Novel inductor coil and circuit

Abstract

This invention discloses a novel inductor coil and circuit. The novel inductor coil includes at least one pair of inductor units. Each pair of inductor units consists of a first inductor and a second inductor with identical structures. The first inductor is connected in series at one end of the load, and the second inductor is connected in series at the other end of the load. The center-to-center distance between the first and second inductors is D, where D ≥ 0. The first and second inductors are symmetrically distributed along the centerline of D / 2. Both the first and second inductors are frameless arc-shaped hollow coils with an arc θ satisfying 0 < θ ≤ π and curvature k2 ≥ 0; when θ = π, D > 0. The inductor provided by this invention does not form a common-mode inductor, which can effectively reduce electromagnetic interference and external electromagnetic radiation. It can also be used on the main power path, and its heat dissipation performance is improved, with flexible adjustment of inductor parameters.

Description

Technical Field

[0001] This utility model relates to the field of electrical component technology. More specifically, this utility model relates to a novel inductor coil and circuit. Background Technology

[0002] There are many types of inductors. In high-frequency, high-current circuits, magnetic core inductors and air-core inductors are commonly used. Both types have certain drawbacks. Magnetic core inductors consist of wire wound around a magnetic core, which leads to several disadvantages. First, core losses: these mainly originate from hysteresis loss and eddy current loss. Hysteresis loss refers to the energy loss caused by domain flipping under an alternating magnetic field, while eddy current loss refers to the eddy currents induced inside the core by the alternating magnetic field, resulting in ohmic losses (heat generation). Second, limited self-resonant frequency: the presence of the core increases the inter-turn capacitance of the coil (the dielectric constant of the core material is usually higher than that of air), resulting in a typically lower self-resonant frequency. This means a lower upper limit to its effective operating frequency range. When approaching or exceeding the SRF (Self-Resonant Frequency), the inductor exhibits capacitive behavior and completely fails. Third, magnetic saturation risk: when the peak current flowing through the inductor is too large, the magnetic flux density of the core will reach the saturation point. Once saturated, the permeability drops sharply. Fourth, the permeability and loss characteristics of the core material are sensitive to temperature, affecting current stability. Fifth, high-performance core materials are expensive. On the other hand, while ordinary air-core inductors have advantages such as no core loss, no magnetic saturation, and high self-resonant frequency due to the absence of an internal magnetic core, they also have some significant drawbacks. First, without a core to constrain the magnetic field, the magnetic lines of force generated by an ordinary air-core inductor diffuse into a large surrounding space, making it susceptible to interference from external magnetic fields generated by nearby components or traces, leading to unstable inductance parameters. Simultaneously, its magnetic field can leak out, potentially interfering with nearby sensitive circuits and causing crosstalk or EMI problems. Second, the copper losses concentrate heat, easily causing inductor overheating and saturation. Third, they do not effectively filter common-mode noise in circuits. Fourth, they cannot reduce differential-mode signal phase imbalance and cannot improve the CMRR (common-mode rejection ratio) of differential circuits. In the prior art, a published invention patent for an X-ray high-voltage generator (application number 202510757502.7) mentions a toroidal hollow inductor. First, because this type of inductor forms a common-mode inductor, the magnetic fields cancel each other out, and the effective inductance comes only from the leakage inductance, resulting in an extremely small effective inductance. To achieve the required inductance parameters in the circuit, a very large volume is required. Even if the large volume meets the inductance parameter requirements, the accuracy of the inductance parameters is difficult to achieve. Second, the toroidal hollow frame and the insulating components inside the inductor result in extremely poor heat dissipation. When the temperature increases, the inductance parameters become unstable, and the inductor is also prone to overheating and saturation. Furthermore, the dielectric constant of the hollow frame and the internal filling medium is greater than that of air (air ≈ 1), resulting in a relatively large distributed capacitance of the inductor, which affects the high-frequency performance of the inductor. Utility Model Content

[0003] One object of this invention is to solve at least the problems described above and to provide at least the advantages that will be explained later.

[0004] Another objective of this invention is to provide a novel inductor coil to address the problems of magnetic loss, magnetic saturation risk, circuit magnetic field interference, unstable inductor parameters, and poor heat dissipation of existing inductors in high-frequency, high-current scenarios.

[0005] To achieve these objectives and other advantages according to the present invention, a novel inductor coil is provided, comprising at least one pair of inductor units, each pair of inductor units consisting of a first inductor and a second inductor with identical structures. The first inductor is connected in series at one end of the load, and the second inductor is connected in series at the other end of the load. The center-to-center distance between the first inductor and the second inductor is D, where D ≥ 0, and the first inductor and the second inductor are symmetrically distributed along the centerline of D / 2. Both the first inductor and the second inductor are frameless arc-shaped hollow coils with an arcuate radius θ satisfying 0 < θ ≤ π and a curvature k2 ≥ 0; when θ = π, D > 0.

[0006] Preferably, the arc-shaped hollow coil is formed by tightly winding multiple strands of wire or a single metal tube in a single layer, with the inner and outer surfaces of the coil directly exposed to the air environment.

[0007] Preferably, the first inductor and the second inductor are fixed together to form a compact structure using high-temperature resistant insulating and thermally conductive adhesive.

[0008] Preferably, the inductor unit is mounted on a dynamic adjustment plate, and the distance D between the two inductors is adjusted in real time by mechanical power to dynamically match the electrical parameters of the circuit.

[0009] Preferably, the dynamic adjustment plate includes: Base plate; A pair of carrier substrates are movably connected to the base plate, which can be relatively close to or far apart from each other, and the first inductor and the second inductor are respectively disposed on the pair of carrier substrates; An electric drive mechanism, connected to a pair of carrier substrates, is used to adjust the distance D between the pair of carrier substrates in real time.

[0010] Preferably, the electric drive mechanism includes a micro motor, a bidirectional lead screw, and a movable block; The supporting substrate is symmetrical along the central axis parallel to the long side on the base plate; A lead screw mounting hole is provided along the central axis parallel to the wide side of the base plate. A bidirectional lead screw is rotatably connected in the lead screw mounting hole. A micro motor connected to the bidirectional lead screw is provided on the side of the base plate. The top surface of the base plate has two shaped holes along the central axis parallel to the wide side. The two shaped holes are connected to the screw mounting hole, and the two shaped holes are respectively facing the parts of the bidirectional screw with different directions of rotation. A movable block is provided at the bottom center of the support substrate, and a screw hole matching the bidirectional lead screw is provided on the movable block. The movable blocks on a pair of support substrates pass through two shaped holes and are threaded to different helical parts of the bidirectional lead screw. The top surface of the base plate has a strip groove parallel to the strip hole on both sides of each strip hole. The inner wall of the strip groove is coated with a conductive material. The bottom surface of the support substrate is provided with a contact that is slidably connected in the strip groove. The ends of the first inductor and / or the second inductor are connected to the contact on the support substrate. The side or bottom surface of the base plate is provided with terminals that connect to the conductive material in the strip groove.

[0011] Preferably, the inductor coil operates in a high-frequency, high-current circuit with a frequency greater than 100kHz and a current greater than 10A, and is used as a power inductor or a resonant inductor.

[0012] Preferably, the first inductor and the second inductor are fixed to the PCB board by soldering terminals or directly connected to the main power path of the circuit by wires.

[0013] This utility model also provides a circuit in which the above-mentioned novel inductor coil is provided.

[0014] This invention offers at least the following advantages: the inductor provided by this invention does not form a common-mode inductor and can be used on the main power path; heat dissipation performance is improved, avoiding inductance instability caused by temperature rise; the inductance can be flexibly adjusted by changing the D value, curvature k2, and radian θ of the two sub-inductors; the dielectric constant of air (air ≈ 1) is smaller than that of the hollow frame and internal filling medium, resulting in a relatively smaller distributed capacitance of the inductor and improved high-frequency performance.

[0015] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the novel inductor coil of this utility model connected to both ends of the load; Figure 2 This is a schematic diagram of the structure of the novel inductor coil described in this utility model; Figure 3 This is a schematic diagram of the structure of the novel inductor coil described in this utility model when k2=0; Figure 4This is a top view of the dynamic adjustment plate described in this utility model; Figure 5 This is a schematic diagram of the internal structure of the dynamic adjustment plate described in this utility model; Figure 6 This is a schematic diagram of the structure of the carrier substrate described in this utility model. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0018] It should be noted that in the description of this utility model, the terms "horizontal", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] like Figure 1 As shown, this utility model provides a novel inductor coil, including at least one pair of inductor units. Each pair of inductor units consists of a first inductor 1 (L1) and a second inductor 2 (L2) with identical structures. The first inductor 1 is connected in series with the load (Z). load One end of the load is connected in series with the second inductor 2 at the other end, as shown in the diagram (Z). load This represents the equivalent total impedance of the resistor, inductor, and capacitor in the circuit. The inductor parameters can be changed by altering the number of inductor pairs (n≥1) in the circuit, while the effect of temperature on the stability of the inductor parameters can be reduced by distributing heat.

[0020] like Figure 2 As shown, the first and second inductors 2 are identical, with a center-to-center distance of D (D≥0). They are symmetrical along the center line of D / 2. The distance D determines the mutual inductance M, which in turn affects the effective inductance. The principle is as follows: Whether the effective inductance of inductors arranged in parallel with opposite currents will change due to the cancellation of magnetic fields depends on the degree of coupling between the two inductors. 1. Uncoupled case: If the two inductors are far enough apart (mutual inductance M≈0), the effective inductance L eff =L1+L2 (Magnetic fields do not affect each other, and there is no cancellation effect); 2. When coupling exists: When there is a certain distance D between the two inductors, the mutual inductance M > 0, and the effective inductance L eff =L1+L2-2M (Magnetic field partially cancels out); 3. In fully coupled mode: the differential mode of the common-mode inductor is formed, the magnetic fields are completely canceled, and the effective inductance L eff =0.

[0021] Therefore, the degree of coupling (coupling coefficient k1) determines the mutual inductance, and the mutual inductance M = The inductor spacing D is a factor that affects the value of the coupling coefficient k1.

[0022] In high-frequency, high-current circuits, radiation is a serious problem. Some inductors on the market reduce radiation by adding shielding, but this approach leads to poor heat dissipation. Therefore, the inductor of this invention, due to the coupling between paired inductors, partially cancels out their magnetic fields, reducing far-field radiation and preventing magnetic field lines from spreading into a large surrounding space. The inductor itself is less susceptible to interference from external magnetic fields generated by nearby components or traces, thus preventing inductor parameter instability. Simultaneously, its low magnetic field leakage reduces interference to nearby sensitive circuits, avoiding crosstalk or EMI problems.

[0023] Furthermore, both the first inductor 1 and the second inductor 2 are frameless arc-shaped hollow coils with an arcuate radius θ satisfying 0 < θ ≤ π and curvature k2 ≥ 0; when θ = π, D > 0.

[0024] For example, L2 and L1 inductors can be stranded wires made of multiple strands of wire or a single metal tube, forming an arc-shaped hollow inductor through a single-layer tight flat winding method. This winding method can reduce the distributed capacitance of the inductor, and the hollow structure is conducive to heat dissipation on the inside and outside of the inductor.

[0025] The surface of the stranded wire / metal tube is coated with high-temperature resistant insulating and thermally conductive adhesive, which makes the inductor structure firm and compact, stable, and provides good heat dissipation.

[0026] The curvature k2 and radian θ of this arc-shaped inductor are also factors affecting the coupling coefficient k1 of the new inductor. The smaller the curvature k2, the smoother the arc; the larger the curvature k2, the more curved the arc; when the curvature k2 is zero, the arc no longer has any curvature but is a straight line (as shown in the image). Figure 3 As shown in the diagram, the inductive coupling coefficient of a straight inductor will be minimized from the perspective of curvature and arc. Furthermore, considering the arc's arc radius, when the radius is π, the arc forms a semicircle. If the center-to-center distance D between the first and second inductors is 0 at this point, a common-mode inductor is formed. To avoid this situation, D cannot be 0.

[0027] In high-frequency, high-current circuits, the heat from an inductor is often difficult to dissipate, which affects the stability of the inductor parameters. The inductor provided by this invention has no frame at the center of the coil. If a cooling system, such as an air-cooling system, is added, air can flow through the center and the outside of the coil simultaneously, quickly carrying away the heat.

[0028] The high-frequency, high-current circuit described herein specifically refers to a circuit with a frequency greater than 100kHz and a current greater than 10A. The novel inductor coil can be used as a power inductor or a resonant inductor. Specifically, the first inductor 1 and the second inductor 2 can be fixed to the PCB board by soldering terminals or directly connected to the main power path of the circuit by wires.

[0029] In another embodiment, the two sub-inductors can be independently mounted on a dynamic adjustment plate, and the spacing D can be adjusted by power to dynamically match the changes in power, voltage or current of the inductor matching circuit.

[0030] Specifically, such as Figures 4-6 As shown, the dynamic adjustment plate includes: Base plate 3; A pair of carrier substrates 4 are movably connected to the base plate 3, which can be relatively close to or far apart from each other. The first inductor 1 and the second inductor 2 are respectively disposed on the pair of carrier substrates 4. An electric drive mechanism is connected to a pair of carrier substrates 4 to adjust the spacing D between the pair of carrier substrates in real time.

[0031] The dynamic adjustment plate is a key mechanical structure for real-time adjustment of the inductor spacing D. This structure mainly consists of a base plate 3, a pair of support substrates 4, and an electric drive mechanism. The base plate 3 serves as the basic mounting platform for the entire device, providing support and positioning for other components. The pair of support substrates 4 are movably connected to the base plate 3 and can move relatively closer or further away from the base plate 3 according to commands. The first inductor 1 and the second inductor 2 are firmly mounted on these support substrates 4, therefore, the movement of the support substrates 4 directly drives the movement of the inductors mounted on them.

[0032] Furthermore, the electric drive mechanism includes a micro motor 5, a bidirectional lead screw 6, and a movable block 7; The supporting substrate 4 is symmetrical along the central axis parallel to the long side on the base plate 3; A lead screw mounting hole is provided along the central axis parallel to the wide side of the base plate 3. A bidirectional lead screw 6 is rotatably connected in the lead screw mounting hole. A micro motor 5 connected to the bidirectional lead screw 6 is provided on the side of the base plate 3. The top surface of the base plate 3 has two shaped holes along the central axis parallel to the wide side. The two shaped holes are connected to the screw mounting hole, and the two shaped holes are respectively facing the parts of the bidirectional screw 6 with different directions of rotation. A movable block 7 is provided at the bottom center of the support substrate 4. The movable block 7 is provided with a screw hole that matches the bidirectional lead screw 6. The movable blocks 7 on a pair of support substrates 4 pass through two shaped holes and are threaded to different helical parts of the bidirectional lead screw 6. The top surface of the base plate 3 has a strip groove parallel to the strip hole on both sides of each strip hole. The inner wall of the strip groove is coated with a conductive material. The bottom surface of the support substrate 4 is provided with a contact 8 that is slidably connected in the strip groove. The ends of the first inductor 1 and / or the second inductor 2 are connected to the contact 8 on the support substrate 4. The base plate 3 has terminals 9 on its side or bottom surface that are connected to the conductive material in the strip groove.

[0033] The arrangement of the supporting substrates 4 on the base plate 3 follows a strict symmetry principle, specifically, they are symmetrically distributed along the central axis of the long side of the base plate 3. This symmetry ensures the system's balance and the consistency of the inductor unit's spatial position during movement. The internal design of the base plate 3, as the core support structure, is crucial for its functional realization. A through-hole for mounting a lead screw is drilled inside the base plate 3 along its width direction (i.e., the direction perpendicular to the long side). This hole accommodates and supports the core transmission component—the bidirectional lead screw 6. The bidirectional lead screw 6 is mounted in this hole via rotating components such as bearings, ensuring its smooth rotation. A micro-motor 5 is fixedly mounted on one side of the base plate 3. The output shaft of the micro-motor 5 is reliably connected to the end of the bidirectional lead screw 6, providing it with rotational power.

[0034] To convert the rotational motion of the bidirectional lead screw 6 into the linear movement of the support plate 4, a corresponding interface structure is provided on the top surface of the base plate 3. On the top surface of the base plate 3, two elongated slots are precisely formed along its width-direction central axis. These two slots are perpendicularly connected to the lead screw mounting holes below. The key design point is that these two slots are precisely aligned with the threaded portions of the bidirectional lead screw 6 with opposite helical directions (i.e., one left-hand thread and one right-hand thread). The movement of the support plate 4 depends on the movable block 7 located at its bottom center. Each movable block 7 has an internally threaded hole machined at its center. The thread specification and direction of this hole must perfectly match the corresponding section (left-hand or right-hand) of the thread on the bidirectional lead screw 6. During installation, the movable blocks 7 at the bottom of the pair of support plates 4 pass downwards through the corresponding slots on the top surface of the base plate 3, and their screw holes are precisely screwed into the threaded portions of the bidirectional lead screw 6 with different helical directions (left-hand and right-hand). In this way, the movable blocks 7 of the two supporting base plates 4 are fixed on different helical sections of the lead screw.

[0035] On the top surface of the base plate 3, parallel slots are formed on both sides of each slot. These slots extend parallel to the slots, and their inner walls are specially treated and coated with a conductive material (such as conductive silver paint, electroplated metal layer, etc.) to form continuous conductive tracks. Conductive contact elements 8 (such as metal springs, conductive sliders, or brushes) are mounted on the bottom surface of each carrier substrate 4. These contacts 8 are designed to embed into the corresponding slots and maintain good and continuous sliding electrical contact with the conductive coating on their inner walls. The electrical leads of the first inductor 1 and / or the second inductor 2 are reliably electrically connected to these conductive contacts 8 on the bottom of their respective carrier substrates 4. To lead current to external circuits, electrical terminals 9 are mounted on the side or bottom surface of the base plate 3. These terminals 9 are connected via wires, internal printed circuits, or directly to the conductive coating within the slots. Therefore, no matter where the carrier substrate 4 is moved, the current path of the inductor coil is always: coil lead → bottom contact 8 of carrier substrate 4 → strip groove conductive coating → terminal 9 of base plate 3 → external circuit.

[0036] The entire structure operates in a mechatronic manner: the micro-motor 5 starts according to the control signal, driving the bidirectional lead screw 6 to rotate. Since the screw holes on the two movable blocks 7 engage with threads of different directions on the bidirectional lead screw 6, the rotation of the bidirectional lead screw 6 forces the two movable blocks 7 to move linearly along the axis of the lead screw. The movement of the movable blocks 7 directly drives the support substrate 4 to move synchronously in opposite directions or backwards on the plane of the base plate 3 through the connection at the bottom of the support substrate 4. This translational movement precisely and in real time changes the center distance D between the two support substrates 4, thereby adjusting the distance between the coils of the first inductor 1 and the second inductor 2 mounted on them. The conductive coating on the inner wall of the slot and the sliding contact 8 at the bottom of the support substrate 4 form a dynamic electrical connection system, providing a stable, low-resistance electrical path to the terminals 9 of the base plate 3 throughout the entire movement of the support substrate 4, eliminating the need for flexible wires that may become tangled or break. This design not only enables stepless, real-time, and symmetrical adjustment of the inductor spacing D, but also completely solves the reliability problem of dynamic electrical connection between moving parts and fixed circuits, ensuring the efficient and stable operation of the inductor unit in dynamic tuning applications.

[0037] This invention also provides a circuit in which the novel inductor described above is incorporated. Therefore, this circuit possesses the same advantages as the novel inductor described in the above embodiments.

[0038] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A novel inductor coil, characterized in that, It includes at least one pair of inductor units. Each pair of inductor units consists of a first inductor and a second inductor with the same structure. The first inductor is connected in series at one end of the load, and the second inductor is connected in series at the other end of the load. The center distance between the first inductor and the second inductor is D, where D≥0. The first inductor and the second inductor are symmetrically distributed along the center line of D / 2. The first inductor and the second inductor are both frameless arc-shaped hollow coils with an arc θ satisfying 0<θ≤π and curvature k2≥0. When θ=π, D>0.

2. The novel inductor coil as described in claim 1, characterized in that, The arc-shaped hollow coil is formed by tightly winding multiple strands of wire or a single metal tube in a single layer, with the inner and outer surfaces of the coil directly exposed to the air environment.

3. The novel inductor coil as described in claim 1, characterized in that, The first inductor and the second inductor are fixed together to form a compact structure using high-temperature resistant insulating and thermally conductive adhesive.

4. The novel inductor coil as described in claim 1, characterized in that, The inductor unit is mounted on a dynamic adjustment plate, and the distance D between the two inductors is adjusted in real time by mechanical power to dynamically match the electrical parameters of the circuit.

5. The novel inductor coil as described in claim 4, characterized in that, The dynamic adjustment plate includes: Base plate; A pair of carrier substrates are movably connected to the base plate, which can be relatively close to or far apart, and the first inductor and the second inductor are respectively disposed on the pair of carrier substrates; An electric drive mechanism, connected to a pair of carrier substrates, is used to adjust the distance D between the pair of carrier substrates in real time.

6. The novel inductor coil as described in claim 5, characterized in that, The electric drive mechanism includes a micro motor, a bidirectional lead screw, and a movable block; The supporting substrate is symmetrical along the central axis parallel to the long side on the base plate; A lead screw mounting hole is provided along the central axis parallel to the wide side of the base plate. A bidirectional lead screw is rotatably connected in the lead screw mounting hole. A micro motor connected to the bidirectional lead screw is provided on the side of the base plate. The top surface of the base plate has two shaped holes along the central axis parallel to the wide side. The two shaped holes are connected to the screw mounting hole, and the two shaped holes are respectively facing the parts of the bidirectional screw with different directions of rotation. A movable block is provided at the bottom center of the support substrate, and a screw hole matching the bidirectional lead screw is provided on the movable block. The movable blocks on a pair of support substrates pass through two shaped holes and are threaded to different helical parts of the bidirectional lead screw. The top surface of the base plate has a strip groove parallel to the strip hole on both sides of each strip hole. The inner wall of the strip groove is coated with a conductive material. The bottom surface of the support substrate is provided with a contact that is slidably connected in the strip groove. The ends of the first inductor and / or the second inductor are connected to the contact on the support substrate. The side or bottom surface of the base plate is provided with terminals that connect to the conductive material in the strip groove.

7. The novel inductor coil as described in claim 1, characterized in that, The inductor coil operates in a high-frequency, high-current circuit with a frequency greater than 100kHz and a current greater than 10A, and is used as a power inductor or a resonant inductor.

8. The novel inductor coil as described in claim 1, characterized in that, The first and second inductors are fixed to the PCB board by soldering terminals, or directly connected to the main power path of the circuit by wires.

9. A circuit, characterized in that, The circuit is provided with a novel inductor coil as described in any one of claims 1 to 8.

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