JPH08182324A - Ac adapter - Google Patents

Abstract

PURPOSE: To facilitate the manufacture and to miniaturize an AC adapter by simplifying the structure of a heat radiating plate for a voltage regulator. CONSTITUTION: An AC adapter 21 comprises a power transformer 27, a PCB 34, a three-terminal regulator 35 mounted as a voltage regulator on the PCB 34, and a heat radiating plate 37 extended at the regulator 35, wherein a support piece 41 is provided on the plate 37. The piece 41 is inserted to an air gap 33 between the core shaft 31 of the center of the transformer 27 and a bobbin 29, thereby fixing the plate 37 to the transformer 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC adapter, and more particularly to a radiator plate for a voltage regulator of the AC adapter.

[0002]

2. Description of the Related Art A conventional AC adapter of this type will be described with reference to FIG. In FIG. 4, 1 is an AC adapter,
It incorporates a power transformer 2 for transforming an AC power source and a PCB 3 on which electronic parts for DC exchange are mounted. The PCB
A voltage regulator 4 such as a three-terminal regulator is planted in 3 to keep the output DC voltage constant even if the input voltage or the load current fluctuates. Since the voltage regulator 4 emits high heat during operation, the heat dissipation plate 5 is extended to the voltage regulator 4. Gripping portions 6 and 7 are provided at the front and rear ends of the heat dissipation plate 5, and the grip portions 6 and 7 are further provided with claws 10 and 11 for engaging with the core shafts 8 and 9 at the front and rear ends of the power transformer 2. And bent portions 12 and 13 at the tip are provided. Then, the heat sink 5 is fixed to the power transformer 2 by gripping the power transformer 2 from both front and rear sides by the grip portions 6 and 7. The grips 6 and 7 also function as heat sinks.

[0003]

Means for providing a heatsink with a grip and gripping the power transformer from the outside by the grip causes an increase in the size of the AC adapter. On the other hand, in order to obtain as large a heat radiation effect as possible within the limited volume of the AC adapter, it is effective to increase the contact area between the heat sink and the core to transfer heat to the core. However, the size of the AC adapter must be increased, and the AC adapter must be increased in size. Also, in order to fix the heat sink to the power transformer, the heat sink must be precisely machined according to the shape of the power transformer, and it is necessary to provide a claw on the grip and bend the tip. It is not easy to manufacture a board, which leads to cost increase.

Therefore, there arises a technical problem to be solved in order to downsize the AC adapter, simplify the structure of the heat dissipation plate, facilitate the production, and reduce the cost. The purpose is to solve.

[0005]

The present invention has been proposed in order to solve the above-mentioned problems, and includes a power transformer and a PC.
B and built-in, the voltage regulator is planted in the PCB,
Further, in an AC adapter in which a heat dissipation plate is extended to the voltage regulator, a support piece is provided on the heat dissipation plate, and the support piece is fitted into a gap between a core shaft around which a coil of a power transformer is wound and a bobbin surrounding the core shaft. By wearing it, an AC adapter in which the heat dissipation plate is fixed to a power transformer is provided.

[0006]

The heat generated from the voltage regulator is conducted through the heat radiating plate, radiated from the exposed portion of the heat radiating plate to the outside of the power transformer to the space inside the AC adapter outer casing, and is also transmitted to the core through the supporting piece. The core also diverges into the space inside the AC adapter outer casing. Then, it is released to the outside through the outer casing of the AC adapter. Alternatively, when the exposed portion of the radiator plate on the outside of the power transformer is in contact with the AC adapter outer casing, the heat of the radiator plate is directly transferred to the AC adapter outer casing and radiated to the outside.

[0007]

Embodiments of the present invention will be described below in detail with reference to FIGS. FIG. 1 shows an AC adapter 21. An outer casing composed of an upper case 22 and a lower case 23 is molded of synthetic resin, and a plug insertion hole 24 is opened in the lower surface of the lower case 23 so that AC power input plug 2
5 is protruding. In addition, the upper case 22 and the lower case 23
A DC output cord 26 is wired to the outside of the AC adapter 21 from the meshing portion on the right side of and.

As shown in FIG. 2, the AC power input plug 25 is fixed to a power transformer 27, and the primary coil 2
Wired to 8. The primary coil 28 is wound around a bobbin 29 made of synthetic resin, and the bobbin 29 has an EI core 30.
A magnetic flux interlinking with the primary coil 28 is generated in the EI core 30 by being inserted into the central core shaft 31 of the. The EI-shaped core 30 is formed by punching a silicon steel plate or the like with a press die and stacking a plurality of layers. Further, a bobbin 29 is wound around a bobbin 29 above the primary coil 28 on the central core shaft 31, and the bobbin 29 surrounds the central core shaft 31 and A gap 33 is formed between the right side surface of the core shaft 31 and the right inner side surface of the bobbin 29. In addition, the primary coil 28
The secondary coil 32 and the EI core 30 are isolated and insulated by the bobbin 29. Then, the secondary coil 32 is changed by the change of the magnetic flux generated in the EI type core 30.
A voltage having the same frequency as that of the input AC power source is induced at the terminal, and the terminal of the secondary coil 32 is wired to the PCB 34 in which a diode, a capacitor and the like are mounted, so that the DC voltage is rectified and output by the DC output code 26.

In order to stabilize the output DC voltage, the P
A three-terminal regulator 35 is implanted in the CB 34 as a voltage regulator. Since the three-terminal regulator 35 generates high heat during operation, it is fastened to the vertical frame 38 in front of the heat radiating plate 37 by bolts 36. The heat dissipation plate 37 is formed in a U shape by a vertical frame 38 to which the three-terminal regulator 35 is fixedly mounted, a vertical frame 39 at the rear, and a bottom plate 40, and a support piece 41 stands on the left end of the bottom plate 40. It is set up. The support piece 41 also functions as a heat dissipation plate, and is formed in conformity with the shape of the gap 33. And FIG.
As shown in FIG. 3, the support plate 41 is inserted into the space 33 and tightly fitted by the central core shaft 31 and the bobbin 29, so that the heat dissipation plate 37 is fixed to the power transformer 27.

Therefore, the components for fixing the heat dissipation plate 37 are housed inside the power transformer 27, so that the AC adapter can be made smaller than the conventional means for holding the power transformer from the outside. be able to. Also,
Since the support piece 41 is in close contact with the entire length of the central core shaft 31, the contact area with the core can be made larger than in the conventional case, and more heat can be transferred to the core to enhance the heat dissipation effect. Further, unlike the prior art, since it is not necessary to form the claws and the bent portions so as to hold the power transformer, it is possible to easily manufacture the heat dissipation plate and reduce the cost. Further, the claws and the bent portions are locked to the core, and the gripping portion is not attached by urging the power transformer. Can be simplified.

The PCB 34 is fixed to the upper right end surface of the bobbin 29 by caulking or soldering, and the front vertical frame 38 and the rear vertical frame 39 of the heat radiating plate 37 are P respectively.
Contact the lower surface of CB34. Then, the three-terminal regulator 35 is soldered to the PCB 34.

The present invention can be modified in various ways without departing from the spirit of the present invention, and it goes without saying that the present invention extends to such modifications.

[0013]

As described in detail in the above one embodiment of the present invention, the support piece of the heat dissipation plate is fitted in the space between the core shaft around which the coil is wound and the bobbin surrounding the core shaft.
The heat sink can be easily attached to the power transformer. In addition, since the supporting piece is housed inside the power transformer, not only can the AC adapter be downsized, but also the claws and bent portions required when gripping it from the outside are not required, so that the manufacturing is easy and the cost is low. Can be down.
Furthermore, since the contact area between the heat sink and the core can be increased,
The heat dissipation effect of the voltage regulator can be increased, etc.
It is an invention that exhibits various kinds of effects.

[Brief description of drawings]

FIG. 1 is a side view showing the outer appearance of an embodiment of the present invention.

FIG. 2 is an exploded perspective view of FIG.

FIG. 3 is a vertical sectional side view of FIG.

FIG. 4 is an exploded perspective view showing a conventional example.

[Explanation of symbols]

 21 AC Adapter 27 Power Transformer 28 Primary Coil 29 Bobbin 30 Core 31 Central Core Shaft 32 Secondary Coil 33 Gap 34 PCB 35 Three-Terminal Regulator 37 Heat Sink 41 Support Piece

Claims (1)

[Claims] 1. A power transformer and a PCB are built-in, and the P
In an AC adapter in which a voltage regulator is planted in CB, and a heat radiating plate is further extended to the voltage regulator, a support piece is provided on the heat radiating plate, and the support piece is provided with a core shaft around which a coil of a power transformer is wound and the core shaft. An AC adapter characterized in that the heat dissipation plate is fixed to a power transformer by being fitted in a gap with a bobbin surrounding the.