JPS5934614A - Leakage transformer for high frequency - Google Patents

Abstract

PURPOSE:To reduce the eddy-current loss due to leakage flux by a method wherein a primary winding and a secondary winding are provided in parallel with each other with a gap between the main core and said windings, and a shunt core is provided in one body with the intermediate part between the primary and the secondary windings on the main core. CONSTITUTION:A main core consists of U type cores 1-1 and 1-2, and I type core 1-3 which is arranged between each leg part of said U type cores 1-1 and 1-2, and a gap is formed at each butting part of the U type cores 1-1, 1-2 and I type core 1-3. The shunt core 4 is provided in one body with the intermediary part of the primary winding 2 and the secondary winding 3 on the main core 1. As the shunt core 4 is provided at the I type core 1-3 of the main core 1, the number of interlinkage of the leakage flux phi1 flowing the shunt core 4 and the windings 2 and 3 is relatively small.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency leakage transformer used as an output transformer of a high frequency inverter.

Conventionally, many devices have been proposed for lighting discharge lamps at high frequencies, and many devices using inverters as high frequency generators in such lighting devices have also been proposed.

A high frequency leakage transformer is used as an output transformer of such an inverter. That is, the leakage inductance is used as a current limiting device for a discharge lamp.

In conventional high-frequency leakage transformers, a main magnetic path is formed by butting together multiple iron cores made of ferrite material, and a gap is formed at the butt part to adjust the number of turns of the winding and the length of the gap. to obtain the desired leakage inductance. The reason why leakage inductance can be obtained in the above manner in a high frequency leakage transformer is because it is used for high frequencies, so the inductance needed to obtain the necessary impedance can be extremely small compared to commercial frequencies. . That is, the leakage inductance relative to the main inductance can be increased by reducing the number of turns of the winding or by increasing the gap length.

However, the conventional high-frequency leakage transformer described above has a problem of high power loss.In other words, as described above, in order to obtain leakage inductance, a relatively large gap is formed, but this gap The leakage magnetic flux is widely distributed around the winding, and this leakage flux interlinks with the windings, causing an eddy current product. Since the thin current product is proportional to the square of the frequency, the eddy current product becomes extremely large in high frequency leakage transformers where alternating magnetic flux of 101 (Hz or more), which is much higher than the commercial frequency, is generated. As mentioned above, this problem is unique to high-frequency leakage transformers that attempt to obtain leakage inductance by using the gaps between the abutting parts of multiple cores that form the main magnetic path. In a leaky transformer for low frequencies such as commercial frequencies, which is provided with a leakage transformer, there is virtually no problem.

The present invention has been made in order to eliminate the drawbacks of the conventional devices described above, and an object of the present invention is to provide a high frequency leakage transformer that can reduce the product of thin current due to leakage magnetic flux and reduce overall power loss. It is something.

The present invention provides the desired leakage inductance while achieving the desired leakage inductance.
This was done in pursuit of reducing the number of linkages between leakage magnetic flux and the windings, and the primary winding and secondary winding are arranged side by side with a gap between them on the main iron core that forms the main magnetic path. , a shunt core is provided integrally with an intermediate portion of the secondary winding and the secondary winding in the main core.

In the present invention, by providing the shunt core, leakage magnetic flux can be passed through the shunt core, and further,
Since the shunt core is provided integrally with the part of the main core around which the primary and secondary windings are wound, it is possible to significantly reduce the leakage flux interlinking with each winding.

That is, in general, the winding can be wound in large numbers on the side of the core to be wound. For example, if the main core is made up of a pair of E-shaped cores butted against each other, the windings are located on the side legs of each E-shaped core where the windings are wound. Therefore, by providing a shunt core integrally with the main core portion around which the windings are wound, leakage magnetic flux interlinking with the windings can be further reduced. Here, the reason why the shunt iron core is provided in the present invention is to make the leakage magnetic flux, which was widely distributed in the past, flow in a concentrated manner. This is completely different from having an iron core. In addition, if the '1.1 shunt core is installed in a conventional high frequency leakage transformer,
Since the leakage flux may become too large, it is necessary to adjust the gap in the main core and the shape of the shunt core, but such adjustments will be easy for the musician.

In the invention, high frequency is 10 KHz or higher.

Further, in the non-invention, iron cores made of phenoite, r-morphous l, etc. are used as the main iron core and the shunt iron core. However, silicon steel sheets, which increase tL power loss when used at high frequencies of 10KI (z or higher), should be avoided. - Also, the shape of the main core and shunt core may be arbitrary. a pair of 1” iron cores;
It is possible to use a molded iron core which is made up of a rounded iron core held between the legs of the necked iron core. Furthermore, the shunt core and a portion of the main core may be integrally formed. In this case, it is easy to assemble, and the main core 1
It is possible to increase the degree of integration of the positional relationship between the shunt core and the winding.

Furthermore, the present invention can be used as an output transformer for an inverter whose load is a discharge lamp. In this case, the leakage inductance is used as a current limiting device for the public market lamp. However, the uses of the present invention are not limited to the above-mentioned ones.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3. (1) is the main core, which is made by butting together a plurality of cores, for example three cores, to form a main magnetic path. That is, in this embodiment, a pair of Ll type iron cores (1-1,
(1-2) and these 1-'' type cores (1-1).

It consists of a ■-shaped iron core (1-) placed between each leg of (1-2). These L” shaped cores (1-1), (], -2
), [A gap is formed at each abutting portion of the shaped iron core (1-3).

A well-known subedator can be interposed in these gaps. t2), (3) is the -order winding and the secondary winding,
The square iron cores (1-3) of the main iron core (1) are arranged in parallel with each other at intervals. (4) is the shunt core,
The main iron core (1) is provided integrally with an intermediate portion of the secondary winding (2) and the secondary winding (3) in the IC. That is, in this embodiment, it is provided at the middle portion of the ■-shaped iron core. This shunt core (4) may be made of cedar integrally with the ■-shaped core (1-3) of the main core (1). Alternatively, a gap L2 may be provided that does not substantially cause leakage (B'1 bundle).

It is said that it has a unique effect. Since the shunt core (4) is installed on the I-type core (1-3) of the main core (1) in the relationship shown in b12 above, the leakage magnetic flux (because of the leakage magnetic flux flowing through this shunt core (4) ), and the number of linkages between glands (2) and (3) is relatively small.

That is, referring to FIGS. 3 and 4, as shown in FIG. 4, the shunt core (4) is connected to the tlfli main core (j -1'), the output (z
2) and the windings (4) and (j), the number of interlinkages is greater than that in FIG. This is the iron core 11i on which the winding is wound! +
Therefore, even if the same magnetic flux (for) and (me2) flows through the shunt core L4) and (J), the number of linkages with the winding will be different.

The above embodiment can be used as the output voltage (T) of the transistor inverter (in) shown in FIG. In FIG. 5, (Fl,) is a discharge lamp as a load. Since the circuit structure of the transistor inverter (In) shown in FIG. 5 is well known, its explanation will be omitted. In the case shown in Fig. 5, (Wb) can be wound on the base, or this Heess winding (sb) can be wound on the upper layer of the input winding (2) in the case shown in Fig. 1. Also,
In FIG. 5, (N f ) is a filament winding, which shows the actual measured value of gravity loss in a leaky transformer when applied to the one in FIG. 1.

Main core material = Ferrai) H7C3 (manufactured by Tokyo Denki Kagaku Kogyo Machishiki Company) Main core external dimensions: 40 (campus x 58 (width x 230!7)
(-m') Frequency: 40Kl-12 Load: 2 110W fluorescent lamps Series input winding (width wire: diameter 0.08 mm x 60 wires) number σ) / output winding (width wire: diameter 0.12#) X 20 pieces) σ) Near 4/99
Distance between winding and main core (1-3) or <1-3':
Approximately 1 mm Distance between winding and main core (1-t) or (1-,'): Approximately 3 Shunt core (4) t or (4) Gap length with main core: 2wn Figure 6 and FIG. 7 shows another embodiment of the invention. In this example, the main iron core (kG
consists of a pair of E-shaped cores (10-1) and (10-2), and each side leg of one E-shaped core (10-1) is formed shorter than the central leg. And these E type iron cores (10
-1), (10-2) at the joint of the central leg with shunt core Q
υ, (1υ) is fixed by adhesive etc.

Other parts that are the same as those in the first embodiment are given the same reference numerals. The operation of this embodiment is similar to that of the first embodiment, so the explanation will be omitted.

FIG. 8 shows still another embodiment of the present invention.

The present embodiment is of the so-called internal iron type, and the main iron core (to) is formed by butting together the core type and the l-shaped iron core (20-1), <2O-2). The shunt core (2]) is provided in a similar relationship to that described above. In this embodiment as well, the same parts as in FIG.
Since it is the same as that shown in the figure, the explanation will be omitted.

As described in detail above, the present invention provides a primary winding and a secondary winding that are arranged side by side with a space between them on a main core that forms a main magnetic path, and the secondary winding and the secondary winding on the main core. Since the shunt core is provided integrally with the middle part of the next winding, the leakage magnetic flux interlinking with the winding can be significantly reduced, and the eddy current loss due to the leakage magnetic flux can be reduced, resulting in the overall 'gravitational loss'. Therefore, it is possible to provide a high frequency leakage transformer with less leakage.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional front view showing one embodiment of the present invention, and FIG.
3 is a perspective view showing the iron core, FIG. 3 is an enlarged view of a part of FIG. 1, FIG. 4 is a view corresponding to FIG. Figure 6 is a circuit diagram showing a transistor inverter to which the present invention is applied, Figure 6 is a partially sectional front view showing another embodiment of the present invention, Figure 7 is a perspective view also showing the iron core, and Figure 8 is FIG. 7 is a partially sectional front view showing still another embodiment of the present invention. (1), (LQ), 4...Main core, (2)...-Next winding, (3)...Secondary winding, (4), Qυ, (21
＞...Shunt core, patent applicant Tokyo Denki Kagaku Kogyo Co., Ltd. Toshiba Electric Materials Co., Ltd.

Claims (4)

[Claims] (1) A main core formed by butting together a plurality of cores to form a main magnetic path; A primary winding and a secondary winding arranged in parallel on this main core at intervals; A high frequency leakage transformer comprising: a shunt core integrally provided with an intermediate portion of the secondary winding and the secondary winding. (2) The high frequency leakage transformer according to claim (1), wherein the shunt core is integrally formed with a part of the core. (3) The main core has a pair of 1" type cores, and these 1
Claim (1) characterized in that the shunt core is provided at an intermediate portion of the shaped iron core, and the shunt core is disposed between the legs of the shaped iron core. Or the high frequency leakage transformer described in (2). (4) Claim (1) characterized in that the main iron core and the shunt iron core are made of ferrite material.
The high frequency leakage transformer according to any one of ) to (3).