Miniaturized u-shaped buried wire type current transformer
By designing a miniaturized U-shaped embedded current transformer, the problems of excessive size and deteriorated insulation performance of miniature current transformers are solved, achieving a combination of miniaturization and high insulation performance, making the manufacturing process simpler and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU JINZHICHUAN ELECTRONICS
- Filing Date
- 2025-07-21
- Publication Date
- 2026-06-12
AI Technical Summary
Existing miniature current transformers suffer from problems such as excessive size and deteriorated insulation performance, and the manufacturing process is time-consuming.
The miniaturized U-shaped embedded current transformer design is adopted, with the primary winding pre-embedded in the second frame. The creepage distance is increased by using bosses, and the processing steps are simplified by combining fully automated surface mount technology.
Miniaturization design was achieved, insulation performance was improved, processing time and cost were reduced, and the yield rate reached over 99%.
Smart Images
Figure CN224355098U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of current transformer technology, and in particular to a miniaturized U-shaped embedded wire current transformer. Background Technology
[0002] With the rapid development of new energy vehicle motor controllers, high-frequency switching power supplies, and other fields, miniature current transformers need to achieve high current carrying capacity, high insulation, and at least 120 turns of secondary winding within the smallest possible size. In existing technologies, to adapt to traditional frame structures, separate copper sheet bending and laser welding are required to form the primary winding, leading to an overall increase in the size of the current transformer and a deterioration in insulation performance. This secondary processing method is also time-consuming. Utility Model Content
[0003] To address the problems of excessive size and deteriorated insulation performance in existing miniature current transformers, this invention provides a miniaturized U-shaped embedded wire current transformer.
[0004] This utility model provides the following technical solution: a miniaturized U-shaped buried wire current transformer, comprising:
[0005] An insulating frame includes a first frame, a second frame, a connecting portion disposed between the first frame and the second frame, a magnetic core mounting groove disposed on the first frame and the second frame, and a central column slot penetrating the first frame, the connecting portion, and the second frame; the second frame is also provided with a U-shaped groove inside, the openings at both ends of the U-shaped groove extending to the bottom surface of the second frame, and a boss is provided on the bottom surface of the second frame facing the connecting portion.
[0006] The magnetic core includes a first magnetic core and a second magnetic core assembled into a sun shape. The first magnetic core and the second magnetic core are respectively disposed in the magnetic core mounting slots of the first frame and the second frame, and the central column of the first magnetic core and the second magnetic core are inserted into the central column slot.
[0007] The winding includes a secondary winding wound on the connecting portion and a primary winding disposed in the U-shaped groove. The primary winding surrounds the central column, and both ends of the primary winding extend away from the secondary winding.
[0008] Preferably, the current transformer has a length ≤13 mm, a height ≤10 mm, and a spacing between the first frame and the second frame ≥4.5 mm.
[0009] Preferably, the height of the boss is 0.5 mm and the thickness is 0.8 mm.
[0010] Preferably, the first frame is further provided with secondary winding pins and winding limiting grooves.
[0011] Preferably, the primary winding is a single-turn U-shaped copper wire.
[0012] The beneficial effects of this utility model are: the primary winding is pre-embedded in the second frame, and the second frame is provided with a boss to increase the creepage distance between the primary and secondary windings, thereby improving the insulation performance and meeting safety standards while meeting the miniaturization requirements of the overall size; the processing is simpler and the processing time is reduced by more than 10%. Attached Figure Description
[0013] Figure 1 This is a three-dimensional schematic diagram of one embodiment of a current transformer.
[0014] Figure 2 This is a side view of one embodiment of a current transformer.
[0015] Figure 3 A cross-section of one embodiment of a current transformer Figure I .
[0016] Figure 4 A cross-section of one embodiment of a current transformer Figure II .
[0017] Reference numerals: 11, First frame; 12, Second frame; 121, U-shaped groove; 122, Bottom surface; 13, Connecting part; 14, Core mounting groove; 15, Center post slot; 16, Boss; 21, First core; 211, Base plate; 212, Center post; 213, Side post; 22, Second core; 31, Primary winding; 32, Secondary winding pin; 33, Winding limiting groove. Detailed Implementation
[0018] The embodiments of this utility model will be described in more detail below with reference to the accompanying drawings and reference numerals, so that those skilled in the art can implement them after reading this specification. It should be understood that the specific embodiments described herein are only for explaining this utility model and are not intended to limit this utility model.
[0019] This utility model provides, for example Figure 1-4 The miniaturized U-shaped buried wire current transformer shown includes an insulating frame, a magnetic core, and windings.
[0020] The insulating frame is made of insulating material and includes a first frame 11, a second frame 12, a connecting part 13, a magnetic core mounting groove 14, and a center post slot 15. A gap is provided between the first frame 11 and the second frame 12, and they are connected by the connecting part 13. Both the first frame 11 and the second frame 12 are provided with magnetic core mounting grooves 14, which are used to mount the first magnetic core 21 and the second magnetic core 22, respectively. The magnetic core mounting groove 14 includes a center post slot 15, which sequentially passes through the first frame 11, the connecting part 13, and the second frame 12.
[0021] The magnetic core includes a first magnetic core 21 and a second magnetic core 22, both of which are E-shaped magnetic cores. Each core includes a base plate 211, a central post 212 located in the center of the base plate 211, and two side posts 213 located on either side of the central post 212. The posts of the first and second magnetic cores are joined together to form a U-shaped structure, creating a closed magnetic circuit. The first and second magnetic cores are respectively installed in two magnetic core mounting slots 14, with the post 212 inserted into the central post slot 15.
[0022] The winding includes a secondary winding and a primary winding 31. The secondary winding is made of FIW-4 wire with an inner diameter of 0.1mm and is highly compactly wound, with each turn capable of carrying 12A of current, exhibiting high current-carrying capacity. The secondary winding is wound on the outer surface of the connecting part 13, located between the first frame 11 and the second frame 12. The bottom of the first frame 11 has two U-shaped secondary winding pins 32 pre-embedded and two winding limiting slots 33. The two ends of the secondary winding pass through the two winding limiting slots 33 and connect to the two secondary winding pins 32. The primary winding 31 uses a single-turn U-shaped copper wire with a rectangular cross-section. Furthermore, the second frame 12 has a U-shaped groove 121 inside, with both ends extending to the bottom surface 122 of the second frame 12. The primary winding 31 is pre-embedded in the U-shaped groove 121 and surrounds the central post 212, with both ends protruding from the bottom surface 122 and extending away from the secondary winding.
[0023] Compared with existing technologies, the above structure is simpler to process, eliminates the copper sheet assembly process, reduces labor time by more than 10%, and is compatible with fully automated surface mount technology, with a yield rate of over 99%.
[0024] To meet miniaturization requirements, the current transformer has a length L1 ≤ 13 mm, a height H1 ≤ 10 mm, and its width is not limited, generally being smaller than its length L1. The spacing between the first and second frames is at least 4.5 mm, ensuring that the secondary winding has at least 120 turns. Furthermore, a boss 16 is provided on the bottom surface 122 of the second frame 12 facing the connection portion 13 to increase the creepage distance between the two windings. Specifically, the height H2 of the boss 16 can be 0.5 mm, and its thickness L2 can be 0.8 mm. According to IEC 62368-1, under the premise of meeting miniaturization requirements, a three-dimensional folding path formed by the aforementioned boss 16 can achieve a creepage distance of 3.2 mm, improving insulation performance.
[0025] The above describes one or more embodiments of this utility model in a relatively specific and detailed manner, but it should not be construed as limiting the scope of this utility model patent. 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 patent should be determined by the appended claims.
Claims
1. A miniaturized U-shaped embedded wire current transformer, characterized in that, include: An insulating frame includes a first frame, a second frame, a connecting portion disposed between the first frame and the second frame, a magnetic core mounting groove disposed on the first frame and the second frame, and a central column slot penetrating the first frame, the connecting portion, and the second frame; the second frame is also provided with a U-shaped groove inside, the openings at both ends of the U-shaped groove extending to the bottom surface of the second frame, and a boss is provided on the bottom surface of the second frame facing the connecting portion. The magnetic core includes a first magnetic core and a second magnetic core assembled into a sun shape. The first magnetic core and the second magnetic core are respectively disposed in the magnetic core mounting slots of the first frame and the second frame, and the central column of the first magnetic core and the second magnetic core are inserted into the central column slot. The winding includes a secondary winding wound on the connecting portion and a primary winding disposed in the U-shaped groove. The primary winding surrounds the central column, and both ends of the primary winding extend away from the secondary winding.
2. The miniaturized U-shaped embedded current transformer according to claim 1, characterized in that, The current transformer has a length ≤13 mm, a height ≤10 mm, and a spacing of ≥4.5 mm between the first frame and the second frame.
3. A miniaturized U-shaped embedded current transformer according to claim 2, characterized in that, The boss has a height of 0.5 mm and a thickness of 0.8 mm.
4. A miniaturized U-shaped embedded current transformer according to claim 1, characterized in that, The first frame is also provided with secondary winding pins and winding limiting grooves.
5. A miniaturized U-shaped embedded current transformer according to claim 1, characterized in that, The primary winding is a single-turn U-shaped copper wire.