JPS6010472B2 - horizontal deflection device - Google Patents

Description

[Detailed Description of the Invention] The present invention effectively prevents the ringing voltage caused by the distributed capacitance and leakage inductance of the high-voltage winding of a flyback transformer from appearing in the horizontal deflection current and appearing as vertical stripes on the cathode ray tube screen. This is what I try to remove.

Figure 1 shows an example of a conventional horizontal deflection circuit.
First, this circuit will be explained.

The output of the horizontal oscillation circuit 1 is the base of the drive transistor 2.
The collector output of the drive transistor 2 is applied via a horizontal drive transformer 3 and a base inductance to the base of a horizontal output transistor 5 which also serves as a damper diode. The collector of the horizontal output transistor 5 is grounded via a resonant capacitor 6 and is also connected to the input terminal 9 of the primary winding 8 of the flyback transformer 7. A horizontal deflection coil 12 and a vertical distortion correction transformer 13 are connected between the ground and the nearness coil 1.
4 and an S-shaped correction capacitor 15 are connected in series. The earth side terminal 16 of the primary winding 8 is the DC power supply terminal 1
A DC voltage is applied from 7. 18 is a smoothing capacitor.

One end of the secondary winding 19 of the flyback transformer 7 is connected to a high voltage terminal 21 via a high voltage rectifier diode 20. -22 is also a DC power supply terminal. The pulses generated at the terminal 9 of the primary winding of the flyback transformer 7 are shown in Figure 2a.
The waveform obtained at the secondary winding 19 has a ringing component A as shown in FIG. 2c. This IJ ringing component is generated due to the distributed capacitance and leakage inductance of the secondary winding. The signal component of this secondary winding is induced in the winding portion 101 of about 4 turns as shown in FIG. 2b. Since the transistor 5 is suitable for conducting the other ringing components induced in the primary winding portion, they fall to the ground, and almost no ringing components exist at the terminal 9. However, a ringing component exists at the terminal 1, and this component flows into the deflection coil 12, causing the deflection current to form a bad sawtooth wave as shown in FIG. 2 d'. When deflection is performed using such a sawtooth wave, vertical stripes appear on the cathode ray tube screen. In addition, if the horizontal deflection coil 12 is connected to the terminal 9, "
Although such vertical stripes will not occur, in order to flow a predetermined deflection current through the deflection coil, a winding portion 10 may be provided in the design, and the horizontal deflection coil may be connected at a point tapped down from the terminal 9. It is necessary to do so.
If it is connected to terminal 9, it will be difficult to design. The present invention prevents the above-mentioned ringing component from flowing into the horizontal deflection coil. The winding portion is formed by dividing it into both ends of the primary winding of the flyback transformer, and the two winding portions are tightly coupled. The structure is such that the ringing component is canceled out.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows an example thereof, and the same parts as those shown in FIG. 1 are given the same numbers.

The circuit shown in FIG. 3 is characterized by dividing the winding portion 10 of the primary winding 8 of the flyback transformer shown in FIG. This rolled up part 2
3 and 25 are tightly combined. As a specific means for tightly coupling, bifilar winding may be used, and it is possible to make the coupling coefficient 0.99 or more. In addition, terminals 8 to 1
The number of turns between 6 and 6 is approximately 100. The one shown in Fig. 1 is an example of a flyback transformer.
This is an example of a case where 25 is bifilar wound. This is an example in which the winding portions 23 and 25 are bifilar wound. The coupling between the wound portions 23 and 26 and the secondary winding 12 must be in a high-voltage insulated state, so the coupling must be loose. The energy is sufficiently small.Furthermore, by reversing the mutual positions of the winding parts 23 and 26, it is possible to make the polarities of the signals generated t mutually opposite.In other words, the winding If the pulses generated in the portion 23 are of positive polarity as shown in FIG. 5A, the pulses generated in the winding portion 25 are of negative polarity as shown in FIG. 5M, and they influence each other. With this configuration, the impedance on the secondary side of the flyback transformer field, which is the source of ringing, is high.Moreover, by making the winding part a close match, the load on the ringing source is reduced to the level shown in Figure 1. The weight is heavier than in the case of a straight line, power consumption occurs at the joint between the winding parts 23 and 25, and almost no ringing component appears.
To give another explanation, the ringing component in FIG. 5a is induced in the winding portion 25 and cancels out the ringing component in FIG. This cancels out the ringing component in Figure a, and the ringing component disappears. Although the heat generation of the flyback transformer 7 increases accordingly, since the number of turns is about three, the heat generation is not large and is not a problem in practice. The winding parts 23 and 25 are shown in Fig. 5 a and b.
A flyback pulse is also generated as shown in FIG. 2, but the source of this flyback pulse is the primary side of the flyback transformer 7 and the power supply impedance is small. Therefore, “
The flyback pulses are output as they are to the winding portions 23 and 24, with the amplitude being slightly reduced. Since the flyback pulse is induced in the winding portions 23 and 25 of each other, a portion thereof is canceled out. Therefore, although the winding part in Figure 1 had four turns, considering that the amplitude of this flyback pulse would be slightly smaller,
In the case of FIG. 3, the number of windings is slightly increased, with each winding part 23 and 25 having three windings each. FIG. 5c shows the flyback pulse applied to the horizontal deflection coil 12, and FIG. 5d shows the deflection current. As described above, according to the present invention, the ringing component generated on the secondary side of the flyback transformer can be prevented from appearing in the horizontal deflection coil.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of a conventional horizontal deflection device.
, cg d is a waveform diagram for explaining the operation of the device, FIG. 3 is a circuit diagram of a horizontal deflection device in embodiments of the present invention, FIG. 3 is a principle diagram of a flyback transformer of the same device, and FIG.
, b, c, and also are waveform diagrams for explaining the same device. 7 Misaki...Flyback transformer, 8...Primary winding~
Winding part 9...Secondary winding, 23, 25...The winding part is also a horizontal deflection coil on the government army side. 1 box, 2 figures, 4 scales, 3 scales, 5 figures

Claims (1)

[Claims] 1. Apply the output of the horizontal output circuit to the input terminal of the primary winding of the flyback transformer, wind the winding a little from this input terminal to form a winding part, and apply a DC voltage to the other end of the primary winding, The winding wire is slightly wound up from the other end to form a winding section, and a horizontal deflection coil is inserted between each end of both winding sections to tightly couple the two winding sections and to control the signal generated at both winding sections. A horizontal deflection device characterized in that both winding portions are positioned so that their polarities are opposite to each other.