JPH04273412A - Transformer for high-frequency power use - Google Patents

Abstract

PURPOSE:To provide a transformer, for high-frequency power use, which is small-sized and whose high-frequency characteristic is good. CONSTITUTION:A first radiator 4 is attached in such a way that it comes into close contact with the outer circumferential face of a core 2 into which a transformer winding 1 has been inserted. The bottom face of the first radiator 4 is fixed and bonded to the surface of a second radiator 5 which is provided with fins 7 at its lower part. Heat generated at the core 2 is conducted to the first and second radiators 4 and 5 is dissipated into the air from the surface of the radiators. It is not required to make the core large in order to increase its heat-dissipating capacity as different from conventional transformers for high-frequency power use, and a transformer can be made small-sized. Even when the core is made large-sized, the winding of the transformer does not become long, and a good high-frequency characteristic can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency power transformer, and more particularly to a high frequency power transformer that is small in size and has good high frequency characteristics.

0002

2. Description of the Related Art Conventionally, in this type of high frequency power transformer, it has been necessary to make the transformer winding as short as possible in order to improve the high frequency characteristics. For this reason, a core material such as ferrite was inserted into the winding to obtain the required inductance. Further, conventional high-frequency power transformers generate a considerable amount of heat due to power loss in the core material when power passes through the transformer. As is well known, when a core material in a high temperature state reaches the Curie temperature determined by the material of the core material, its magnetic permeability decreases extremely and it loses its function as a transformer. To avoid this, conventional high-frequency power transformers must be designed so that the core material has a large dimension to ensure thermal capacity and the required passing power can be obtained without reaching the Curie temperature. was there.

[Problem to be solved by the invention]

The conventional high frequency power transformer described above is
In order to suppress the temperature rise of the core, it is necessary to increase the dimensions of the core, and the temperature rise due to the heat generated by the core increases as the passing power increases, so there is a problem that the required dimensions of the core increase cumulatively. . Additionally, increasing the core dimensions also increases the length of the transformer windings.
There is a problem that the high frequency characteristics of the transformer deteriorate.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a high-frequency power transformer that is small in size and has good high-frequency characteristics.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the high frequency power transformer of the present invention includes a winding forming a high frequency power transformer circuit, a core through which the winding is inserted, and a core that extends through the winding. The structure includes a heat radiator that is provided in close contact with each other.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a high frequency power transformer according to an embodiment of the present invention. In the figure, 1 is a transformer winding, 2 is a core (material), 4 is a first heat radiator, 5 is a second heat radiator, 6 is a printed wiring board, and 10 is a power amplification element.

The transformer winding 1 forms a transformer circuit. The transformer winding 1 is inserted into a through hole 3 of a core 2 made of a core material such as ferrite, and the core 2 ensures a predetermined inductance.

The first heat radiator 4 is formed so that the outer peripheral surface of the core 2 is covered with a box-shaped body made of a material such as a metal having good thermal conductivity, and the core 2 is buried therein. However, the external shape of the first radiator 4 is not limited to the box-like shape shown in FIG. The second heat radiator 5 has an area comparable to that of the printed wiring board 6, and has fins 7 formed at the bottom to improve heat radiation efficiency.

[0009] The printed wiring board 6 is placed on the upper surface of the second heat radiator 5. The printed wiring board 6 is provided with cutouts 8 and 9, through which a part of the upper surface of the radiator is exposed. The heat sink 4 and the power amplification element 10 are fixed to the exposed surface of the second heat sink 5 exposed by the cutouts 8 and 9. The power amplifying element 10 is fixed onto the second heat radiator 5 via a mount 11. Further, the power amplification element 10 is connected to the transformer winding 1 via a printed wiring 12, and supplies high frequency power to the transformer.

Next, the operation of the high frequency power transformer of the present invention having the above structure will be explained. Power amplification element 10
High frequency power is supplied to the transformer, and as it passes through the transformer, the core 2 itself generates heat due to power loss caused by the core 2. This heat is first conducted to the first radiator 4 and then to the second radiator 5. Then, it is radiated into the air from the surfaces of the first radiator 4 and the second radiator 5. The second radiator 5 also serves as a radiator for the power amplification element 10, and radiates heat generated by the power amplification element 10 into the air.

In the above embodiment, the core 2, the first heat radiator 4, and the second heat radiator 5 are constructed as separate parts, and these are constructed in close contact with each other to suit heat conduction. These parts may not be separate parts but may be constructed integrally.

[0012] The first and second heat sinks 4, 5 described above each produce a considerable heat radiation effect even when they are used alone, so depending on the type of transformer, the first and second heat sinks 4, 5,
In some cases, only one of 5 is sufficient. Therefore, the radiator in the present invention includes only one of the first and second radiators 4 and 5.

[0013]

[Effects of the Invention] As explained above, the high-frequency power transformer of the present invention is equipped with a radiator with high heat dissipation capacity, so unlike the conventional high-frequency power transformer, the core is enlarged to increase the heat dissipation capacity. There is no need to do this, and the transformer can be made smaller. Further, the winding of the transformer does not become long due to the increase in the size of the core, and therefore good high frequency characteristics can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a high-frequency power transformer according to an embodiment of the present invention.

[Explanation of symbols]

1...Transformer winding 2...Core 4...First radiator 5...Second radiator 6...Printed wiring board 10...Power amplification element

Claims (2)

[Claims] 1. A transformer for high frequency power, comprising a winding forming a transformer circuit for high frequency power, a core through which the winding is inserted, and a radiator provided in close contact with the core. Trance. [Claim 2] The heat radiator is composed of a first radiator formed to cover the outer peripheral surface of the core and bury the core, and a second radiator that also serves as a radiator for a heat generator other than the transformer. The high frequency power transformer according to claim 1, characterized in that: