JPH08316071A - Flyback transformer - Google Patents

Abstract

PURPOSE: To suppress ripple on the focus voltage by providing a tertiary winding in a flyback transformer, generating a negative pulse in the tertiary winding and connecting the negative pulse voltage with a focus volume earth terminal. CONSTITUTION: The flyback transformer 31 comprises a primary winding 38, a secondary winding 39 and a tertiary winding 55 wound reversely to the primary winding 38 in order to generate a negative pulse voltage. Since a negative pulse voltage 53 generated in the tertiary winding 55 is connected with a focus volume earth terminal 53, a focus output voltage 52 equal to 25-35% of the difference between a high DC voltage 51 containing the ripple voltage 54 of final stage comprising several layers of secondary winding 39 and high voltage diode 41 and the negative pulse voltage 53 generated in the tertiary winding 55 is produced thus suppressing the ripple voltage 54 on the focus output voltage 52. Consequently, the ripple voltage can be suppressed without requiring any static focus capacitor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer device used in a television receiver or the like.

[0002]

2. Description of the Related Art In recent years, cost reduction and size reduction of flyback transformer devices have been rapidly progressing.

The structure of a conventional CRT image display device will be described below with reference to FIGS. 3 and 4. FIG.
Is a circuit diagram of a conventional flyback transformer device, FIG.
FIG. 7 is a focus output voltage waveform diagram generated in a conventional flyback transformer device. Here, 1 is a flyback transformer, 2 is a focus volume pack for outputting a focus voltage, 3 is a horizontal output transistor, 4
Is a damper diode, 5 is a resonance capacitor, 6 is a deflection yoke, and 7 is an S-shaped capacitor.

The flyback transformer 1 has primary windings 8 and 2.
Next winding 9, ferrite core 10, high voltage diode 11,
It is composed of a high voltage protection resistor 12, an anode lead 13 and an anode cap 14. Also, the focus volume pack 2 is a dynamic focus output lead 1.
5, dynamic focus condenser 16, static focus output lead 17, static focus condenser 18, screen output lead 19, focus volume earth terminal 20, focus volume earth terminal 20 is earth 23
It is connected to the.

The operation of the flyback transformer device configured as described above will be described below.

1 constituting the flyback transformer 1
The + B voltage is input to the secondary winding 8, the horizontal output transistor 3 is turned on and off, and the primary winding 8 has a collector by the resonant circuit including the damper diode 4, the resonance capacitor 5, the deflection yoke 6, and the S-shaped capacitor 7. A pulse voltage is generated. This collector pulse voltage is applied to the ferrite core 10
A pulse voltage is generated in the secondary winding 9 through
High-voltage DC voltage 21 is generated in the anode cap 14 connected to the anode lead 13 by being rectified by the high-voltage diode 11. The focus volume pack 2 is connected to the flyback transformer 1, and the high voltage DC voltage 21 is input as an input. By connecting the focus volume earth terminal 20 to the earth, it is possible to output a dynamic focus voltage 22, a static focus voltage, a screen voltage, etc. as a divided voltage of the high voltage DC voltage 21.

[0007]

However, in the above-mentioned conventional structure, since the focus volume earth terminal 20 is connected to the earth 23, the ripple voltage 24 included in the high voltage DC voltage is input to the focus volume pack 2. Dynamic focus output voltage 2
2. A DC voltage including the ripple voltage 24 is also output to the static focus output voltage. Therefore, by connecting the static focus condenser 18 between the static focus output lead 17 and the focus volume earth terminal 20, the ripple voltage 24 is smoothed and the ripple voltage 24 is reduced. Therefore, the static focus condenser 18 is required. Had the problem.

The present invention solves the above-mentioned conventional problems, and provides a flyback transformer device capable of reducing the ripple voltage of a dynamic focus voltage and a static focus voltage without using a static focus capacitor. It is an object.

[0009]

In order to achieve this object, a flyback transformer device of the present invention comprises a primary coil to which a pulse voltage is input, a core around which the primary coil is wound, and a core. Mounted secondary coil for boosting the pulse voltage input to the primary coil, rectifying diode for rectifying the high voltage pulse obtained in the secondary coil, and secondary coil voltage connected to the high voltage side of the secondary coil To a predetermined voltage value and outputs the voltage, and a tertiary coil wound around the core and having one end connected to the voltage output unit.

[0010]

According to the present invention, the focus voltage outputs about 30% of the potential difference between the high voltage DC voltage and the focus volume ground terminal. The present invention cancels the ripple voltage contained in the high voltage DC voltage because the potential of the focus volume earth terminal has a negative pulse potential, and it is possible to output a DC voltage that does not include the ripple voltage in the focus voltage. , It is possible to remove the static focus condenser that was built in the flyback transformer to remove the focus ripple voltage.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a circuit diagram of a flyback transformer device according to an embodiment of the present invention.

In FIG. 1, 31 is a flyback transformer, 32 is a focus volume pack, 33 is a horizontal output transistor, 34 is a damper diode, 35 is a resonance capacitor, 36 is a deflection yoke, and 37 is an S-shaped capacitor.

The flyback transformer 31 has a primary winding 3
8, secondary winding 39, ferrite core 40, high voltage diode 41, high voltage protection resistor 42, anode lead 43, anode cap 44 and focus volume pack 32
It consists of.

The focus volume pack 32 is composed of a dynamic focus output lead 45, a dynamic focus condenser 46, a static focus output lead 47, and a screen output lead 49.

In one embodiment of the present invention, the flyback transformer 31 contains a tertiary winding 55 for generating a negative pulse voltage. The terminal of the tertiary winding 55 is connected by a lead wire 56 to the focus volume earth terminal 50 which is the earth side terminal of the focus volume pack 32.

The operation of the flyback transformer device having the above structure will be described below. First, the + B voltage is input to the primary winding 38 that constitutes the flyback transformer 31, and the horizontal output transistor 33 is turned on and off.
With the resonance circuit of the damper diode 34, the resonance capacitor 35, the deflection yoke 36, and the S-shaped capacitor 37,
A collector pulse voltage is generated in the primary winding 38.
The collector pulse voltage generated in the primary winding 38 causes a pulse voltage in the secondary winding 39 and the tertiary winding 55 using the ferrite core 40 as a medium. Since the secondary winding 39 is wound in the same direction as the primary winding 38, a positive pulse voltage is generated. This positive pulse voltage is applied to the high voltage diode 4
Rectify by 1. By forming the secondary winding 39 and the high voltage diode 41 in several layers, a high voltage DC voltage 51 is generated, and the high voltage DC voltage 51 is generated in the anode lead 43 and the anode cap 44 for connecting to the cathode ray tube. Since the tertiary winding 55 is wound in the opposite direction to the primary winding 38, a negative pulse voltage is generated.

A focus volume pack 32 is connected to the final stage output section in which the secondary winding 39 and the high voltage diode 41 are composed of several layers, and a slide resistance (variable resistance) is built in the focus volume pack 32. As outputs of this slide resistance, the dynamic focus output lead 45, the static focus output lead 47, and the screen output lead 49 are connected.

The output voltage of each of the dynamic focus output, the static focus output, and the screen output is the high-voltage DC voltage of the final stage in which the secondary winding 39, which is the input voltage of the focus volume pack 32, and the high-voltage diode 41 are formed in several layers. It is determined by the difference between the potential of the focus volume earth terminal 50 and 51, and changes depending on the resistance value of the focus volume pack 32.
A voltage of about 5% to 35% is output as the focus output voltage 52.

The final high-voltage DC voltage in which the secondary winding 39 and the high-voltage diode 41 are composed of several layers is 51, and the primary winding 38 is
The ripple voltage 54 is included in the high-voltage DC voltage 51 because the collector pulse voltage generated in step 1 is boosted and rectified. Since the high-voltage DC voltage 51 including the ripple voltage 54 becomes the input voltage of the focus volume pack 32, when the focus volume earth terminal 50 is connected to the ground potential as in the conventional case, the high-voltage DC voltage 51 including the ripple voltage 54 is obtained. Focus volume ground terminal 50
Since the focus output voltage 52 of about 25% to 35% of the potential difference is output, the focus output voltage 52 includes a ripple voltage.

In this embodiment, the focus pulse ground terminal 50 has a negative pulse voltage 5 generated in the tertiary winding 55.
Since 3 is connected, the high voltage DC voltage 51 including the ripple voltage 54 at the final stage in which the secondary winding 39 and the high voltage diode 41 are composed of several layers, and the negative pulse voltage generated in the tertiary winding 55 Since the focus output voltage 52 of about 25% to 35% of the potential difference from 53 is output, the ripple voltage 54 is reduced in the focus output voltage 52. Conventionally, the static focus condenser 18 was connected between the static focus output lead 17 and the focus volume earth terminal 20 as one means for reducing the focus ripple voltage. However, in this embodiment, the ripple voltage 54 of the focus output voltage is changed. Since it can be reduced, the static focus condenser 18 can be eliminated, and the flyback transformer can be downsized and the cost can be reduced.

[0021]

As described above, according to the present invention, a tertiary winding is provided in the flyback transformer, a negative pulse voltage is generated in the tertiary winding, and the negative pulse voltage is applied to the focus volume earth terminal. By connecting them, the ripple voltage of the focus voltage can be reduced and an excellent flyback transformer device can be realized.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a flyback transformer device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram of a focus output voltage generated in a flyback transformer device according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of a conventional flyback transformer device.

FIG. 4 is a waveform diagram of a focus output voltage generated in a conventional flyback transformer device.

[Explanation of symbols]

 1,31 Flyback transformer 2,32 Focus volume pack 3,33 Horizontal output transistor 4,34 Damper diode 5,35 Resonance capacitor 6,36 Deflection yoke 7,37 S-shaped capacitor 8,38 Primary winding 9,39 2 Next winding 10,40 Ferrite core 11,41 High voltage diode 12,42 High voltage protection resistor 13,43 Anode lead 14,44 Anode cap 15,45 Dynamic focus output lead 16,46 Dynamic focus capacitor 17,47 Static focus output lead 18 Static focus condenser 19,49 Screen output lead 20,50 Focus volume earth terminal 21,51 High voltage DC voltage 22,52 Focus output voltage 23 Earth 24, 54 Ripple voltage 53 Pulse voltage 55 Third winding 56 Lead wire

Claims (4)

[Claims] 1. A primary coil to which a pulse voltage is input, a core on which the primary coil is wound, and a secondary coil which is wound on the core and boosts the pulse voltage input to the primary coil. A rectifying diode for rectifying the high voltage pulse obtained in the secondary coil; and a voltage output unit connected to the high voltage side of the secondary coil for changing the voltage of the secondary coil to a predetermined voltage value and outputting the voltage. A flyback transformer device, comprising: a tertiary coil wound around the core and having one end connected to the voltage output unit. 2. The flyback transformer device according to claim 1, wherein the output voltage of the voltage output section is in the range of 25 to 35% of the output voltage of the secondary coil. 3. A primary coil to which a pulse voltage is input, a core on which the primary coil is wound, and a secondary coil which is wound on the core and boosts the pulse voltage input to the primary coil. A rectifying diode for rectifying the high voltage pulse obtained in the secondary coil, a tertiary coil wound around the core to generate a negative pulse voltage, and a focus loop volume for supplying a predetermined voltage to the focus loop circuit. A flyback transformer device, comprising: an input terminal of the focus loop is connected to a high voltage side of the secondary coil, and a ground terminal of the focus loop is connected to the tertiary coil. 4. The flyback transformer device according to claim 3, wherein the output voltage of the focus loop is in the range of 25 to 35% of the output voltage of the secondary coil.