JP2760235B2 - Flyback transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a television (television).
The present invention relates to a flyback transformer for supplying a high voltage to an anode of a CRT, such as a receiver or a CRT display device. It is another object of the present invention to provide a flyback transformer which can remove ringing by using a capacitor having a small withstand voltage and can easily insulate a primary coil.

[0002]

2. Description of the Related Art The inventors of the present invention can perform high-order resonance without increasing the number of layers of high voltage coils and the number of diodes used and without increasing the length of coils and ferrite cores. We proposed a flyback transformer with good ringing and little ringing as Japanese Patent Application No. 1-83753. This flyback transformer will be briefly described with reference to FIGS.

FIG. 2 is a structural sectional view of a conventional flyback transformer 10, and FIG. 3 is a circuit diagram of the flyback transformer 10 including peripheral circuits.

In FIG. 2, 1a is one leg of the core 1, 1b
Is the other leg of the core 1, and 2a and 2b are low-voltage coil bobbins fitted (fitted) to the legs 1a and 1b, respectively. 3a and 3b are primary windings (also referred to as "coils") wound around the low-voltage coil bobbins 2a and 2b, respectively, and 4a and 4b are high-voltage coil bobbins fitted to the low-voltage coil bobbins 2a and 2b, respectively. Reference numerals 5a and 5b denote respective winding sections of the high voltage coil 5 wound around the high voltage coil bobbins 4a and 4b, respectively, and reference numerals 6a and 6b denote interlayer insulating materials for insulating the respective winding sections 5a and 5b of the high voltage coil 5 respectively. Reference numerals 7a and 7b denote terminals mounted on the high-voltage coil bobbins 4a and 4b, respectively. The winding start and end of each winding section 5a and 5b of the high-voltage coil 5 are wound around the terminals 7a and 7b, respectively. A diode 8 is connected to these terminals 7a and 7b.
a and 8b are connected respectively.

[0005] Reference numerals 11a and 11b denote first and second coil units respectively composed of the above components. The first coil unit 11a is fitted to one leg 1a of the core 1. The second coil unit 11b is fitted to the other leg 1b of the core 1. The primary winding 3a of the first coil unit 11a is connected in parallel with the primary winding 3b of the second coil unit 11b.

Reference numeral 9 denotes a case which covers each of the coil units 11a and 11b. The inside of each case 9 is filled with an insulating resin 13 such as an epoxy resin to electrically insulate each component.

[0007] The first and second coil units 11
For a and 11b, the number of turns of the low-voltage coil, the type of voltage to be taken out, the number of turns and the number of layers of the high-voltage coil, and the like need not necessarily be the same.

As shown in FIG. 3, a primary winding of a low-voltage coil
The high voltage side (end of winding) of 3a, 3b is connected to the horizontal output circuit 20 via the terminal p1. This horizontal output circuit 20
It comprises an NPN horizontal output transistor Q1, a damper diode D1, a resonance capacitor C1, a horizontal coil L1 of a deflection yoke (not shown), an S-shaped correction capacitor C2, and the like. The collector of the transistor Q1 is connected to the high-voltage terminal p1 of the primary windings 3a and 3b, the emitter is grounded, and the base is connected to the oscillation circuit 21 from which a basic pulse is applied. A collector pulse generated by the transistor Q1 from the basic pulse is applied to the terminal p1.

The low-voltage side (starting side of the winding) of the primary windings 3a and 3b is connected to a DC power supply E for applying a DC (direct current) voltage to which a DC voltage is applied.
The primary windings 3a and 3b of a and 11b are connected in parallel between the terminals p1 and p2 such that the generated magnetic flux is in the same direction.

As shown in FIG. 2, a plurality (arbitrary number) of the winding sections 5a and 5b of the high-voltage coil 5 are arranged via interlayer insulating materials 6a and 6b, respectively. The winding section 5a is composed of three winding sections 5a1, 5a2 and 5a3 from the most input side, and the winding section 5b is a winding section 5b1 and 5b2 from the most input side.
, 5b3. Winding section 5a1, 5a
2, 5a3 are connected in series via a diode 8a such that voltages generated in respective winding sections adjacent to each other via an interlayer insulating material have the same phase. Winding section 5b1,
Similarly, 5b2 and 5b3 are also connected in series via a diode 8b so that the voltages generated in adjacent winding sections have the same phase via an interlayer insulating material. Thus, the high-voltage coil 5 of each of the coil units 11a and 11b is formed.

The first and second coil units 11a, 11a,
The high-voltage coil 5 of 11b is connected in series via a diode 8c so that each high-voltage output is added and rectified.
The output side of the high voltage coil 5 of the second coil unit 11b is connected to the CRT 17 via a diode 8d.

Next, in Japanese Patent Application No. 1-83753, the fourth
FIG. 4 shows a flyback transformer shown as an embodiment. This flyback transformer is obtained by adding a parallel circuit including a resistor R2 and an inductance element L2 and a capacitor C3 to the flyback transformer shown in FIG. 3 to further reduce ringing.

In FIG. 4, the first coil unit 11a
On the input side of the winding section 5a1 on the most input side of the high voltage coil 5 of
Resistance R2 (for example, 8.2 kΩ) and inductance element L2
(For example, 2.7 mH) are connected in series. Further, as shown in the figure, a capacitor C3 (for example, 470 pF) is added by connecting the input sides of the winding sections 5a1 and 5b1 on the most input side of the first and second coil units 11a and 11b. Thereby, the first and second coil units 11a,
Ringing generated in 11b can be sufficiently attenuated.

[0014]

However, in the structure shown in FIG. 4, since a high voltage is applied to the capacitor C3, a capacitor having a large withstand voltage is required for the capacitor C3, which results in an increase in the size of the capacitor and an increase in cost. Had an effect on reliability. Further, in the coil units other than the first coil unit 11a, the DC potential of the winding section 5b1 in the innermost layer of the high voltage coil 5 increases (for example, the high voltage output to the CRT 17 becomes 15 kV at 30 kV). 5b1
And the primary coil 3b located on the inner side thereof has a larger potential difference. Therefore, the insulation distance between the winding section 5b1 and the primary coil 3b must be increased, and the insulation is not easy.

An object of the present invention is to provide a flyback in which a capacitor with a low withstand voltage can be used, cost reduction and miniaturization can be achieved, and insulation with a primary coil is easy and reliability is improved. The point is what kind of measures should be taken to make a transformer.

[0016]

Therefore, in order to solve the above problems, the present invention provides a coil unit as follows.
A low-voltage coil is wound around the low-voltage coil bobbin, and a high-voltage coil bobbin is fitted around the low-voltage coil bobbin,
A high-voltage coil is wound around the high-voltage coil bobbin in a single layer or a plurality of layers, and a layered winding structure is formed by alternately arranging the winding sections of the divided and wound high-voltage coil with an interlayer insulating material. The winding sections are connected in series via a diode so that the voltages generated in the respective winding sections adjacent to each other via the insulating material have the same phase, and are configured by:
A plurality of coil units having the above configuration are provided, and the high-voltage coils of each of the coil units are connected in series via a diode so that their high-voltage outputs are added and rectified, and one of the low-voltage coils of each of the coil units is connected. In the flyback transformer, the secondary coils are connected in parallel so that the generated magnetic fluxes are in the same direction, and each of the coil units is fitted to each leg of a core having a plurality of legs. Are the first, second,... Coil units from the lower potential of the high voltage coil.
A first parallel circuit or a second resistor composed of a first resistor and an inductance element is connected to the input side of the winding section on the most input (start of winding) side of the high voltage coil of the coil unit;
A ringing removing coil is formed on the innermost side of the high voltage coil of at least one of the coil units other than the first in the same direction as the high voltage coil, and is applied to the primary coil at one end of the ringing removing coil. One end of the capacitor is connected to the other end of the ringing removal coil, and one end of the capacitor is connected to the other end of the first parallel circuit or the second end of the second end of the capacitor so that a voltage having the same phase as the collector pulse is generated. The present invention provides a flyback transformer characterized in that the flyback transformer is connected between the resistor of the first coil unit and the input side of the winding section on the most input side of the high voltage coil of the first coil unit.

[0017]

FIG. 1 shows a circuit diagram of one embodiment. In the figure, the same parts as those of the conventional example are denoted by the same reference numerals, and the detailed description of those parts is omitted. Further, the structure of this embodiment is the same as the structure of the conventional example shown in FIG. 2, and the description thereof is omitted here.

The feature of this embodiment is that a ringing removing coil 31 and a capacitor C3a are provided. This point will be mainly described.

In FIG. 1, the first coil unit 11a
A parallel circuit composed of a resistor R2 (for example, 8.2 kΩ) and an inductance element L2 (for example, 2.7 mH) is connected in series to the input side of the winding section 5a1 on the most input (starting of winding) side of the high voltage coil 5.

The high voltage coil 5 of the second coil unit 11b
A ringing removing coil 31 is formed on the innermost side (inside the winding section 5b1) in the same direction as the high-voltage coil 5. One end of the ringing removing coil 31 is connected to one end thereof.
The open ends are set so that a voltage having the same phase as the collector pulse applied to the next coils 3a and 3b is generated. The other end of the ringing removal coil 31 is connected to one end of a capacitor C3a.
Then, the other end of the capacitor C3a is connected between the parallel circuit and the input side of the winding section 5a1 (the winding section on the most input side of the high voltage coil 5 of the first coil unit 11a).

With the above configuration, the voltage applied to the capacitor C3a can be reduced, and a capacitor having a small withstand voltage can be used as the capacitor C3a. This will be described. The ringing removal coil 31 and the winding section 5b1 of the high-voltage coil 5 located immediately outside thereof are capacitively coupled (the capacitance is C10), and considering an equivalent circuit,
It becomes a series circuit of the capacitor C10 and the capacitor C3a. For example, CRT
If the high-voltage output to is 30 kV, 15 kV is applied to this series circuit because there are two coil units. Therefore, a voltage divided from 15 kV is applied to the capacitor C3a. On the other hand, in the conventional example shown in FIG.
Almost 15 kV is applied to 3. As can be seen from this example, in the present embodiment, the capacitor C
3a can be used with low pressure resistance. Therefore, the size and cost of the capacitor C3a can be reduced, and the reliability of the capacitor C3a also improves. Further, the applied voltage of the capacitor C3a divided from 15 kV is almost inversely proportional to the capacitance of the capacitor C3a, so that the withstand voltage of the capacitor C3a can be set quite freely by adjusting the capacitance.

The DC potential of the ringing removing coil 31 (voltage applied to the capacitor C3a) is also low since the voltage is divided from 15 kV in the same manner as described above. Therefore, the primary winding of the low-voltage coil located inside the ringing removal coil 31
The potential difference from the primary winding 3b is reduced (there was a DC potential difference of 15 kV in the past), and the insulation of the primary winding 3b is facilitated. further,
Since the potential difference between the ringing removing coil 31 and the high voltage coil 5 located outside thereof is only a DC component, the insulation between the ringing removing coil 31 and the high voltage coil 5 can be easily performed.

In the case of a flyback transformer having three or more coil units, when the coil units are the first, second,. At least one of
Resistance R2 and inductance element L in one coil unit
2, a ringing removal coil 31 and a capacitor C3a may be provided. Further, a parallel circuit composed of the resistor R2 and the inductance element L2 may be simply used as a resistor.

Of course, in the present embodiment, high-order resonance can be achieved without increasing the number of layers of high-voltage coils, the number of diodes used, or the length of coils and ferrite cores, as in the conventional example. , High pressure regulation,
It is a flyback transformer with almost no ringing.

[0025]

As described above, the flyback transformer according to the present invention can use a capacitor with a small withstand voltage, can reduce the cost and reduce the size, and furthermore, even in the coil units other than the first, a ringing-kig removing coil is provided. In the coil unit, the insulation with the primary winding of the low-voltage coil becomes easy, and the reliability is improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment.

FIG. 2 is a diagram showing a structure of a conventional example.

FIG. 3 is a circuit diagram including a peripheral circuit of a conventional example.

FIG. 4 is a circuit diagram showing another conventional example.

[Explanation of symbols]

 1 Core 1a, 1b Core leg 2a, 2b Low-voltage coil bobbin 3a, 3b Primary winding (primary coil) 4a, 4b High-voltage coil bobbin 5 High-voltage coil 5a, 5a1, 5a2, 5a3 Winding section 5b, 5b1, 5b2, 5b3 Winding section 6a, 6b Interlayer insulating material 7a, 7b Terminal 8a to 8d Diode 9 Case 10 Flyback transformer 11a First coil unit 11b Second coil unit 13 Insulating resin 31 Ringing removal coil C3a Capacitor L2 Inductance element R2 Resistance ( First resistance)

Claims (1)

(57) [Claims] 1. A low pressure coil is wound around a low voltage coil bobbin and a high voltage coil bobbin is fitted around the low voltage coil bobbin as follows:
A high-voltage coil is wound around the high-voltage coil bobbin in a single layer or a plurality of layers, and a layered winding structure is formed by alternately arranging the winding sections of the divided and wound high-voltage coil with an interlayer insulating material. The winding sections are connected in series via a diode so that the voltages generated in the winding sections adjacent to each other via the insulating material have the same phase, and a plurality of coil units having the above configuration are provided. The high-voltage coils of the respective coil units are connected in series via a diode so that the respective high-voltage outputs are added and rectified. The primary coil of the low-voltage coils of the respective coil units is generated in the same direction as the generated magnetic flux. In a flyback transformer configured by fitting each of the coil units to each of legs of a core having a plurality of legs, wherein the plurality of coil units are The Tsu bets, top input of the first from the lowest electric potential of the high voltage coil, when the second, ... of the coil unit, the high pressure coil of the first coil unit (winding starting)
A first parallel circuit comprising a first resistor and an inductance element or a second resistor is connected to the input side of the winding section on the other side, and the most high voltage coil of at least one of the coil units other than the first is connected. A ringing removing coil is formed on the inner peripheral side in the same direction as the high voltage coil, and one end of the ringing removing coil is connected to one end of the coil so that a voltage having the same phase as a collector pulse applied to the primary coil is generated. One end of a capacitor is connected to the other end of the ringing removing coil as an open end, and the other end of the capacitor is connected to the first parallel circuit or the second resistor and the most input of the high voltage coil of the first coil unit. Characterized in that it is connected between the input side of the winding section on the side.