A small current transformer

Abstract

The utility model discloses a small current transformer, its technical scheme main points include framework body, magnetic core subassembly, set up the pass -through passageway for installing magnetic core subassembly on the framework body, the framework body is close to the recessed structure of two end surfaces of passageway opening respectively and sets up the annular groove coaxial with passageway, the annular groove has the secondary coil, the recessed structure is provided with the through -hole of diameter greater than the pin end, the through -hole is used to install the primary coil, the primary coil pin end is provided with the stop portion for limiting the motion of primary coil, the recessed structure is close to magnetic core subassembly, and part is surrounded by the magnetic core, the recessed structure still is provided with the shielding block in. The utility model discloses through setting up the shielding block of contact with magnetic core subassembly and the stop portion limit the motion of primary coil, prevent the upfloating of coil installation. Through setting up the through -hole of greater than the pin end has reduced the installation resistance, makes primary coil can be installed in the through -hole smoothly.

Description

Technical Field

[0001] This utility model relates to the field of current transformer technology, and more specifically to a small current transformer. Background Technology

[0002] Currently, a current transformer is an electrical component used to measure current, commonly used in high-power household appliances such as air conditioners and IH (indoor heating) systems. A current transformer consists of a primary coil, a secondary coil, and a common magnetic core. The secondary coil is connected to a current-sensing resistor. When AC current is applied to the primary coil, the current coupled to the magnetic core induces a current in the secondary coil. This induced current is then input to a microprocessor to adjust the input and output power of the device.

[0003] However, there are still some defects in the above-mentioned existing technology. When the primary coil terminal is connected to the circuit board, it may be squeezed, causing the coil to float off the frame. At the same time, insufficient pin bending accuracy may lead to difficulty in insertion, and forced insertion may easily cause the frame to break. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the present invention provides a small current transformer.

[0005] To achieve the above objectives, this utility model provides the following technical solution: It includes a skeleton body and a magnetic core assembly. The skeleton body has a through channel for mounting the magnetic core assembly. The skeleton body has concave structures and annular grooves coaxial with the channel on both ends near the channel opening. A secondary coil is wound around the annular groove. The concave structure has a through hole with a diameter larger than the pin end, used to mount a primary coil. The primary coil pin end has a stop portion for restricting the movement of the primary coil. The concave structure is close to the magnetic core assembly and partially surrounded by the magnetic core. A shielding block is also provided inside the concave structure.

[0006] The present invention is further configured such that: a shrinking portion with a reduced diameter is provided at the lower part of the through hole, a transition slope is provided at the upper part of the shrinking portion, the shrinking portion is larger than the pin end, and the diameter of the stop portion is larger than that of the shrinking portion and smaller than that of the through hole.

[0007] The present invention is further configured such that the stop part is formed by flattening.

[0008] The present invention is further configured such that the skeleton body is made of resin material.

[0009] The present invention is further configured such that: the magnetic core assembly includes a U-shaped magnetic core and an I-shaped magnetic core, the U-shaped magnetic core and the I-shaped magnetic core are alternately stacked and embedded in the channel to form a closed magnetic circuit.

[0010] The present invention is further configured such that: the surface of the skeleton body is provided with positioning protrusions adapted to the magnetic core assembly.

[0011] In summary, this utility model has the following beneficial effects: the shielding block that contacts the magnetic core assembly restricts the movement of the primary coil, and the stop restricts the movement of the primary coil when it is pulled out. The shielding block and the stop work together to prevent the coil from floating during installation. By setting a gap larger than the pin end of the through hole, the assembly resistance is reduced, allowing the primary coil to be easily installed in the through hole. It is also compatible with primary coils with certain processing errors, enabling them to be installed normally, and effectively avoiding the risk of frame breakage when forcibly inserted. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this embodiment;

[0013] Figure 2 This is an exploded view diagram of this embodiment;

[0014] Figure 3 This is a cross-sectional view of this embodiment;

[0015] Figure 4 This is a schematic diagram of the combination of U-shaped magnetic core and I-shaped magnetic core in this embodiment;

[0016] Reference numerals: 1. Skeleton body; 11. Channel; 12. Annular groove; 13. Concave structure; 131. Through hole; 1311. Tightening part; 1312. Transition slope; 14. Positioning protrusion; 2. Magnetic core assembly; 21. U-shaped magnetic core; 22. I-shaped magnetic core; 23. Solder joint; 3. Secondary coil; 4. Primary coil; 41. Pin end; 42. Stop part; 5. Shielding block. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings.

[0018] This embodiment discloses a small current transformer, such as Figures 1 to 3As shown, the assembly includes a skeleton body 1 and a magnetic core assembly 2. The skeleton body 1 has a through channel 11 for mounting the magnetic core assembly 2. The skeleton body 1 has a concave structure 13 and an annular groove 12 coaxial with the channel 11 on both ends near the opening of the channel 11. A secondary coil 3 is wound in the annular groove 12. The annular groove 12 provides a regular winding space for the secondary coil 3, restricts the radial displacement of the coil, and ensures that the coil is evenly distributed in the annular groove 12. The concave structure 13 has a through hole 131 with a diameter larger than the pin end 41. The through hole 131 is used to mount the primary coil 4. The primary coil 4 has a U-shaped pin. The pin end 41 of the primary coil 4 has a stop part 42 for restricting the movement of the primary coil 4, which can prevent the primary coil 4 from falling out of the through hole 131 during assembly, transportation, or use. The concave structure 13 is close to the magnetic core assembly 2 and is partially surrounded by the magnetic core. A shielding block 5 is also provided in the concave structure 13. The shielding block 5 is made of insulating material, which can insulate and isolate the primary coil 4 from the magnetic core assembly 2 to prevent insulation breakdown or short circuit under high voltage. At the same time, the upper and lower end faces of the shielding block 5 filling the gap of the concave structure 13 abut against the primary coil 4 and the magnetic core assembly 2 respectively, which can restrict the movement of the primary coil 4 and prevent the primary coil 4 from floating.

[0019] To further improve the design, a reduced-diameter tightening part 1311 is provided at the lower part of the through hole 131, and a transition slope 1312 is provided at the upper part of the tightening part 1311. The tightening part 1311 is larger than the pin end 41, and the diameter of the stop part 42 is larger than the tightening part 1311 but smaller than the through hole 131. By reserving a gap, the assembly resistance is reduced, allowing the pin end 41 to move freely within the through hole 131 without obstruction. The transition slope 1312 guides the stop part 42 through the tightening part 1311, so that the stop part 42 only requires a small force to pass through the tightening part 1311, completing the installation of the primary coil 4. Moreover, when the pin end 41 passes through the through hole 131, the stop part 42 will be locked on the outside of the tightening part 1311, mechanically limiting it and preventing the primary coil 4 from falling off.

[0020] Furthermore, the stop part 42 is formed by flattening. This flattening process eliminates the need for complex molds, reducing costs; it is simple and easy to automate; and it does not require increasing material thickness, resulting in a compact structure and contributing to weight reduction.

[0021] Furthermore, the skeleton body 1 is made of resin material. Resin material has excellent insulation properties, ensuring electrical isolation between the primary coil 4 and the secondary coil 3; good machinability, enabling precise molding of complex structures; and the lightweight and low-cost characteristics of resin material, meeting the needs of miniaturized mass production; at the same time, the balance between the toughness and strength of resin material effectively reduces the risk of assembly damage.

[0022] Further improvements include the following: the magnetic core assembly 2 comprises a U-shaped magnetic core 21 and an I-shaped magnetic core 22, wherein the U-shaped magnetic core 21 and the I-shaped magnetic core 22 are alternately stacked and embedded within the channel 11 to form a closed magnetic circuit. (Refer to...) Figure 4 As shown, the U-shaped magnetic core 21 and the I-shaped magnetic core 22 are connected by side solder joints 23 to form a composite plate. The composite plate can be conveniently stacked and embedded into the channel 11. The side solder joints 23 reinforce the installed magnetic core assembly 2, so that the magnetic core assembly 2 obtains a stable and reliable installation state. The U-shaped magnetic core 21 and the I-shaped magnetic core 22 are made of silicon steel sheets with an insulating coating. The alternating stacked structure can divide the magnetic core assembly 2 into multiple thin sheets, cut off the annular path of eddy currents, so that eddy currents can only flow in a single layer of thin sheet. The path is shortened and the resistance is increased, thereby significantly reducing eddy current loss. In addition, the alternating stacked structure of the U-shaped magnetic core 21 and the I-shaped magnetic core 22 can be precisely matched with the bobbin channel 11, improving assembly stability. The magnetic core assembly 2 forms a closed magnetic circuit by combination to reduce magnetic leakage, ensure efficient magnetic coupling between the primary and secondary sides, and improve the current detection accuracy.

[0023] To further improve the design, the surface of the skeleton body 1 is provided with positioning protrusions 14 that are adapted to the magnetic core assembly 2. The positioning protrusions 14 help to position the magnetic core assembly 2 during installation and simplify assembly through their guiding effect; the positioning protrusions 14 contact the edge of the magnetic core assembly 2 to avoid concentrated pressure on the skeleton from the edge of the magnetic core, thereby reducing the stress deformation of the magnetic core itself.

[0024] Working principle of this utility model

[0025] During assembly, the secondary coil 3 is wound into the annular groove 12, the primary coil 4 is placed into the concave structure 13, the stop part 42 can easily enter the through hole 131, and the primary coil 4 is gently pushed so that the stop part 42 and the tightening part 1311 undergo slight deformation. The stop part 42 can easily pass through the tightening part 1311, so that the tightening part 1311 and the stop part 42 form a limit. The shielding block 5 is placed in the concave structure 13, and then the U-shaped magnetic core 21 and the I-shaped magnetic core 22 are sequentially placed into the channel 11 to complete the stacking installation.

[0026] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the design concept of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A small current transformer, comprising a frame body (1) and a magnetic core assembly (2), characterized in that: The skeleton body (1) is provided with a through channel (11) for installing the magnetic core assembly (2). The skeleton body (1) is provided with a concave structure (13) and an annular groove (12) coaxial with the channel (11) on both ends near the opening of the channel (11). The annular groove (12) is wound with a secondary coil (3). The concave structure (13) is provided with a through hole (131) with a diameter larger than the pin end (41). The through hole (131) is used to install the primary coil (4). The pin end (41) of the primary coil (4) is provided with a stop (42) for restricting the movement of the primary coil (4). The concave structure (13) is close to the magnetic core assembly (2) and is partially surrounded by the magnetic core. A shielding block (5) is also provided in the concave structure (13).

2. A small current transformer according to claim 1, characterized in that: The lower part of the through hole (131) is provided with a shrinking part (1311) with a reduced diameter, and the upper part of the shrinking part (1311) is provided with a transition slope (1312). The shrinking part (1311) is larger than the pin end (41), and the diameter of the stop part (42) is larger than that of the shrinking part (1311) and smaller than that of the through hole (131).

3. A small current transformer according to claim 2, characterized in that: The stop part (42) is formed by flattening.

4. A small current transformer according to claim 1, characterized in that: The skeleton body (1) is made of resin material.

5. A small current transformer according to claim 1, characterized in that: The magnetic core assembly (2) includes a U-shaped magnetic core (21) and an I-shaped magnetic core (22). The U-shaped magnetic core (21) and the I-shaped magnetic core (22) are stacked alternately and embedded in the channel (11) to form a closed magnetic circuit.

6. A small current transformer according to claim 1, characterized in that: The surface of the skeleton body (1) is provided with positioning protrusions (14) adapted to the magnetic core assembly (2).

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