Filter inductor for audio amplifier circuit

Abstract

The utility model relates to filter inductance field, concretely relates to a kind of filter inductance applied to audio amplifier circuit, comprising: coil winding, it is flat coil structure, with first end electrode and second end electrode;And, first core and second core, first core and second core combination form have the chamber for easy coil winding;Coil winding is fixedly connected with the inner wall of the chamber by epoxy resin glue;First core is equipped with the column in the chamber, and coil winding is connected on this column;The front side of the chamber is equipped with the first opening for first end electrode and second end electrode to extend out.It is fixed by flat coil and double-core combination structure and epoxy resin, solves traditional inductance vibration noise, magnetic leakage and high temperature stability problem.

Description

Technical Field

[0001] This utility model relates to the field of filter inductors, specifically to a filter inductor used in audio amplifier circuits. Background Technology

[0002] As Class D audio amplifiers evolve towards higher frequencies (switching frequency ≥ 2.1MHz) and smaller sizes, filter inductors must meet three core performance indicators: high-frequency stability (inductance attenuation rate < 15% in the 2MHz band), low electromagnetic radiation (CISPR 25 Class 5 standard), and high power density (≥ 1.5W / cm³). In high-end applications such as automotive audio, traditional inductor designs can no longer overcome the contradiction between size limitations and performance requirements, necessitating structural innovation.

[0003] Existing inductors suffer from four major structural defects: insecure coil mounting leads to 120Hz mechanical noise under vehicle vibration; gaps in the core assembly cause magnetic leakage, resulting in EMC radiation exceeding the standard by 8dB; stress concentration at the leads causes breakage and failure at the PCB solder joints; and high-temperature adhesive layer failure (above 125℃) leads to inductance drift of up to 23%. These problems are particularly prominent in 5.4μH inductors (commonly used in Class D amplifier configurations), directly affecting audio signal fidelity (THD≥0.05%) and reliability. Utility Model Content

[0004] To address the aforementioned issues, a filter inductor for use in audio amplifier circuits is provided. This inductor solves the problems of vibration noise, magnetic leakage, and high-temperature stability associated with traditional inductors by using a combination structure of a flat coil and a dual iron core, fixed with epoxy resin.

[0005] To address the problems in the existing technology, this utility model provides a filter inductor for use in audio amplifier circuits, comprising: The coil winding has a flat coil structure and has a first end electrode and a second end electrode; and, The first iron core and the second iron core are combined to form a cavity for easy coil winding. The coil winding is fixedly connected to the inner wall of the chamber by epoxy resin adhesive; The first iron core has a central column located in the cavity, and the coil winding is wound on the central column; The front side of the chamber is provided with a first opening for the first end electrode and the second end electrode to extend out.

[0006] Preferably, the first end electrode extends from the first opening and bends downward to form a first pin, closely attached to the bottom wall of the chamber, and the extension end of the first end motor is fixedly connected to the bottom wall of the chamber by epoxy resin adhesive.

[0007] Preferably, the second end electrode extends from the first opening and bends downward to form a second pin, closely attached to the top wall of the chamber, and the extension end of the second end motor is fixedly connected to the top wall of the chamber by epoxy resin adhesive.

[0008] Preferably, the rear side of the chamber is provided with a second opening, and the coil winding is fixedly connected to the chamber near the second opening by epoxy resin adhesive.

[0009] Preferably, both the first iron core and the second iron core are formed by pressing iron powder, and the first iron core and the second iron core are combined and sintered at high temperature.

[0010] Preferably, the nominal inductance of the filter inductor is 5.4 μH, with an allowable deviation range of ±13%.

[0011] Preferably, the maximum DC resistance of the filter inductor is 0.6mΩ.

[0012] Preferably, the operating temperature range of the filter inductor is -40°C to 125°C.

[0013] Compared with the prior art, the advantages of this utility model are: by combining a flat coil with a double iron core, using epoxy resin for multi-point fixing and a double-opening magnetic circuit design, it solves the problems of vibration noise, electromagnetic leakage and high-temperature stability of traditional inductors, and achieves a comprehensive improvement in structural stability, electromagnetic compatibility and temperature adaptability. Attached Figure Description

[0014] Figure 1 This utility model relates to a three-dimensional filter inductor applied to an audio amplifier circuit. Figure 1 .

[0015] Figure 2 This utility model relates to a three-dimensional filter inductor applied to an audio amplifier circuit. Figure 2 .

[0016] Figure 3 This is a three-dimensional exploded view of a filter inductor used in an audio amplifier circuit according to this utility model.

[0017] Figure 4 This utility model relates to a filter inductor used in an audio amplifier circuit, which transparently displays the first and second iron cores in a three-dimensional manner. Figure 1 .

[0018] Figure 5 This utility model relates to a filter inductor used in an audio amplifier circuit, which transparently displays the first and second iron cores in a three-dimensional manner. Figure 2 .

[0019] The numbers in the diagram are as follows: 1. Coil winding; 11. First end electrode; 12. Second end electrode; 13. First pin; 14. Second pin; 2. First iron core; 21. Middle column; 3. Second iron core; 4. First opening; 5. Second opening; 6. Epoxy resin adhesive. Detailed Implementation

[0020] To further understand the features, technical means, and specific objectives and functions achieved by this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments.

[0021] Reference Figures 1-5 The aforementioned filter inductor for use in an audio amplifier circuit includes: a coil winding 1, which is a flat coil structure and has a first end electrode 11 and a second end electrode 12; and a first iron core 2 and a second iron core 3, which together form a cavity for facilitating the coil winding 1; the coil winding 1 is fixedly connected to the inner wall of the cavity by epoxy resin 6; the first iron core 2 has a central post 21 located in the cavity, and the coil winding 1 is wound around the central post 21; the front side of the cavity has a first opening 4 for the first end electrode 11 and the second end electrode 12 to extend out.

[0022] Reference Figure 1 As shown, the first end electrode 11 extends from the first opening 4 close to the bottom wall of the chamber and is bent downwards to form a first pin 13. The extension end of the first end motor is fixedly connected to the bottom wall of the chamber by epoxy resin adhesive 6. The second end electrode 12 extends from the first opening 4 close to the top wall of the chamber and is bent downwards to form a second pin 14. The extension end of the second end motor is fixedly connected to the top wall of the chamber by epoxy resin adhesive 6.

[0023] Reference Figure 2 As shown, a second opening 5 is provided on the rear side of the chamber, and the coil winding 1 is fixedly connected to the chamber near the second opening 5 by epoxy resin glue 6.

[0024] Reference Figure 1 and Figure 3 As shown, the first iron core 2 and the second iron core 3 are both formed by pressing iron powder, and the first iron core 2 and the second iron core 3 are combined and formed by high-temperature sintering.

[0025] The performance parameters of the filter inductor of this invention are as follows: Inductance (L): The nominal inductance is 5.4μH, with an allowable deviation range of ±13%, and a reference value of 5.35μH.

[0026] Load inductance (L Load): At a current of 120A, the minimum limit for inductance is 3.8μH, and the reference value is 3.99μH.

[0027] DC resistance (DCR): The maximum DC resistance is 0.6mΩ, and the reference value is 0.43mΩ.

[0028] Inductor turns (TURNS); 3.0 turns reference.

[0029] Operating temperature (Ope.Temp): The operating temperature range is -40℃ to 125℃. Under operating conditions, the product temperature (ambient temperature + temperature rise) should not exceed 125℃.

[0030] Product weight: 187.15g / PCS.

[0031] The above embodiments only illustrate one or more implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.

Claims

1. A filter inductor used in an audio amplifier circuit, characterized in that, include: The coil winding (1) has a flat coil structure and has a first end electrode (11) and a second end electrode (12). as well as, The first iron core (2) and the second iron core (3) are combined to form a cavity for easy coil winding (1); The coil winding (1) is fixedly connected to the inner wall of the chamber by epoxy resin glue (6); The first iron core (2) is provided with a central column (21) located in the cavity, and the coil winding (1) is wound on the central column (21); The front side of the chamber is provided with a first opening (4) for the first end electrode (11) and the second end electrode (12) to extend out.

2. The filter inductor applied to an audio amplifier circuit according to claim 1, characterized in that, The first end electrode (11) extends from the first opening (4) and bends downward to form the first pin (13) close to the bottom wall of the chamber. The extension end of the first end motor is fixedly connected to the bottom wall of the chamber by epoxy resin glue (6).

3. The filter inductor applied to an audio amplifier circuit according to claim 1, characterized in that, The second end electrode (12) extends from the first opening (4) close to the top wall of the chamber and is bent downward to form a second pin (14). The extension end of the second end motor is fixedly connected to the top wall of the chamber by epoxy resin glue (6).

4. The filter inductor applied to an audio amplifier circuit according to claim 1, characterized in that, The chamber has a second opening (5) on its rear side, and the coil winding (1) is fixedly connected to the chamber near the second opening (5) by epoxy resin glue (6).

5. The filter inductor applied to an audio amplifier circuit according to claim 1, characterized in that, The first iron core (2) and the second iron core (3) are both formed by pressing iron powder. The first iron core (2) and the second iron core (3) are combined and formed by high-temperature sintering.

6. The filter inductor applied to an audio amplifier circuit according to claim 1, characterized in that, The nominal inductance of the filter inductor is 5.4μH, with an allowable deviation range of ±13%.

7. The filter inductor applied to an audio amplifier circuit according to claim 1, characterized in that, The maximum DC resistance of the filter inductor is 0.6mΩ.

8. The filter inductor for use in an audio amplifier circuit according to claim 1, characterized in that, The operating temperature range of the filter inductor is -40℃ to 125℃.

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