JPH061979B2 - High voltage generator - Google Patents

Description

The present invention relates to a high voltage generator suitable for use in supplying a high voltage to a television receiver, a CRT display device, etc., and more particularly to a high voltage bobbin. The present invention relates to a flyback transformer of a type in which a coil of layers is wound in a coaxial multilayer winding.

[Prior art]

In general, a high voltage generator called a flyback transformer generates a harmonic having a frequency much higher than the fundamental wave of the flyback pulse due to the distributed capacitance and the leakage inductance of the high-voltage coil on the secondary side. It becomes ringing and is piled up. The ringing energy spreads to the television circuit, the display circuit, etc. by capacitive coupling, electromagnetic coupling, etc., and appears as bright and dark vertical stripes on the screen of the cathode ray tube, which causes deterioration of image quality.

On the other hand, the horizontal deflection frequency of television receivers, CRT display devices, etc. is set to 15.75 KHz, but with the increasing use of CRT display devices as computer terminals in recent years, higher definition screens and higher In order to obtain a quality screen, the horizontal deflection frequency has been increased. Therefore, even in the high voltage generator, the horizontal deflection frequency is, for example, 60 to 65 as compared with the normal one used when the horizontal deflection frequency is 15.75 KHz.
There is a need for a device that can be applied to KHz and that can reliably remove ringing energy.

In such a situation, in order to improve the high-voltage regulation with respect to the load, reduce the occurrence of ringing during the scanning period, and increase the high-order tuning order, a plurality of high-voltage coils are arranged in the radial direction of the high-voltage bobbin. BACKGROUND ART Coaxial multi-layer high voltage generators, which are formed by dividing and winding a high voltage block of layers, have been used.
However, even if the high voltage generator has such a configuration, it is not possible to completely remove the ringing, and a method of attenuating the ringing energy by an appropriate ringing removing means is usually adopted.

As such a coaxial multilayer winding type high voltage generator, those shown in FIGS. 5 and 6 are conventionally known.

In FIG. 1, reference numeral 1 is a core formed by abutting “U” -shaped core members, and 2 is a low pressure bobbin inserted through one leg of the core 1. A low-voltage coil 3 having a predetermined number of turns is wound around the outer periphery by section winding. Reference numeral 4 denotes a high-pressure bobbin located on the outer circumference of the low-voltage coil 3 so as to be fitted into the low-pressure bobbin 2. The outer circumference of the high-voltage bobbin 4 has five layers of intercalation papers 5, 5, 5.
, And high-voltage blocks 6A, 6B, ... 6E of the first to fifth layers constituting the high-voltage coil 6 are alternately wound in the radial direction in a coaxial cylindrical shape. Here, the number of coil turns of each layer of the high voltage blocks 6A to 6E is usually 6 to 7 times the number of coil turns of the low voltage coil 3. As shown in FIG. 6, 7A, 7B, ... 7E are five high voltage diodes alternately connected in series with the high voltage blocks 6A to 6E (collectively referred to as diodes 7), and each diode 7 is a high voltage diode. It is provided between the terminal pins 8 and 8 provided on the collar of No. 4.

Further, FIG. 6 shows the entire circuit configuration. The collector side of the low-voltage coil 3 is composed of a horizontal scanning transistor 9, a damper diode 10, a resonance capacitor 11, a deflection yoke 12, an S-shaped correction capacitor 13, and the like. The power supply side is connected to the output circuit 14 and is grounded via the DC power supply circuit 15. On the other hand, the high voltage coil 6 is
The low-voltage side end of the first high-voltage block 6A, which is the lowest pressure layer, is grounded through the resistor 16 for removing ringing energy, and the fifth high-voltage block, which is the highest pressure side, is connected to the cathode ray tube (not shown) through the high-voltage diode 7E. No.) is connected to the anode.

In the high voltage generator configured as above, when a basic pulse is input from the horizontal output circuit 14 to the low voltage coil 3, a high voltage determined by the number of coil turns is obtained in each of the high voltage blocks 6A to 6E, and a high voltage is obtained. Diodes 7A-7E
The high voltage is subjected to additive rectification by means of which a desired high voltage is applied to the anode of the cathode ray tube. On the other hand, in the ringing superimposed on the basic pulse during the scanning period, the ringing energy is consumed by the resistor 16 and the ringing can be attenuated.

[Problems to be solved by the invention]

However, the above-mentioned conventional high voltage generator has the following problems.

That is, when the coaxial multi-layer winding is first used, the distributed capacitance formed between the low voltage coil 3 and the high voltage coil 6 is
It is experimentally known that it is proportional to about the square of the winding width of the high-voltage block 6A, but in the case of the coaxial multi-layer winding, the winding width becomes wide, and thus the distributed capacitance becomes large. As a result, the resonance current flowing between the low-voltage coil 3 and the low-voltage coil 3 becomes large, and there is a problem that the heat generation due to the low-voltage coil 3 and the dielectric loss becomes large especially with the increase in the horizontal deflection frequency.

Secondly, since the resistor 16 is provided on the low-voltage side of the first high-voltage block 6A, the current of the fundamental wave component of the flyback pulse induced in the first high-voltage block 6A is also accompanied by the harmonic component. There is a problem that the basic pulse is consumed by the resistor 16 and is lost, resulting in a decrease in high voltage output.

Thirdly, the resistor 16 consumes the ringing energy and the energy of the fundamental wave partially lost, so that there is a problem that the resistor 16 generates a large amount of heat.

Fourth, when the horizontal deflection frequency is set to a high frequency, it is necessary to increase the impedance of the resistor 16. Therefore, the ringing current does not flow from the resistor 16 to the ground and directly returns from the high-voltage coil 6 to the low-voltage coil 3, so that the ringing cannot be completely removed.

The present invention has been made in view of the above-mentioned problems of the prior art. By reducing the distributed capacitance, the resonance current is reduced, the temperature rise due to heat generation is suppressed, and ringing can be reliably removed. By doing so, it is an object of the present invention to provide a high-voltage generator capable of improving the screen quality and the high-voltage regulation.

[Means for solving problems]

In order to solve the above problems, the feature of the configuration adopted by the present invention is that the number of coil turns of the first high-voltage block, which is the lowest pressure side of the high-voltage coil, and the number of coil turns of the low-voltage coil are set substantially equal to The first high-voltage block is located between the low-voltage side end of the second high-voltage block and approximately the center and wound around a high-pressure bobbin, and ringing removing means is provided between the high-voltage side of the first high-voltage block and the collector side of the low-voltage coil. Is connected.

[Action]

Since the first high-voltage block is wound from the low-pressure side end of the second high-voltage block to almost the center, the winding width of the first high-voltage block can be narrowed, and thus the distributed capacity can be reduced. As a result, the resonance current can be reduced. Further, by setting the number of turns of the first high-voltage block to be almost equal to that of the low-voltage coil, that is, the number of turns up to about twice the number of turns of the low-voltage coil,
The collector side of the low-voltage coil and the high-voltage side end of the first high-voltage block can be held at substantially the same potential as viewed from the peak value of the basic pulse. Even if a ringing removing means is provided between these, Only the harmonic component flows, and the fundamental component is not lost. Further, by setting the constant of the ringing removing means to the critical braking condition, the ringing can be surely removed and the high pressure regulation can be improved.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 4. Since there is no difference from the prior art except for the high voltage coil and the ringing removing means, the same components are designated by the same reference numerals and the description thereof will be omitted.

Therefore, 21 is a high-voltage coil used in the present embodiment, and the high-voltage coil 21 also has five layers of tank interleaf 5, 5 on the outer periphery of the high-voltage bobbin 4.
5, and high-pressure blocks 21A, 21 of the first to fifth tanks
B, ..., 21E are alternately wound in the radial direction in a coaxial cylindrical shape. Here, as shown in FIG. 1, the second high-voltage block 21 among the high-voltage blocks 21A to 21E.
The four layers of high-voltage blocks 21B to 21E after B are wound in full width with respect to the winding width of the high-voltage bobbin 4, and the number of coil turns is 6 to 7 times the number of coil turns of the low-voltage coil 3. Has been done. On the other hand, the first high-pressure block 21A, which is the lowest pressure side, is located between the low-pressure side end of the second high-pressure block 21B and substantially the center in the axial direction, and is wound around the innermost peripheral side of the high-pressure bobbin 4. . The number of coil turns of the first high-voltage block 21A wound in this way is set to be substantially equal to the number of coil turns of the low-voltage coil 3.

It should be noted that here, to position the first high-pressure block 21A between the low-pressure side end of the second high-pressure block 21B and substantially the center in the axial direction does not necessarily mean that the first high-pressure block 21A is positioned almost at the intermediate position in the axial direction, and the distributed capacity Is proportional to the square of the winding width, and thus may be any winding width that does not reach the center in the axial direction. On the other hand, the number of turns substantially equal to the number of coil turns of the low-voltage coil 3 mentioned above includes a state in which the number of coil turns of the first high-voltage block 21A is wound up to about twice, and the number of turns of the first high-voltage block 21A If the number of coil turns becomes too large, the fundamental wave component flowing to the low-voltage coil 3 via the ringing removal circuit 22 described later increases, resulting in a large loss and the ringing removal circuit 22.
It is not preferable because the capacitor 22B must have a high breakdown voltage.

Further, 22 is a ringing removal circuit as the ringing removal means of the present embodiment, and the ringing removal circuit 22 is composed of a series connection circuit of a resistor 22A and a capacitor 22B,
The resistor 22A side is connected to the high voltage side end of the first high voltage block 21A via a connection point A, and the capacitor 22B side is connected to the collector side end of the low voltage coil 3 via a connection point B. Here, several tens of PFs are used as the capacitor 22B.
To several thousand PF, resistance 22A is 100Ω
It is possible to use a material having a degree of about 20 KΩ.

Further, in the present embodiment, the resistor 16 according to the prior art is not used, the low voltage side of the first high voltage block 21A is immediately grounded or grounded via the diode, and the high voltage blocks 21A to 21E and the high voltage diode 7A are also connected. ~ 7
Es are alternately connected in series.

Although the present embodiment is configured in this way, the operation of the high voltage generator is not different from that of the prior art.

Therefore, in the present embodiment, the first high voltage block 21A forming the high voltage coil 21 is replaced with the second high voltage block 21B.
Since it is arranged between the low pressure side end of the high pressure bobbin 4 and almost the center in the axial direction and is wound around the innermost peripheral side of the high pressure bobbin 4,
The winding width of the first high-voltage block 21A can be made significantly narrower than that of the prior art. As a result, the distributed capacitance proportional to the square of the winding width of the first high-voltage block 21A can be significantly reduced, and the resonance current can be reduced. Thus, heat generation due to the low voltage coil 3 and the presence of the dielectric can be eliminated.

On the other hand, since the number of coil turns of the first high voltage block 21A is set to be substantially equal to the number of coil turns of the low voltage coil 3, the peak value of the basic pulse applied to the collector side of the low voltage coil 3 and the first The peak value of the basic pulse induced at the high voltage side end of the high voltage block 21A has substantially the same potential. As a result, the ringing elimination circuit 2 is provided between them.
Even if number 2 is provided, the voltage across the ringing removal circuit 22 is maintained at a substantially equal value, and the basic pulse induced in the first high voltage block 21A does not flow to the low voltage coil 3. Therefore, the basic pulse is the ringing elimination circuit 22.
Is prevented from being attenuated. On the other hand, when a harmonic component is superimposed on the fundamental pulse, only the harmonic component flows through the ringing removal circuit 22, and this can be attenuated as heat. it can.

Further, the flyback transformer as the high voltage generator has an equivalent circuit as shown in FIG. That is, C ₁ is the capacitance of the resonance capacitor 11, L ₁ is the combined inductance of the deflection yoke 12 and the low voltage coil 3, C ₂ is the value obtained by converting the distributed capacitance of the high voltage diode 7 and the distributed capacitance of the high voltage coil 21 to the primary side, When L ₂ is a value obtained by converting the leakage inductance of the low-voltage coil 3 and the high-voltage coil 21 to the primary side, and C ₃ is an equivalent distributed capacitance in parallel with the inductance L ₂ , the equivalent circuit shown in the drawing is obtained. The arrangement of the ringing removing circuit 22 as described above means that the ringing removing circuit 2 is arranged in parallel with the leakage inductance L ₂ and the distributed capacitance C _3.
2 is connected. Therefore, the ringing energy can be reliably removed by appropriately setting the constants of the resistor 22A and the capacitor 22B forming the ringing removal circuit 22 in the vicinity of the critical braking condition.

As the ringing removal circuit 22, a series circuit of a resistor 22A and a capacitor 22B is illustrated, but as shown in FIG. 4, a resistor 32A, a coil 32B and a capacitor 32C are connected as the ringing removal circuit 22 as shown in the figure. May be used, and those having various circuit configurations can be used. Further, the low-pressure bobbin 2 and the high-pressure bobbin 4 are not limited to a cylindrical shape, but may have an arbitrary shape such as a rectangular tube shape. Furthermore, it goes without saying that the present invention is not limited to high-frequency high-voltage generators.

〔The invention's effect〕

The present invention is as described in detail above, and since the distributed capacitance by the first high-voltage block forming the high-voltage coil is made small, the resonance current can be made as small as possible, while the first high-voltage block is made. The fundamental wave induced in the coil and the fundamental wave applied to the low voltage coil are held at substantially the same potential, and ringing removing means is provided between the high voltage side of the first high voltage block and the collector side of the low voltage coil. , The ringing can be removed with a small loss of the fundamental wave, a stable high voltage output can be obtained, the high voltage regulation can be improved, good image quality characteristics can be obtained, and the ringing removal means can be set. This has the effect of increasing the degree of freedom.

[Brief description of drawings]

1 to 4 relate to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a high voltage generator according to this embodiment, FIG. 2 is a circuit configuration diagram thereof, and FIG. 3 is a high voltage generator. Equivalent circuit diagram of
FIG. 4 is a circuit diagram showing another ringing removal circuit, and FIG.
6 and 6 relate to a conventional technique, FIG. 5 is a longitudinal sectional view of a high voltage generator according to the conventional technique, and FIG. 6 is a circuit configuration diagram thereof. 2 ... Low-voltage bobbin, 3 ... Low-voltage coil, 4 ... High-voltage bobbin, 7
... High-voltage diode, 21 ... High-voltage coil, 21A to 21E
... First to fifth high voltage blocks 22, 32 ... Ringing removing circuits.

Claims (1)

[Claims] 1. A low-voltage coil wound around a low-voltage bobbin, a high-voltage coil wound around a high-voltage bobbin located on the outer peripheral side of the low-voltage coil in a coaxial multilayer in a plurality of divided high-voltage blocks, and the high-voltage coil. In a high voltage generator comprising a high voltage block of each layer and a plurality of high voltage diodes alternately connected in series, the number of coil turns of the first high voltage block of the high voltage coil is substantially equal to the number of coil turns of the low voltage coil. The first high-voltage block is positioned between the low-voltage side end of the second high-voltage block and approximately the center of the second high-voltage block, and is wound around the high-voltage bobbin to connect the high-voltage side of the first high-voltage block and the collector side of the low-voltage coil. A high voltage generator characterized in that a ringing removing means is connected between them.