, especially a two-part construction scheme.

[0052] Particularly preferred is that the two-part shielding component is constructed such that the two shielding parts overlap or at least partially overlap on the outer wall of the shielding component.

[0053] More particularly preferably, the two-part shielding component is constructed in such a way that the two shielding parts do not contact each other on the inner wall of the shielding component, wherein the two shielding parts of the two-part shielding component further preferably form a gap located on the inner wall of the shielding component.

[0054] A "through hole" refers to a free cross-section formed in the internal region of a magnetic field-sensitive element.

[0055] Particularly preferably, the outer contour of the magnetic field sensing element is oval, and the inner contour of the magnetic field sensing element is also oval with two axes of symmetry.

[0056] The inner contour of the magnetic field sensing element forms the through hole of the magnetic field sensing element.

[0057] Preferably, the material thickness of the magnetic field sensing element is substantially constant, or constant. In the special case where the cross-section of the magnetic field sensing element is circular and the material thickness of the magnetic field sensing element is constant, the magnetic field sensing element has a ring geometry in the cross-section.

[0058] An "oval" is a flat, convex circular shape. The oval encompasses the special cases of circles and ellipses, where, unlike circles and ellipses, an arbitrary oval does not require an "axis of symmetry." Specifically, an oval is a closed, planar convex curve capable of continuous differentiation in two dimensions.

[0059] If the curves of an oval are arranged in mirror image on both sides of an imaginary line, then the oval has one axis of symmetry. If the curves of an oval are arranged in mirror image on both sides of two non-overlapping imaginary lines, then the oval has "two axes of symmetry". Specifically, both circles and ellipses are ovals with two axes of symmetry.

[0060] "Wire turn" refers to the winding that is coiled around the magnetic field sensitive element once.

[0061] "Cavity" refers to a chamber formed by the shielding inside the shielding and is suitable for accommodating other components, particularly magnetic field sensitive components, the first main winding and the test winding, and preferably also suitable for accommodating the second main winding, the insulator and the spacer ring.

[0062] "Radial" refers to the direction that extends radially relative to the central axis from the central axis, which is the smallest possible cross-section of the sensor along the through hole.

[0063] "Shielding outer wall" refers to the outer surface viewed radially, which is composed of shielding components, particularly two-part shielding components inserted together.

[0064] "Inner wall of shielding" refers to the inner surface viewed radially, which is composed of shielding components, particularly the projection surface of the components having inner shielding sections and surrounding gaps.

[0065] "A surround gap" refers to a gap that surrounds the inner wall of the shielding component, between the partitions of the inner wall formed by the shielding component. Viewed radially and emanating from the central axis, the surround gap opens the shielding component towards its receiving cavity.

[0066] "Electrical conductor" refers to any medium having movable charge carriers and thus being able to transport charge. Preferably, electrical conductor refers to copper and / or aluminum cables that act as conductors through which electrons can move.

[0067] The “inner width” along the axis of symmetry of a through hole refers to the extent of the through hole in both direction and height along the axis of symmetry of interest.

[0068] If the through-hole of the magnetic field sensing element forms an oval shape in cross-section with two axes of symmetry, and their extensions along the axes of symmetry are different, then a first inner width along the first axis of symmetry and a second inner width along the second axis of symmetry are generated.

[0069] Whenever the inner width is mentioned only in this specification, it refers to the inner width along the axis of symmetry with greater extension.

[0070] "Limiting current" refers to the differential current that the sensor can detect with sufficient accuracy and speed, so that once the differential current detected by the sensor reaches or exceeds the limit current of the protection switch, the protection switch can immediately cut off the voltage in the circuit monitored by the sensor.

[0071] The smaller the limiting current of the protective switch, the smaller the differential current that the sensor is suitable for measuring, and the faster the differential current can be reliably identified by the sensor, the smaller the potential danger caused by the differential current.

[0072] In the prior art, the inner width of the through-hole of the magnetic field sensing element of a known sensor is smaller than that proposed herein.

[0073] Traditional solutions, in particular, aim to reduce the inner width of the through-hole in magnetic field sensitive elements.

[0074] The motivation for this pursuit is to achieve smaller and faster detection of differential currents, requiring magnetic field sensing elements to be arranged as close as possible to the live wires of the monitored circuit.

[0075] The magnetic field strength originating from a charged conductor is inversely proportional to the distance between the conductor and the magnetic field sensing element. Therefore, the farther away the magnetic field sensing element is from the charged conductor of the monitored circuit, the smaller the magnetic flux density in the magnetic field sensing element caused by the magnetic field strength surrounding the charged conductor.

[0076] Furthermore, the magnetic field strengths of at least two charged conductors in the monitored circuit (both of which need to pass through the vias of the magnetic field-sensitive element in order to monitor the differential current, and have opposite current directions) overlap, and in an idealized observation, these magnetic field strengths cancel each other out when no differential current is present in the monitored circuit.

[0077] This results in a particularly small magnetic field strength acting on the magnetic field sensing element, especially when the differential current in the monitored circuit is small, which in turn causes a particularly small magnetic flux density in the magnetic field sensing element.

[0078] The smaller the magnetic flux density in the magnetic field sensing element, the smaller the current induced by the magnetic flux density in the magnetic field sensing element in the test winding and / or the first main winding and / or the second main winding.

[0079] In other words, the larger the inner width of the through-hole of the magnetic field sensing element, the greater the distance between the wires of the monitored circuit and the magnetic field sensing element, making it impossible or extremely difficult to detect small differential currents.

[0080] For this reason, in order to detect smaller differential currents, there is a technological pursuit to minimize the inner width of the through-hole of the magnetic field sensing element.

[0081] The smallest possible magnetic field sensing element also makes the sensor lightweight and requires less material, thereby reducing cost and space requirements.

[0082] Therefore, many factors support reducing the inner width of the through-hole in magnetic field sensitive elements.

[0083] It is known in the prior art that protective switches with very small differential currents are prone to false triggering during the switching-on process of a monitored circuit.

[0084] The reason is that sensors known in the prior art generate sensor signals during circuit connection, which can be interpreted as differential current, even though differential current is not required in the monitored circuit. The need for a smaller differential current leads to an increase in the number of false triggers of protective switches.

[0085] Contrary to conventional wisdom, laboratory experiments have unexpectedly revealed an optimal range for the inner width of the through-hole of a magnetic field sensing element. Within this range, the smallest possible differential current can be detected for a sufficient amount of time, while simultaneously significantly reducing the probability of false triggering of the protective switch connected to the sensor. The range required for the inner width of the through-hole of the magnetic field sensing element is larger than that known to date in the prior art.

[0086] In other words, by discovering a range of the inner width of the via, it is possible to reliably measure the smallest possible differential current, so that during the process of connecting the circuit monitored by the sensor, there will be no sensor signal with a differential current that can be interpreted as exceeding the required limit current, or the probability of such a differential current occurring will be greatly reduced.

[0087] In order to achieve a minimum limiting current that can be reliably measured by a sensor in a monitored circuit, it is proposed that the inner width of the through-hole of the magnetic field sensing element be in the range of 25.2 to 32 mm.

[0088] Preferably, the inner width of the through hole of the magnetic field sensing element is in the range of 25.5 to 29 mm.

[0089] It is particularly preferred that the inner width of the through hole of the magnetic field sensing element is in the range between 25.8 and 27 mm.

[0090] It should be clearly pointed out that the above values ​​for the inner width of the through-hole of the magnetic field sensing element should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the size of the inner width of the through-hole of the magnetic field sensing element presented herein.

[0091] Of course, the range boundaries given for the inner width can be arbitrarily combined with each other.

[0092] During the process of connecting the power supply to the circuit to be monitored, a physical functional connection is established between the magnetic field propagating around the conductor and the functionally related magnetic flux density.

[0093] This results in short-term, time-varying pulses of magnetic flux in the magnetic field-sensitive element during the switching process, which are also position-dependent.

[0094] This briefly causes the magnetic flux in the magnetic field-sensitive element to oscillate.

[0095] Based on this brief oscillation characteristic in the magnetic field sensing element, a short-term pulse current also appears in the test winding and / or the first main winding and / or the second main winding, which are inductively associated with the magnetic field sensing element.

[0096] Laboratory studies show that this may result in short-term sensor signals that can be interpreted as differential current, potentially exceeding predefined current limits in the protective switch during the sensor's intended operation. This could lead to the protective switch tripping during power-on of the monitored circuit.

[0097] Several different factors inhibit this transient oscillatory characteristic. Some of these factors cannot be affected by creative measures.

[0098] Laboratory studies have revealed that one of these factors is determined by the relative distance between the electrical conductors being monitored by the sensors presented herein. The greater the aforementioned distance, the stronger the dynamic correlation between the conductors and the sensor signals during power-on.

[0099] For the distance between the conductors in the cross-section of the through-hole of a magnetic field-sensitive element, existing safety considerations always require a relatively high distance to avoid short circuits between the conductors. This exacerbates this factor and increases the tendency for unexpected sensor signals to occur during circuit connection.

[0100] Another factor identified in laboratory studies involves the ratio of the distance between the first conductor and a point in the magnetic field sensing element to the distance between the other conductor and that point. The greater this ratio deviates from the number one, the greater the short-term regional differences in magnetic flux density within the magnetic field sensing element. The greater these regional differences, the more pronounced the dynamic start-up characteristics of the sensor are during circuit switching.

[0101] By increasing the inner width of the through hole of the magnetic sensing element, the ratio of the distance between the first conductor and a point in the magnetic field sensing element to the distance between the other conductor and that point can approach a value of one, thereby effectively suppressing the sensor characteristics through the aforementioned switching effect.

[0102] Increasing the inner width of the orifice of the magnetic sensing element will also lead to a decrease in sensitivity to particularly small differential currents. Therefore, an optimal range for the inner width of the orifice of the magnetic sensing element is proposed here. This optimal range takes into account two physical effects: on the one hand, it allows sufficient time to identify the minimum differential current during the control operation of the sensor, and on the other hand, it prevents the generation of sensor signals that would cause false detection of non-existent differential currents during the connection of the circuit monitored by the sensor.

[0103] Specifically, it is also proposed here that sensors be constructed in a manner that allows them to be arranged around all conductors of the circuit that, during normal operation, draw current into and out of the circuit to be monitored. In particular, it is proposed that the sensors proposed herein should not be arranged around the protective grounding wire.

[0104] Specifically, it is proposed that the sensor described herein be arranged around the phase line and the neutral line in a specified application in a single-phase power grid. Accordingly, the sensor should be arranged around both conductors in a single-phase power grid.

[0105] Furthermore, for specific applications in three-phase power grids, it is proposed that the sensors be arranged around the three phase lines and the neutral line. Accordingly, the sensors should be arranged around a total of four conductors in the three-phase power grid.

[0106] Preferably, the cross-section of the through hole of the magnetic field sensing element is circular, that is, an oval shape with two equal half-radius lengths.

[0107] Further preferably, the cross-section of the through hole of the magnetic field sensing element is elliptical, that is, an egg shape with two half-radii of different lengths.

[0108] It should be clearly pointed out that the fact that the cross-section of the through hole of the magnetic field sensing element is oval with two axes of symmetry is not the essence of this invention.

[0109] Specifically, a geometry that achieves a good trade-off in the aforementioned physical effects can also be used for the magnetic field sensing element. Preferably, these geometries also revert to an oval cross-section.

[0110] Corresponding to the geometry of the magnetic field sensitive element, the geometry of the shielding component is also adjusted accordingly.

[0111] Specifically, it is also mentioned here that the magnetic field sensing element has high permeability.

[0112] The "permeability" of a magnetic field sensing element refers to the magnetization of a material in an external magnetic field. The higher the permeability of a magnetic field sensing element, the greater the ratio of the magnetic flux density in the magnetic field sensing element to the magnetic field strength acting on the magnetic field sensing element.

[0113] Therefore, a magnetic field sensing element with high permeability exhibits a relatively high magnetic flux density even under low magnetic field strength. Consequently, the high permeability of the magnetic field sensing element enhances the sensor's sensitivity and assists in detecting even small differential currents.

[0114] Preferably, the magnetic field sensing element has a permeability of 35,000 H / m or greater, more preferably 45,000 H / m or greater, and particularly preferably 50,000 H / m or greater. More preferably, the magnetic field sensing element has a permeability of 60,000 H / m or greater, more preferably 70,000 H / m or greater, and particularly preferably 80,000 H / m or greater. Even more preferably, the magnetic field sensing element has a permeability of 90,000 H / m or greater, more preferably 100,000 H / m or greater, and particularly preferably 110,000 H / m or greater. Further preferably, the magnetic field sensing element has a permeability of ≥120000 H / m, more preferably ≥130000 H / m, and particularly preferably ≥140000 H / m. More preferably, the permeability of the magnetic field sensing element is ≥150000 H / m.

[0115] The above values ​​for permeability apply to magnetic fields oscillating at 50 Hz.

[0116] It should be clearly pointed out that the above values ​​for the permeability of the magnetic field sensing element should not be interpreted as strict limits. Rather, on an engineering scale, values ​​may be exceeded or decreased without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the magnitude of the permeability of the magnetic field sensing element presented herein.

[0117] Preferably, the magnetic field sensing element has a saturation magnetic flux density greater than or equal to 1 T; more preferably, it has a saturation magnetic flux density greater than or equal to 1.1 T; and particularly preferably, it has a saturation magnetic flux density greater than or equal to 1.2 T. More preferably, it has a saturation magnetic flux density greater than or equal to 1.3 T.

[0118] It should be clearly pointed out that the above values ​​for the saturation magnetic flux density of the magnetic field sensing element should not be interpreted as strict limits. Rather, on an engineering scale, these values ​​may be exceeded or decreased without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the magnitude of the saturation magnetic flux density of the magnetic field sensing element presented herein.

[0119] Preferably, the magnetic field sensing element has a high degree of linearity in terms of magnetic permeability, particularly higher linearity than that of ferrite materials. In other words, it is preferable not to use ferrite materials in the magnetic field sensing element.

[0120] The higher the linearity of the magnetic field sensing element in terms of magnetic permeability, the higher the achievable measurement accuracy of the sensor.

[0121] Preferably, the magnetic field sensing element has a coercive field strength of ≤30 mA / cm; more preferably, it has a coercive field strength of ≤20 mA / cm; and particularly preferably, it has a coercive field strength of ≤15 mA / cm. More preferably, it has a coercive field strength of ≤10 mA / cm; more preferably, it has a coercive field strength of ≤5 mA / cm; and particularly preferably, it has a coercive field strength of ≤2 mA / cm. Even more preferably, it has a coercive field strength of ≤1 mA / cm; more preferably, it has a coercive field strength of ≤0.5 mA / cm; and particularly preferably, it has a coercive field strength of ≤0.2 mA / cm. Preferably, it has a coercive field strength of ≤0.1 mA / cm.

[0122] The above values ​​for coercive field strength apply to magnetic fields oscillating at 50 Hz.

[0123] High measurement accuracy can be achieved by using a small coercive field strength of the magnetic sensing element, especially when the magnetic field strength varies. The smaller the coercive field strength of the magnetic sensing element, the higher the measurement accuracy of the sensor.

[0124] It should be clearly pointed out that the above values ​​for the coercive field strength of the magnetic field sensing element should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the magnitude of the coercive field strength of the magnetic field sensing element presented herein.

[0125] Preferably, a magnetic field sensing element is selected from soft magnetic materials, or a magnetic field sensing element is manufactured using soft magnetic materials.

[0126] Preferably, the magnetic field sensing element is made of an alloy having ≥70 WT of iron, preferably ≥71.5 WT of iron, and particularly preferably ≥73 WT of iron. More preferably, the magnetic field sensing element is made of an alloy having ≥73.5 WT of iron.

[0127] Preferably, the magnetic field sensing element is made of an alloy having copper in the range of 0.75 to 1.25 WT%, more preferably in the range of 0.85 to 1.15 WT, and particularly preferably in the range of 0.95 to 1.05 WT. More preferably, the alloy of the magnetic field sensing element has a copper content of 1 WT.

[0128] Preferably, the magnetic field sensing element is composed of an alloy having 2 to 4 WT of niobium, preferably 2.5 to 3.5 WT of niobium, and particularly preferably 2.8 to 3.2 WT of niobium. More preferably, the alloy of the magnetic field sensing element has a niobium content of 3 WT.

[0129] Preferably, the magnetic field sensing element is composed of an alloy having boron in the range of 5 to 9 WT, preferably in the range of 6 to 8 WT, and particularly preferably in the range of 6.5 to 7.5 WT. More preferably, the alloy of the magnetic field sensing element has a boron content of 7 WT.

[0130] Preferably, the magnetic field sensing element is made of an alloy having silicon in the range of 14 to 17 WT%, preferably in the range of 15 to 16 WT, and particularly preferably in the range of 15.4 to 15.6 WT. Preferably, the alloy of the magnetic field sensing element has a silicon content of 15.5 WT.

[0131] It should be clearly pointed out that the above values ​​for the alloy composition of magnetic field sensitive elements should not be interpreted as strict limits. Rather, on an engineering scale, values ​​may be exceeded or fallen below these values ​​without departing from the aspects described herein. In short, these values ​​are used to provide a basis for the variables in the alloy composition of the magnetic field sensitive elements presented herein.

[0132] Preferably, the magnetic field sensing element is made of a nanocrystalline soft magnetic material having a typical particle size in the range of 5 to 30 μm, more preferably a nanocrystalline soft magnetic material having a typical particle size in the range of 7 to 20 μm, and particularly preferably a nanocrystalline soft magnetic material having a typical particle size in the range of 8 to 15 μm.

[0133] Preferably, the magnetic field sensing element is made of a strip with a particularly small thickness, because this allows the eddy current losses in the magnetic sensing element to be kept at a low level according to Maxwell's equations.

[0134] Preferably, the magnetic field sensing element has a band thickness in the range of 5 to 50 μm. More preferably, the band thickness of the magnetic field sensing element is in the range of 7.5 to 40 μm, and particularly preferably in the range of 10 to 30 μm.

[0135] It should be clearly pointed out that the above values ​​for the band thickness of the magnetic field sensing element should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the magnitude of the band thickness of the magnetic field sensing element presented herein.

[0136] Preferably, the cross-sectional area of ​​the iron in the magnetic field sensing element is between 0.03 and 0.15 cm². 2 The range is further preferably between 0.04 and 0.12 cm². More preferably, the iron cross-sectional area of ​​the magnetic field sensing element is between 0.04 and 0.12 cm². 2 The range between 0.05 and 0.1 cm² is particularly preferred. 2 Within the range between.

[0137] Preferably, the magnetic field sensing element has a height between 3 and 7 mm, more preferably between 3.4 and 6.6 mm, and particularly preferably between 3.8 and 6.2 mm.

[0138] It should be clearly pointed out that the above values ​​for the iron cross-sectional area and height of the magnetic field sensing element should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the size of the iron cross-sectional area and height of the magnetic field sensing element presented herein.

[0139] Preferably, the sensor is based on a Foster probe. The working principle of this method is to measure the differential current.

[0140] Preferably, the number of windings in the first main winding is distributed equidistantly throughout the entire winding range of the magnetic field sensitive element.

[0141] Preferably, the first main winding has a number of turns in the range of 25 to 150, more preferably in the range of 35 to 135, and particularly preferably in the range of 40 to 130. More preferably, the first main winding has a number of turns in the range of 45 to 125, more preferably in the range of 50 to 120, and particularly preferably in the range of 60 to 110.

[0142] By utilizing the number of turns in the first main winding proposed herein, the magnetic field sensing element can be advantageously wound in a manner where the turns are as equidistant as possible, thereby achieving a locally as uniform magnetic flux density as possible in the magnetic field sensing element during the energization of the first main winding.

[0143] It should be clearly pointed out that the above values ​​for the number of turns of the first main winding should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the size of the number of turns of the first main winding as presented herein.

[0144] Preferably, the number of windings in the test winding is evenly distributed throughout the entire winding range of the magnetic field sensitive element.

[0145] Preferably, the test winding has a number of turns in the range of 3 to 40, more preferably in the range of 4 to 35, and particularly preferably in the range of 5 to 30. More preferably, the test winding has a number of turns in the range of 6 to 25, more preferably in the range of 8 to 22, and particularly preferably in the range of 10 to 18.

[0146] By means of the number of turns of the test winding proposed herein, the magnetic flux density in the magnetic field sensitive element can be determined with great precision by means of the induction effect induced in the test winding, especially since the test winding can be uniformly distributed within the range of the magnetic field sensitive element in a manner that is equidistant between adjacent turns.

[0147] It should be clearly pointed out that the above values ​​for the number of turns of the test winding should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described herein. In short, these values ​​are used to provide a basis for the size of the number of turns of the test winding presented herein.

[0148] When the shielding component has an ideal functional design, it is proposed that the range of the through-hole of the magnetic field sensitive element results in the inner dimension of the through-hole of the shielding component being in the range of 18.2 to 30 mm, preferably in the range of 19.5 to 27.5 mm, and particularly preferably in the range of 20.5 to 24.2 mm. Particularly preferably, the inner dimension of the through-hole of the shielding component is in the range of 20.8 to 22.2 mm.

[0149] It should be clearly pointed out that the above values ​​for the range of inner dimensions of the through-holes in the shielding component should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the size range of inner dimensions of the through-holes in the shielding component presented herein.

[0150] Of course, the range limits given for the inner dimensions can be arbitrarily combined with each other.

[0151] According to a preferred embodiment, the magnetic sensing element is encased in an insulator, wherein the insulator is disposed between the magnetic sensing element and the first main winding and between the magnetic sensing element and the test winding.

[0152] The terminology is explained as follows:

[0153] An "insulator" is a component made of a material with such low electrical conductivity that it has only a very small ability to conduct current compared to the surrounding material.

[0154] Preferably, the insulator is constructed in a two-part configuration, allowing it to be opened to accommodate a magnetic field-sensitive element and subsequently closed again.

[0155] Preferably, the two-part insulator has a form fit and / or compression fit between the two parts of the insulator, thereby reliably surrounding the magnetic field sensitive element and preventing accidental opening and / or re-release of the magnetic field sensitive element.

[0156] Preferably, the insulator has a lower hardness compared to the winding, so that possible friction between the insulator and the winding is more likely to damage the insulator than the winding.

[0157] By using an insulator, it is advantageous to separate the magnetic field sensing element from the first main winding and the test winding, and, depending on the situation, from the second main winding, thereby reducing the possibility of winding damage.

[0158] As long as the hardness and / or elastic modulus of the insulator is lower than that of the winding materials of the first main winding, the test winding, and, depending on the circumstances, the second main winding, the winding can be installed in a certain way by means of preload, so that the winding causes deformation of the insulator and, in turn, causes shape fit between the insulator and the winding, thereby improving the positional stability of the winding relative to each other, thus improving the reliability of the sensor.

[0159] Furthermore, an insulator can be used to maintain a constant distance between the winding and the magnetic field sensing element. This advantageously keeps the physical connection between the winding and the magnetic field sensing element constant, thereby continuously maintaining the measurement accuracy of the sensor signal.

[0160] Preferably, the sensor has a second main winding, wherein the second main winding surrounds the magnetic sensing element and / or insulator with several turns of wire.

[0161] The terminology is explained as follows:

[0162] "Second main winding" refers to the main winding that is wound around the magnetic field sensitive element, other than the first main winding.

[0163] Preferably, the winding direction of the second main winding is different from the winding direction of the first main winding.

[0164] In the specified operation of a sensor having a first main winding but not a second main winding according to the first aspect of the invention, an alternating voltage is supplied to the first main winding such that whenever the sign of the supply voltage changes, the current in the first main winding also reverses its sign.

[0165] As an alternative, the first main winding is powered by a current source with alternating reversed current directions. Using this current source can advantageously improve the sensor's measurement accuracy.

[0166] In other words, the first main winding has a periodically different current direction during the specified operation of the sensor.

[0167] During the operation of a specified sensor, the time characteristic curve of the current in the first main winding can be sinusoidal or rectangular, or have another oscillation mode.

[0168] The oscillating current in the first main winding is suitable for inducing the same oscillating magnetic flux density in the magnetic field sensitive element.

[0169] The sensor proposed herein has two main windings, a first main winding and a second main winding.

[0170] Preferably, the number of windings in the second main winding is the same as the number of windings in the first main winding.

[0171] In this way, a single main winding does not require a sign change in the current direction to make the sensor operate in a specified manner. Specifically, both main windings can operate in pulses, thus alternating between having current and not having current.

[0172] If the two main windings are wound around the magnetic field sensing element in different directions of rotation, an alternating magnetic flux density can be induced in the magnetic field sensing element. Specifically, the two main windings are alternately connected to the same voltage or current source, which can have a constant initial value. This allows for a more convenient circuit design for the specified encoder. Although an additional main winding is required, this reduces the overall cost of the sensor and operating circuitry.

[0173] Preferably, the number of windings in the second main winding is equidistantly distributed throughout the entire winding range of the magnetic field sensitive element.

[0174] Preferably, the second main winding has a number of turns in the range of 25 to 150, more preferably in the range of 35 to 135, and particularly preferably in the range of 40 to 130. More preferably, the second main winding has a number of turns in the range of 45 to 125, more preferably in the range of 50 to 120, and particularly preferably in the range of 60 to 110.

[0175] By utilizing the number of turns in the second main winding proposed herein, the magnetic field sensing element can be advantageously wound in a manner where the turns are as equidistant as possible, thereby achieving a locally as uniform magnetic flux density as possible in the magnetic field sensing element during the energization of the second main winding.

[0176] It should be clearly pointed out that the above values ​​for the number of turns of the second main winding should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the size of the number of turns of the second main winding presented herein.

[0177] According to a particularly preferred embodiment, the sensor has a spacer ring, wherein the spacer ring is arranged between the inner wall of the shield and the first main winding.

[0178] The terminology is explained as follows:

[0179] "Spacer ring" refers to a ring-shaped element suitable for placement between the inner wall of the sensor's shield and the first main winding.

[0180] Preferably, the spacer ring is adapted to reduce or fill the radial gap in the accommodating cavity between the inner wall of the shield and the main winding.

[0181] Preferably, the spacer ring is adapted to fill the axial gap between the first shield and the second shield, such that the spacer ring can define the width of the circumferential gap when the two shields abut against each other.

[0182] Preferably, the spacer ring is made of plastic or another material with relatively low specific conductivity.

[0183] Advantageously, spacer rings can also be used to protect the wires of the main winding and / or test winding during sensor installation. This allows the spacer ring, along with the magnetic field sensitive element already wound with one or more main or test windings, to be inserted into, in particular, the first part of the shield, especially the portion where the preferred outer surface of the shield is at least partially covered in a specified manner by another part of the shield. This allows the magnetic field sensitive element to be carefully inserted visually into the first part of the shield, where it is protected from mechanical loads by the spacer ring on its inner side, particularly the windings surrounding the magnetic field sensitive element. Subsequently, the second part of the shield can be inserted in such a way that the windings are protected from mechanical loads by the spacer rings and the overlapping first part of the shield. In this respect, even when particularly sensitive components are not visible during the installation of the second part of the shield, the spacer rings advantageously improve the mechanical protection of these sensitive components.

[0184] A preferred embodiment is a spacer ring having an insert within its base material. This insert is made of a material with relatively high permeability, particularly approximately equivalent to that of a shield. This insert is preferably completely surrounded by the base material of the spacer ring, thus providing insulation due to the relatively low conductivity of the base material.

[0185] Therefore, due to the high permeability of the spacer ring, leakage at the surrounding gap of the magnetic field emitted from the magnetic field sensing element can be reduced during the operation of the sensor in a specified manner, thereby advantageously improving the measurement accuracy of the sensor and reducing the power requirements of the sensor.

[0186] Optionally, the shielding element has a coating, particularly an electrically insulating coating.

[0187] The terminology is explained as follows:

[0188] "Coating" refers to an adhesive layer formed by amorphous substances on the surface of a shielding component.

[0189] Preferably, the coating is particularly unfavorable for current conduction. That is, the coating preferably has extremely low electrical conductivity.

[0190] Preferably, the coating is formed of epoxy resin.

[0191] Preferably, the coating is applied to the shielding in such a way that it at least covers a localized area of ​​the outer shielding surface that is arranged in a specified manner near the printed circuit board.

[0192] Advantageously, the shield can be insulated relative to the designated circuit board, thereby advantageously preventing short circuits between the shield and the designated circuit board.

[0193] According to a preferred embodiment, the shielding member has a material thickness ranging from 0.25 mm to 0.45 mm, preferably from 0.3 mm to 0.4 mm, and particularly preferably from 0.32 mm to 0.38 mm.

[0194] The terminology is explained as follows:

[0195] "Material thickness" or material dimension refers to the extent to which an object extends along the direction of its surface normal.

[0196] Eddy currents are currents induced in extended conductors in time-varying magnetic fields and / or in moving conductors in time-constant but spatially non-uniform magnetic fields. If the conductor has finite resistance, it will heat up due to eddy currents. The energy converted into heat is called "eddy current loss".

[0197] It is proposed to reduce the material thickness of the magnetic field sensing element and the shielding of at least one main winding and test winding surrounding the magnetic field sensing element.

[0198] The solution to reduce the material thickness within the shielding component area is based on innovations in the shielding component manufacturing field.

[0199] Preferably, the shielding component is deep-drawn or injection-molded.

[0200] This allows for cost reductions relative to the size of thicker shielding materials.

[0201] When the sensor operates in a specified manner, the magnetic field sensing element exhibits an oscillating magnetic flux density. The shield, also formed of a highly conductive material, is thus affected by induction due to changes in the magnetic flux density of the sensing element. This induction is undesirable because it generates eddy current losses.

[0202] By reducing the material thickness of the shielding, eddy current losses generated when the sensor operates in a specified manner can be effectively reduced.

[0203] This can effectively reduce the power requirements of the sensor and improve its measurement accuracy.

[0204] It should be clearly pointed out that the above values ​​for the material thickness of the shielding component should not be interpreted as strict limits. Rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the magnitude of the shielding component material thickness proposed herein.

[0205] Preferably, the circumferential gap has a gap width ranging from 0.1 mm to 2.0 mm, more preferably from 0.3 mm to 1.7 mm, and particularly preferably from 0.6 mm to 1.3 mm.

[0206] The terminology is explained as follows:

[0207] "Gap width" refers to the width of the gap. Preferably, the gap width refers to the width of the circumferential gap on the inner wall of the shielding component.

[0208] A surrounding gap in the shielding is particularly advantageous; otherwise, the shielding would become a winding of highly conductive material surrounding the magnetic field sensing element. This winding would be affected by induction when the sensor operates in a specified manner, causing oscillations in the magnetic flux density within the sensing element. This increases eddy current losses associated with the shielding, leading to increased power demands and reduced measurement accuracy.

[0209] However, the surrounding gap in the sensor's shield can also cause a depression to form in the magnetic field surrounding the magnetic field sensing element. This is mainly because the permeability of the air in the surrounding gap is much lower than the permeability of the shield.

[0210] Therefore, an excessively wide surrounding gap can also lead to other types of physical effects, which can also adversely affect the sensor's power requirements and measurement accuracy.

[0211] This paper proposes a specific range for the width of the surrounding gap, thereby advantageously achieving an optimal state between the best sensor measurement accuracy related to the excessively small width of the surrounding gap and the best sensor measurement accuracy related to the excessively large width of the surrounding gap, based on different physical effects.

[0212] Furthermore, the power requirements for sensor operation can be advantageously minimized by utilizing the surround gap width proposed herein.

[0213] It should be clearly pointed out that the above values ​​for the width of the circumferential gap should not be interpreted as strict limits; rather, these values ​​can be exceeded or decreased on an engineering scale without departing from the aspects described in this invention. In short, these values ​​are used to provide a basis for the size of the circumferential gap presented herein.

[0214] According to a preferred embodiment, the sensor has an electrical connector, wherein the electrical connector has a mounting plate, a connector neck, and a plurality of electrical contacts.

[0215] -The electrical connector described herein has at least two electrical contacts for each winding.

[0216] -The electrical contacts are arranged radially on the outside of the outer wall of the shield.

[0217] -The mounting plate is arranged between the outer wall of the shield and the first main winding.

[0218] -The connector neck extends through an opening in the outer wall of the shield and connects the mounting plate to the electrical contacts.

[0219] -The mounting plate and the connector neck each have a corresponding groove, wherein the groove is adapted to receive two wires in an active connection with each winding from the receiving cavity and to guide them from the receiving cavity through an opening in the outer wall of the shield to the electrical contacts.

[0220] -The groove has a cut in a direction parallel to the outer wall of the shield, through which a wire can be inserted into the central area of ​​the groove.

[0221] The terminology is explained as follows:

[0222] An “electrical connector” is a component that is adapted to be fastened to a sensor and has at least the required number of accessible electrical contacts.

[0223] Preferably, the connector enables the electrical and / or electronic components of the sensor to be electrically connected to the electrical contacts of the connector, wherein the electrical contacts of the connector have relatively good accessibility.

[0224] Preferably, the connector enables the electrical contacts to be arranged in a fixed position relative to the sensor, at least indirectly.

[0225] Therefore, overall, the connector can preferably and advantageously allow the sensor to be inserted in a fixed relative arrangement between the magnetic field sensitive element and the electrical contacts, wherein the electrical and / or electronic components of the sensor are already electrically connected to the electrical contacts during the manufacture of the sensor.

[0226] This allows the sensor to be advantageously connected to the circuit board directly by soldering or indirectly by other contact elements, particularly plugs, using the electrical contacts of the electrical connector. This makes it possible to determine, in particular, the relative position of the magnetic field sensitive element to the circuit board by connection achieved at least indirectly by the electrical connector.

[0227] Preferably, the electrical connector has plastic, particularly plastic with relatively low conductivity, as the base material.

[0228] Preferably, the electrical contacts of the electrical connector are at least partially surrounded by the base material of the connector, such that there is a compression fit and / or form fit connection between the base material and the electrical contacts. Furthermore, the electrical contacts are preferably arranged in a manner spatially spaced apart by the base material of the electrical connector, thereby advantageously preventing any direct electrical contact between two electrical contacts, thus preventing short circuits between the electrical and / or electronic components of the sensor.

[0229] "Mounting plate" refers to an area of ​​an electrical connector that is adapted to form at least an indirect connection, such as a form-fit and / or compression fit, between a magnetic field sensitive element and the electrical connector.

[0230] Preferably, the mounting plate can be housed inside the housing cavity of the shield, particularly between the shield and the main winding, and more preferably between the main winding and the outer wall of the shield.

[0231] Preferably, the mounting plate is adapted to be inserted into the shield along with the magnetic field sensing element and the winding surrounding the magnetic field sensing element. This allows the mounting plate to advantageously provide additional protection to the winding from mechanical loads during the insertion of the shield.

[0232] The “connector neck” refers to the area of ​​the electrical connector suitable for connecting the mounting plate to the electrical contacts.

[0233] "Electrical contact" refers to an electrical connector element suitable for creating contact between electrical and / or electronic components of a sensor.

[0234] Preferably, the electrical contacts are constructed to protrude from the base material of the electrical connector in two directions. Specifically, contact can be established between the electrical and / or electronic components of the sensor and the electrical contacts at the protruding ends of the contacts. Furthermore, contact can be established with the sensor's operating circuitry at the other protruding end of the electrical contacts, particularly by means of soldering or by means of a connector corresponding to the electrical contacts or multiple electrical contacts.

[0235] Preferably, the electrical contacts are made of an alloy having a nickel content ranging from 17 to 19 WT, more preferably from 17.5 to 18.5 WT, and particularly preferably 18 WT.

[0236] Preferably, the electrical contacts are made of an alloy having a zinc content ranging from 18 to 22 WT, more preferably from 19 to 21 WT, and particularly preferably 20 WT.

[0237] Preferably, the electrical contacts are made of an alloy having 58 WT or more of copper, more preferably 60 WT or more of copper, and particularly preferably 61 WT or more of copper. More preferably, the electrical contacts are made of an alloy having 62 WT or more of copper, more preferably 63 WT or more of copper, and particularly preferably 64 WT or more of copper.

[0238] The aforementioned alloy composition of the electrical contacts achieves excellent electrical conductivity, as well as relatively high elastic modulus and excellent hot-dip tinning and soldering properties.

[0239] It should be clearly pointed out that the above values ​​for the alloy composition of electrical contacts should not be interpreted as strict limits. Rather, on an engineering scale, values ​​may be exceeded or fallen below these values ​​without departing from the aspects described herein. In short, these values ​​are used to provide a basis for the variables in the alloy composition of the electrical contacts presented herein.

[0240] Preferably, the electrical contacts have a gold coating, thereby advantageously improving the conductivity of the electrical contacts.

[0241] An "opening" refers to a region within the shielding component through which the connector neck, which connects the mounting plate and electrical contacts, extends from the internal cavity of the shielding component into the external region, allowing the electrical contacts of the connector to be positioned outside the shielding component. Therefore, the shielding component preferably has an opening corresponding to the connector neck.

[0242] In a two-part shield, one or both parts of the shield have grooves that form an opening when the shield parts are joined together.

[0243] Preferably, the opening is located within the area of ​​the outer wall of the shielding component.

[0244] A "groove" refers to a region in the cross-section of a component that is not formed from the component's base material, allowing other objects to pass through it without damaging the component.

[0245] Preferably, the groove is a channel through which the base material of the element passes.

[0246] More preferably, the groove is constructed in the form of a recess in the base material of the element, so that another object can be inserted into the groove through the opening of the recess.

[0247] The “corresponding groove” in the connector neck and mounting plate refers to a groove that passes through the mounting plate and through the connector neck with a generally unchanged orientation along the main extension direction of the groove.

[0248] "Electric wire" refers to a thin and flexible metal relative to its longitudinal length. Preferably, the electric wire has a circular cross-section. Preferably, the electric wire has multiple strands. Preferably, the wire has a high copper content.

[0249] A "cut" refers to a gradually tapering or wedge-shaped cut.

[0250] The sensor according to a first aspect of the invention has a plurality of electrical and / or electronic components. During operation of the sensor in a specified manner, current is generated in the electronic and / or electrical components, or current is actively fed into the components.

[0251] These electrical and / or electronic components of the sensor are arranged in a specified manner within the housing of the shield and must be electrically contacted from outside the shield.

[0252] The simplest form of electrical contact is based on: passing wires connected to electrical and / or electronic components through a shield and soldering them externally to a printed circuit board containing the sensor's operating circuitry.

[0253] In this solution, there are numerous different sources of damage to the wires and, consequently, to the sensor as a whole, which can lead to sensor malfunction. On one hand, wires, typically with very small cross-sections, are easily damaged by mechanical loads, particularly shear loads within the shielding area, tensile loads between windings, or the connection between the wire and the printed circuit board. Such tensile loads can occur during sensor installation or operation, due to relative movement between the wires and the printed circuit board and the magnetic field-sensitive element.

[0254] Therefore, the present invention proposes that the wires of the sensor should be made so that they can be mechanically connected and electrically connected by means of electrical connectors, thereby advantageously enhancing the robustness and usability of the sensor.

[0255] The electrical connector proposed herein has a mounting plate disposed within a receiving cavity of a shield. A connector neck, as a second part of the connector, extends from the mounting plate. Specifically, the connector neck passes through the shield, particularly in a region outside the shield. The connector neck connects multiple electrical contacts adapted for electrical contact with electrical and / or electronic components of the sensor.

[0256] The mounting plate enables the electrical connector to be pressed and / or shaped to the sensor, particularly the sensor's shielding.

[0257] The connector neck is adapted to accommodate the wire, thereby preventing the wire from being subjected to mechanical loads, particularly in the shielding area. For this purpose, the connector neck has a corresponding groove in the mounting plate into which the wire can be fed, and this groove prevents the wire from being subjected to external mechanical loads.

[0258] Furthermore, the connector neck fixes the relative position between the sensor's magnetic field-sensitive element and the contacts suitable for electrical contact. Wires can be guided through corresponding grooves in the connector neck and mounting plate to the electrical contacts, where they connect to the contacts for making contact.

[0259] The corresponding grooves in the connector neck and mounting plate are formed as recesses that open in a direction transverse to the longitudinal extension direction of the corresponding groove. This allows wires to be guided into the grooves both longitudinally and transversely. This structure facilitates sensor assembly because wires can be fed into the grooves individually or in bundles, both longitudinally and transversely, greatly simplifying the process of laying the wires into the grooves.

[0260] The connector neck and mounting plate have corresponding recesses with cutouts that extend transversely to the longitudinal axis of the corresponding recess, with the apex of the cut pointing towards the recess. These cutouts allow for easy transverse insertion of wires, individually or in bundles, into the recess, where each individual wire must pass through a narrow portion of the cut. This narrow portion of the cut is configured so that once a wire is inserted into the recess, it can only be re-expelled from the recess with greater force, transversely to the longitudinal direction of the recess, thus stopping in a designated manner within the recess's protective area. This simplifies the sequential installation of wires and ensures that the wires are protected from mechanical loads in all directions after insertion into the recess.

[0261] According to a second aspect of the invention, the solution for achieving the above-mentioned objective is a protective switch for cutting off the circuit when the differential current in the circuit exceeds a limit value, the protective switch having a sensor, a working circuit, an electronic data processing and evaluation unit, and a switching device according to a first aspect of the invention.

[0262] -The sensor is arranged around at least two electrical wires, which form a circuit.

[0263] -The switching device described herein is adapted to disconnect the circuit.

[0264] The operating circuit described herein is adapted to operate the sensor.

[0265] -The electronic data processing and evaluation unit described herein is adapted to evaluate the sensor signal of the sensor.

[0266] -The electronic data processing and evaluation unit is adapted to control the switching device to cut off the circuit when a differential current is detected, particularly when a differential current with AC / DC sensitivity is detected with a current intensity greater than a limit value, particularly an adjustable limit value.

[0267] The terminology is explained as follows:

[0268] A "protective switch" is a device designed to disconnect the voltage of a monitored circuit when a defined differential current, particularly an adjustable differential current, is exceeded in the circuit it monitors. This effectively reduces the harm caused by differential current to people and infrastructure.

[0269] "Operating circuit" refers to the circuit that enables the sensor to operate actively or passively. Preferably, the operating circuit is adapted to provide voltage to the sensor's first main winding and / or second main winding.

[0270] In addition, the working circuit is preferably adapted to intercept the voltage on the test winding of the sensor and transmit it as a signal to the data acquisition and evaluation unit.

[0271] Similarly, the operating circuit is preferably adapted to intercept the voltage on the first main winding and / or the second main winding of the sensor and transmit it as a signal to the data acquisition and evaluation unit.

[0272] Preferably, the operating circuit has a power consumption measuring device suitable for evaluating the current consumption of the test winding and / or the first main winding and / or the second main winding.

[0273] The "Electronic Data Processing and Evaluation Unit" is an electronic unit that processes large amounts of data in an organized manner, with the aim of obtaining relevant information about these data or modifying them. In this process, data from the dataset is collected, processed by humans or machines using pre-defined methods, and the results are output.

[0274] "Data" specifically refers to measured values, especially measured signals, or the values ​​or variables of other physical or chemical measured variables.

[0275] "Switching device" refers to a device suitable for cutting off the power supply to a circuit, especially a circuit monitored by a protective switch.

[0276] A "circuit" refers to a circuit composed of a system of wires, which is a closed circuit.

[0277] "Sensor signal" refers to the state variable provided by a sensor. The sensor signal is specifically configured so that the differential current in the circuit monitored by the sensor can be inferred from the sensor signal by means of physical and / or chemical correlations. Preferably, the differential current in the circuit monitored by the sensor can be calculated directly from the sensor signal. Preferably, the sensor signal is a measurable current intensity and / or a measurable voltage.

[0278] "Current intensity" refers to the current intensity measured as a physical variable, particularly the current in a circuit. Here, current intensity involves a suitable oriented surface, preferably the cross-section of a conductor. In this case, current intensity is the amount of charge flowing through the cross-section and is related to the observed time span.

[0279] Preferably, the sensor signal refers to the current consumption of the first main winding, which can be converted into differential current through mathematical rules.

[0280] "Limit value" refers to a defined value of a state variable, particularly the differential current, that the switching device must cut off the power supply to the circuit monitored by the protection switch no later than the value is exceeded in the circuit monitored by the protection switch. Preferably, the limit value of the switching device can be adjustable.

[0281] Specifically, a protective switch for a monitoring circuit utilizing a sensor according to the first aspect of the invention is proposed herein.

[0282] Of course, the advantages of the sensor for measuring differential current according to the first aspect of the invention extend directly to the protection switch having the protection switch according to the first aspect of the invention, as described above.

[0283] Therefore, it is particularly advantageous to achieve a protective switch with higher sensitivity to differential current, enabling the switch to disconnect the circuit even when the differential current in the monitored circuit is extremely small. Furthermore, advantageously, the probability of the protective switch erroneously detecting a differential current that is mistakenly considered to exceed the limit current when the monitored circuit is switched on is extremely low.

[0284] It should be noted that the subject matter of the second aspect can be advantageously combined with the subject matter of the foregoing aspects of the present invention, either alone or in any combination.

[0285] According to a third aspect of the invention, the solution for achieving the above-mentioned objective is a charging cable for charging an electric vehicle, wherein the charging cable has a sensor according to a first aspect of the invention and / or a protection switch according to a second aspect of the invention.

[0286] The terminology is explained as follows:

[0287] A "charging cable" refers to an electrical connector suitable for connecting an electric vehicle to a current source, wherein the charging cable is adapted to charge the traction battery of the electric vehicle. Preferably, the charging cable has a monitoring device for possible differential current.

[0288] "Electric vehicle" means a vehicle that is at least partially driven by an electric motor. Preferably, the electric vehicle is not restricted to a track, or at least is not permanently restricted to a track.

[0289] A charging cable for charging the battery of an electric vehicle is proposed herein, which has a protective switch according to a second aspect of the invention and / or a sensor according to a first aspect of the invention.

[0290] Of course, the advantages of the sensor for measuring differential current according to the first aspect of the invention and / or the protective switch for cutting off the circuit when the differential current in the circuit exceeds the limit value according to the second aspect of the invention extend directly to the charging cable for charging electric vehicles, wherein the charging cable has the sensor according to the first aspect of the invention and / or the protective switch according to the second aspect of the invention.

[0291] It should be noted that the subject matter of the third aspect can be advantageously combined with the subject matter of the foregoing aspects of the present invention, either alone or in any combination.

[0292] According to a fourth aspect of the invention, the solution for achieving the above-mentioned objective is a charging station for charging electric vehicles, wherein the charging station has a sensor according to a first aspect of the invention and / or a protection switch according to a second aspect of the invention.

[0293] The terminology is explained as follows:

[0294] A "charging station" or "wall-mounted charging station" refers to a charging device used to charge electric vehicles. In a wall-mounted charging station, the station is particularly suitable for being fixed to a wall. Preferably, the charging station is a mobile device that can be variably installed in different locations. Preferably, in addition to the plug-in connection for connecting the charging cable to the electric vehicle and the function of connecting to the power grid, the charging station or wall-mounted charging station also provides other functions, particularly for monitoring possible differential current.

[0295] A charging station for charging electric vehicles is proposed herein, which has a protective switch according to a second aspect of the invention and / or a sensor according to a first aspect of the invention.

[0296] Of course, the advantages of the sensor for measuring differential current according to the first aspect of the invention and / or the protective switch for cutting off the circuit when the differential current in the circuit exceeds the limit value according to the second aspect of the invention extend directly to charging stations for charging electric vehicles, wherein the charging station has the sensor according to the first aspect of the invention and / or the protective switch according to the second aspect of the invention.

[0297] It should be noted that the subject matter of the fourth aspect can be advantageously combined with the subject matter of the foregoing aspects of the present invention, either alone or in any combination.

[0298] Other advantages, details, and features of the invention will become apparent from the embodiments described below. Specifically:

[0299] Figure 1 : A schematic diagram of the sensor layout in the circuit according to the present invention;

[0300] Figure 2 A schematic diagram illustrating the physical functional connections when the circuit is connected.

[0301] Figure 3 A schematic diagram showing the dynamic development of magnetic flux density over a period of time when the circuit is switched on at an exemplary location in the magnetic field-sensitive element.

[0302] Figure 4 The physical relationship between the inner width of the magnetic field sensing element, the sensor's tendency to falsely trigger, and the characteristic curve of the sensor's minimum measurable differential current relative to the inner width.

[0303] Figure 5 : A schematic diagram of the cross-section of the sensor of the present invention;

[0304] Figure 6 Schematic diagram of different views of an electrical connector.

[0305] In the following description, the same reference numerals denote the same parts or features; therefore, a description of a part with reference to one drawing also applies to other drawings to avoid repetition. Furthermore, various features already described in conjunction with one embodiment may also be used individually in other embodiments.

[0306] Figure 1 The sensor 100, schematically illustrated, is arranged around the wires 110 and 120, through which specified currents 112 and 114 flow into a circuit (not shown) monitored by the sensor 100 and then out again.

[0307] During this process, current 112 flows into the circuit (not shown) monitored by sensor 100 via phase line 110 and flows out via neutral line 120.

[0308] When the voltage feeding device (not shown) in the circuit (not shown) is turned on, a magnetic field 114, 124 is formed between the magnetic field 114, 124 surrounding the conductors 110, 120 and the regional magnetic flux densities 116, 118 in the magnetic field sensing element 10. Figure 2 Dynamic physical interaction connections in the context.

[0309] When the voltage feed device (not shown) is turned on, the magnetic fields 114 and 124 emanating from the conductors 110 and 120 exert regional and time-limited influence on the magnetic field sensing element 10 in different ways, thereby forming reverse magnetic flux densities 116 and 126 in the magnetic field sensing element 10 for a short period of time.

[0310] like Figure 3 As shown, during the compensation process of these magnetic flux densities over time 130, at an exemplary location (not shown) in the magnetic field sensing element 10, short-term regional reverse magnetic flux densities 116, 126 in the magnetic field sensing element 10 cause dynamic characteristics of the magnetic flux density, which take the form of oscillations 132 of the magnetic flux density.

[0311] The magnetic flux density oscillation 132, caused by the switching on of the power supply device (not shown) of the observed circuit (not shown), gradually weakens and approaches its time limit along asymptotes 132 and 134.

[0312] The short-term oscillations 132 of the magnetic flux density also cause physical interaction (not shown) with the test winding (not shown) and / or the first main winding and / or the second main winding, thereby generating a sensor signal (not shown), which can be interpreted as a differential current (not shown) exceeding a defined limit (not shown). It can also be described as a switching fault.

[0313] Figure 4 The relationship between the inner width 12 of the through-hole (not shown) of the magnetic field sensing element 10, the false triggering tendency 140 of the protective switch of the sensor 100 applied in a specified manner, and the minimum differential current 150 that can be measured by the sensor 100 shows that there is an optimal value 160 for the inner width 12 of the through-hole (not shown) of the magnetic field sensing element 10, at which a good compromise is achieved between the measurable minimum differential current 150 and the false triggering tendency 140.

[0314] In the schematic diagram shown here, the optimal value of 160 is located at the intersection of characteristic curves 142 and 152.

[0315] Furthermore, the optimal range 165 of the inner width 12 of the through hole (not shown) of the magnetic field sensing element 10 is around the optimal value 160.

[0316] Figure 5 The sensor 100 generally consists of a magnetic field sensing element 10, an insulator 20 surrounding the magnetic field sensing element 10, a main winding 30, a test winding (not shown), a spacer ring 40, a shield 50, an electrical connector 60, and multiple electrical contacts 70.

[0317] The insulator 20 is constructed in a two-part configuration, wherein the parts of the insulator 20 (unlabeled) are connected in a shape-fitting manner.

[0318] The main winding 30 is connected to the electrical contacts 70 carried by the electrical connector 60 by means of the wire 75.

[0319] The shielding element 50 is constructed in a two-part configuration, and a circumferential gap 55 is formed on the inner wall 58 of the shielding element.

[0320] Figure 6 The electrical connector 60 in the middle is generally composed of a mounting plate 80, a connector neck 90 and multiple electrical contacts 70.

[0321] Figure 6 The letter b) in the diagram shows a three-dimensional view of the electrical connector 60.

[0322] Figure 6 The letter a) shows a front view of the electrical connector 60, which is drawn from the outside with respect to the specified sensor.

[0323] Figure 6 The letter c) shows a top view of the electrical connector 60. Cut lines AA and BB are also shown.

[0324] The letter d) shows a cross-section AA of the electrical connector 60.

[0325] The letter e) shows a cross-section BB of the electrical connector 60.

[0326] Figure 6 The letter f) shows a front view of the electrical connector 60, which is drawn from the inside with respect to the specified sensor.

[0327] Figure 6 The letter g in the diagram shows a side view of the electrical connector 60.

[0328] Mounting plate 80 is adapted to be housed in a receiving cavity (not shown) of a shield (not shown).

[0329] The connector neck 90 connects multiple electrical contacts 70 to the mounting plate 80.

[0330] The connector neck 90 has a recess 92 adapted to receive two wires (not shown) in an active connection with each winding (not shown) from a receiving cavity (not shown) and to guide them from the receiving cavity (not shown) through an opening (not shown) in the outer wall of the shielding to the electrical contact (70).

[0331] The groove 92 also has a cutout 94 in a direction parallel to the outer wall of the shield (not shown), through which a wire (not shown) can be inserted into the central region (not labeled) of the groove 92.

[0332] The notch 94 allows for the easy insertion of wires (not shown) one by one or in bundles laterally into the recess 92, where each individual wire (not shown) must pass through a narrow portion (not labeled) of the notch 94. The narrow portion (not labeled) of the notch 94 is configured such that, once a wire (not shown) is inserted into the recess 92, it can only be re-exited from the recess 92 laterally (not labeled) with greater force, thus remaining within the protected area (not labeled) of the recess 92 in a designated manner.

[0333] Appendix Label Table

[0334] 10. Magnetic field sensing element

[0335] 12 Inner Width

[0336] 20 Insulators

[0337] 30 main winding

[0338] 40 spacer rings

[0339] 50 shielding components

[0340] 55 Circumferential Gap

[0341] 58. Inner wall of shielding component

[0342] 60 electrical connector

[0343] 70 electrical contacts

[0344] 75 wire

[0345] 80 Mounting Plate

[0346] 90 Connector Neck

[0347] 92 Grooves

[0348] 94 Incision

[0349] 100 sensors

[0350] 110 Electrical conductor / phase wire

[0351] 112 Current direction

[0352] 114 Magnetic Field

[0353] 116 magnetic flux density

[0354] 120 conductor / neutral wire

[0355] 122 Current direction

[0356] 124 Magnetic Field

[0357] 126 magnetic flux density

[0358] 130 Timeline

[0359] 132 Oscillations in magnetic flux density

[0360] 134 asymptotes

[0361] 136 asymptotes

[0362] 140 Tendency to trigger accidentally

[0363] 142 Characteristic curve of the tendency to trigger false triggers

[0364] 150 Minimum measurable differential current

[0365] 152 Characteristic curve of the smallest measurable differential current

[0366] 160 is the optimal value.

[0367] 165 Optimal Range

Claims

1. A sensor (100) for measuring differential current sensitively in AC / DC mode. -The sensor (100) wherein the sensor (100) has a magnetic field sensing element (10), a first main winding (30), a test winding and a shield (50). -The magnetic field sensing element (10) has a through hole, wherein the cross-section of the through hole of the magnetic field sensing element (10) is constructed as an ellipse with two axes of symmetry. - wherein the first main winding (30) and the test winding are respectively surrounded by multiple turns of wire around the magnetic field sensing element (10). -The shielding element (50) has a receiving cavity adapted to receive the magnetic field sensing element (10), the first main winding (30), and the test winding. -The accommodating cavity of the shielding member (50) is radially limited by the outer wall of the shielding member and the inner wall of the shielding member (58). -The inner wall (58) of the shielding member defines the through hole of the shielding member (50), wherein the through hole of the shielding member (50) is constructed as an ellipse with two axes of symmetry. -The shielding element (50) has a circumferential gap (55) in the area of ​​the inner wall (58) of the shielding element. -The sensor (100) is adapted to be arranged around at least two electrical wires (110, 120). -The through-hole of the magnetic field sensing element (10) has at least one inner width along the axis of symmetry. Its features are, The at least one inner width is in the range of 25.2 mm to 32 mm.

2. The sensor (100) according to claim 1, characterized in that, The magnetic field sensing element (10) is encased in an insulator (20), wherein the insulator (20) is arranged between the magnetic field sensing element (10) and the first main winding (30) and between the magnetic field sensing element (10) and the test winding.

3. The sensor (100) according to claim 2, characterized in that, The sensor (100) has a second main winding, wherein the second main winding surrounds the magnetic field sensing element (10) and / or the insulator (20) with several turns of wire.

4. The sensor (100) according to claim 1 or 2, characterized in that, The sensor (100) has a spacer ring (40) arranged between the inner wall of the shield and the first main winding (30).

5. The sensor (100) according to claim 1 or 2, characterized in that, The shielding element (50) has a coating.

6. The sensor (100) according to claim 1 or 2, characterized in that, The shield (50) has a material thickness ranging from 0.25 mm to 0.45 mm.

7. The sensor (100) according to claim 1 or 2, characterized in that, The circumferential gap (55) has a gap width ranging from 0.1 mm to 2.0 mm.

8. The sensor (100) according to claim 1 or 2, characterized in that, The sensor (100) has an electrical connector (60), wherein the electrical connector (60) has a mounting plate (80), a connector neck (90) and a plurality of electrical contacts (70). -The electrical connector (60) wherein the electrical connector (60) has at least two electrical contacts (70) for each winding. -The electrical contacts (70) are arranged radially on the outside of the outer wall of the shield. -The mounting plate (80) is arranged between the outer wall of the shield and the first main winding (30). - wherein the connector neck (90) extends through an opening in the outer wall of the shield and connects the mounting plate (80) to the electrical contacts (70). -The mounting plate (80) and the connector neck (90) each have a corresponding groove (92), wherein the groove (92) is adapted to receive two wires (75) in an active connection with each winding from the receiving cavity and to guide them from the receiving cavity through an opening in the outer wall of the shield to the electrical contact (70). -The groove (92) has a cut (94) in a direction parallel to the outer wall of the shield, through which the wire (75) can be inserted into the central region of the groove (92).

9. The sensor (100) according to claim 1, characterized in that, The at least one inner width is in the range of 25.5 mm to 29 mm.

10. The sensor (100) according to claim 1, characterized in that, The at least one inner width is in the range of 25.8 mm to 27 mm.

11. The sensor (100) according to claim 5, characterized in that, The coating is an electrically insulating coating.

12. The sensor (100) according to claim 6, characterized in that, The shielding element (50) has a material thickness ranging from 0.3 mm to 0.4 mm.

13. The sensor (100) according to claim 6, characterized in that, The shielding element (50) has a material thickness ranging from 0.32 mm to 0.38 mm.

14. The sensor (100) according to claim 7, characterized in that, The surrounding gap (55) has a gap width ranging from 0.3 mm to 1.7 mm.

15. The sensor (100) according to claim 7, characterized in that, The circumferential gap (55) has a gap width ranging from 0.6 mm to 1.3 mm.

16. A protective switch for cutting off a circuit when the differential current in the circuit exceeds a limit value, the protective switch comprising a sensor (100) according to any one of claims 1 to 15, a working circuit, an electronic data processing and evaluation unit, and a switching device. - wherein the sensor (100) is arranged around at least two electrical wires (110, 120), the electrical wires forming the circuit. -The switching device thereon is adapted to disconnect the circuit. -The operating circuit described therein is adapted to operate the sensor (100). -The electronic data processing and evaluation unit thereunder is adapted to evaluate the sensor signal of the sensor (100). -The electronic data processing and evaluation unit is adapted to control the switching device upon detecting a differential current, such that the switching device disconnects the circuit.

17. The protective switch according to claim 16, wherein, The electronic data processing and evaluation unit is adapted to control the switching device to disconnect the circuit when a differential current with a current intensity greater than the limit value is detected by AC / DC sensitivity.

18. The protective switch according to claim 17, wherein, The limit value is an adjustable limit value.

19. A charging cable for charging an electric vehicle, wherein the charging cable has a sensor (100) according to any one of claims 1 to 15 and / or a protective switch according to any one of claims 16 to 18.

20. A charging station for charging an electric vehicle, wherein the charging station has a sensor (100) according to any one of claims 1 to 15 and / or a protection switch according to any one of claims 16 to 18.

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