High-power switching power supply planar transformer with adjustable turn ratio

Abstract

The utility model provides a high-power switching power supply planar transformer with an adjustable turn ratio, which comprises a magnetic core, and a winding component is fixed in the magnetic core; the winding assembly is formed by stacking a plurality of secondary winding copper sheets and a plurality of primary winding copper sheets in a crossed mode, two primary leading-out terminals are arranged on the side portion of the same end of each primary winding copper sheet, and two secondary leading-out terminals are arranged on the end portion of each secondary winding copper sheet. The primary leading-out terminal connects a plurality of primary winding copper sheets in series through a primary fixing bolt, and the secondary leading-out terminal connects a plurality of secondary winding copper sheets in series through a secondary fixing bolt. According to the utility model, a plurality of primary leading-out terminals and secondary leading-out terminals are arranged on the winding, and the primary and secondary turns of the transformer can be flexibly selected by connecting different leading-out terminals; and the tedious process in the PCB winding manufacturing process is omitted, the raw material cost and the production and processing cost are greatly reduced, and the production period is shortened.

Description

Technical Field

[0001] This utility model relates to a planar transformer for a high-power switching power supply with adjustable turns ratio. Background Technology

[0002] The current processing of planar transformer windings for switching power supplies in the industry includes a series of processing steps such as blanking, grinding, lamination, exposure, development, copper plating, tin plating, tin removal, browning, film removal, copper plating, drilling, lamination, pressing, and routing, to realize the production and processing of winding boards.

[0003] The drawbacks of conventional switching power supply transformer winding board processing in the industry include: 1. Numerous processes and long cycles; 2. The need to use large amounts of acid and alkali solutions during production, which is detrimental to environmental protection requirements; 3. High costs due to the extensive use of equipment, personnel, and various fixtures and tooling during production; 4. The designed switching power supply transformer cannot flexibly select a fixed number of turns, requiring high customization and hindering parameter adjustment by power supply designers. For example, a planar transformer disclosed in CN119480364B has multiple PCB boards installed inside the magnetic core as windings, but its lead terminals are integrated on the PCB board, increasing its processing cost, and its fixed turns ratio limits its application to fixed transformer circuits. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a high-power switching power supply planar transformer with adjustable turns ratio.

[0005] This utility model is achieved through the following technical solution.

[0006] This utility model provides a high-power switching power supply planar transformer with adjustable turns ratio, including a magnetic core, and a winding assembly fixed inside the magnetic core; the winding assembly is composed of multiple secondary winding copper sheets and multiple primary winding copper sheets stacked in a cross manner, each primary winding copper sheet has two primary lead-out terminals on the same side, and each secondary winding copper sheet has two secondary lead-out terminals at its end; the primary lead-out terminals connect multiple primary winding copper sheets in series through primary fixing bolts, and the secondary lead-out terminals connect multiple secondary winding copper sheets in series through secondary fixing bolts.

[0007] The secondary winding copper sheet and the primary winding copper sheet are electrically isolated by an insulating pad. The surfaces of the secondary winding copper sheet, the primary winding copper sheet, and the insulating pad are all covered with a polyimide film and are fixed together by the polyimide film.

[0008] The primary leads of multiple secondary winding copper sheets are arranged in a stepped manner, and adjacent primary leads are in the same vertical direction and are connected and fixed by primary fixing bolts.

[0009] The secondary lead-out terminals are located at the middle and edge of the end of the primary winding copper sheet, respectively, and the secondary lead-out terminals on the upper and lower parts of the winding assembly are in opposite directions. The secondary lead-out terminals in the same vertical direction are connected by secondary fixing bolts.

[0010] The secondary winding copper sheet and the primary winding copper sheet have lateral protrusions at their ends that extend out of the magnetic core and face different directions.

[0011] The advantages of this invention are as follows: multiple primary and secondary lead-out terminals are provided on the winding, and the number of primary and secondary turns of the transformer can be flexibly selected by connecting different lead-out terminals; and the processes of grinding, pressing, exposure, development, copper plating, tin plating, tin removal, browning, film removal, copper plating, drilling, lamination, pressing, and routing in the PCB winding manufacturing process are eliminated, which greatly reduces the cost of raw materials and production and processing, and shortens the production cycle. Attached Figure Description

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

[0013] Figure 2 This is a schematic diagram illustrating the electrical principle of this utility model;

[0014] Figure 3 This is a schematic diagram of the lead-out terminals connected in series according to this utility model;

[0015] Figure 4 This is a schematic diagram of the lead-out terminal arrangement of this utility model;

[0016] In the diagram: 1-Magnetic core, 2-Secondary lead-out terminal, 3-Secondary winding copper sheet, 4-Primary winding copper sheet, 5-Primary lead-out terminal, 6-Insulating gasket, 7-Secondary fixing bolt, 8-Adhesive, 9-Primary fixing bolt. Detailed Implementation

[0017] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0018] A planar transformer for a high-power switching power supply with adjustable turns ratio includes a magnetic core 1 made of high-permeability ferrite material to concentrate the magnetic field and reduce losses. A winding assembly is fixed within the magnetic core 1. The winding assembly is composed of multiple secondary winding copper sheets 3 and multiple primary winding copper sheets 4 stacked in a cross-stack manner. Each primary winding copper sheet 4 has two primary lead-out terminals 5 on the same end side, and each secondary winding copper sheet 3 has two secondary lead-out terminals 2 at its end. The primary lead-out terminals 5 connect the multiple primary winding copper sheets 4 in series via primary fixing bolts 9, and the secondary lead-out terminals 2 connect the multiple secondary winding copper sheets 3 in series via secondary fixing bolts 7. The cross-stacked primary and secondary copper sheet windings optimize the magnetic field distribution and improve energy transmission efficiency.

[0019] Furthermore, the secondary winding copper sheet 3 and the primary winding copper sheet 4 are electrically isolated by an insulating gasket 6. The surfaces of the secondary winding copper sheet 3, the primary winding copper sheet 4, and the insulating gasket 6 are all covered with a polyimide film and fixed together by the polyimide film. Using an insulating gasket to isolate the windings avoids the risk of short circuits, increases the heat dissipation efficiency of the transformer, and simplifies the packaging process.

[0020] Furthermore, such as Figure 3 and 4 As shown, the primary lead-out terminals 5 of multiple secondary winding copper sheets 3 are arranged in a stepped manner, and adjacent primary lead-out terminals 5 are in the same vertical direction and are connected and fixed by primary fixing bolts 9. One of the primary lead-out terminals on the primary winding copper sheets 3 at both ends is located at both ends of the primary winding copper sheet 3, and the remaining primary winding terminals are in the same vertical direction as their adjacent primary winding terminals, so as to facilitate bolt connection.

[0021] Furthermore, the secondary lead-out terminals 2 are located at the middle and edge of the ends of the primary winding copper sheets 4, respectively, and the secondary lead-out terminals 2 on the upper and lower parts of the winding assembly are in opposite directions. The secondary lead-out terminals 2 in the same vertical direction are connected by secondary fixing bolts 7. After the secondary windings located on the upper and lower parts of the winding assembly are connected in parallel, the upper and lower secondary windings are connected in series by bolts.

[0022] Furthermore, the secondary winding copper sheet 3 and the primary winding copper sheet 4 have lateral protrusions at their ends that extend out of the magnetic core 1 and are oriented in different directions. Since the primary lead-out terminals and secondary lead-out terminals on each secondary winding copper sheet 3 and primary winding copper sheet 4 need to be separated in order to form different turns ratios in the subsequent connection process, the protrusions at the ends of the secondary winding copper sheet 3 and the primary winding copper sheet 4 can not only connect the lead-out terminals with larger areas and reduce the temperature rise, but also, after the winding assembly is formed as a whole, the protrusions on both sides form square grooves on both sides of the middle part of the winding assembly to limit the magnetic core.

[0023] Example: Figure 2 As shown, the transformer has six primary winding copper sheets connected sequentially to form six primary windings; four secondary winding copper sheets are connected in parallel in pairs and then in series to form two secondary windings. In use, a flexible wire is connected to the corresponding lead-out terminal bolt, and then the lead is tightened with a nut. The other end of the lead is connected to the power module. By connecting to different terminals, the number of primary and secondary turns of the transformer can be flexibly changed, which can quickly help power supply designers to debug the power module in the early stages, saving the time of secondary mold opening of the transformer and enabling rapid debugging to achieve the expected requirements.

Claims

1. A planar transformer for a high-power switching power supply with adjustable turns ratio, comprising a magnetic core (1), wherein a winding assembly is fixed inside the magnetic core (1), characterized in that: The winding assembly is composed of multiple secondary winding copper sheets (3) and multiple primary winding copper sheets (4) stacked in a cross manner. Each primary winding copper sheet (4) has two primary lead-out terminals (5) on the same side, and each secondary winding copper sheet (3) has two secondary lead-out terminals (2) at its end. The primary lead-out terminals (5) connect multiple primary winding copper sheets (4) in series by primary fixing bolts (9), and the secondary lead-out terminals (2) connect multiple secondary winding copper sheets (3) in series by secondary fixing bolts (7).

2. The high-power switching power supply planar transformer with adjustable turns ratio as described in claim 1, characterized in that: The secondary winding copper sheet (3) and the primary winding copper sheet (4) are electrically isolated by an insulating pad (6). The surfaces of the secondary winding copper sheet (3), the primary winding copper sheet (4), and the insulating pad (6) are all covered with a polyimide film and are fixed together by the polyimide film.

3. The high-power switching power supply planar transformer with adjustable turns ratio as described in claim 1, characterized in that: The primary lead-out terminals (5) of multiple secondary winding copper sheets (3) are arranged in a stepped manner, and adjacent primary lead-out terminals (5) are connected and fixed in the same vertical direction by primary fixing bolts (9).

4. The high-power switching power supply planar transformer with adjustable turns ratio as described in claim 1, characterized in that: The secondary lead-out terminals (2) are located at the middle and edge of the end of the primary winding copper sheet (4), respectively, and the secondary lead-out terminals (2) on the upper and lower parts of the winding assembly are in opposite directions. The secondary lead-out terminals (2) in the same vertical direction are connected by secondary fixing bolts (7).

5. The high-power switching power supply planar transformer with adjustable turns ratio as described in claim 1, characterized in that: The secondary winding copper sheet (3) and the primary winding copper sheet (4) have lateral protrusions at their ends that extend out of the magnetic core (1) and are oriented in different directions.

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