5 [mu] H linear impedance stabilization network for providing accurate input impedance

Abstract

The utility model discloses a 5 [mu] H linear impedance stabilization network providing accurate input impedance, comprising a metal housing, one side of the metal housing is provided with an input terminal and a grounding terminal, and the other side of the metal housing is provided with an output terminal, a grounding terminal and a BNC connector signal terminal. A blocking capacitor C1, a blocking capacitor C2, a blocking capacitor C3, an isolation inductor L, a matching resistor R1, a matching resistor R2, a matching resistor R3, a matching resistor R4 and a matching resistor R5 are arranged in the metal housing. One side provided with the BNC connector signal terminal is used for connecting to-be-tested equipment and is defined as a load side; and the other side is connected with a power grid and is defined as a power supply side. The utility model can work in a high-voltage and severe power supply environment, and provides ideal power supply impedance.

Description

Technical Field

[0001] The utility model relates to an electromagnetic compatibility test device, which is used in electromagnetic compatibility tests to provide a specified stable power impedance to a device under test within the radio frequency range and isolate the device under test from high-frequency interference on the power grid, belonging to the field of information security technology. Background Art

[0002] Due to various factors affecting the power grid, its line impedance is unstable. However, impedance is very important in electromagnetic compatibility tests, especially in the measurement of conducted interference. In order to have a unified test condition in the measurement of conducted emission voltage using the voltage method, a stable line impedance is artificially simulated.

[0003] In addition, the power supply to the device under test must be pure. Otherwise, the power grid will inject interference into the device under test, and the device under test will also feed interference into the power grid, making it unclear on the measurement receiver which interferences are from the device under test. Therefore, only by isolating the two can the measurement result be valid.

[0004] A linear impedance stabilization network is a network added between the power grid and the device under test in the conducted interference emission test to objectively assess the interference of the device under test. The network has the following functions:

[0005] (1) Provide a specified stable line impedance within a specified frequency range;

[0006] (2) Isolate between the power grid and the device under test;

[0007] (3) Use the high-pass filter of the linear impedance stabilization network to couple the interference signal generated by the device under test to the measurement receiver and prevent the power grid voltage from being applied to the measurement receiver. Content of the Utility Model

[0008] The purpose of the utility model is to provide a linear impedance stabilization network that can effectively isolate high-frequency interference from the power grid and provide a specified stable line impedance within a specified frequency range.

[0009] To solve the above technical problems, the utility model provides a 5μH linear impedance stabilization network that provides accurate input impedance, including a metal housing. One side of the metal housing is the load side, and the other side is the power supply side. A current-carrying screw and a grounding screw are provided on both the load side and the power supply side of the metal housing. The current-carrying screw on the power supply side of the metal housing is the input terminal, and the current-carrying screw on the load side of the metal housing is the output terminal. Both grounding screws are grounding terminals. An insulating terminal is provided between the current-carrying screw and the metal housing. A BNC connector is also provided on the load side of the metal housing, and the BNC connector is the signal terminal.

[0010] Inside the metal housing, there are a matching resistor R1, a matching resistor R2, a matching resistor R3, a matching resistor R4, a matching resistor R5, a DC-blocking capacitor C1, a DC-blocking capacitor C2, a DC-blocking capacitor C3, and an isolation inductor L.

[0011] The DC-blocking capacitor C1 is close to the power supply side of the metal housing. One end of the DC-blocking capacitor C1 is fastened to the current-carrying screw located on the power supply side of the metal housing, and the other end of the DC-blocking capacitor C1 is connected to the grounding screw located on the power supply side of the metal housing.

[0012] The matching resistor R1 and the DC-blocking capacitor C2 are close to the power supply side of the metal housing. One end of the DC-blocking capacitor C2 is fastened to the current-carrying screw located on the power supply side of the metal housing, one end of the matching resistor R1 is connected to the grounding screw located on the power supply side of the metal housing, and the other end of the DC-blocking capacitor C2 is connected to the other end of the matching resistor R1.

[0013] The matching resistor R5 and the DC-blocking capacitor C3 are close to the load side of the metal housing. One end of the matching resistor R5 and one end of the DC-blocking capacitor C3 are respectively connected and fixed to the signal terminal of the BNC connector; the other end of the DC-blocking capacitor C3 is fastened to the current-carrying screw located on the load side of the metal housing, and the other end of the matching resistor R5 is connected to the grounding screw located on the load side of the metal housing.

[0014] The wire ends on both sides of the isolation inductor L are respectively connected to the current-carrying screws on the power supply side and the load side of the metal housing; the matching resistor R2, the matching resistor R3, and the matching resistor R4 are all connected in parallel to the isolation inductor L.

[0015] Preferably, the current-carrying screw is a double-headed bolt. After the current-carrying screw passes through the insulating terminal and the metal housing in sequence, it is fixed by a fastener 1.

[0016] Preferably, one end of each of the two grounding screws extends into the metal housing. The two grounding screws are connected by a metal grounding plate inside the metal housing and fixed by a fastener 2.

[0017] Preferably, the isolation inductor L includes a hollow spring coil and a coil skeleton. The coil skeleton is detachably arranged on the inner wall of the metal housing, and the hollow spring coil is wound around the coil skeleton.

[0018] Furthermore, the structure of the coil skeleton is a hollow cylinder, and a threaded hole for connecting and fixing with the metal housing is provided on one side of the coil skeleton.

[0019] Even further, threaded notches are equidistantly arranged on the outer surface of the cylinder of the coil skeleton, and the hollow spring coil is evenly distributed on the coil skeleton through the threaded notches.

[0020] Preferably, two explosion-proof aluminum shell capacitors are selected and connected in series for the DC-blocking capacitor C2; two gold aluminum shell resistors with heat sinks are selected and connected in parallel for the matching resistor R1; the DC-blocking capacitors C1 and C3 are both composed of multiple capacitors connected in series and parallel; the matching resistor R5 is composed of multiple resistors connected in series and parallel.

[0021] Preferably, the inductance of the isolation inductor L is stable at 5 μH within the frequency range of 10 kHz - 400 MHz; the DC-blocking capacitor C1 is 0.22 μF; the DC-blocking capacitor C2 is 4 μF; the DC-blocking capacitor C3 is 0.1 μF; the matching resistor R1 is 5 Ω; the matching resistor R5 is 1 kΩ.

[0022] The 5 μH linear impedance stabilization network for providing accurate input impedance provided by the present utility model has the following advantages:

[0023] The inductance of the coil in the linear impedance stabilization network is small, only 5 μH, which can meet the design requirements of large current passing; at the same time, the resistors and capacitors in the linear impedance stabilization network can all be composed of series and parallel structures, and can work under high voltage and harsh power supply environments, and provide an ideal power impedance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the circuit structure diagram of the linear impedance stabilization network of the present utility model;

[0025] Figure 2 is the front view of the linear impedance stabilization network of the present utility model;

[0026] Figure 3 is the internal structure diagram of the linear impedance stabilization network of the present utility model;

[0027] Figure 4 is the side view of the load side of the linear impedance stabilization network of the present utility model;

[0028] Figure 5 is the cross-sectional schematic diagram mainly showing the overall structure of the coil skeleton of the present utility model;

[0029] Figure 6 is the schematic diagram of the ground plate structure of the present utility model;

[0030] In the figure:

[0031] 1 - metal cover; 2 - current-carrying screw; 3 - grounding screw; 4 - insulating terminal; 41 - inner insulator; 42 - outer insulator; 5 - fastener one; 6 - BNC connector; 7 - hollow spring coil; 8 - coil skeleton; 81 - threaded notch; 9 - metal partition; 10 - gold aluminum shell resistor; 11 - capacitor bracket; 12 - aluminum shell capacitor; 13 - ground plate; 14 - fastener two. Detailed implementation mode

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present utility model.

[0033] Refer to Figures 1 - 4 , a 5μH linear impedance stabilization network that provides precise input impedance, including a metal housing 1 made of an aluminum plate. One side of the metal housing 1 is the load side, and the other side is the power supply side. A current-carrying screw 2 and a grounding screw 3 are provided on both the load side and the power supply side of the metal housing 1. The current-carrying screw 2 is a brass rod M8 double-headed bolt that meets the 100A current-carrying capacity. An insulating terminal 4 is installed between the current-carrying screw 2 and the metal housing 1. The installation order of the current-carrying screw 2 from inside to outside is the double-headed bolt head, the inner insulator 41, the metal housing 1, and the outer insulator 42, and it is fixed by a fastener 5. The current-carrying screw 2 on the power supply side of the metal housing 1 is the input terminal, and the current-carrying screw 2 on the load side of the metal housing 1 is the output terminal. Both grounding screws 3 are grounding terminals; a BNC connector 6 is also installed on the load side of the metal housing 1, and the BNC connector 6 is a signal terminal.

[0034] Refer to Figures 1 - 6 , an isolation inductor L is installed in the inner cavity of the load side of the metal housing 1. The isolation inductor L is composed of a hollow spring coil 7 and a coil skeleton 8. The coil skeleton 8 is made of a polysulfone rod with an inner diameter of 48mm and an outer diameter of 58mm. Threaded notches 81 are equidistantly opened on the outer surface of the cylinder of the coil skeleton 8. The hollow spring coil 7 is wound with a 4mm diameter copper wire. The hollow spring coil 7 is evenly distributed on the coil skeleton 8 through the threaded notches 81, with a pitch of 8mm and a total of 16 turns, and the inductance is 5μH; a threaded hole is provided on one side of the coil skeleton 8, which is matched with the installation hole of the metal housing 1 and is fixedly connected by a fastener.

[0035] Mount the matching resistors R2, R3, and R4 on the isolation inductor L; the matching resistor R2 is a 100Ω lead resistor, the matching resistor R3 is a 100Ω lead resistor, and the matching resistor R4 is a 2kΩ lead resistor. One end of the matching resistor R4 is connected in series with one end of the matching resistor R3. The other end of the matching resistor R4 is connected to the wire head of the hollow spring coil 7 close to the load side. The series connection end is connected to the position of the fourth turn counted from the load side. The other end of the matching resistor R3 is connected to the position of the eighth turn of the hollow spring coil 7 counted from the load side; one end of the matching resistor R2 is connected to the wire head of the hollow spring coil 7 close to the power supply side, and the other end is connected to the position of the fifth turn of the hollow spring coil 7 counted from the power supply side.

[0036] A matching resistor R1 is installed inside the metal housing 1. In this embodiment, the matching resistor R1 is composed of two 10Ω RX24 gold aluminum shell resistors 10 in parallel. Each RX24 gold aluminum shell resistor 10 is installed on the metal partition 9, and then the metal partition 9 is installed on the metal housing 1. The purpose of using the metal partition 9 and the two RX24 gold aluminum shell resistors 10 for separate installation is to ensure good heat dissipation and ensure the long-term safe and reliable operation of the linear impedance stable network.

[0037] A DC blocking capacitor C2 is installed inside the metal housing 1; the DC blocking capacitor C2 is composed of two 8 μF CBB65 type aluminum shell capacitors 12 in series; the two 8 μF CBB65 type aluminum shell capacitors 12 are installed on the capacitor bracket 11, and then the capacitor bracket 11 is installed on the bottom plate of the metal housing 1 and fixed with fasteners.

[0038] A DC blocking capacitor C3 and a matching resistor R5 are also installed inside the metal housing 11; the DC blocking capacitor C3 is composed of two 0.22 μF safety film capacitors in series, and the matching resistor R5 is composed of eight 2kΩ lead resistors in series in pairs and then in parallel. One end of the two 0.22 μF safety film capacitors in series is connected to the load side current-carrying screw 2, and the other side is connected to the signal terminal of the BNC connector 6; one end of the eight 2kΩ lead resistors in series and parallel is connected to the signal terminal of the BNC connector 6, and the other end is connected to the metal housing 1.

[0039] A DC blocking capacitor C1 is also installed inside the metal housing 1. The DC blocking capacitor C1 is composed of two 0.47 μF safety film capacitors in series. One end of the two 0.47 μF safety film capacitors in series is connected to the power supply side current-carrying screw 2, and the other end is connected to the metal housing 1.

[0040] A metal grounding plate 13 is installed inside the metal housing 1. Both ends of the grounding plate 13 are connected to the grounding screws 3 on the load side and the power supply side and fixed with fasteners two 14.

[0041] The linear impedance stabilization network provided by the present utility model can effectively isolate the interference from the power grid. In the frequency range of 10 kHz - 400 MHz, the measured impedance value of the example of the present utility model meets the impedance value requirements specified in the international standard RTCA / DO - 160G, and can withstand long - term normal operation in the environment of 1000 VDC / 440 VAC rated voltage and 100 A current.

[0042] The above - mentioned is only the preferred embodiment of the present utility model, and it does not impose any formal or substantial limitations on the present utility model. It should be pointed out that for those of ordinary skill in the technical field, without departing from the premise of the present utility model, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present utility model. For those skilled in the art, without departing from the spirit and scope of the present utility model, any equivalent changes made by using the technical content disclosed above through slight modifications, decorations, and evolutions are all equivalent embodiments of the present utility model; at the same time, any equivalent changes made to the above - mentioned embodiments based on the substantial technology of the present utility model through modifications, decorations, and evolutions still fall within the scope of the technical solution of the present utility model.

Claims

1. A 5μH linear impedance stabilization network providing precise input impedance, characterized in that, It includes a metal housing. One side of the metal housing is the load side, and the other side is the power supply side. There is a current-carrying screw and a grounding screw on both the load side and the power supply side of the metal housing. The current-carrying screw on the power supply side of the metal housing is the input terminal, and the current-carrying screw on the load side of the metal housing is the output terminal. Both of the two grounding screws are grounding terminals. There is an insulating terminal between the current-carrying screw and the metal housing. There is also a BNC connector on the load side of the metal housing, and the BNC connector is the signal terminal. There are a matching resistor R1, a matching resistor R2, a matching resistor R3, a matching resistor R4, a matching resistor R5, a DC-blocking capacitor C1, a DC-blocking capacitor C2, a DC-blocking capacitor C3, and an isolation inductor L inside the metal housing. The DC-blocking capacitor C1 is close to the power supply side of the metal housing. One end of the DC-blocking capacitor C1 is fastened to the current-carrying screw on the power supply side of the metal housing, and the other end of the DC-blocking capacitor C1 is connected to the grounding screw on the power supply side of the metal housing. The matching resistor R1 and the DC-blocking capacitor C2 are close to the power supply side of the metal housing. One end of the DC-blocking capacitor C2 is fastened to the current-carrying screw on the power supply side of the metal housing. One end of the matching resistor R1 is connected to the grounding screw on the power supply side of the metal housing, and the other end of the DC-blocking capacitor C2 is connected to the other end of the matching resistor R1. The matching resistor R5 and the DC-blocking capacitor C3 are close to the load side of the metal housing. One end of the matching resistor R5 and one end of the DC-blocking capacitor C3 are respectively connected and fixed to the signal terminal of the BNC connector. The other end of the DC-blocking capacitor C3 is fastened to the current-carrying screw on the load side of the metal housing, and the other end of the matching resistor R5 is connected to the grounding screw on the load side of the metal housing. The wire ends on both sides of the isolation inductor L are respectively connected to the current-carrying screws on the power supply side and the load side of the metal housing. The matching resistor R2, the matching resistor R3, and the matching resistor R4 are all connected in parallel to the isolation inductor L.

2. The 5μH linear impedance stabilization network for providing precise input impedance according to claim 1, wherein The current-carrying screw is a double-headed bolt. After the current-carrying screw passes through the insulating terminal and the metal housing in sequence, it is fixed by a fastener one.

3. A 5μH linear impedance stabilization network for providing precise input impedance as claimed in claim 1, wherein One end of each of the two grounding screws extends into the metal housing. The two grounding screws are connected by a metal grounding plate inside the metal housing and fixed by a fastener two.

4. A 5μH linear impedance stabilization network providing precise input impedance as claimed in claim 1, wherein, The isolation inductor L includes a hollow spring coil and a coil skeleton. The coil skeleton is detachably arranged on the inner wall of the metal housing, and the hollow spring coil is wound around the coil skeleton.

5. The 5μH linear impedance stabilization network for providing precise input impedance according to claim 4, wherein The structure of the coil skeleton is a hollow cylinder, and there is a threaded hole for connecting and fixing to the metal housing on one side of the coil skeleton.

6. The 5μH linear impedance stabilization network for providing precise input impedance as claimed in claim 5, wherein Threaded notches are equidistantly arranged on the outer surface of the cylinder of the coil skeleton, and the hollow spring coil is evenly distributed on the coil skeleton through the threaded notches.

7. A 5μH linear impedance stabilization network for providing precise input impedance as claimed in claim 1, wherein, Two explosion-proof aluminum shell capacitors are selected in series for the DC-blocking capacitor C2. Two gold aluminum shell resistors with heat sinks are selected in parallel for the matching resistor R1. The DC-blocking capacitor C1 and the DC-blocking capacitor C3 are both composed of multiple capacitors connected in series and parallel. The matching resistor R5 is composed of multiple resistors connected in series and parallel.

8. A 5μH linear impedance stabilization network for providing precise input impedance as claimed in claim 1, characterized in that, The inductance of the isolation inductor L is stable at 5 μH within the frequency range of 10 kHz - 400 MHz; the DC-blocking capacitor C1 is 0.22 μF; the DC-blocking capacitor C2 is 4 μF; the DC-blocking capacitor C3 is 0.1 μF; the matching resistor R1 is 5 Ω; the matching resistor R5 is 1 kΩ.

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