Power adapter

A power adapter includes a circuit board, an electromagnetic interference filter, a shielding element, a power factor correction (PFC) inductor, a transformer and heating elements. The circuit board has a front side and a back side corresponding to each other, and a first long side and a second long side parallel to each other. The front side of the circuit board is divided into a first region, a second region and a third region along an extending direction of the first long side. The electromagnetic interference filter is disposed in the first region and close to the first long side. The shielding element is disposed in the first region and close to the electromagnetic interference filter. The PFC inductor is disposed in the first region of the circuit board and close to the second long side. The PFC inductor has a first long axis. The transformer is disposed in the third region and close to the first long side. The transformer has a second long axis, and the first long axis is perpendicular to the second long axis. The heating elements are disposed at the back side of the circuit board.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan application serial no. 110137181, filed on Oct. 6, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technology Field

The disclosure relates to a power supply, and particularly, to a power adapter.

Description of Related Art

Power adapters are widely applied in portable electronic products, such as notebook computers or game consoles. The power of a power adapter is subject to the electrical parameters and the dimensions of electronic elements, such as power factor correction transistors, bridge rectifiers, power factor correction inductors, capacitors, and transformers configured inside the power adapter.

With the advancement and development of technology, consumers have an increasing demand for electronic products, such as notebook computers or game consoles, with characteristics of being lightweight, thin, and compact. Therefore, how to reduce the overall volume of a power adapter without affecting the power of the power adapter so as to implement electronic products with the characteristics of being lightweight, thin, and compact and to meet the demand of the consumers is one of future research directions.

SUMMARY

The disclosure provides a power adapter capable of effectively improving the space utilization rate and the power density of a circuit board.

The power adapter of the disclosure includes a circuit board, an electromagnetic interference filter, a shielding element, a power factor correction (PFC) inductor, a transformer, and multiple heating elements. The circuit board has a front side and a back side opposite to each other, and a first long side and a second long side parallel to each other. The front side of the circuit board is sequentially divided into a first region, a second region, and a third region in an extending direction of the first long side. The electromagnetic interference filter is disposed in the first region and close to the first long side on the circuit board. The shielding element is disposed in the first region and close to the electromagnetic interference filter on the circuit board. The power factor correction (PFC) inductor is disposed in the first region and close to the second long side on the circuit board. The power factor correction inductor has a first long axis. The transformer is disposed in the third region and close to the first long side on the circuit board. The transformer has a second long axis, and the first long axis of the power factor correction inductor is perpendicular to the second long axis of the transformer. The heating elements are disposed on the back side of the circuit board.

In an embodiment of the disclosure, the power adapter further includes a first capacitor disposed at a position across the second region and the third region and close to the second long side on the circuit board.

In an embodiment of the disclosure, in the power adapter, the first capacitor has a third long axis, and the third long axis of the first capacitor is perpendicular to the second long axis of the transformer.

In an embodiment of the disclosure, the power adapter further includes a second capacitor, a half-bridge resonant capacitor, and a half-bridge resonant inductor, disposed in the second region and between the electromagnetic interference filter and the transformer on the circuit board.

In an embodiment of the disclosure, in the power adapter, the second capacitor is close to the first long side, the half-bridge resonant capacitor is farther from the first long side compared with the second capacitor, and the half-bridge resonant inductor is disposed between the second capacitor and the half-bridge resonant capacitor.

In an embodiment of the disclosure, in the power adapter, the half-bridge resonant capacitor includes a fourth long axis, the half-bridge resonant inductor includes a fifth long axis, and the fourth long axis is perpendicular to the fifth long axis.

In an embodiment of the disclosure, in the power adapter, the fifth long axis is parallel to the second long axis.

In an embodiment of the disclosure, in the power adapter, the heating elements include a bridge rectifier switch, a power factor correction transistor, and/or a half-bridge resonant transistor, and the bridge rectifier switch is disposed at a position on the back side corresponding to the first region.

In an embodiment of the disclosure, the power adapter further includes an input plug. The circuit board has a first short side and a second short side parallel to each other, the input plug is disposed in the first region and close to the first long side and the first short side on the circuit board, and the shielding element is L-shaped and disposed between the electromagnetic interference filter and the power factor correction inductor and also between the electromagnetic interference filter and the transformer.

In an embodiment of the disclosure, the transformer further includes a wire frame, a coil, a magnetic core, and an insulating cover. The wire frame has a first end and a second end, a first pin portion is disposed at the first end, and a winding hook portion is disposed at the second end. The coil is wound around the wire frame, the coil has an input end and an output end, the input end is electrically connected to the first pin portion, and the output end is in contact with the winding hook portion. The magnetic core is in combination with the wire frame and the coil. The insulating cover is sleeved outside the wire frame and the magnetic core. A second pin portion corresponding to the first pin portion is disposed on the insulating cover. The output end of the coil is in contact with the winding hook portion, passes over the insulating cover, and is then connected to the second pin portion.

In summary, in the power adapter of the disclosure, the electromagnetic interference filter and the power factor correction inductor are disposed in the first region, and the shielding element is disposed in the first region and close to the electromagnetic interference filter on the circuit board. The transformer is disposed in the third region close to the first long side on the circuit board, and the first long axis of the power factor correction inductor and the second long axis of the transformer are perpendicular to each other. The heating elements are disposed at the back side of the circuit board. With such design, the overall volume of the power adapter of the disclosure can be reduced without affecting the power, and the space utilization rate of the circuit board can be improved to attain the characteristics of electronic products being lightweight, thin, and compact to meet the consumer demand.

DESCRIPTION OF THE EMBODIMENTS

FIG.1is a schematic view of the front side of a power adapter according to an embodiment of the disclosure. Referring toFIG.1, in the embodiment, a power adapter100includes a circuit board110, and the circuit board110has a front side110F and a back side110B opposite to each other (as shown inFIG.2).

In addition, the circuit board110further has a first long side112and a second long side114parallel to each other, and a first short side111and a second short side113parallel to each other. As shown inFIG.1, the circuit board110can be sequentially divided into a first region115, a second region116, and a third region117along the direction of the first long side112and the second long side114. In the embodiment, the first region115is larger than the third region117, and the third region117is larger than the second region116.

The power adapter100further includes an electromagnetic interference filter120, a shielding element130, a power factor correction inductor140, a transformer150, a first capacitor160, a second capacitor170, a half-bridge resonant capacitor180, and a half-bridge resonant inductor190configured on the front side110F of the circuit board110.

In the embodiment, the electromagnetic interference filter120is disposed at a position of the first region115close to the first long side112on the circuit board110. The power factor correction inductor140is disposed at the position of the first region115close to the second long side114on the circuit board110. The power factor correction inductor140has a first long axis140L. The first long axis140L of the power factor correction inductor140is parallel to the second long side114, so that the space occupied by the power factor correction inductor140in the short side direction of the circuit board110can be reduced.

The transformer150is disposed at a position of the third region117close to the first long side112on the circuit board110. The transformer150has a second long axis150L. The second long axis150L of the transformer150is perpendicular to the first long axis140L of the power factor correction inductor140, so that the space occupied by the transformer150in the long side direction of the circuit board110can be reduced.

That is, in the power adapter100, the large-sized power factor correction inductor140and the transformer150are configured on the front side110F of the circuit board110in a manner by which the second long axis150L is perpendicular to the first long axis140L, and the available space of the circuit board110in the long side direction or in the short side direction can be increased.

Furthermore, in the embodiment, the shielding element130is disposed at a position of the first region115close to the electromagnetic interference filter120and between the electromagnetic interference filter120and the power factor correction inductor140. The shielding element130is also disposed at a position between the electromagnetic interference filter120and the half-bridge resonant inductor190to block the noise from the power factor correction inductor140, the transformer150, and the half-bridge resonant inductor190. The shielding element130is L-shaped, for example; but in other embodiments, the shielding element130may also be annular or in other shapes.

By first designing how to configure the larger-sized elements on the circuit board110and next designing how to configure the smaller-sized first capacitor160, second capacitor170, half-bridge resonant capacitor180, and half-bridge resonant inductor190on the circuit board110, the layout of the elements of the power adapter100can be determined, so that the configuration density of elements on the circuit board110can be increased.

In the embodiment, the first capacitor160is disposed at a position across the second region116and the third region117close to the second long side114on the circuit board110. In addition, the first capacitor160has a third long axis160L, and the third long axis160L is perpendicular to the second long axis150L of the transformer150.

In the embodiment, the design in which the third long axis160L is perpendicular to the second long axis150L may allow the transformer150to be partially overlapped with the first capacitor160in the long side direction of the circuit board110, thereby increasing the configuration density.

In other embodiments, the third long axis160L of the first capacitor160may also be parallel to the second long axis150L of the transformer150, and the third long axis160L is parallel to the first short side111. Such a design allows the transformer150to be partially overlapped with the first capacitor160in the short side direction of the circuit board110, thereby increasing the configuration density.

In addition, the second capacitor170is disposed at a position of the second region116close to the first long side112on the circuit board110. The half-bridge resonant capacitor180is disposed at a position of the second region116farther from the first long side112compared with the position of the second capacitor170on the circuit board110. The half-bridge resonant inductor190is disposed at a position of the second region116between the second capacitor170and the half-bridge resonant capacitor180on the circuit board110.

In the embodiment, the half-bridge resonant capacitor180and the half-bridge resonant inductor190have a fourth long axis180L and a fifth long axis190L, respectively. The fourth long axis180L of the half-bridge resonant capacitor180is parallel to the third long axis160L of the first capacitor160. The fifth long axis190L of the half-bridge resonant inductor190is perpendicular to the fourth long axis180L of the half-bridge resonant capacitor180and parallel to the second long axis150L of the transformer150.

According toFIG.1, the half-bridge resonant capacitor180is disposed between the shielding element130and the transformer150, and the length of the half-bridge resonant capacitor180is only slightly less than the distance between the shielding element130and the transformer150. That is, the length of the half-bridge resonant capacitor180is quite equal to the length of the second region116in the long side direction.

In the embodiment, the design in which the fourth long axis180L of the half-bridge resonant capacitor180is parallel to the third long axis160L of the first capacitor160allows the half-bridge resonant capacitor180to make full use of the length of the second region in the long side direction, and the space occupied by the half-bridge resonant capacitor180in the short side direction of the second region can be reduced. Accordingly, the space of the second region in the short side direction can be released for configuring the half-bridge resonant inductor190with a longer length.

In addition, in the embodiment, the circuit board110has an input plug200disposed in the first region115close to the first long side112and the first short side111on the circuit board110.

FIG.2is a schematic view of the back side of the power adapter inFIG.1. Referring toFIG.2, in the embodiment, the power adapter100includes multiple heating elements disposed on the back side110B of the circuit board110. The heating elements at least include a bridge rectifier switch210, a power factor correction transistor220, and/or a half-bridge resonant transistor230. According toFIG.2, the bridge rectifier switch210and the power factor correction transistor220are disposed on the back side corresponding to the first region115, and the half-bridge resonant transistor230is disposed on the back side corresponding to the second region116.

In addition, the heating element adopts, for example, a metal-oxide-semiconductor (MOS) as a raw material, which can be produced at a lower cost compared to gallium nitride (GaN). The type and material of the heating element are not limited thereto.

Note that, for example, the dimensions of the power adapter100in the embodiment are about 113.5 mm in length, 64.5 mm in width, and 23 mm in thickness. The dimensions of a conventional power adapter are approximately 140.1 mm in length, 65.1 mm in width, and 25.4 mm in thickness. Therefore, the volume of the power adapter100of the embodiment is reduced by about 27.3%. Moreover, if it is assumed that the power of the power adapter100of the embodiment and the power of the conventional power adapter are both 180 W, then the power density of the power adapter100of the embodiment is about 1.069 (W/cm3), and the power density of the conventional power adapter is 0.777 (W/cm3). In short, the power density of the power adapter100of the embodiment is improved by about 37.58% compared with the power density of the conventional power adapter.

In addition, note that in other embodiments, the detailed dimensions of the power adapter100in the embodiment may be slightly different, the power and the power density of the power adapter100are only illustrated as examples, and the disclosure does not limit the detailed dimensions, the power, and the power density of the power adapter100.

In addition to improving the configuration of the power adapter, the disclosure also improves the transformer. To meet the requirement of the insulation distance of safety regulations, the conventional method of manually bundling insulating tapes makes it difficult to process the power adapter, which fails to contribute to mass production and cannot be improved to an automated process. Referring toFIG.3toFIG.5in the subsequent paragraphs,FIG.3is a schematic view of the transformer of the power adapter inFIG.1,FIG.4is an exploded view of the transformer inFIG.3, andFIG.5is a cross-sectional view of the transformer inFIG.3. Note that coils are not shown inFIG.3andFIG.4but shown inFIG.5.

Referring toFIG.3toFIG.5altogether, the transformer150includes a wire frame1501, a coil1502(as shown inFIG.5), two magnetic cores1503(as shown inFIG.4), and an insulating cover1504. As shown inFIG.4, the two magnetic cores1503are disposed in a central hole of the wire frame1501by passing therethrough. As shown inFIG.3, the magnetic core1503(as shown inFIG.4) along with the wire frame1501and the coil1502(as shown inFIG.5) are sheathed by the insulating cover1504.

The wire frame1501has a first end1501A and a second end1501B. A first pin portion1505is disposed at the first end1501A, and a winding hook portion1506is disposed at the second end1501B. A second pin portion1507is disposed on the insulating cover1504.

As shown inFIG.5, the coil1502is wound around the wire frame1501, and the coil1502has an input end1502A and an output end1502B. The input end1502A of the coil1502is connected to the first pin portion1505of the wire frame1501. The output end1502B of the coil1502is wound around the winding hook portion1506, passes over the insulating cover1504, and then is connected to the second pin portion1507of the insulating cover1504.

The winding hook portion1506allows the output end1502B to effectively widen the distance between the output end1502B and the coil1502inside the insulating cover1504, by which not only is the requirement of the insulation distance of safety regulations met, but also the probability of the mutual contact between the output end1502B and the coil1502is reduced. In addition, the insulating cover1504of the transformer150can keep the output end1502B outside the insulating cover1504, and thereby the mutual contact between the output end1502B and the coil1502is prevented. On the other hand, a second pin portion1507conforming to different parameters according to actual requirements can be disposed on the insulating cover1504, and the design margin and flexibility are large.

In summary, in the element layout of the power adapter of the disclosure, the positions and directions of four elements, the electromagnetic interference filter, the shielding element, the power factor correction inductor, and the transformer on the front side of the circuit board, are designed first. Next, the positions and directions of smaller-sized electronic elements, such as the first capacitor, the second capacitor, the half-bridge resonant capacitor, and the half-bridge resonant inductor, are arranged. Furthermore, the heating elements including the bridge rectifier switch, the power factor correction transistor, and/or the half-bridge resonant transistor are disposed on the back side of the circuit board. Accordingly, without affecting the power, the overall volume of the power adapter can be reduced, the space utilization and power density of the circuit board can be improved, and thereby the characteristics of electronic products being lightweight, thin, and compact can be attained to meet the consumer demand.

In addition, the transformer of the power adapter of the disclosure is designed with an insulating cover and a winding hook portion, so that the output end of the coil is in contact with the winding hook portion and then connected to the second pin after passing over the insulating cover. This processing method is not only easy but can effectively increase the safety distance between the output end of the second pin and the coil, and meanwhile the mutual contact between the output end and the coil can be further prevented, thereby improving safety.