JP2000091139A - Transformer device with central tap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transformer device with a central tap of which manufacturing is easy and of which output capacity can be changed by only changing a primary winding. SOLUTION: This device is provided with a pair of holding plates 7 and 8 which are provided by facing each other, plural cylinder cores 2a and 2b which are provided between the pair of the holding plates 7 and 8 in parallel, and secondary windings 3a1, etc., and 3b1, etc., with central taps which are constituted of plate conductors being provided on the internal and the external surfaces of the cylinder cores 2a and 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer device having a center tap and having a transformer core and a secondary winding, which is used for a switching power supply or the like.

[0002]

2. Description of the Related Art A transformer used for a switching power supply or the like has a primary winding wound on a core, an insulating tape wound thereon, and a secondary winding wound thereon. In this transformer, the output capacity is determined by the number of turns of the primary winding and the number of turns of the secondary winding, and the number of turns of the primary winding and the number of turns of the secondary winding are different for each output capacity. Kinds of things are produced.

[0003]

In the above transformer, the primary winding is wound on the core, the insulating tape is wound thereon, and then the secondary winding is wound. Therefore, the production is troublesome. The output capacity is determined by the number of turns of the primary winding and the number of turns of the secondary winding and cannot be changed, and the number of turns of the primary winding and the number of turns of the secondary winding are previously determined for each output capacity. A plurality of types having different numbers of windings must be prepared.

An object of the present invention is to provide a transformer device with a center tap which can be easily manufactured and whose output capacity can be changed only by changing the primary winding.

[0005]

Means for Solving the Problems In order to achieve the above object, the invention according to claim 1 comprises a pair of holding plates provided so as to face each other, and a primary winding mounted side by side between the pair of holding plates. It is provided with a plurality of cylindrical cores to be wound, and a secondary winding with a center tap formed by a plate-shaped conductor provided on the inner and outer surfaces of the cylindrical core.

[0006]

1 and 2 show a side view and a plan view of one embodiment of an integrated transformer device to which the present invention is applied, and FIG. 3 shows a circuit configuration of this embodiment. In this embodiment, a transformer device with a center tap, which is one embodiment of the present invention, and a choke coil 4 and rectifier diodes 5 and 6 are integrally formed, but the choke coil 4 and rectifier diodes 5 and 6 are integrated. May be separate from the core 2 and the secondary winding 3 of the transformer 1, and the choke coil 4 and the rectifying diodes 5 and 6 may be omitted. This embodiment is used, for example, for a switching power supply, and a pair of elongated holding plates 7 and 8 are provided in parallel to each other. The pair of holding plates 7 and 8 have conductivity and also serve as an electrode plate, and have high thermal conductivity and also serve as a radiation fin.

A transformer 1 is provided between one ends of the holding plates 7 and 8.
A plurality of tubular cores, for example, two tubular cores 2a and 2b constituting the core 2 are arranged side by side. This cylindrical core 2
a and 2b are formed in a rectangular tube shape as shown in FIG. 4, for example, and are arranged such that the hollow portions are parallel to the short direction of the holding plates 7 and 8. As shown in FIG. 5, the secondary winding 3 is composed of plate-shaped conductors 3a and 3b provided in contact with the inner and outer surfaces of the rectangular cores 2a and 2b. The plate-shaped conductor 3a has inner end portions 3a1 and 3a2 whose both end portions are formed obliquely with respect to the inner circumferential direction of the rectangular core 2a and are brought into contact with the inner surface of the rectangular core 2a.
a2 and two conductive plates including outer surface portions 3a3 to 3a6 in contact with corners of the outer surface of the rectangular cylindrical core 2a.

[0008] Both ends of the inner surface 3a1 are connected to the outer surfaces 3a3, 3a.
5, both ends of the inner surface 3a2 are connected to the outer surfaces 3a4, 3a.
a6. The inner surface portions 3a1 and 3a2 are provided on the inner surface of the prismatic core 2a with an oblique slit-shaped gap so that both ends do not contact each other.
a1 does not contact the outer surface portions 3a4 and 3a6, and the inner surface portion 3a2 is arranged so as not to contact the outer surface portions 3a3 and 3a5.

Similarly, the plate-shaped conductor 3b has inner ends 3b1 and 3b2 whose both ends are formed obliquely with respect to the inner circumferential direction of the rectangular core 2b and are in contact with the inner surface of the rectangular core 2b. ,
An outer surface portion 3b3 in contact with a corner of the outer surface of the prismatic core 2b
To 3b6. Both ends of the inner surface 3b1 are connected to the outer surfaces 3b3, 3b5,
Both ends of the inner surface 3b2 are connected to the outer surfaces 3b4, 3b6. The inner surface portions 3b1 and 3b2 are provided on the inner surface of the prismatic core 2b.
An oblique slit-shaped gap is provided so that each end does not contact each other, and the inner surface 3b1 is
The inner surfaces 3b2 are arranged so as not to contact the outer surfaces 3b3 and 3b5 while not contacting the outer surfaces 3b3 and 3b5.

The cylindrical cores 2a, 2b are arranged side by side between the holding plates 7, 8 as shown in FIG.
3 are connected by solder, and the outer surface portions 3a5 and 3b6 are connected by solder. Therefore, the outer surface portion 3a3, the inner surface portion 3a1, the outer surface portions 3a5, 3b6, the inner surface portion 3b2, and the outer surface portion 3b4 are connected in series and the first 2 wound around the cylindrical cores 2a, 2b.
A secondary winding is formed, and the outer surface portion 3a6, the inner surface portion 3a2, the outer surface portions 3a4, 3b3, the inner surface portion 3b1, and the outer surface portion 3b5 are connected in series and are wound around the cylindrical cores 2a, 2b. Construct the winding. The first secondary winding and the second secondary winding are connected to the outer surface portions 3a5 and 3a6 by solder, so that a secondary tap with a center tap having a solder connection portion of the outer surface portions 3a5 and 3a6 as a center tap is provided. The winding 3 is configured.

A choke coil 4 is mounted between the other ends of the holding plates 7 and 8, and the choke coil 4 is wound three times around a winding shaft planted in the center of a rectangular cylindrical core. It was what was. One end of the choke coil 4 is connected to the solder connection portions of the outer surface portions 3a5 and 3a6 by solder, and is connected to a tap corresponding to the solder connection portion of the outer surface portions 3a5 and 3a6 of the secondary winding 3. . The other end of the choke coil 4 is connected to a holding plate 7 also serving as an electrode plate by soldering.

The rectifying diodes 5, 6 are integrated into one.
And one rectifier unit 9.
Are provided with connection terminals 10 and 11 connected to the anodes of the rectifier diodes 5 and 6, respectively, and a connection terminal 12 connected to the cathodes of the rectifier diodes 5 and 6. The rectifier unit 9 has connection terminals 10 and 11
Are connected to the outer surface portions 3b4 and 3b5 serving as both ends of the secondary winding by soldering, and the connection terminals 12 are connected to the holding plate 8 also serving as an electrode plate by soldering, so that the connecting terminals 12 are integrated with the holding plates 7 and 8. It is composed of The tubular cores 2a, 2b are fixed to the holding plates 7, 8 via insulating layers 13, 14, and the choke coil 4 is fixed to the holding plates 7, 8 via insulating layers 15, 16. The holding plates 7 and 8 also serving as electrode plates are output terminals 1
7, 18 are provided at the ends.

In this embodiment having such a configuration, the primary winding 19 of the transformer 1 is wound around the cylindrical cores 2a, 2b through the hollow portions of the cylindrical cores 2a, 2b. Is connected to the capacitor 20. The AC input voltage input to the primary winding 19 is transformed by the transformer 1, rectified by the rectifying diodes 5 and 6, and smoothed by the choke coil 4 and the capacitor 20.

This embodiment is an embodiment of an integrated transformer device to which the invention according to claim 1 is applied. A pair of holding plates 7 and 8 provided to face each other, and the pair of holding plates 7 and 8 and the primary winding 19
And a secondary winding 3 having a center tap formed of a plate-shaped conductor provided on the inner and outer surfaces of the cylindrical cores 2a and 2b. Therefore, the output voltage of the transformer can be determined by the number of turns of the primary winding. For this reason, transformers having different output capacities can be realized only by changing the primary winding with one type of transformer. In addition, the primary winding need only be wound through the cylindrical core, which facilitates manufacture. Note that the present invention is not limited to the above embodiment, and for example, three or more cylindrical cores may be provided.

[0015]

As described above, according to the first aspect of the present invention, with the above configuration, the output voltage of the transformer can be determined by the number of turns of the primary winding.
Transformers with different output capacities can be realized only by changing the primary winding. In addition, the primary winding need only be wound through the cylindrical core, which facilitates manufacture.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of an integrated transformer device to which the present invention is applied.

FIG. 2 is a plan view showing the same embodiment.

FIG. 3 is a circuit diagram showing a circuit configuration of the embodiment.

FIG. 4 is a perspective view showing a prismatic core of the embodiment.

FIG. 5 is a perspective view showing a secondary winding of the embodiment.

FIG. 6 is a perspective view showing a prismatic core and a secondary winding of the embodiment.

[Explanation of symbols]

 2a, 2b cylindrical core 3 secondary winding 7, 8 holding plate 19 primary winding

Claims (1)

[Claims] 1. A pair of holding plates provided to face each other, a plurality of cylindrical cores mounted side by side between the pair of holding plates and having a primary winding wound thereon, and inner and outer surfaces of the cylindrical cores. And a secondary winding having a center tap formed by a provided plate-shaped conductor.