TW201506964A - Transformer - Google Patents

Abstract

The present invention provides a transformer, which is coupled between a power circuit and an output circuit. The transformer includes a drum, a primary winding set surrounding the drum and coupled to the power circuit, a first secondary winding set surrounding the drum and coupled to the output circuit, and a first auxiliary winding set surrounding the drum, sandwiched in the first secondary winding set, and coupled to power circuit. As such, the first auxiliary winding set is arranged in between the first secondary winding set, such that a better crossing capacitor effect can be formed between the primary winding set and the first secondary winding set so as to improve EMI.

Description

transformer

This invention relates to a transformer, and more particularly to a transformer structure having improved common mode noise.

In switched-mode power systems, magnetic components such as transformers and inductors are often important. The magnetic component can be directly wound around a magnetic core, such as a single-layer insulated wire or a three-layer insulated wire, or the insulated wire can be wound into a wire cake or an insulated wire. It is placed on the winding area of the bobbin and then assembled with the magnetic core. Switched power systems generate electromagnetic interference (EMI) problems due to the use of switching components. Electromagnetic interference can interfere with conduction and radiation, and even damage other electronic components or electronic devices. Magnetic components, especially transformers, are one of the main electromagnetic interference propagations in switched-mode power systems because the parasitic capacitance between the primary and secondary sides of the transformer causes electromagnetic interference to propagate out of the image.

When the application environment improves the noise conduction requirements of the transformer primary and secondary, it is common practice to increase or increase the jump capacitor (Y-CAP) for the primary or secondary in the external line. However, since this method is located outside the transformer, it is actually limited by the circuit layout, and the noise has been dissipated by the traces. Therefore, in terms of the same capacitance value, the effect is far less than that in the transformer of the noise source. Please refer to FIG. 1 , which is a schematic diagram of a prior art. A transformer (1) in the figure is coupled to a power circuit (2) And an output circuit (3), the transformer includes a bobbin (10), a primary winding group (12), a secondary winding group (14) and an auxiliary winding group (16). The primary winding set (12) can surround the winding frame (10) and be coupled to the power circuit (2). The secondary winding set (14) can surround the winding frame (10) and be coupled to the output circuit (3). The auxiliary winding group (16) can surround the winding frame (10) and be disposed outside the secondary winding group (44) and coupled to the power circuit (6).

The transformer made by the above method can form a crossover capacitance between the primary winding group and the secondary winding group, so that the inside of the transformer can have the capability of improving EMI. However, due to the increasing demand for EMI, and in the pursuit of light weight, thin thickness, small size, the skill of the conventional technology will not meet the demand.

In view of the above, an object of the present invention is to provide a transformer which can improve the EMI by changing the winding structure.

To achieve the above or other objects, the present invention provides a transformer for coupling between a power supply circuit and an output circuit, including a bobbin, a primary winding group surrounding the bobbin. And coupled to the power circuit, a first secondary winding group, surrounding the winding frame, coupled to the output circuit, and a first auxiliary winding group, surrounding the winding frame and sandwiching the The first secondary winding group is coupled to the power circuit. Thus placing the first auxiliary winding set between the first secondary winding sets allows for a better jump capacitor effect between the primary winding set and the first secondary winding set to improve EMI.

In summary, this method can achieve a multiple of the suppression of EMI, and can even omit the external Y-CAP, resulting in effective cost reduction and volume reduction benefits.

1‧‧‧Transformer

10‧‧‧ Winding frame

12‧‧‧Primary winding group

14‧‧‧Secondary winding group

16‧‧‧Auxiliary winding group

2‧‧‧Power circuit

3‧‧‧Output circuit

4, 7‧‧‧ transformer

40, 70‧‧‧ Winding frame

42, 72‧‧‧Primary winding group

44, 74‧‧‧ First secondary winding group

75‧‧‧Second secondary winding group

46, 76‧‧‧First auxiliary winding group

75‧‧‧Second auxiliary winding group

5, 8‧‧‧ power circuit

6, 9‧‧‧ output circuit

1 is a schematic illustration of a preferred embodiment of the prior art.

2 is a schematic view of a preferred embodiment of the present invention.

Figure 3 is a schematic illustration of another preferred embodiment of the present invention.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Please refer to FIG. 2, which is a schematic diagram of a preferred embodiment of the present invention. The invention provides a transformer (4) for coupling between a power supply circuit (5) and an output circuit (6). The transformer (4) includes a bobbin (40), a primary winding set (42), a first secondary winding set (44), and a first auxiliary winding set (46). ). The primary winding set (42) can surround the winding frame (40) and be coupled to the power circuit (5). The first secondary winding set (44) can surround the winding frame (40) and be coupled to the output circuit (6). The first auxiliary winding group (46) can surround the winding frame (40) and be sandwiched in the first secondary winding group (44) and coupled to the power circuit (6).

Since the first auxiliary winding group (46) is sandwiched in the first secondary winding group (44), the primary winding group (42) and the first secondary winding group (44) can be The formation of a double-connected capacitor effect is twice as long as the conventional technique, and the total capacitance value can be Doubled, even with the elimination of extra capacitors, the EMI effect can be improved.

Please refer to FIG. 3, which is a schematic diagram of another preferred embodiment of the present invention. The invention provides a transformer (7) for coupling between a power supply circuit (8) and an output circuit (9). The transformer (7) includes a bobbin (70), a primary winding set (72), a first secondary winding set (74), and a second secondary winding. A line set (75), a first auxiliary winding set (76) and a second auxiliary winding set (77). The primary winding set (72) can surround the winding frame (70) and be coupled to the power supply circuit (8). The first secondary winding set (74) can surround the winding frame (70) and be coupled to the output circuit (9). The first auxiliary winding group (76) can surround the winding frame (70) and be sandwiched in the first secondary winding group (74) and coupled to the power circuit (8). The second auxiliary winding group (77) surrounds the winding frame (70) and is disposed on an outer side of the first secondary winding group (74), the second auxiliary winding group (77) and the The power circuit (8) is coupled. The second secondary winding set (75) surrounds the winding frame (70) and is disposed between the primary winding set (72) and the second auxiliary winding set (77), and the first A second secondary winding set (75) is coupled to the output circuit (9).

Since the first auxiliary winding group (76) is sandwiched in the first secondary winding group (74), and the second auxiliary winding group (77) is sandwiched between the first secondary winding group (74) And between the second secondary winding group (75), so the primary winding group (72) and the first secondary winding group (74) and the second secondary winding group (75) can be It can form the effect of multiple sets of jumper capacitors, and can have better anti-EMI function.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

4‧‧‧Transformers

40‧‧‧ Winding frame

42‧‧‧Primary winding group

44‧‧‧First secondary winding group

46‧‧‧First auxiliary winding group

5‧‧‧Power circuit

6‧‧‧Output circuit

Claims (2)

A transformer is coupled between a power circuit and an output circuit, and includes: a bobbin; a primary winding group surrounding the bobbin and coupled to the power circuit; a first sub a winding group surrounding the winding frame and coupled to the output circuit; and a first auxiliary winding group surrounding the winding frame and sandwiched in the first secondary winding group, and coupled to the power circuit . The transformer of claim 1, wherein the transformer further has a second auxiliary winding group and a second secondary winding group, wherein the second auxiliary winding group is disposed on the first secondary winding The outer side of the group, and the second secondary winding group is disposed between the second auxiliary winding group and the primary winding group.