Current measuring component, current measuring device, and current measuring method

Abstract

The current measuring member includes: a mounting portion mounted to a pair of side portions; a pair of coaxial members respectively fitted to the pair of side portions and each having an inner conductor passing through a hole formed in the corresponding side portion; a connecting portion electrically connecting the inner conductors of the pair of coaxial members to each other; and a cylindrical portion surrounding the connecting portion with a gap formed in an outer peripheral portion of the connecting portion. The pair of side portions and the mounting portion are electrically conductive to electrically connect outer conductors of the pair of coaxial members to each other. A base end portion of the cylindrical portion is electrically connected to the first side portion, and a top end portion of the cylindrical portion is electrically separated from the outer conductor of the coaxial member fitted to the second side portion.

Description

TECHNICAL FIELD

[0001] The present application relates to a current measuring member, a current measuring device, and a current measuring method. BACKGROUND

[0002] A current measuring device is disclosed in JP 1979-078574 U, which measures a current flowing through a measuring fitting connected to a return conductor of a coaxial cable by fitting a measuring coil to the measuring fitting. SUMMARY

[0003] In the current measuring device as described above, sometimes the measurement of a current transmitted from a coaxial transmission line is performed in a state where a conductor is laid outside a current sensor composed of a measuring coil or the like. In such a case, the current sensor is sometimes affected by an electric field and an electromagnetic field or the like generated by a potential difference between a conductor passing outside the current sensor and a conductor passing inside the current sensor, and the measurement accuracy can be reduced accordingly.

[0004] The present application is completed in view of such a problem point, and aims at measuring a current transmitted from a coaxial transmission line with high accuracy.

[0005] According to a first aspect of the present application, a current measuring member includes a pair of side portions separated from each other and arranged in opposition to each other, a bridging portion bridging the pair of side portions to form a space between the pair of side portions, and a pair of coaxial members fitted to the pair of side portions, respectively, and including inner conductors passing through hole portions formed in the corresponding side portions. The current measuring member further includes a connecting portion electrically connecting the inner conductors of the pair of coaxial members to each other, and a cylindrical portion surrounding an outer peripheral portion of the connecting portion in a state where a gap is formed in the outer peripheral portion of the connecting portion. Moreover, the pair of side portions and the bridging portion are electrically conductive to electrically connect outer conductors of the pair of coaxial members to each other, a base end portion of the cylindrical portion is electrically connected to the first side portion, and a top end portion of the cylindrical portion is electrically separated from the outer conductor of the coaxial member fitted to the second side portion.

[0006] According to the second aspect, the current measurement member includes: a pair of side portions that are separated from each other and disposed in opposition to each other; a bridge portion that is disposed between the pair of side portions and forms a space between the pair of side portions; a pair of coaxial members that are respectively attached to the pair of side portions and include inner conductors that pass through holes formed in the respective side portions; a connection portion that electrically connects the inner conductors of the pair of coaxial members to each other; and a cylindrical portion that surrounds an outer peripheral portion of the connection portion with a gap formed in the outer peripheral portion of the connection portion. In the current measurement member, the outer conductors of the pair of coaxial members are electrically connected to each other using the pair of side portions and the bridge portion, the base end portion of the cylindrical portion is electrically connected to the first side portion, and the top end portion of the cylindrical portion is electrically separated from the outer conductors of the coaxial members of the second side portion. The current measurement method is a method of measuring a current flowing through the coaxial members using the current measurement member, and includes a step of disposing a current sensor in the space so that the cylindrical portion is surrounded by the current sensor, and a step of detecting the current flowing through the connection portion by the current sensor.

[0007] According to these aspects, the base end portion of the cylindrical portion is electrically connected to the outer conductors of the coaxial members, and the top end portion of the cylindrical portion is electrically separated from the outer conductors of the other coaxial members.

[0008] By adopting such a configuration, the potential of the outer conductors of one of the coaxial members, the cylindrical portion, the pair of side portions, and the bridge portion can be made substantially the same as the potential of the outer conductors of the other coaxial member. In addition, the current flowing through the inner conductors of one of the coaxial members, the connection portion, and the inner conductors of the other coaxial member in sequence by the current sensor disposed in the current measurement member, the second electrode bodies of the outer conductors of the other coaxial member, the cylindrical portion, and the outer conductors of one of the coaxial members in sequence by the current sensor, and the return can be prevented.

[0009] Therefore, the current can be measured by the current sensor disposed around the cylindrical portion, and the current sensor can be less affected by the electric field and the electromagnetic field and the like generated by the potential difference between the pair of side portions, the bridge portion, and the inner conductors of the coaxial members.

[0010] Therefore, the current transmitted from the coaxial transmission line connected to the current measurement member can be measured with high accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a diagram showing one example of a coaxial transmission system in which a current measurement device according to a first embodiment of the present application is disposed.

[0012] Figure 2 is a side view showing the appearance of the current measurement device.

[0013] Figure 3 is a sectional view showing the structure of the current measurement device.

[0014] Figure 4 is a perspective view showing the appearance of the current measurement instrument that constitutes the current measurement device.

[0015] Figure 5 is a sectional view along the line V-V shown in Figure 4 .

[0016] Figure 6 is a circuit diagram showing one example of an equivalent circuit of a measurement system in which the current measurement device is arranged.

[0017] Figure 7 is a schematic view showing a current path of the current measurement instrument.

[0018] Figure 8 is a view showing a modification example of a transmission line that constitutes the current measurement instrument.

[0019] Figure 9 is a sectional view showing the structure of the current measurement device in the second embodiment.

[0020] Figure 10 is a view for explaining the power loss generated in the current measurement instrument.

[0021] Figure 11 is a sectional view showing a modification example of a transmission line that constitutes the current measurement instrument.

[0022] Figure 12 is a flowchart showing one example of a current measurement method using the current measurement instrument. DETAILED DESCRIPTION

[0023] Hereinafter, each embodiment of the present application will be described with reference to the drawings.

[0024] (First Embodiment)

[0025] Figure 1 is a view showing one example of a coaxial transmission system in which the current measurement device is arranged in the first embodiment.

[0026] The current measurement device 100 is a device for measuring a current transmitted to a coaxial transmission line (coaxial line) in a coaxial transmission system 1.

[0027] The coaxial transmission system 1 is a system that transmits a telecommunication signal through a coaxial transmission line connected between a plurality of devices. The coaxial transmission system 1 is provided with an alternating current device 10, a load device 20, a plurality of coaxial cables 30a to 30c, a terminal resistor 41 on the signal source side, and a terminal resistor 42 on the load side.

[0028] The AC device 10 is a device that generates an AC signal. The AC device 10 generates an AC current of, for example, several [Hz] to several hundred [MHz]. As shown in FIG. 1, an equivalent circuit of the AC device 10 can be represented by a signal source impedance 11 and an AC signal source 12. Figure 1

[0029] In the present embodiment, the AC device 10 is provided with a switch 13 for measuring an AC current output from the AC signal source 12. The switch 13 connects between the AC signal source 12 and the load device 20, for example, when supplying an AC current from the AC signal source 12 to the load device 20, and cuts off the connection state between the AC signal source 12 and the load device 20 when measuring an AC current of the AC signal source 12.

[0030] The AC device 10 is, for example, a power supply device for supplying an AC power to the load device 20, or an analysis device for generating an AC signal in order to analyze a transmission characteristic, and the like. The AC device 10 supplies the generated AC signal to the load device 20 via the coaxial cable 30b.

[0031] The coaxial cable 30b is a coaxial transmission line having an inner conductor 31 and an outer conductor 32 in a concentric circular shape. In the coaxial cable 30b, a dielectric is interposed between the inner conductor 31 and the outer conductor 32. The interposed dielectric is, for example, an insulating member such as polyethylene or air, or the like. Further, the coaxial cable 30b has a characteristic impedance Z0 of, for example, 50 [Ω] or 75 [Ω]. Similarly to the coaxial cable 30b, the coaxial cables 30a, 30c have the inner conductor 31 and the outer conductor 32.

[0032] The load device 20 is a device that operates by receiving an AC signal supplied from the AC device 10 via the coaxial cable 30b. As shown in FIG. 1, an equivalent circuit of the load device 20 can be represented by a load impedance 21. Figure 1

[0033] In the present embodiment, the load device 20 is provided with a switch 22 for measuring an AC signal supplied to the load impedance 21. The switch 22 cuts off the connection between the AC signal source 12 and the load device 20, for example, when measuring an AC current supplied from the AC signal source 12 via the coaxial cable 30b.

[0034] ​​In the coaxial transmission system 1 described above, the current measuring device 100 in the present embodiment is disposed at a plurality of points for the purpose of, for example, partitioning a failure site. For example, the current measuring device 100 is disposed between the AC device 10 and the terminal resistor 41 on the signal source side for the purpose of measuring the AC current flowing through the coaxial cable 30a. Further, the current measuring device 100 is disposed between the AC device 10 and the load device 20 for the purpose of measuring the AC current flowing through the coaxial cable 30b, and is disposed between the load device 20 and the terminal resistor 42 on the load side for the purpose of measuring the AC current flowing through the coaxial cable 30c.

[0035] Next, the configuration of the current measuring device 100 in the present embodiment will be described with reference to Figures 2 to 5 The configuration of the current measuring device 100 in the present embodiment will be described. Hereinafter, the coaxial cables 30a to 30c will be collectively referred to as the coaxial cable 30.

[0036] Figure 2 is a side view showing the appearance of the current measuring device 100, Figure 3 is a sectional view showing the internal structure of the current measuring device 100. Figure 4 is a perspective view showing the appearance of the current measuring apparatus 300 that constitutes the current measuring device 100, Figure 5 is a sectional view of the current measuring apparatus 300 along the V-V line shown in Figure 4

[0037] As shown in Figure 2 and Figure 3 , the current measuring device 100 is provided with a current sensor 200 that detects a current in a non-contact manner, and a current measuring apparatus 300 in which the current sensor 200 is fitted inside a housing (frame) 300A.

[0038] As shown in Figure 3 , the current sensor 200 is a sensor that detects an AC current flowing through a measurement target such as a circuit (an electric wire) in which the AC current flows, in a state in which the measurement target is inserted through a ring-shaped portion 220 of the current sensor 200, in a non-contact manner. The current sensor 200 is connected to a measurer such as an oscilloscope or a spectrum analyzer, and a current measurer measures a current flowing through the measurement target, or a physical quantity such as a magnetic field generated from the measurement target, on the basis of a detection signal of the current sensor 200.

[0039] As shown in Figure 3 , the current sensor 200 is constituted by, for example, a coil 210 that is wound around the outer periphery of the measurement target. Alternatively, the current sensor 200 can have a coil in which a wire is wound around a ring-shaped magnetic core through which the measurement target is inserted. Further, the current sensor 200 can be a clamp type that has a structure capable of clamping the measurement target, or can be a through type that has a fixed structure. ​

[0040] The current measuring instrument 300 is a current measuring component for measuring the current flowing through the coaxial cable 30 using the current sensor 200. As shown in Figure 4 and Figure 5 indicated, the current measuring instrument 300 is provided with a transmission line 360 for transmitting the alternating current flowing through the coaxial cable 30 inside a housing 300A for accommodating the current sensor 200.

[0041] The shape of the housing 300A is not limited to the rectangular cylindrical shape as exemplified in Figure 4 and Figure 5 For example, it can be a cuboid, a polygonal prism, or a cylindrical or elliptical cylindrical shape. Furthermore, the current measuring instrument 300 can be a structure that cannot be disassembled, or a structure that can be assembled so that the transmission line 360 passes through the ring-shaped portion 220 of the through-type current sensor 200.

[0042] The current measuring instrument 300 is provided with a pair of side portions 310, 320 for accommodating the current sensor 200, a standing portion 330 standing on the pair of side portions 310, 320, and a pair of coaxial connectors 340, 350 fitted to the pair of side portions 310, 320. Furthermore, the current measuring instrument 300 is provided with the above-mentioned transmission line 360, which is inserted through the ring-shaped portion 220 of the current sensor 200 as indicated in Figure 3 .

[0043] The pair of side portions 310, 320 composed of the first side portion 310 and the second side portion 320 are separated from each other and arranged in an opposed manner.

[0044] In the present embodiment, the pair of side portions 310, 320 are plate-shaped members arranged in an opposed manner to each other. Furthermore, the pair of side portions 310, 320 are conductors composed of, for example, a metal having electrical conductivity such as stainless steel.

[0045] By providing the pair of side portions 310, 320, a space (arrangement space) S required for arranging the current sensor 200 is formed between the first side portion 310 and the second side portion 320. Thereby, circuits and electronic components other than the measurement target can be physically distanced from the current sensor 200.

[0046] Furthermore, as indicated in Figure 3 , a pair of hole portions 313, 323 opposed to each other are formed in the pair of side portions 310, 320. One hole portion 313 is for the pin 341 as an internal conductor of the coaxial connector 340 to pass through. Similarly, the other hole portion 323 is for the pin 351 as an internal conductor of the coaxial connector 350 to pass through.

[0047] Furthermore, as indicated in Figure 4 andFigure 5 As shown, a plurality of threaded holes 324 for fitting the coaxial connectors 350 are formed in the side portion 320. Similarly to the side portion 320, a plurality of threaded holes are also formed in the side portion 310.

[0048] The mounting portion 330 is mounted to the pair of side portions 310, 320 and forms a space S between the pair of side portions 310, 320.

[0049] In the present embodiment, the mounting portion 330 is composed of plate-shaped members that oppose each other. Specifically, the mounting portion 330 is mounted between one end portion of the side portion 310 and one end portion of the side portion 320, and is mounted between the other end portion of the side portion 310 and the other end portion of the side portion 320. The mounting portion 330 is also a conductor, for example composed of a metal having electrical conductivity, similarly to the pair of side portions 310, 320.

[0050] The mounting portion 330 of the present embodiment is composed of two plate-shaped members that oppose each other, and the mounting portion 330 can be composed of one or three plate-shaped members, or can also be composed of a cylindrical member. Further, in the present embodiment, in order to insert the current sensor 200, the mounting portion 330 is shaped so that a portion of the outer periphery of the mounting portion 330 is open, but the mounting portion 330 can also be shaped so as to cover the entire outer periphery of the current sensor 200.

[0051] The pair of coaxial connectors 340, 350 composed of the first coaxial connector 340 and the second coaxial connector 350 are coaxial components for connecting the coaxial cables 30 to the transmission lines 360 inside the housing 300A.

[0052] The coaxial connectors 340, 350 each have an inner conductor and an outer conductor on a coaxial line, similarly to the coaxial cables 30. The coaxial connectors 340, 350 are composed of, for example, a BNC type, an SMA type, an SMB type, a TNC type, an N type, an M type, or an F type connector.

[0053] In the present embodiment, the coaxial connectors 340, 350 are each composed of the same, and the coaxial connectors 340, 350 are connected to the top ends of the pair of coaxial cables 30, respectively. In the present embodiment, the coaxial connectors 340, 350 are connected to the top ends of the pair of coaxial cables 30, respectively, but the present application is not limited thereto. For example, the coaxial connectors 340, 350 can be connected to the middle portions of the pair of coaxial cables 30, respectively. Figure 3 and Figure 5 In the example shown, the combination structure of the coaxial connectors 340, 350 and the coaxial cables 30 is simply shown, but as a combination method, for example, a threaded method, a bayonet lock method, a snap lock method, or the like can be used.

[0054] The coaxial connector 340 has a pin 341 as an inner conductor, a body portion 342 as an outer conductor, a dielectric layer 343 for insulating between the pin 341 and the body portion 342, and a flange 344 protruding radially from a top end portion of the body portion 342.

[0055] The inner conductor 31 of the coaxial cable 30 is electrically connected to the pin 341 of the coaxial connector 340, and the outer conductor 32 of the coaxial cable 30 is electrically connected to the body portion 342. Further, as shown in Figure 4 a plurality of screw holes 345 for fixing the coaxial connector 340 to the side surface portion 310 are formed in the flange 344, and the coaxial connector 340 is fixed to the outer surface 312 of the side surface portion 310 by screws inserted into the screw holes 345.

[0056] As shown in Figure 3 and Figure 5 The coaxial connector 350 has a pin 351 as an inner conductor, a body portion 352 as an outer conductor, a dielectric layer 353 for insulating between the pin 351 and the body portion 352, and a flange 354 protruding radially from a top end portion of the body portion 352, like the coaxial connector 340 described above. The pin 351, the body portion 352, the dielectric layer 353, and the flange 354 are configured similarly to the coaxial connector 340, and thus the description thereof is omitted here.

[0057] The pair of coaxial connectors 340, 350 are fitted to the pair of side surface portions 310, 320, respectively, and have the pins 341, 351 that pass through the hole portions 313, 323 formed in the corresponding side surface portions. That is, the pair of coaxial connectors 340, 350 are fitted to the outer surfaces 312, 322 of the pair of side surface portions 310, 320, respectively, with the pins 341, 351 passing through the hole portions 313, 323.

[0058] Specifically, the coaxial connector 340 is fitted to the outer surface 312 of the side surface portion 310 with the pin 341 passing through the hole portion 313 of the side surface portion 310. Thus, the flange 344 of the coaxial connector 340 abuts against the outer surface 312 of the side surface portion 310.

[0059] Similarly, the coaxial connector 350 is fitted to the outer surface 322 of the side surface portion 320 with the pin 351 passing through the hole portion 323 of the side surface portion 320. Thus, the flange 354 of the coaxial connector 350 abuts against the outer surface 322 of the side surface portion 320. The outer surfaces 312, 322 mentioned here are surfaces opposite to the inner surfaces 311, 321, respectively, which are surfaces of the pair of side surface portions 310, 320 facing each other.

[0060] As described above, the pair of side portions 310, 320 and the mounting portion 330 constituting the housing 300A are conductive, so that the main body portions 342, 352 of the pair of coaxial connectors 340, 350 are electrically connected to each other. As a result, the external conductors of the pair of coaxial connectors 340, 350 are electrically connected to each other via the pair of side portions 310, 320 and the mounting portion 330. This suppresses noise from the outside of the current measuring instrument 300 that enters the space S inside the housing 300A.

[0061] Next, the configuration of the transmission line 360 ​​provided by the current measuring instrument 300 will be described.

[0062] like Figure 5 As shown, the transmission line 360 ​​includes: a connecting portion 361 that electrically connects the internal conductors of a pair of coaxial connectors 340 and 350 to each other; and a cylindrical portion 362 that is disposed off the ground from the outer periphery of the connecting portion 361. Furthermore, a hollow portion 363 is formed between the connecting portion 361 and the cylindrical portion 362.

[0063] The transmission line 360 ​​also has a flange 365 that protrudes radially from the base end of the cylindrical portion 362, and the flange 365 is fixed to the inner surface 311 of the side portion 310.

[0064] The connector 361 is a circuit that electrically connects the pins 341 and 351 of a pair of coaxial connectors 340 and 350 to each other for transmitting electrical signals flowing through the internal conductor 31 of the coaxial cable 30.

[0065] In this embodiment, the connecting portion 361 is formed in a cylindrical shape. Furthermore, the connecting portion 361 is a conductor, for example, made of a metal such as copper. Holes are formed at both ends of the connecting portion 361 along its longitudinal direction; one hole of the connecting portion 361 is for insertion of pin 341 of the coaxial connector 340, and the other hole is for insertion of pin 351 of the coaxial connector 350. The connecting portion 361 is joined to both pins 341 and 351, for example, using solder.

[0066] Alternatively, threaded holes can be formed at both ends of the connecting portion 361, and the pins 341 and 351 can be formed into external threads to join the two parts. Alternatively, the pins 341 and 351 can be pressed into the two holes of the connecting portion 361 to fit together. In addition, the connecting portion 361 can also be formed into a polygonal prism or an elliptical cylinder instead of a cylindrical shape.

[0067] The cylindrical portion 362 is a component used to suppress noise such as electric and electromagnetic fields that radiate radially from the outer periphery of the connecting portion 361, and to reduce noise mixed into the connecting portion 361 from the outside of the cylindrical portion 362. For example... Figure 3 As shown, the cylindrical portion 362 is inserted into the annular portion 220 of the current sensor 200.

[0068] The cylindrical portion 362 surrounds the outer peripheral portion of the connecting portion 361 in a state where a gap is formed in the outer peripheral portion of the connecting portion 361. Further, the base end portion of the cylindrical portion 362 is electrically connected to the first side surface portion 310, and the tip end portion of the cylindrical portion 362 is electrically separated from the outer conductor, i.e., the main body portion 352 of the coaxial connector 350 fitted to the second side surface portion 320.

[0069] In the present embodiment, in order to electrically separate the tip end portion of the cylindrical portion 362 from the main body portion 352 of the coaxial connector 350, a gap 364 is formed in the transmission line 360 to cut the electrical connection of the main body portions 342, 352 of the pair of coaxial connectors 340, 350 to each other.

[0070] Thus, the current flowing through the pin 341 of the coaxial connector 340, the connecting portion 361, the pin 351 of the coaxial connector 350 in this order by the current sensor 200 being inserted through the cylindrical portion 362 can be prevented from returning (folding back) through the main body portion 352 of the coaxial connector 350, the cylindrical portion 362, and the main body portion 342 of the coaxial connector 340 in this order by the current sensor 200.

[0071] As a result, the magnetic field generated by the current flowing through the pin 341 of the coaxial connector 340, the connecting portion 361, and the pin 351 of the coaxial connector 350 can be suppressed from being canceled by the magnetic field generated by the returning current flowing through the main body portion 352 of the coaxial connector 350, the cylindrical portion 362, and the main body portion 342 of the coaxial connector 340.

[0072] Therefore, a magnetic field is generated in the space S in the current measuring instrument 300 centered on the connecting portion 361 through which the alternating current flows, and thus in the current sensor 200, the magnetic field generated by the alternating current flowing through the connecting portion 361 can be detected.

[0073] Further, the cylindrical portion 362 is a conductor, e.g., composed of a metal such as copper. Also, the cylindrical portion 362 is formed in a cylindrical shape. The cylindrical portion 362 is not limited to a cylindrical shape, and may, for example, be formed in a polygonal prism shape or an elliptic cylinder shape.

[0074] As shown in Figs. 7 and 8, the cylindrical portion 362 extends from the inner surface 311 of the side surface portion 310 to the inner surface 321 of the side surface portion 320, and is separated from the side surface portion 320 in order to provide the gap 364. Figure 3 Figure 5 Thus, by providing the gap 364 in the hole portion 323 of the side surface portion 320 or in the vicinity thereof, the current sensor 200 can be distanced from the gap 364. Therefore, the noise such as an electric field and an electromagnetic field radiated from the exposed connecting portion 361 to the current sensor 200 can be reduced.

[0075] Thus, by providing the gap 364 in the hole portion 323 of the side surface portion 320 or in the vicinity thereof, the current sensor 200 can be distanced from the gap 364. Therefore, the noise such as an electric field and an electromagnetic field radiated from the exposed connecting portion 361 to the current sensor 200 can be reduced.

[0076] ​The gap 364 at the top of the cylindrical portion 362 is designed to be narrower than the length (width) of the current sensor 200 in the longitudinal direction between the pair of side portions 310, 320. As a result, the length of the connecting portion 361 exposed from the cylindrical portion 362 becomes shorter, thereby reducing noise such as electric and electromagnetic fields radiated from the exposed connecting portion 361.

[0077] Furthermore, by providing a gap 364 at the top of the cylindrical portion 362, the electrical connection between the main bodies 342 and 352 of a pair of coaxial connectors 340 and 350 is cut off, and the characteristic impedance of the transmission line 360 ​​can be easily adjusted to be in the same direction and magnitude as the characteristic impedance Z0 of the coaxial cable 30.

[0078] It should be noted that, in this embodiment, as described above, the top end of the cylindrical portion 362 is formed separately from the inner surface 321 of the side portion 320, but it is not limited thereto.

[0079] For example, by thickening the side portion 320 and making the inner diameter of the hole 323 larger than the outer diameter of the cylindrical portion 362, the top end of the cylindrical portion 362 can extend further than the inner surface 321 of the side portion 320, as long as the cylindrical portion 362 does not contact the main body 352 of the coaxial connector 350. In this case, the top end of the cylindrical portion 362 is formed to be at least separate from the main body 352 of the coaxial connector 350.

[0080] In this embodiment, the cylindrical portion 362 is fitted to the inner surface 311 of the side portion 310, but it is also possible that the cylindrical portion 362 is fitted to the inner surface 321 of the side portion 320. In this case, the top end of the cylindrical portion 362 is formed to extend from the side portion 320 to the side portion 310 and is separate from the main body portion 342 of the coaxial connector 340.

[0081] Next, refer to Figure 6 and Figure 7 The electrical characteristics of the current measuring device 300 in this embodiment will be explained.

[0082] Figure 6 It means Figure 1 The circuit diagram shown is of the equivalent circuit of the measurement system 1A, in which the current measuring device 100 is arranged on the coaxial cable 30a connecting the AC device 10 and the terminating resistor 41 on the signal source side, in the coaxial transmission system 1 shown.

[0083] exist Figure 6 The diagram shows the resistance Rm and characteristic impedance Zm of the current measuring instrument 300 constituting the current measuring device 100, the characteristic impedance Z0 of a pair of coaxial cables 30a connected to the current measuring instrument 300, and the resistance Rt of the terminating resistor 41.

[0084] In the measurement system 1A, in order to suppress reflection of the alternating current output from the alternating current signal source 12 by the termination resistor 41, the resistance Rt of the termination resistor 41 is set to the same value as the signal source impedance 11.

[0085] Further, in order to suppress power loss of the alternating current transmitted from the alternating current signal source 12 to the termination resistor 41, the resistance Rm of the current measurement device 300 is reduced to zero (0) in resistance value. At the same time, the characteristic impedance Zm of the current measurement device 300 is designed to the same value as the characteristic impedance Z0 of the coaxial cable 30a. Thereby, the alternating current flowing through the coaxial cable 30a can be measured with high accuracy in the current measurement device 300.

[0086] In the present embodiment, the impedance adjustment of the current measurement device 300 is performed by adjusting the gap 364 for insulating the cylindrical portion 362 from the coaxial connector 350, the interval of the connecting portion 361 and the cylindrical portion 362, and the dielectric inserted between the connecting portion 361 and the cylindrical portion 362. Thus, by adjusting the structure of the connecting portion 361 and the cylindrical portion 362 constituting the transmission line 360, the characteristic impedance Zm of the current measurement device 300 can be adjusted to the characteristic impedance Z0 of the coaxial cable 30.

[0087] Therefore, by adjusting the gap 364 of the cylindrical portion 362, the interval of the cylindrical portion 362 and the connecting portion 361, and the like, the characteristic impedance Zm of the current measurement device 300 can be adjusted, and thus the impedance between the alternating current device 10 and the termination resistor 41 can be simply matched.

[0088] Figure 7 is a schematic view showing a path of the current flowing through the current measurement device 300 when the alternating current flowing through the coaxial cable 30a is positive (+).

[0089] First, the current flowing through the inner conductor 31 of one coaxial cable 30a is transmitted to the inner conductor 31 of the other coaxial cable 30a in order via the pin 341 of the coaxial connector 340, the connecting portion 361, and the pin 351 of the coaxial connector 350. Thereafter, the current flows from the outer conductor 32 of the other coaxial cable 30a to the main body portion 352 of the coaxial connector 350 via the termination resistor 41.

[0090] At this time, the housing 300A constituted by the pair of side portions 310, 320 and the stand portion 330 has conductivity, and thus the main body portions 342, 352 of the pair of coaxial connectors 340, 350 are electrically connected to each other. Therefore, as shown in Figure 7 the current flows from the main body portion 352 of the coaxial connector 350 to the main body portion 342 of the coaxial connector 340 via the pair of side portions 310, 320 and the stand portion 330.

[0091] Further, the cylindrical portion 362 also has electrical conductivity like the case 300A, and thus current also flows from the main body portion 342 of the coaxial connector 340 to the cylindrical portion 362. Thus, the case 300A and the cylindrical portion 362 have substantially the same potential. Therefore, the electric field and electromagnetic field and the like noise generated between the case 300A and the connecting portion 361 are shielded by the cylindrical portion 362 having substantially the same potential as the case 300A. As a result, the electric field and electromagnetic field and the like that are radiated from the connecting portion 361 to the space S inside the case 300A as noise can be suppressed.

[0092] On the other hand, the main body portion 352 of the coaxial connector 350 and the cylindrical portion 362 are in non-contact due to the gap 364, and thus a magnetic field generated by the current flowing through the connecting portion 361 can be generated in the space S in which the current sensor 200 is accommodated.

[0093] Thus, by providing the gap 364 at the top end of the cylindrical portion 362, a magnetic field generated by the current flowing through the connecting portion 361 can be generated inside the annular portion 220 of the current sensor 200, and the periphery of the current sensor 200 can be made to have substantially the same potential. Therefore, the space S inside the case 300A becomes a state in which noise is less likely to mix into the current sensor 200, and thus the current sensor 200 can accurately detect the magnetic field generated by the current flowing through the connecting portion 361.

[0094] Here, the noise generated in the space S inside the current measuring instrument 300 will be described in detail. First, in the configuration in which the cylindrical portion 362 having electrical conductivity is omitted from the periphery of the connecting portion 361, an electric field and electromagnetic field and the like noise are generated in the space S inside the current measuring instrument 300 due to the potential difference between the case 300A and the connecting portion 361. Due to the influence of this noise, the detection accuracy of the current sensor 200 disposed in the space S can be reduced.

[0095] In contrast to this, in the present embodiment, the cylindrical portion 362 is provided at the outer peripheral portion of the connecting portion 361, and the cylindrical portion 362 is electrically connected to the case 300A. As a result, the potential difference between the case 300A and the cylindrical portion 362 is substantially zero, and thus the generation of an electric field and electromagnetic field and the like noise is suppressed in the space S in which the current sensor 200 is disposed, as described above. Therefore, compared to the configuration in which the cylindrical portion 362 is omitted, the noise mixed into the current sensor 200 can be suppressed.

[0096] Next, the effects of the first embodiment will be described.

[0097] In the present embodiment, the current measurement device 300 that constitutes the current measurement unit is provided with a pair of side portions 310, 320 that are separated from each other and disposed in opposition to each other, and a bridge portion 330 that is bridged to the pair of side portions 310, 320. The current measurement device 300 further includes a pair of coaxial components that are fitted to the pair of side portions 310, 320, respectively, and are provided with inner conductors that pass through hole portions 313, 323 formed in the corresponding side portions 310, 320. As the pair of coaxial components, a coaxial connector or a terminal, etc. that is constituted by an inner conductor and an outer conductor formed on the outer periphery thereof can be cited, and the coaxial components in the present embodiment are a pair of coaxial connectors 340, 350 that are provided with pins 341, 351 as inner conductors. Further, the current measurement device 300 is provided with a connection portion 361 that electrically connects the pins 341, 351 of the pair of coaxial connectors 340, 350 to each other.

[0098] In addition to this, the current measurement device 300 is provided with a cylindrical portion 362 that surrounds the outer periphery of the connection portion 361 in a state in which a gap is formed in the outer periphery of the connection portion 361. Also, the pair of side portions 310, 320 and the bridge portion 330 are electrically conductive so as to electrically connect the main body portions 342, 352 that are outer conductors in the pair of coaxial connectors 340, 350 to each other. At the same time, the base end portion of the cylindrical portion 362 is electrically connected to the first side portion 310, and the tip end portion of the cylindrical portion 362 is electrically separated from the main body portion 352 of the coaxial connector 350 fitted to the second side portion 320.

[0099] According to the above-described structure, the bridge portion 330 is provided between the pair of side portions 310, 320. Due to this, it is possible to physically distance a circuit or an electronic component, etc. that is different from the coaxial cable 30 connected to at least one of the coaxial connectors 340, 350 from the connection portion 361 inside the current measurement device 300. As a result, it is possible to reduce noise generated in a space S formed by the pair of side portions 310, 320 and the bridge portion 330, and thus it is possible to accurately measure a current transmitted from a coaxial transmission line such as the coaxial cable 30 to the current measurement device 300.

[0100] In addition to this, by making the pair of side portions 310, 320 and the bridge portion 330 electrically conductive so that the main body portions 342, 352 of the pair of coaxial connectors 340, 350 are electrically connected to each other, it is easy to shield noise that can be mixed from the outside of the current measurement device 300. Further, by disposing the cylindrical portion 362 in a state in which it is separated from the outer periphery of the connection portion 361, it is possible to enclose an electric field and an electromagnetic field generated from the connection portion 361 inside the cylindrical portion 362.

[0101] Furthermore, as described above, the current measurement device 300 is provided with the pair of side portions 310, 320 and the bridge portion 330 that are electrically conductive, and the cylindrical portion 362 that surrounds the outer periphery of the connection portion 361 in a state in which a gap is formed in the outer periphery of the connection portion 361. Due to this, it is possible to shield noise that can be mixed from the outside of the current measurement device 300, and it is possible to enclose an electric field and an electromagnetic field generated from the connection portion 361 inside the cylindrical portion 362. Figure 7As shown, by electrically connecting the pair of side portions 310, 320 and the bridge portion 330 with the cylindrical portion 362, the space S has substantially the same electric potential. Thus, noise generated by the potential difference between the pair of side portions 310, 320 and the bridge portion 330 and the cylindrical portion 362 can be reduced.

[0102] Meanwhile, by providing the gap 364 at the top end of the cylindrical portion 362, current flowing through the pin 341 of one coaxial connector 340, the connection portion 361, the pin 351 of the other coaxial connector 350 in that order through the current sensor 200 can be prevented from flowing through the body portion 352 of the other coaxial connector 350, the cylindrical portion 362, the body portion 342 of one coaxial connector 340, and back through the current sensor 200. As a result, in the space S in the current measuring device 300, a magnetic field can be generated by the current flowing through the connection portion 361 with the connection portion 361 as the center.

[0103] Thus, by providing the cylindrical portion 362 at the outer peripheral portion of the connection portion 361 and electrically connecting the cylindrical portion 362 with the pair of side portions 310, 320 and the bridge portion 330, noise mixed into the space S in the current measuring device 300 can be reduced. Therefore, the current flowing through the connection portion 361 can be measured with high accuracy.

[0104] Further, in the present embodiment, the current measuring device 100 is provided with the current sensor 200 that detects the current flowing through the measurement target in a state in which the measurement target is inserted therethrough, and the current measuring device 300 described above. Moreover, the bridge portion 330 forms the space S between the pair of side portions 310, 320, and the current sensor 200 is disposed in the space S in a state of surrounding the cylindrical portion 362, and detects the current transmitted to the connection portion 361.

[0105] According to this structure, by providing the bridge portion 330 between the pair of side portions 310, 320, the space S for disposing the current sensor 200 can be ensured. Therefore, circuits or electronic components other than the coaxial cable 30 that transmits the current to the connection portion 361 can be physically distanced from the current sensor 200. As a result, noise mixed into the current sensor 200 is reduced, and thus the measurement accuracy when measuring the current flowing through the connection portion 361 using the current sensor 200 is improved.

[0106] Further, in the present embodiment, the cylindrical portion 362 and the connection portion 361 are structured to have the same characteristic impedance as the coaxial connectors 340, 350. Thus, in the case where the current flowing through the coaxial cable 30 is high frequency, reflection generated in the current measuring device 300 can be reduced. As a result, the current transmitted from the coaxial cable 30 to the connection portion 361 of the current measuring device 300 can be measured with high accuracy.

[0107] Further, in the present embodiment, the pair of side portions 310, 320 and the mounting portion 330 are conductors. According to this structure, it is not necessary to perform a process of attaching a conductive portion to the surface of the pair of side portions 310, 320 and the mounting portion 330, or a process of applying a conductive member, and thus the current measuring instrument 300 can be easily manufactured.

[0108] Further, in the present embodiment, the gap 364 formed at the tip end of the cylindrical portion 362 in the direction between the pair of side portions 310, 320, that is, the long dimension direction of the connection portion 361 is narrower than the width of the current sensor 200. According to this structure, the exposed portion of the connection portion 361 can be reduced, and thus the noise such as an electric field and an electromagnetic field radiated from the exposed portion can be reduced.

[0109] Further, in the present embodiment, the cylindrical portion 362 extends from the inner surface 311 of the first side portion 310 to be separated from the second side portion 320 with the gap 364. According to this structure, since the gap 364 is formed in the second side portion 320 or in the vicinity thereof, the current sensor 200 can be disposed so as to be away from the gap 364. Thus, the noise such as an electric field and an electromagnetic field radiated from the exposed connection portion 361 to the current sensor 200 can be reduced.

[0110] <Modification Example>

[0111] Next, the structure of the current measuring instrument 301 as a modification example of the current measuring instrument 300 in the first embodiment will be described with reference to FIG. 12. Figure 8 A modification example of the current measuring instrument 300 in the first embodiment will be described. Figure 8 is a cross-sectional view showing the structure of the current measuring instrument 301 as a modification example of the current measuring instrument 300.

[0112] The current measuring instrument 301 in the present modification example is provided with a transmission line 360A instead of the transmission line 360 of the current measuring instrument 300 shown in FIG. 1. The transmission line 360A is provided with a cylindrical portion 462 and a flange 465 protruding in the radial direction from the base end portion of the cylindrical portion 462 in addition to the cylindrical portion 362 whose tip end is retreated toward the first side portion 310. As shown in FIG. 12, as for other configurations, the same reference numerals are attached because the configurations are the same as those of the current measuring instrument 300, and the repeated description is omitted. Figures 2 to 5 Figure 8 The cylindrical portion 462 extends from the inner surface 321 of the side portion 320 in the long dimension direction of the connection portion 361. The tip end of the cylindrical portion 462 is separated from and opposes the tip end of the cylindrical portion 362.

[0113] The cylindrical portion 462 extends from the inner surface 321 of the side portion 320 in the long dimension direction of the connection portion 361. The tip end of the cylindrical portion 462 is separated from and opposes the tip end of the cylindrical portion 362.

[0114] ​The gap 364A formed between the top end of the cylindrical portion 362 and the top end of the cylindrical portion 462 is formed in the middle between the pair of side portions 310, 320. The length of this gap 364A is designed to be shorter than the width of the current sensor 200, as with the current measuring instrument 300, in order to suppress noise radiated from the connection portion 361. Further, the flange 465 is fixed to the inner surface 311 of the side portion 310, as with the flange 365.

[0115] Thus, by providing the cylindrical portion 462 in opposition to the cylindrical portion 362, the gap 364A provided at the top end of the cylindrical portion 362 is formed in the middle between the pair of side portions 310, 320. Even with such a configuration, noise radiated from the connection portion 361 to the space S is suppressed, and a magnetic field generated by the alternating current flowing through the connection portion 361 is generated in the space S of the current measuring instrument 301.

[0116] Note that, in the present modification, the housing 300A composed of the pair of side portions 310, 320 and the stand portion 330 is a conductor, but in the housing 300A, it is only necessary that the body portions 342, 352 of the pair of coaxial connectors 340, 350 be electrically connected to each other. As a result, the body portions 342, 352 of the pair of coaxial connectors 340, 350 can also be electrically connected to each other by applying a process of attaching a conductive portion to the surfaces of the pair of side portions 310, 320 and the stand portion 330 having insulating properties, or a process of applying a conductive member.

[0117] (Second Embodiment)

[0118] Figure 9 is a sectional view showing the structure of the current measuring device 101 in the second embodiment. The current measuring device 101 is provided with Figure 2 and Figure 3 the current sensor 200 and the current measuring instrument 302 shown in

[0119] In the present embodiment, the current measuring instrument 302 is provided with a terminator 450 instead of the coaxial connector 350. As for other configurations, the same configurations as those of the current measuring instrument 300 shown in Figures 2 to 5 are employed. Therefore, the same reference numerals are affixed to the configurations common to those of the current measuring instrument 300, and the description thereof is omitted here.

[0120] The terminator 450 is a coaxial component for terminating one end of the transmission line 360 of the current measuring instrument 302. In the present embodiment, the terminator 450 is a connector component having a termination resistor, which houses the termination resistor 41 shown in Figure 1 and Figure 6

[0121] As shown in Figure 9 ​As shown, the terminal resistor 41 is composed of a first electrode body 411 that constitutes an inner conductor of the coaxial member, a resistor body 412, and a second electrode body 413. The first electrode body 411 has a first electrode 411A and a pin 411B that protrudes from the first electrode 411A in the extension direction of the resistor body 412.

[0122] The terminal 450 is provided with the above-described terminal resistor 41, a spring electrode 451 that covers the second electrode body 413 of the terminal resistor 41, and a main body portion 452 that houses the terminal resistor 41 and the spring electrode 451. The terminal 450 is also provided with a hole portion 453 that opens from the top end portion of the main body portion 452 and a flange 454 that protrudes in the radial direction from the top end portion of the main body portion 452. Note that the second electrode body 413, the spring electrode 451, and the main body portion 452 of the terminal 450 constitute an outer conductor of the coaxial member.

[0123] The spring electrode 451 is formed so as to be embedded in the bottom of the hole portion 453, and the main body portion 452 is formed of a conductor. The terminal resistor 41 is pressed in such a way that the spring electrode 451 abuts against the bottom surface of the hole portion 453. Thus, the terminal resistor 41 is fixed to the main body portion 452, and the pin 411B of the terminal resistor 41 protrudes from the main body portion 452.

[0124] Further, although not shown in Figure 9 , the flange 454 is formed with a plurality of screw holes in the same manner as the flange 344 shown in Figure 4 and Figure 5 , and the terminal 450 is fixed to the outer surface 322 of the side portion 320 with screws inserted into the screw holes.

[0125] The terminal 450 thus configured is fitted to the outer surface 322 of the second side portion 320 in such a way that the pin 411B that constitutes the first electrode body 411 passes through the hole portion 323 of the second side portion 320. Also, the connection portion 361 electrically connects the pin 341 that constitutes the inner conductor of the coaxial connector 340 and the pin 411B that constitutes a part of the inner conductor of the terminal 450 to each other.

[0126] Further, the pair of side portions 310, 320 and the stand portion 330 are electrically conductive in the same manner as in the first embodiment, so that the main body portion 342 that constitutes the outer conductor of the coaxial connector 340 is electrically connected to the second electrode body 413 of the terminal 450. Also, the base end portion of the cylindrical portion 362 is electrically connected to the first side portion 310, and the top end portion of the cylindrical portion 362 is electrically separated from the main body portion 452 of the terminal 450 that is fitted to the second side portion 320.

[0127] Note that although the gap 364 is provided at a position of the cylindrical portion 362 that is close to the side portion 320 in the present embodiment, it is not limited thereto. For example, as shown in FIG. 17, the gap 364 can be provided at a position of the cylindrical portion 362 that is close to the first side portion 310.Figure 8 The gap 364 can also be provided in the middle of the pair of side portions 310, 320 as shown.

[0128] Next, the effects of the second embodiment will be described with reference to Figure 10 The power loss of the current measuring instrument 302 in the present embodiment will be described.

[0129] Figure 10 is a graph for illustrating the relationship between the frequency [Hz] of the alternating current flowing from the coaxial cable 30 to the transmission line 360 via the coaxial connector 340 of the current measuring instrument 302 and the power loss [dB] of the current measuring instrument 302.

[0130] In Figure 10 , the frequency characteristic of the input reflection coefficient S11 of the current measuring instrument 302 is indicated by a solid line, and the frequency characteristic of the input reflection coefficient S11 of the comparative object instrument in which the cylindrical portion 362 is omitted is indicated by a broken line as a comparative example.

[0131] In Figure 10 the example shown, the characteristic impedance Z0 of the coaxial cable 30 is 50 [Ω], and the value of the terminal resistor 41 fitted in the terminal 450 of the current measuring instrument 302 is 50 [Ω]. Further, the comparative object instrument is fitted with another terminal that shorts the housing 300A and the connecting portion 361 instead of the terminal 450.

[0132] As Figure 10 shown, the higher the frequency of the alternating current flowing through the transmission line 360, the closer the input reflection coefficient S11 of the current measuring instrument 302 in the present embodiment to zero. That is, it is known that the higher the frequency of the alternating current flowing through the coaxial cable 30, the smaller the power loss in the current measuring instrument 302.

[0133] In addition, it is known that the input reflection coefficient S11 of the current measuring instrument 302 is improved compared to the input reflection coefficient S11 of the comparative object instrument in the entire frequency range. The reason for this is that not only is the reflection of the alternating current generated at the terminal 450 suppressed, but also by providing the cylindrical portion 362 that is electrically connected to the housing 300A in the current measuring instrument 302, the electromagnetic wave leaking from the connecting portion 361 to the space S of the housing 300A is reduced.

[0134] Next, the effects of the second embodiment will be described with reference to

[0135] In the present embodiment, the current measuring instrument 302 includes a pair of side portions 310, 320 that are separated from each other and disposed in opposition to each other, and a bridge portion 330 that is disposed on the pair of side portions 310, 320. The current measuring instrument 302 further includes a coaxial connector 340 that is attached to the first side portion 310 and includes a pin 341 that functions as an inner conductor and that penetrates a hole portion 313 formed in the first side portion 310, and a terminal device 450 that is attached to the second side portion 320 and includes a pin 411B that constitutes a first electrode body 411 and that penetrates a hole portion 323 formed in the second side portion 320.

[0136] The coaxial connector 340 and the terminal device 450 constitute a pair of coaxial components. In the present embodiment, the inner conductor of one of the coaxial components is implemented by the pin 341 of the coaxial connector 340, and the outer conductor is implemented by a main body portion 342 of the coaxial connector 340. Also, the inner conductor of the other of the coaxial components is implemented by the first electrode body 411 of the terminal device 450, and a portion of the outer conductor is implemented by a second electrode body 413 of the terminal device 450.

[0137] In addition, the current measuring instrument 302 includes a connection portion 361 that electrically connects the pin 341 of the coaxial connector 340 and the pin 411B of the terminal device 450 to each other, and a cylindrical portion 362 that surrounds an outer peripheral portion of the connection portion 361 in a state in which a gap is formed in the outer peripheral portion of the connection portion 361. Also, the pair of side portions 310, 320 and the bridge portion 330 are electrically conductive so as to electrically connect the outer conductor, i.e., the main body portion 342 of the coaxial connector 340 and the second electrode body 413 of the terminal device 450. Furthermore, a base end portion of the cylindrical portion 362 is electrically connected to the first side portion 310, and a top end portion of the cylindrical portion 362 is electrically separated from the second electrode body 413 of the terminal device 450 that is attached to the second side portion 320.

[0138] According to this structure, as in the first embodiment, the bridge portion 330 is provided between the end portions of the pair of side portions 310, 320. Thus, circuits and electronic components that are different from the coaxial cable 30 that is connected to the coaxial connector 340 can be physically distanced from the connection portion 361 inside the current measuring instrument 302. As a result, noise that is mixed into a space S formed by the pair of side portions 310, 320 and the bridge portion 330 can be reduced, and thus the current that is transmitted from the coaxial cable 30 to the current measuring instrument 302 can be measured with high accuracy.

[0139] In addition, as with the first embodiment, by making the pair of side portions 310, 320 and the stand portion 330 conductive, it is easy to shield noise that can be mixed into the space S inside the housing 300A from the outside of the current measurement instrument 302. Further, by providing the cylindrical portion 362 that surrounds the outer peripheral portion of the connection portion 361, it is possible to enclose the electric field and the electromagnetic field generated from the connection portion 361 inside the cylindrical portion 362.

[0140] Further, by electrically connecting the pair of side portions 310, 320 and the stand portion 330 to the cylindrical portion 362, it is possible to reduce noise generated in the space S inside the housing 300A due to the potential difference between the pair of side portions 310, 320 and the stand portion 330 and the cylindrical portion 362.

[0141] Thus, according to the present embodiment, as with the first embodiment, by providing the cylindrical portion 362 and electrically connecting the cylindrical portion 362 to the pair of side portions 310, 320 and the stand portion 330, it is possible to reduce noise mixed into the space S inside the current measurement instrument 302. As a result, it is possible to measure the current flowing through the current measurement instrument 302 with high accuracy.

[0142] Further, in the present embodiment, the current measurement device 101 is provided with the current sensor 200 that detects the current flowing through the measurement target, and the current measurement instrument 302 described above. Also, the stand portion 330 forms the space S between the pair of side portions 310, 320, and the current sensor 200 is disposed in the space S in a state of surrounding the cylindrical portion 362, and detects the current transmitted to the connection portion 361.

[0143] According to this structure, as with the first embodiment, noise mixed into the current sensor 200 disposed in the space S inside the current measurement instrument 300 is reduced, and thus it is possible to measure the current flowing through the connection portion 361 with high accuracy using the current sensor 200.

[0144] Further, in the present embodiment, the structure of the cylindrical portion 362 and the connection portion 361 is configured to have the same characteristic impedance as the coaxial connector 340 and the termination device 450. Thus, in the case where the current flowing through the coaxial cable 30 is high frequency, it is possible to reduce reflection generated in the current measurement instrument 302. Therefore, it is possible to measure the current transmitted from the coaxial cable 30 to the cylindrical portion 362 and the connection portion 361 of the current measurement instrument 302 with high accuracy.

[0145] Further, in the present embodiment, the pair of side portions 310, 320 and the stand portion 330 are conductors as with the first embodiment. According to this structure, it is not necessary to perform a process of attaching a conductive portion to the surface of the pair of side portions 310, 320 and the stand portion 330 or a process of applying a conductive member, and thus it is possible to easily manufacture the current measurement instrument 302.

[0146] Furthermore, in this embodiment, the gap 364 at the top of the cylindrical portion 362 in the direction between the pair of side portions 310, 320 is narrower than the width of the current sensor 200 disposed between the pair of side portions 310, 320, similar to that in the first embodiment. According to this structure, the exposed portion of the connection portion 361 can be reduced, thus reducing noise such as electric and electromagnetic fields radiated from the exposed portion.

[0147] Furthermore, in this embodiment, the cylindrical portion 362, similar to that in the first embodiment, extends from the inner surface 311 of the first side portion 310 and is separated from the second side portion 320 by forming a gap 364. According to this structure, since the gap 364 is formed on or near the second side portion 320, the current sensor 200 can be positioned away from the gap 364. Therefore, noise such as electric and electromagnetic fields radiated from the exposed connection portion 361 to the current sensor 200 can be reduced.

[0148] Furthermore, in this embodiment, such as Figure 11 As shown, the current measuring device 302 constituting the current measuring device 100 may also have a dielectric 363A with a dielectric constant smaller than that of air between the connecting portion 361 and the cylindrical portion 362. As a result, compared with the transmission line 360 ​​having a hollow portion 363, the distance between the connecting portion 361 and the cylindrical portion 362 can be shortened, thus enabling the current measuring device 302 to be miniaturized.

[0149] It should be noted that in this embodiment, the coaxial connector 340 is mounted on the first side portion 310, and the terminator 450 is mounted on the second side portion 320. However, it is also possible that the terminator 450 is mounted on the first side portion 310, and the coaxial connector 340 is mounted on the second side portion 320. In this case, the base end of the cylindrical portion 362 is electrically connected to the first side portion 310, and the top end of the cylindrical portion 362 is electrically separated from the outer conductor, i.e., the main body portion 342, of the coaxial connector 340 mounted on the second side portion 320.

[0150] Furthermore, in this embodiment, the terminator 450 with the terminating resistor 41 is mounted on the side portion 320, but a terminator that short-circuits the transmission line 360 ​​of the current measuring device 302 can also be mounted on the side portion 320. Even with such a configuration, noise generated in the space S within the current measuring device 302 can be reduced in the same way as in this embodiment.

[0151] <Variation Example>

[0152] Next, refer to Figure 11 A modified example of the transmission line 360 ​​constituting the current measuring device 302 in the second embodiment will be described. Figure 11is a sectional view showing the structure of a transmission line 360B which is a modification of the transmission line 360.

[0153] The transmission line 360B in this modification is provided with a dielectric 363A having a dielectric constant smaller than the hollow portion 363 in place of the hollow portion 363 of the transmission line 360 shown in FIG. 6. Figure 9 As the dielectric 363A, for example, polyethylene or the like can be cited.

[0154] Thus, the transmission line 360B can shorten the distance between the connecting portion 361 and the cylindrical portion 362 as compared with the above-described transmission line 360, and thus can miniaturize the current measuring instrument 302, and in addition, can use a current sensor 200 having a small ring-shaped portion 220.

[0155] Next, with reference to Figure 12 A current measuring method of measuring the current flowing through the coaxial connector 340 using any one of the current measuring instruments 300 to 302 in the above-described embodiments will be described.

[0156] Figure 12 is a flowchart showing one example of the current measuring method using the current measuring instrument 300.

[0157] In this example, first, Figure 1 The coaxial cables 30 shown in FIG. 6 are connected to the pair of coaxial connectors 340, 350 constituting the current measuring instrument 300, respectively. Note that in the case of using the current measuring instrument 302, the coaxial cables 30 are connected only to the coaxial connector 340.

[0158] In step S1, the current sensor 200 is disposed in the space S formed between the pair of side portions 310, 320 by the erecting portion 330, and becomes a state of surrounding the cylindrical portion 362 by the current sensor 200.

[0159] In step S2, the current flowing through the connecting portion 361 of the current measuring instrument 300 is detected using the current sensor 200. At this time, the current sensor 200 is electrically connected to a measurer, and the measurer measures the magnitude of the current flowing through the coaxial connector 340, for example, based on a detection signal output from the current sensor 200.

[0160] When the current sensor 200 detects the current flowing through the connecting portion 361 and the measurement of the current flowing through the coaxial connector 340 is performed by the measurer, the current measuring method ends.

[0161] Thus, the current measurement method measures the current flowing through the coaxial components using any of the current measurement components of the current measurement apparatuses 300 to 302. The current measurement component electrically connects the outer conductors of the pair of coaxial components to each other using the pair of side portions 310, 320 and the spanning portion 330, electrically connects the base end portion of the cylindrical portion 362 to the first side portion 310, and electrically separates the top end portion of the cylindrical portion 362 from the outer conductor of the coaxial component of the second side portion 320. For example, one of the coaxial components is the coaxial connector 340, and the other of the coaxial components is the coaxial connector 350 or the terminator 450. In the second embodiment, one of the pair of coaxial components is the coaxial connector 340, and the other of the pair of coaxial components is the terminator 450, the inner conductor of the other of the pair of coaxial components is the first electrode body 411 of the terminator 450, and the outer conductor of the other of the pair of coaxial components is the second electrode body 413 of the terminator 450.

[0162] Further, the current measurement method includes a step S1 of arranging the current sensor 200 in the space S in a state in which the cylindrical portion 362 is surrounded by the current sensor 200, and a step S2 of detecting the current flowing through the connection portion 361 by the current sensor 200.

[0163] According to this configuration, the cylindrical portion 362 is electrically connected to the pair of side portions 310, 320 and the spanning portion 330, and thus the noise mixed into the current sensor 200 arranged in the space S can be reduced. As a result, the current flowing through the connection portion 361 can be measured with high accuracy.

[0164] The above describes the embodiments of the present application, but the above-described embodiments merely show a part of application examples of the present application and are not intended to limit the technical scope of the present application to the specific configurations of the above-described embodiments.

[0165] For example, in the above-described embodiments, the current measurement apparatuses 100, 101 are used to measure the current flowing through the coaxial cable 30, but the current measurement apparatuses 100, 101 can be used to calibrate the current sensor 200. In this case, the current sensor 200 is calibrated by comparing the AC signal output from the AC apparatus 10, which has high accuracy, with the measurement result of the current sensor 200. Even in this case, the influence of the noise mixed into the current sensor 200 can be reduced, and thus the current sensor 200 can be calibrated with high accuracy.

[0166] In the above-described embodiment, the housing 300A is rectangular cylindrical in shape, and for example, the housing 300A can be formed in a concentric circular shape with the transmission line 360 as the center. By this, a magnetic field can be generated in a concentric circular shape with the transmission line 360, 360A, 360B as the center by the current flowing through the transmission line 360, 360A, 360B. As a result, by properly disposing the current sensor 200 in the current measuring device 301 to 303, the detection accuracy of the current sensor 200 with respect to the current flowing through the transmission line 360, 360A, 360B can be improved.

[0167] Further, Figure 11 The modification of the second embodiment shown can also be applied to the current measuring device 100, 101 of the first embodiment. Even in this case, the outer diameter of the transmission line 360B can be reduced.

[0168] This application claims priority based on Japanese Patent Application No. 2020-109004 filed on June 24, 2020, in the Japan Patent Office and this application claims priority based on Japanese Patent Application No. 2021-080639 filed on May 11, 2021, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0169] Explanation of Reference Numerals

[0170] 100, 101 current measuring device

[0171] 200 current sensor

[0172] 300 to 302 current measuring device (current measuring member)

[0173] 300A housing

[0174] 310, 320 side portion (first side portion, second side portion)

[0175] 311, 321 inner surface

[0176] 312, 322 outer surface

[0177] 313, 323 hole portion

[0178] 330 mounting portion

[0179] 340, 350 coaxial connector (coaxial member)

[0180] 341, 351 pin (internal conductor)

[0181] 342, 352, 452 body portion (external conductor)

[0182] 361 connection portion

[0183] 362 barrel

[0184] 363A dielectric

[0185] 364, 364A gap

[0186] 411 first electrode body (inner conductor)

[0187] 411A first electrode (first electrode body)

[0188] 411B pin (first electrode body)

[0189] 413 second electrode body (outer conductor)

[0190] 450 terminator (coaxial component)

Claims

1. A current measuring component comprising: a pair of side portions separated from each other and arranged in opposition to each other; a bridge portion bridged to the pair of side portions to form a space between the pair of side portions; a pair of coaxial components respectively fitted to the pair of side portions and each having an inner conductor passing through a hole portion formed in the corresponding side portion; a connection portion electrically connecting the inner conductors of the pair of coaxial components to each other; and a cylindrical portion surrounding an outer periphery of the connection portion with a gap formed in the outer periphery of the connection portion, wherein the pair of side portions and the bridge portion are electrically conductive to electrically connect outer conductors of the pair of coaxial components to each other, wherein a base end portion of the cylindrical portion is electrically connected to a first side portion and a top end portion of the cylindrical portion is electrically separated from the outer conductor of the coaxial component fitted to a second side portion, wherein the current measuring component further comprises a space for arranging a current sensor required to detect a current flowing through the connection portion in a state of surrounding the cylindrical portion formed between the pair of side portions by the bridge portion, and wherein the cylindrical portion is electrically conductive.

2. The current measuring component according to claim 1, wherein a structure of the cylindrical portion and the connection portion has a same characteristic impedance as the coaxial components.

3. The current measuring component according to claim 1 or 2, wherein the pair of side portions and the bridge portion are conductors.

4. The current measuring component according to claim 1, wherein the gap provided at the top end of the cylindrical portion is narrower than a width of the current sensor arranged between the pair of side portions.

5. The current measuring component according to claim 1, wherein the cylindrical portion extends from an inner surface of the first side portion to be separated from the second side portion with the gap.

6. The current measuring component according to claim 1, wherein a dielectric having a dielectric constant smaller than air is provided between the connection portion and the cylindrical portion.

7. The current measuring component according to claim 1, wherein the coaxial components are coaxial connectors.

8. The current measuring component according to claim 1, wherein one of the pair of coaxial components is a coaxial connector and the other is a terminator, wherein the inner conductor of the other coaxial component is a first electrode body of the terminator, and wherein the outer conductor of the other coaxial component is a second electrode body of the terminator.

9. A current measuring device comprising: the current measuring component according to any one of claims 1 to 8; and a current sensor arranged in the space formed between the pair of side portions by the bridge portion to detect a current flowing through the connection portion in a state of surrounding the cylindrical portion.

10. A current measuring method for measuring a current flowing through a coaxial component by using a current measuring component comprising: a pair of side portions separated from each other and arranged in opposition to each other; a bridge portion bridged to the pair of side portions to form a space between the pair of side portions; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A pair of coaxial members respectively fitted to the pair of side portions, each having an inner conductor that penetrates a hole portion formed in the corresponding side portion; a connecting portion that electrically connects the inner conductors of the pair of coaxial members to each other; and a cylindrical portion that surrounds an outer peripheral portion of the connecting portion in a state in which a gap is formed in the outer peripheral portion of the connecting portion, In the current measuring member, the outer conductors of the pair of coaxial members are electrically connected to each other using the pair of side portions and the bridge portion, the base end portion of the cylindrical portion is electrically connected to the first side portion and the top end portion of the cylindrical portion is electrically separated from the outer conductor of the coaxial member of the second side portion, and the current measuring member further includes a space for arranging a current sensor required for detecting a current flowing through the connection portion in a state of surrounding the cylindrical portion, the cylindrical portion having electrical conductivity, wherein The current measurement method includes: a step of arranging a current sensor in the space in a state in which the cylindrical portion is surrounded by the current sensor; and a step of detecting, by the current sensor, a current flowing through the connecting portion.

11. The current measurement method according to claim 10, wherein the coaxial members are coaxial connectors.

12. The current measurement method according to claim 10, wherein one of the pair of coaxial members is a coaxial connector, and the other coaxial member is a terminator, the inner conductor of the other coaxial member is a first electrode body of the terminator, the outer conductor of the other coaxial member is a second electrode body of the terminator.

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