JPS6022590B2 - flyback transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flyback transformer, and more particularly to an improvement in a flyback transformer in which a high voltage coil is wound around a divided bobbin and divided by diodes.

For example, as described in Japanese Utility Model Publication No. 41-17292, when a high-voltage coil is wound around a split bobbin, distributed capacitance, leakage inductance, etc. of a flyback transformer are reduced, and performance is improved.

In order to further improve performance, for example, Samurai Kosho 52-362
As described in Publication No. 46 or Samurai Koshokyu-7008, a configuration is adopted in which a high voltage coil is divided by diodes.

All of these configurations attempt to reduce distributed capacitance and improve regulation by dividing the high-voltage coil with diodes, and are particularly effective for color TVs that require more power than black and white TVs. . By the way, in the flyback transformer described in Samurai Publication No. 52-36246, as shown in FIGS. 4 and 5, the dividing diode is inserted into the groove of the divided bobbin, or A terminal is installed on top of the gold poison, and a diode is connected to this.

However, when the diode is inserted into the groove, the following drawback occurs. {1} The position of the diode is not stable.

Therefore, for example, if the diode ○ is located biased toward the high voltage coil L, as shown in FIG. 1, the resistance to the coil L becomes a problem. '21 If the diode D moves freely during assembly, such as moving toward the high-voltage coil L, or moving toward the high-voltage coil L, the distributed capacitance changes, and the tuning of high-order harmonics may be achieved for each coil, or There may be none.

[3' If the diode D is twisted in the direction of the bobbin B or rolled in the radial direction, the resistance between the AC side and other coils will deteriorate.

These drawbacks deteriorate the characteristics and reliability of the flyback transformer.

In addition, the coil usually uses a wire with a wire diameter of 0.08 to 0.12, while the diode lead wire uses a wire with a wire diameter of 0.5 to 1.0.
It's the skin.

For this reason, if the diode moves, it becomes difficult to wrap the lead wire of the coil around the lead wire of the diode, and there is a risk of disconnection after connection. On the other hand, when mounting a diode on the collar of a split bobbin, there are disadvantages such as {1) the shape of the coil becomes large and it is very difficult to attach a terminal because the thickness of the '21 collar is thin.

The present invention has been made in order to eliminate the above-mentioned drawbacks.The present invention has been made in order to eliminate the above-mentioned drawbacks. It provides a flyback transformer with

Embodiments of the present invention will be described in detail below with reference to FIG. 2 and subsequent figures.

FIG. 2 shows an example of a diode used in the flyback transformer of the present invention, where A is a plan view and B is a right side view.

As is clear from the figure, this diode 10 has a middle portion 11 with a large diameter, and both end portions 12 to 12.
is made narrow and small in diameter. This diode 10' is embedded in one collar of the split bobbin, as shown in FIGS. 3 and 4, for example. The third is one tsuba 13 of the split bobbin.
FIG. 4 is a cross-sectional view of FIG. 3 taken along the line W--W. As is clear from these FIGS. 3 and 4, the middle portion 1 of the diode 10' is
The turtle is molded integrally with the bobbin's collar. Both end portions 12, 12 of the diode 10 are supported by a mold when forming the split bobbin, and when resin is injected, the diode 1
This is to prevent 0 from moving unsteadily. For example, the bobbin material such as epoxy resin has high fluidity, so the diode does not shake much, but when molding with high pressure like polycarbonate resin, it is necessary to hold the diode with a mold, and the second It is necessary to take the structure of the diagram. Note that when arranging the diode near the outer periphery of the bobbin, it is preferable to make the structure of the diode to match the circumference of the collar. If the adhesion between the bobbin material and the diode coating material is poor, it is necessary to prevent creeping discharge that propagates through the diode surface by using a resin that will later mold the entire flyback transformer.

In this case, as shown in FIG. 5, both end portions 22, 22 of the diode 20 supported by the mold are formed long, and the intermediate portion 21, which is embedded integrally in the collar, is formed short. With this configuration, since the portion of the diode 20 covered with the molding resin becomes longer, creeping discharge can be reliably prevented. Note that it is necessary to use a molding resin that has good adhesion to the covering material of the diode 20. - If the collar into which the diode is inserted is made thicker, sink marks may occur during bobbin molding and the bobbin may become deformed.

Furthermore, if the diode and the winding of the high-voltage coil are brought too close together, this will cause problems in terms of pulse withstand voltage, and furthermore, the distributed capacitance will increase and the characteristics will deteriorate. In this case, as shown in FIG. 6, slits 32 are provided between the collar 31 of the bobbin in which the diode 30 is buried and the high voltage coils L, .
With this foundation, the diode 30 and the high voltage coil L
,,L are separated and the collar 31 becomes thinner. slit 32,
Since the molding resin will enter into 32, the insulation will also be improved. As described above, in the present invention, the diode is integrally inserted and fixed in the collar of the bobbin when forming the split bobbin, so the position of the diode is stable, and there are no problems such as withstand voltage problems and changes in distributed capacitance. becomes.

Therefore, the characteristics and reliability of the flyback transformer are further improved. Also, there is no need to respect the terminal to the crocodile,
It has many advantages such as ease of manufacture and ease of operation.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view showing an example of a secondary flyback transformer, and Fig. 2 is an example of a diode used in the flyback transformer according to the present invention, where A is a plan view and B is a right side view. Figure 3 is a schematic side view of the main part showing one embodiment of the flyback transformer according to the present invention, and Figure 4 is a
A sectional view taken along the line W-W in the figure, FIG. 5 is a plan view showing another example of the diode used in the flyback transformer according to the present invention, and FIG. 6 is a plan view showing another example of the diode used in the flyback transformer according to the present invention. This is a cross-sectional view of the European competition requiring punishment. In the figure, the diodes 0, 20, and 30' are the diodes, 11 and 21 are the intermediate portions of the diodes 10 and 20, 12 and 22 are the both end portions of the diodes 10 and 20, and 13 and 31 are the bobbin collars.
32 is a slit, and L, , L are high voltage coils. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A flyback transformer in which a high-voltage coil is wound around a split bobbin having a flange, and the high-voltage coil is divided by diodes, in which the middle part of the diode has a large diameter, and both ends have a large diameter. is formed to have a small diameter, and when forming the split bobbin, the intermediate portion of the diode is integrally buried in the flange so that its longitudinal direction is in the plane direction of the flange. Flyback transformer. 2. The flyback transformer according to claim 1, characterized in that a slit is formed between the collar containing the diode and the high voltage coil.