JPS5926188B2 - flyback transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flypack transformer that supplies high voltage to a cathode ray tube of a television receiver or the like.

Flypack transformers are generally configured to generate high voltage using a so-called high-order harmonic tuning method. That is, in a television receiver. The above-mentioned high-order harmonic tuning can be achieved by setting the leakage inductance between the primary and secondary windings and the distributed capacitance on the secondary side, which together with the inductance of the deflection yoke and the resonant capacitance form the flyback transformer, to appropriate values. is facilitated. Therefore,
recently . Now, a method has been considered in which the secondary winding is divided into a plurality of coil units using a plurality of diodes, and the distributed capacitance on the secondary side is reduced in appearance. This method is preferable from the standpoint of insulation, since the high-voltage generated pulses are also small when considering each coil unit.
In this case, a so-called split bobbin in which a winding groove is formed by a plurality of flanges is generally used. However, the above-mentioned bobbin has a complicated structure, is difficult to mold, and requires a considerable amount of time to wind up the secondary winding, resulting in an increase in the price of the product. Furthermore, since a large number of windings are made and stacked in each winding groove of the bobbin, there is a limit to the reduction in distributed capacity. There is also a coil unit in which each coil unit divided by a diode has a flat winding structure without using a complicated bobbin as described above.

In this case, each coil unit is formed as a single wound layer on an interlayer paper or a simple cylindrical bobbin with the same winding direction and winding width. As a result, the interlayer potential difference between the corresponding upper and lower turns between adjacent turns becomes zero or smaller, thereby reducing the interlayer distributed capacitance. However, in such a configuration, the leakage inductance between the primary winding and each coil unit becomes non-uniform. That is, the coil unit on the side farther from the primary winding has a larger geometric dimension with respect to the primary winding than the side closer to the primary winding, and the leakage inductance also becomes larger. Therefore, the degree of coupling between the primary winding and each coil unit is insufficient, and harmonic tuning becomes uneven.
Setting high-order harmonic tuning for the entire secondary winding becomes extremely difficult in practice. As a result, it has not been possible to improve high voltage power conversion efficiency or high voltage regulation. The present invention particularly improves the latter type of flyback transformer having a flat winding configuration.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a wiring diagram showing the configuration of a flypack transformer according to the present invention. 1 is a primary winding, 2 is a secondary winding, and the secondary winding 2 has four diodes D1, D2, D3 and D4.
From VC, four coil units Ll, L2, L3 and L4 are divided and connected in series.

This specific configuration is illustrated in FIG. On the primary winding 1 wound on the core 3, four coil units L1 to L4 are stacked as a single winding layer, and on the outer periphery of these secondary windings 2, Diodes D are arranged in parallel (only one is shown in the figure) on a support base 4 made of an insulating material. The coil units are connected sequentially at the beginning and end of the winding as shown in Figure 1.The above coil units are all wound in the same direction.In particular, in the present invention, the inner coil unit closest to the primary winding 1 The winding pitch of each coil unit is smaller than the winding width of the farthest coil unit.In this case, the winding pitch of each coil unit is the same.In other words, each stacked coil unit has a distance from the primary winding that is Therefore, if each coil unit were to have the same winding configuration, the degree of coupling would decrease and the leakage inductance would increase as the coil unit is closer to the outer circumference, but with such a configuration, It is possible to equalize the leakage inductance between each coil unit.Of course, there is a potential difference between the corresponding upper and lower turns between adjacent winding layers, and there is a concern that the interlayer distributed capacitance will increase, but the present invention As shown in FIG. 4, each coil unit is divided into a single winding layer by a diode, and can be ignored in practical terms because they are all wound in the same direction. An example is shown. According to FIG. 4, each coil unit L
1 to L4, the winding start sides are all set at the same position, and the winding width on the side far from the primary winding is larger than that on the side closer to the primary winding. This configuration is preferable in terms of distributed capacitance because most of the coil units can have equal interlayer potential differences. FIG. 5 shows yet another embodiment. In this embodiment, each coil unit has the same number of turns, but the farther the coil unit is from the primary winding, the thinner the winding pitch is, the wider the winding depression is to compensate for the decrease in the degree of coupling with the primary winding. . FIG. 6 additionally shows another embodiment. In this embodiment, the winding widths are kept constant, but the winding pitch is made denser and the number of turns is increased as the coil unit is further away from the primary winding. Furthermore, the third
The figure is a side view of FIG. 2 shown for explaining the mounting state of the diode. The support base 4 has legs 41 that are in contact with the outer periphery of the secondary winding, and each of the diodes Dl, D2,
D3 and D4 are arranged in parallel. Further, 21 is interlayer paper interposed between each coil unit, and a cylindrical bobbin can also be used. In this case, in order to clarify the explanation, each winding wire material and the interlayer paper are illustrated so as to have a space between them. Further, the area 5 surrounded by the dashed line is an impregnated molding material that covers the primary winding, secondary winding, diode, etc., integrally after they are installed, and an insulating resin such as epoxy resin or polybutadiene resin is used. . As described above, in the present invention, each coil unit divided by diodes has a different winding structure so as to equalize the leakage inductance between each coil unit and the primary winding. The degree of coupling of each coil unit to the winding can be made equal, making it easy to adjust the harmonic tuning in each coil unit to the same order. Therefore, the high voltage power conversion efficiency and high voltage regulation between the primary winding and the secondary winding can be further improved, and higher harmonics can be generated without using the conventional expensive split bobbin. The effects of practical soil, such as facilitating synchronization, are extremely large. Although the number of diodes and coil units is shown as four, it is not particularly limited as long as it is at least two or more.

[Brief explanation of the drawing]

Fig. 1 is a wiring diagram showing the configuration of a flyback transformer according to the present invention, Fig. 2 is an explanatory diagram of assembly showing an embodiment of the invention, Fig. 3 is a side view thereof, and Figs. 4 to 6 are FIG. 7 is an explanatory diagram of other embodiments showing essential parts of the present invention. 1...Primary winding, 2...Secondary winding, L
l. L2, L3, L4... Coil unit, D
l, D2, D3, D4...Diode.

Claims (1)

[Claims] 1 Consisting of a primary winding and a secondary winding divided into multiple coil units by multiple diodes, each coil unit is wound in the same direction and formed by a single winding layer, and these coils are In a flyback transformer configured to stack units in sequence, each coil unit has a different winding structure so as to equalize leakage inductance between the primary coil and each coil unit. flyback transformer.