JPS6014576A - Flyback transformer - Google Patents

Abstract

PURPOSE:To reduce ringing with very simple constitution by constituting the primary winding of conductor wires and constituting at least a part of the secondary windings coupled magnetically with the primary winding of resistance wires. CONSTITUTION:In an equivalent circuit of the flyback transformer during the scanning period of a horizontal deflection circuit, the ringing is expressed as a voltage V2 across the stray capacitance C2 of the secondary windings. The theoretical equation to obtain this V2 depends on the two values of 1/C2 and R<2>/4L2. To reduce the ringing, the stray capacitance C2 of the secondary side is increased, or the leakage inductance L2 at the secondary side is decreased or the resistive component R of the secondary side is increased. However, there is a limit inevitable on the structure of the flyback transformer when the stray capacitance of the secondary side or the leakage inductance is decreased. The secondary windings 2-4 are constituted of resistance wires as a concrete means to increase the resistive component R of the secondary side through the reason above.

Description

DETAILED DESCRIPTION OF THE INVENTION This defense (J, 1' relates to a flyback lance used for supplying DC high voltage to a cathode ray tube such as a V image receiving 1FM, and particularly during scanning 111 of a horizontal deflection circuit) This invention relates to a flyback lance designed to reduce ringing induced in its secondary winding.

The one shown in Figure 1 is a typical flyback in recent years, 5
, 6.7 are diodes connected alternately to the plurality of secondary windings. Normally, when a low-voltage bobbin with one winding wire is wound on the flyback 1-run or the core with a pair of U-shaped cores having this circuit configuration. 6, in this ten, multiple 2
It is constructed by winding a large number of windings into a divided high voltage small bottle FE on the right side. 13, A tertiary winding for taking out power sources such as AFC and secondary 13 power is wound as necessary on the low voltage bobbin, etc., and these windings (,
1 It is housed in an insulating goose and molded with resin. These 1i′I? .

The windings, secondary windings, etc. are, of course, made of nine electric wires made of pure cotton.

By the way, as shown in Fig. 2, water 31' in the secondary winding of this J, 114 configuration flyback transformer deteriorates the electrical characteristics such as high II range. It is necessary to minimize the amount of noise caused by the leakage inductance of the secondary winding. All you have to do is derive
This naturally has its limits. Therefore, the leakage inductance of the secondary winding and the 11'i column resonant circuit of the stray capacitance are usually tuned to the odd-numbered harmonics that are 3.1 times higher than the high frequency of the input power source of the primary winding. , so-called harmonic tuning is used to improve electrical characteristics such as high voltage regulation. However, even with this method, there is still a limit to the improvement of the electrical characteristic t1.

The present invention has been made in view of the above points, and an object thereof is to provide a flyback transformer that can reduce ringing with an extremely simple configuration and thereby improve electrical QJi characteristics. The purpose is to

To this end, the present invention is based on FIG. 1. Secondary winding 2.3
．． It is replaced with a wire consisting of >9713 wires such as those made by the conventional Keishi wires, and the resistivity of manganin wires, Nikum wires, Cu-Ni copper alloy wires, etc. It is constructed by using a resistance wire that has the same characteristics.

It has been experimentally confirmed that ringing can be considerably reduced by configuring the secondary winding with this J:-connected resistance wire.

That is, during the scanning period of the horizontal deflection circuits of flyback 1 to lance, 6'3G:J etc. tIIIi circuit [Yo] is shown as shown in FIG. Here, E is the human power voltage on the primary side, 1.
+ is the inductance of the primary side, C+ l, L primary side q
Monthly t1 capacity, L2 is secondary side leakage inductance, 0
2 is 1 on the secondary side? In the idle jet, 1< is a resistance component such as the winding resistance of the secondary flllll. , in such a 11η1 circuit -C, the linking is due to both of the stray capacitance 02 on the secondary side? 72. The theoretical formula for calculating this v2 is 5i based on the magnitude relationship of the two first shifts, old and young.
n(ωf't+6)]......(1) is expressed as v2 = E ('1-'5'; and e-t su+l
+ ((/JS t +O-) ) −・・・・・・(3
). In these formulas,
ωo1τ, ω1. O, θ)s, 0-1;L 1, respectively, ω0〒τ-hua, ωf-YuingLt(:2 0; [old)-1ωfτ, ωs −-j 'aH, e −
=ta plane 1ωSτ. The waveform of v2 expressed by equation (1) is as shown by the solid line in FIG. 8, and the waveform of V2 expressed by equation (2) is as shown by the solid line in FIG. Also, v2 expressed by equation (3)
The waveform is the solid line J in FIG. As is clear from these figures, although the waveform shown in Figure 1 is ideal, it is actually very difficult to satisfy the condition of IC2, and the waveform is usually +41y'. So, is it possible () to approach the condition of Hiroshi=Ishi (on the secondary side to reduce the ringing)? It would be better to reduce the free capacitance G2, reduce the leakage inductance L2 on the secondary side, or increase the resistance component 1 on the secondary side. However, i on the secondary side
Due to the structure of the flyback transformer, in order to increase the play capacity and reduce the leakage inductance,
There are inevitable limits. Therefore, ';
(Focusing on the fact that C24Lz can approach '1, and as a concrete means of increasing the resistance component 1, we made the secondary winding J:') consisting of a resistance wire. be.

As explained above, the flyback 1 Herance of the present invention is extremely simple because the primary winding is made up of conventional wire and the secondary winding is made up of resistance wire. This structure not only reduces ringing, but also improves the mechanical characteristics of high-pressure regulation, etc.

In addition, in the above explanation, it is assumed that all of the secondary windings 2.3.4 in Figure 1 are composed of resistance wires, but it is not necessary to (It's 4f.) Even if either the secondary winding 2 or 3.4 is configured with Idhr + tt resistance wire, the overall electrical characteristics can be improved and the resistance wire can be removed. If the resistivity of
It is not constructed by connecting several secondary windings and multiple diodes alternately () as shown in Figure 1, but it is constructed by connecting even one secondary winding. . ;1. This defense is
Although the circuit is configured as follows,
It goes without saying that the secondary winding can be applied to a split-type high-pressure bobbin with a small number of secondary windings stacked coaxially in sequence without winding. Nor. In view of these differences, as mentioned above, it is sufficient that at least a portion of the secondary winding is made of a resistance wire.

[Brief explanation of the drawing]

Figure 1: IJ, ##iI> Electrical circuit diagram of flyback transformer; Figure 2: Electrical waveform diagram induced in the secondary winding;
Figure 3 shows 1 between flyback 1 and lance scan 1111.
13LJ equivalent circuit diagrams, FIGS. 4, 5, and 6 respectively show the voltage waveforms of the secondary winding during the scanning period. 1... Primary winding, 2, 3, 4...
...Secondary winding, 5,6.7...Tie A-de, 8...Seat 1 pulse waveform, 9...
・Ringing waveform, [...human power supply, Ll...
...Primary side inductance, C1...1
Same ra container on the next side, L2... Leakage inductance on the secondary side, 02 Stray capacitance on the secondary side, 1<......
Resistance component on the secondary side. Fig. 1 Fig. 2 Fig. 5 431- Fig. 4,・Pa Fig. 5-17-111

Claims (1)

[Claims] A flyback transformer characterized by having a portion made up of resistance wire.