JPS6118898B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flyback transformer used for supplying anode voltage to a cathode ray tube such as a TV receiver.

As shown in the circuit diagram in Figure 1, a conventional flyback transformer has a rectifier circuit 2 connected to the output end of a high-voltage coil 1, and the output end of the high-voltage coil 1 usually has a voltage of 10-odd KV to 20-odd KV. Since high alternating current voltages are induced, the insulation against alternating current must be extensive, and the device itself inevitably becomes larger. However, in recent years, in order to simplify the insulation of the high-voltage coil against alternating current and to downsize the device itself, a second method has been developed.
As shown in the circuit diagram in the figure, there is a so-called multi-singler type flyback transformer in which the high-voltage coil is divided into a plurality of coils 1' and each of these coils 1' is connected in series through a diode 3. Proposed. However, the specific structure of the high-voltage coil in this multi-singler type flyback transformer is a so-called split-winding structure in which the conductor wire is randomly wound around each winding groove of a split-type coil bobbin having a plurality of flanges. When connecting diodes between the divided coils of such a split-winding high-voltage coil, the coils and diodes may be arranged alternately in each winding groove of the split-type coil bobbin, or the grooves for arranging the diodes may be The coil bobbin was formed integrally with the coil bobbin in a separate part from the winding groove around which the coil was wound. Therefore, even if insulation against alternating current could be simplified, as the number of divided stages of the high-voltage coil increases, more space is required to place the diodes on the coil bobbin, so the high-voltage coil itself cannot be made much smaller. However, due to its structure, the work of installing the diode had to be complicated. Moreover, the leakage inductance of the high-voltage coil is as large as that of conventional ones, so the conversion efficiency is poor, and as a result, the heat generated inside the device increases, so it is necessary to cover it thickly with resin, etc., which has good thermal conductivity. This also hinders miniaturization. In addition, the conventional flyback transformer selects the resonant frequency of the series resonant circuit formed by the leakage inductance and stray capacitance of the high-voltage coil to the frequency of the odd-numbered harmonic of the fundamental wave applied to the low-voltage coil. There was no choice but to adopt a high-order tuning method in which a high-voltage pulse was obtained by superimposing these odd-order harmonics on the fundamental wave. This is because it is difficult to minimize the leakage inductance and stray capacitance of high-voltage coils, which are the cause of harmonic components that adversely affect high-voltage regulation. By setting this value to a certain value, the influence can be substantially reduced. However, this type of flyback transformer lacks versatility, and further improvements in high pressure regulation have been desired. In other words, in a flyback transformer, its low-voltage coil is connected in parallel with the horizontal deflection coil of a cathode ray tube in a TV receiver, etc., so when achieving high-order tuning, the inductance of this horizontal deflection coil must be included. The inductance of the horizontal deflection coil must be designed according to the circuit design of different models such as TV receivers, and the flyback transformer must also be individually designed accordingly. I had to. As a result, it lacks versatility and is difficult to standardize, resulting in a large loss in terms of productivity and cost in the industry in this technical field. Moreover, even if the model is the same, if there are large variations in inductance that inevitably occur due to the manufacturing process of horizontal deflection coils, fine adjustment is required to achieve more accurate high-order tuning for each set of TV receivers, etc. As a result, the assembly process of the set becomes complicated.
Furthermore, by adopting a higher-order tuning method, the high-voltage regulation is improved, but it is not in a fully satisfactory condition, and the image projected on the cathode ray tube of a TV receiver etc. is further stabilized. Therefore, further improvement of high pressure regulation has been desired.

The present invention has been made in view of these points, and an object of the present invention is to provide a flyback transformer that can be extremely miniaturized and is easy to manufacture, and also has increased versatility and high pressure regulation. It is possible to make further improvements, and on the low voltage coil wound on the core,
A plurality of solenoid-wound high-voltage coils having a winding width approximately equal to at least the winding width of the low-voltage coil are sequentially stacked and wound so as to cover the low-voltage coil, and each of these high-voltage coils is
A plurality of high-voltage coils are connected in series via diodes, and each of the high-voltage coils is wound in the same direction, and an insulating material is placed on the outermost layer of the high-voltage coil, and the diode is provided on this insulating material. It is characterized by:

An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 3, reference numeral 11 denotes a low-voltage coil, and 9 of a split-type coil bobbin 13 having a plurality of flanges 12.
It was formed by randomly winding a conductor wire with a wire diameter of 101 turns in a divided winding groove with a total of 101 turns. 14,1
5, 16, 17, 18, and 19 are high-voltage coils wound in the same direction, and wire diameters are set in high-voltage coil bobbins 20, 21, 22, 23, 24, and 25 made of resin with a wall thickness of 1 mm and each having a different inner diameter. 0.08
Conductive wires each having a diameter of 540 mm were wound in a single layer using 540-turn solenoid windings, and the winding width thereof was formed to be approximately the same as the winding width of the low voltage coil 11, and the conductive wires were sequentially stacked and wound on the low voltage coil 11. It is something. 26 is a bobbin-shaped insulating material stacked on the outermost high-voltage coil 19; 27;
Reference numeral 28 denotes a plurality of terminals provided at both ends of the bobbin-shaped insulating material 26, and the low-voltage coil 11 and each high-voltage coil 14, 15, 1 are connected to the plurality of terminals 27, 28, respectively.
The respective leader lines 6, 17, 18, and 19 are connected as appropriate. 29 is a plurality of diodes connected between terminals 27 and 28 provided at both ends of the bobbin 26, and the high voltage coil 14,
The high voltage coils 15, 16, 17, 18, and 19 are connected between adjacent high voltage coils and to the winding end of the outermost high voltage coil 19, so that these high voltage coils are connected in series via each diode 29. It is equivalent to the above-mentioned second
This is a multi-singular type circuit as shown in the figure. 30 is a high voltage output lead wire led out from the winding end of the outermost high voltage coil 19 via a diode 29; 31 is a 15 mm diameter ferrite core inserted into the coil bobbin 13 of the low voltage coil 11; Low voltage coil 11, high voltage coils 14, 15, 16, 1
Together with 7, 18, and 19, this constitutes a flyback transformer. The flyback transformer is completed by coating the entire low-voltage coil and high-voltage coil with resin, or by loading each coil into a resin case and casting with resin.

It should be noted that the above-mentioned embodiment merely shows one embodiment of the present invention, and the present invention is not limited thereto in any way. For example, the low-voltage coil 11 of this embodiment has a divided winding that is irregularly wound, but it may also be a solenoid-wound undivided winding.
4, 15, 16, 17, 18, and 19 may not be formed on the bobbin, but may be wound on the low voltage coil 11 in sequence through a sheet-like insulating material such as an insulating film. Further, it is desirable that the winding width of the high voltage coil is as large as possible, but it may be at least approximately equal to the winding width of the low voltage coil, and its shape may also be multilayer solenoid winding instead of single layer solenoid winding. Furthermore, the number of divided stages of the high voltage coil is not limited to six stages as in this embodiment, and the diodes interposed between the high voltage coils do not necessarily need to be provided every other high voltage coil, but instead may be provided every several high voltage coils. Good too. The arrangement of the diodes and the terminal treatment of each coil are completely arbitrary, and as in this embodiment, terminals 2 are placed at both ends of the outer peripheral surface of the insulating material 26.
7 and 28, the main body or lead wire portion of the diode 29 is directly attached to the outer peripheral surface of the insulating material 26 with adhesive or adhesive tape, and the lead wire tip of the diode 29 and both sides of each high voltage coil are attached. The wires may be twisted together with the leader wires derived from the wires and fixed by soldering, or other appropriate means may be used. In addition, the bobbin-shaped insulating material on which the diode is placed is not intended for winding a coil, so by forming cuts or through holes in appropriate locations, material can be saved and the high-voltage coil Optionally, things can be done to improve heat dissipation from.

As explained above, in the flyback transformer of the present invention, a plurality of solenoid-wound high-voltage coils are stacked and wound to cover a low-voltage coil, so that the lead wires of each high-voltage coil are connected to both sides of each coil. Since the diodes connected between each high-voltage coil and the winding end of the outermost high-voltage coil can be easily placed on the outer circumferential surface of the outermost high-voltage coil, it is possible to There is no need to take up extra space such as a winding groove to arrange the diode, and the winding width of the high-voltage coil is formed to be at least approximately equal to the winding width of the low-voltage coil. Secondly, the leakage inductance is extremely small, improving the conversion efficiency, and as a result, unnecessary heat generation is reduced, so that the unnecessary resin coating for promoting heat dissipation can be reduced, and the winding of each high voltage coil is improved. Since the directions are the same, the potential gradients between each coil are approximately the same, and since diodes are interposed between the high-voltage coils, the alternating current that causes corona discharge in each high-voltage coil is absorbed by that high-voltage coil. Since the potential is low according to the number of division stages, insulation between the high-voltage coils is simplified, and miniaturization of the entire device is extremely promoted. Furthermore, since the diode is provided outside the high-voltage coil in the outermost layer, the diode has an excellent heat dissipation effect and is highly reliable. In addition, when manufacturing such a flyback transformer, the high-voltage coils for each stage are made separately in advance, and the flyback transformer is constructed by simply fitting them onto the low-voltage coils one after another and connecting them as appropriate. Therefore, the assembly process is extremely simplified. If the high-voltage coil is wound with a sheet-like insulating material such as an insulating film, after forming the first-stage high-voltage coil, the sheet-like insulating material is wound on top of the first-stage high-voltage coil, and then It becomes possible to sequentially construct a plurality of high voltage coils by winding a wire on the insulating material, and automation of the winding work becomes extremely easy.

The above-mentioned effects are seen from the structural and manufacturing viewpoints, but the flyback transformer of the present invention also has extremely excellent electrical characteristics.

That is, as a result of measuring the output pulse waveform of the flyback transformer configured as shown in Fig. 3 with a synchroscope, it showed a pulse waveform approximately the same shape as the input pulse waveform as shown in Fig. 4a, and the scanning period was The high-frequency component of the waveform also had a very small amplitude waveform, and could be regarded as a substantially straight line. On the other hand, although the circuit is of the multi-singular type shown in Figure 2, conventional flyback transformers using high-voltage coils that are wound separately on a split-type coil bobbin have some differences in structure. Even though there are differences, the general output pulse waveform shows a pulse waveform different from the input pulse waveform, as shown in FIG. 4b, and the high frequency component of the scanning period also has a large amplitude. This high-frequency component with large amplitude has an adverse effect on high-pressure regulation. In addition, as a result of measuring the relationship between the composite inductance L ₁ and the output resistance R ₀ (including the rectifier circuit) representing the magnitude of high voltage regulation when the low voltage coil and the horizontal deflection coil of the cathode ray tube are connected in parallel, The results shown in FIG. 5A were obtained. In other words, the output resistance of the flyback transformer of the present invention is a flat value of about 1.0 MΩ in the range of 1.20 to 1.50 mH, which is the normal value of the parallel combined inductance _L1 of the low voltage coil and horizontal deflection coil of the flyback transformer. It has certain characteristics. This shows that even if the inductance value of the horizontal deflection coil changes, there is no need for tuning in the flyback transformer according to the present invention. On the other hand, as shown in Figure 5B, a conventional high-order tuning type flyback transformer is tuned, for example, when L ₁ is set to 1.35 mH, the output resistance changes by 1.35 mH if L ₁ changes. It has the characteristic of drawing a curve with a minimum value. This means that if models such as TV receivers change and the inductance value of the horizontal deflection coil differs, a flyback transformer with the minimum high voltage regulation must be designed for each model, and even if the inductance is the same, This shows that even with horizontal deflection coils, fine adjustments must be made due to variations that inevitably occur in the manufacturing process of the inductance. Moreover, the minimum value of the output resistance _R0 , which represents the magnitude of high voltage regulation, was normally only about 2.0MΩ in conventional products, but the present invention has a revolutionary characteristic of 1.0MΩ. ing.

The resonant frequency of the series resonant circuit between the leakage inductance and stray capacitance of the high-voltage coil of the flyback transformer with the structure shown in Figure 3 was approximately 550 KHz, but this resonant frequency depends on the winding width of the high-voltage coil and each coil. According to the results of experiments conducted with different configurations, the
At 400 KHz or higher, good characteristics similar to those of the above embodiment were exhibited, but when the frequency was lower than 400 KHz, the high voltage regulation became large, making it necessary to use the conventional high-order tuning method. However, the flyback transformer of the present invention does not necessarily have to be used as a so-called non-tuned type, and it is completely optional to configure the resonant frequency to be 400 KHz or less and use it as a high-order tuned type. Needless to say, even in this case, there are significant advantages in miniaturization and manufacturing as described above.

[Brief explanation of the drawing]

Figures 1 and 2 are electric circuit diagrams of a flyback transformer, Figure 3 is a sectional view of a main part of a flyback transformer according to an embodiment of the present invention, and Figure 4 shows an output pulse waveform of the flyback transformer. 5 shows a parallel composite inductance of a low-voltage coil and a horizontal deflection coil of a flyback transformer, and FIG.
FIG. 3 is a diagram showing the relationship with output resistance. 11-Low voltage coil, 12-Tsuba, 13-Low voltage coil bobbin, 14, 15, 16, 17, 18, 19
-High voltage coil, 20, 21, 22, 23, 24,
25-High voltage coil bobbin, 26-Insulating material, 27,
28-terminal, 29-diode, 30-high voltage output lead wire, 31-core.

Claims (1)

[Claims] 1. A plurality of solenoid-wound high-voltage coils having a winding width approximately equal to at least the winding width of this low-voltage coil are sequentially stacked and wound on a low-voltage coil wound around a core, and these high-voltage coils are A flyback transformer in which one or more high-voltage coils are connected in series through diodes, and each of the high-voltage coils is wound in the same direction, and an insulating material is placed on the outermost high-voltage coil. A flyback transformer characterized in that the diode is provided on the insulating material.