JP3360342B2 - High voltage generating circuit and flyback transformer, and flat type cathode ray tube device using them - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage generating circuit and a flyback transformer suitable for use in a small television receiver or a television monitor using a cathode ray tube, and a flat cathode ray tube device using the same.

[0002]

2. Description of the Related Art FIG. 6 shows a flat type cathode ray tube (flat type CR).
T) 1 is shown. In the figure, 1a is a neck portion provided with an electron gun (not shown), 1b is a funnel portion,
c is a screen panel, 1d is a front panel, and 1e is a phosphor screen formed on the screen panel 1c. The screen panel 1c and the front panel 1d are formed of transparent glass. The phosphor screen 1e is inclined at a relatively small angle with respect to the center axis of the electron gun.
Is observed from the front panel 1d side substantially perpendicular to the central axis of the electron gun.

[0003] In such a flat cathode ray tube 1, keystone distortion (inverted trapezoidal distortion) occurs due to its structure. That is,
The horizontal deflection scanning is performed from the upper portion to the lower portion of the fluorescent screen 1e. However, since the upper deflection angle θ1 and the lower deflection angle θ2 are different, the horizontal deflection scanning approaches the lower portion when performing horizontal deflection scanning with a constant deflection power (current). As the scanning amplitude decreases, keystone distortion occurs.

In order to correct the keystone distortion, it is necessary to dynamically increase the horizontal deflection current Ipp as the fluorescent screen 1e is scanned from the upper part to the lower part. Here, the power supply voltage eo of the horizontal deflection circuit and the horizontal deflection current Ipp
Has a relationship of eo = Ly (Ipp / Ts) = K · Ipp, where Ly is the inductance of the horizontal deflection coil (H · DY) and Ts is the horizontal scanning period. Here, K = (Ly / Ts). That is, in order to dynamically increase the horizontal deflection current Ipp, it is understood that the power supply voltage eo needs to be dynamically changed. In order to realize this, a so-called power supply modulation method in which a power supply voltage is modulated by a sawtooth signal having a vertical period is generally widely used.

The high-voltage generating circuit and the horizontal deflection circuit of the cathode ray tube include a conventional type in which the high-voltage generating circuit and the horizontal deflection circuit are separated as conventionally known, and a conventional type in which these circuits are not separated.
The conventional type is suitable when the image distortion such as pincushion distortion and keystone distortion is small, but is not suitable when the image distortion is large because the correction has a very large effect on the high-voltage generating circuit. As described above, in flat-type cathode ray tubes, the amount of correction of keystone distortion is very large,
Separate type is adopted.

FIG. 7 shows a separate type high voltage generating circuit. Reference numeral 11 denotes a high-voltage output transistor. A drive pulse is supplied to the base of the transistor 11 from a high-voltage drive circuit (not shown). The emitter of the transistor 11 is grounded, and a damper diode 12 and a resonance capacitor 13 are connected in parallel between the collector and the ground.

The collector of the transistor 11 is connected to a power supply terminal 15 to which a DC voltage + Vcc is supplied via a low voltage coil (primary winding) 14a of a flyback transformer (transformer for generating high voltage) 14. One end of a high-voltage coil (secondary winding) 14 b of the transformer 14 is connected to a high-voltage rectifier circuit 16 having a multiple voltage. The high-voltage rectification circuit 16 rectifies the boosted pulse voltage obtained at one end of the high-voltage coil 14b, and a high voltage HV is led out to a terminal 17. The other end of the high voltage coil 14b of the transformer 14 is connected to the low voltage coil 1
4a is connected to one end.

FIG. 8 shows waveforms at various points in the example of FIG. FIG. 2A shows a state where 1 is supplied to the base of the transistor 11.
Drive pulse of horizontal cycle, FIG.
p, FIG. C shows the damper current id, and FIG. D shows the low voltage coil 14a.
, And FIG. 5E shows the collector voltage Vcp. Here, tr is a blanking period, and ts is a scanning period.

The low-voltage coil 14a of the transformer 14
Is L1, the maximum value icpm of the collector current icp is as follows.

Vcc = L1 · di / dt = L1 · icpm / (ts / 2) ∴icpm = (ts / 2) · (Vcc / L1) (1) Flowing through the low-voltage coil 14a during the retrace period tr The current iL is as follows.

IL = icpmcosωot (2) where ωo is a resonance angular frequency between the low-voltage coil 14 a of the transformer 14 and the resonance capacitor 13, and
Assuming that the inductance of 4a is L1 and the capacitance of the resonance capacitor 13 is C1, the following equation is established. fo is a resonance frequency, and a half cycle thereof is ωo = 2πfo = 1 / √ (L1C1) (L1C1) (3) fo is a resonance frequency, and a half cycle thereof is a retrace period. tr
And the following equation holds.

Tr = 1 / (2fo) (4) From equation (2), the following equation is obtained.

L1 · diL / dt = −ωoL1 · icpmsinωot (5) Accordingly, the maximum value Vcpm of the collector voltage Vcp can be obtained by the following equation.

Vcpm = ωoL1 · icpm + Vcc = ωoL1 · (ts / 2) · (Vcc / L1) + Vcc = Vcc (1 + πfoots) {Vcc ｛1+ (π / 2) · (ts / tr)} (6) In the high-voltage generation circuit in the example of FIG. 7, a high voltage HV is obtained from a pulse voltage obtained by boosting the resonance pulse voltage obtained from the relationship of Expression (6) by the turns ratio of the transformer 14.

From equation (6), it can be seen that the collector voltage Vcpm increases as the retrace period tr decreases. The retrace period tr is determined by the inductance L1 of the low-voltage coil 14a of the transformer 14 and the capacitance C1 of the resonance capacitor 13, as is apparent from the equations (3) and (4). Therefore, in order to keep the high voltage HV constant, it is necessary to consider variations in both the inductance L1 and the capacitance C1.

Generally, the resonance capacitor 13 is mounted on a circuit board as an external component. Therefore, if the resonance capacitor 13 is opened due to a work error or a cut pattern of the board, the collector voltage Vcpm becomes extremely high, and the circuit and the transformer 14 There is a problem that smoke is ignited by destroying the tube and that the high voltage HV supplied to the cathode ray tube becomes abnormally high and X-rays and the like are emitted from the cathode ray tube.

In order to prevent such an abnormal operation, conventionally, an abnormally high voltage is detected to operate a protection circuit, or a four-legged capacitor is used as the resonance capacitor 13. The four-legged capacitor has two terminal pins connected to each terminal, and by connecting each of these two terminal pins to the circuit board, the frequency of occurrence of an open state due to disconnection of the capacitor can be reduced. .

However, small cathode ray tubes such as flat cathode ray tubes are compact and low-cost products, so that expensive protection circuits and four-legged capacitors cannot be used. Is supported.

[0019]

However, when driving a cathode ray tube at a reduced high voltage, the acceleration of the electron beam is reduced and the focusing is deteriorated, so that the resolution is reduced and a high quality image is obtained. Is not possible.

FIG. 9 shows the structure of a conventional flyback transformer 14. In the figure, reference numeral 14c denotes a low-pressure bobbin, on which the above-described low-voltage coil 14a is wound. Reference numeral 14d denotes a high-pressure bobbin, on which the high-voltage coil 14b described above is wound. 14e is a core.

In the transformer 14, the low-voltage coil 14a and the high-voltage coil 14b are wound around separate concentric bobbins 14c and 14d in order to reduce the influence of the wetting magnetic flux such as high-voltage fluctuation and raster ringing. The configuration is such that the coupling between the low-voltage coil 14a and the high-voltage coil 14b is made dense and the distribution capacity is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent occurrence of an abnormal state due to an opening of a resonance capacitor due to a work error, a cut of a pattern of a substrate, or the like.

[0023]

According to a first aspect of the present invention, there is provided a high voltage generating circuit including a low voltage coil and a plurality of high voltage coils.
When split and wound into body-shaped split slit bobbin
The side of the plurality of high-voltage coils adjacent to the low-voltage coil
The number of turns of the high-voltage coil must be greater than the number of turns of the other high-voltage coils.
A flyback transformer is provided, and a resonance circuit is constituted only by the inductance and internal distribution capacitance of the low voltage coil of the flyback transformer, and a resonance pulse voltage boosted from the high voltage coil of the flyback transformer is obtained .

According to a second aspect of the present invention, there is provided a flyback transformer in which a low-voltage coil and a plurality of high-voltage coils are divided and wound on a bobbin integrally formed with a split slit , and a plurality of coils are wound.
The high voltage coil on the side of the high voltage coil adjacent to the low voltage coil
The number of windings Le is shall such as a higher number of windings other high pressure coil. Flat type cathode ray tube apparatus according to the invention of claim 3 is the flat type cathode-ray tube apparatus that is adapted to supply a high voltage to the anode of the flat type cathode ray tube of a high pressure generation circuit, high-voltage generation circuit includes a low pressure coil, wound around divided into integral division slit structure bobbins and a plurality of high-pressure coil
With the low-voltage coil of the plurality of high-voltage coils.
The number of turns of the high-voltage coil on the
With a flyback transformer as the top
Inductance and internal distribution of low voltage coil of transformer
This flyback transformer constitutes a resonance circuit with
A shall obtain a boosted resonance pulse voltage from the high voltage coil.

For example, the high-voltage coil includes a first high-voltage coil wound adjacent to the low-voltage coil and a second high-voltage coil wound adjacent to the first high-voltage coil. The number of turns of the first high-voltage coil is equal to or greater than the number of turns of the second high-voltage coil.

[0026]

According to the first and third aspects of the present invention, a low-voltage coil is provided.
And multiple high-voltage coils are integrated
And wrap it around multiple high-voltage coils.
In other words, the number of turns of the high-voltage coil adjacent to the low-voltage coil
Flyback tiger with more than the number of turns of high voltage coil
It has a sense. This flyback transformer
Is the connection between the low-voltage coil and the high-voltage coil loose?
The distribution capacity between the low-voltage coil and the high-voltage coil is large.
In addition, this distributed capacity has a small variation.
You. Therefore, a resonance circuit can be constituted only by the inductance of the low-voltage coil and the internal distributed capacitance of the flyback transformer . Therefore , it is not necessary to mount the resonance capacitor on the circuit board, and it is possible to prevent the occurrence of an abnormal state due to an opening of the resonance capacitor due to a work error, a cut pattern of the board, or the like. Also, as described above, the low voltage coil and the high
High leakage magnetic flux due to poor coupling with the pressure coil
But adjacent to the low voltage coil of the flyback transformer
The number of turns of the high-voltage coil on the side is equal to or greater than the number of turns of the other high-voltage coil.
Therefore, when there is no such relationship of the number of windings,
In comparison, the number of magnetic fluxes linked to the high-voltage coil increases,
Is reduced, and as a result, the leakage flux can be reduced.
This suppresses the effects of leakage flux, for example, image quality degradation.
Can control.

According to the second aspect of the present invention, the low-voltage coil and the plurality of high-voltage coils are divided and wound on an integral split-slit structure bobbin, and the connection between the low-voltage coil and the high-voltage coil is poor. from becoming, distributed capacitance between the low pressure coil and the high voltage coil is increased, also the volume of distribution that Do small ones variation. Also, as mentioned above
In addition, the coupling between the low-voltage coil and the high-voltage coil
And the leakage flux increases, but on the side adjacent to the low-voltage coil
Set the number of windings of the high-voltage coil to
Compared to the case where the number of windings is not related
As a result, the number of magnetic fluxes linked to the high-voltage coil increases,
The engagement is reduced, and as a result, the leakage flux is reduced.

The number of turns of the first high-voltage coil wound adjacent to the low-voltage coil is equal to or greater than the number of turns of the second high-voltage coil wound adjacent to the first high-voltage coil. This makes it possible to reduce the leakage magnetic flux.

[0029]

An embodiment of the present invention will be described below with reference to FIG.

In the figure, reference numeral 20 denotes a horizontal deflection circuit.
Reference numeral 21 denotes an N-channel enhancement type MOS field effect transistor as a horizontal output transistor. A horizontal drive pulse is supplied to the gate of the transistor 21. The source of the transistor 21 is grounded, and its drain is connected to the DC voltage + V via the choke coil 22.
It is connected to a power supply terminal 23 to which cc is supplied. A resonance capacitor 24, a horizontal deflection coil 25 and an S-shaped correction capacitor
6 series circuits are connected in parallel.

FIG. 2 shows a MOS field effect transistor 21
The horizontal axis shows the drain-source voltage VDS, and the vertical axis shows the drain current ID. And
The curve a in the figure shows the relationship between the voltage VDS and the current ID when the transistor 21 is on (on characteristics), and the curve b shows the relationship between the voltage VDS and the current ID when the transistor 21 is off (diode characteristics) Is shown.

Next, the operation will be described with reference to the waveform diagram of FIG. 6A shows a horizontal drive pulse, FIG. 6B shows a drain current, FIG. 6C shows a drain voltage, FIG. 7D shows a resonance capacitor current, and FIG. 7E shows a deflection current.

When a horizontal drive pulse as shown in FIG. 3A is supplied to the gate of the transistor 21, a deflection current (sawtooth current) flows through the deflection coil 25 as shown in FIG.

That is, when a positive pulse is supplied to the base of the transistor 21, the transistor 21 is turned on, and a current that increases linearly with time flows in the deflection coil 25 (t11 to t12).

Next, when a negative pulse is supplied to the gate of the transistor 21, the transistor 21 is turned off, and the current continues to flow in the same direction due to the inertia of the inductance, and charges the resonance capacitor 24. This charging current decreases with time, and the voltage of the resonance capacitor 24 increases. The charging current becomes zero, and the voltage (drain voltage) of the resonance capacitor 24 reaches a peak (t12 to t13).

Next, the resonance capacitor 24 is connected to the deflection coil 2.
5, the voltage gradually decreases, and the current in the reverse direction increases in the deflection coil 25. Resonant capacitor 24
Returns to the original voltage, and the reverse current reaches a peak (t13 to t14).

Next, the transistor 21 conducts as a diode due to the back electromotive force of the deflection coil 25 (see the diode characteristic of the curve b in FIG. 2), and the current continues to flow in the same direction. The magnitude of the current gradually decreases (t14 to t15). Then, when a positive pulse is supplied to the gate of the transistor 21 and the transistor 21 is turned on, the transistor 21 is turned on by the on characteristic (see the characteristic of the curve a in FIG. 2), and the current continues to flow in the same direction. The magnitude of the current gradually decreases to zero (t15 to t16).

Next, since the transistor 21 is turned on, a current that increases linearly with time flows through the deflection coil 25 again. With the above cycle, a sawtooth current flowing through the deflection coil 25 is formed.

Returning to FIG. 1, reference numeral 40 denotes a high voltage generating circuit. Reference numeral 41 denotes an N-channel enhancement type MOS field effect transistor as a high voltage output transistor. A horizontal drive pulse is supplied to the gate of the transistor 41. The source of the transistor 41 is grounded, and the drain is connected to a power supply terminal 44 to which a DC voltage + Vcc is supplied via a low-voltage coil (primary winding) 42a of a flyback transformer (high-voltage generating transformer) 42 and a low-pass filter 43. Connected. One end of a high-voltage coil (secondary winding) 42b of the transformer 42 is connected to a terminal 46 via a high-voltage rectifier circuit 45 of a multiple voltage. Transformer 4
The other end of the high-voltage coil 42b is connected to the low-voltage coil 42a.
Is connected to one end.

In the above configuration, the MOS field effect transistor 41 is used as the high voltage output transistor, and its operation is basically the same as the operation of the horizontal deflection circuit 20 described above. However, in this high-voltage generation circuit 40, no resonance capacitor is connected, and a resonance circuit is constituted only by the inductance of the low-voltage coil 42a of the transformer 42 and the internal distributed capacitance.

A resonance pulse voltage is obtained at the drain of the transistor 41 (see FIG. 3C), a boosted pulse voltage is obtained at the high voltage coil 42b of the transformer 42, and a high voltage HV is derived from the high voltage rectifier circuit 45 to the terminal 46. Is done.

In this embodiment, since the resonance circuit is constituted only by the inductance and the internal distribution capacitance of the low-voltage coil 42a, there is no need to mount a resonance capacitor on the circuit board as in the prior art. It is possible to prevent the occurrence of an abnormal state due to the opening of the resonance capacitor or the like. Therefore, when the high-voltage generating circuit of the present embodiment is used for a CRT television receiver or the like, it is not necessary to lower the high voltage, and it is possible to prevent a reduction in resolution due to focusing deterioration. Further, a protection circuit for detecting and protecting an abnormally high voltage is not required.

FIG. 4 shows the internal structure of the flyback transformer 42. In the figure, reference numeral 42c denotes a bobbin having a low-pressure / high-pressure integral type and a split slit structure. This bobbin 42
A low-voltage coil 42a is wound around the first slit c.
A first high voltage coil 42b1 constituting the high voltage coil 42b is wound around the second slit, and a second high voltage coil 42b2 constituting the high voltage coil 42b is wound around the third slit. The end of winding of the high voltage coil 42b is connected to the high voltage rectification circuit 45. 42d is a core.

The flyback transformer 42 is shielded by covering its outer periphery with a metal shield case 47.
Then, a silicon insulating resin 48 is filled between the shield case 47 and the flyback transformer 42 to increase the dielectric strength.

In this flyback transformer 42, FIG.
As shown in FIGS.
7 and between the low-voltage coil 42a and the high-voltage coil 42b. As described above, the low-voltage coil 42
a and the high-voltage coil 42b are wound separately on the bobbin 42c, so that the low-voltage coil 42a and the high-voltage coil 42b
The connection between the low-voltage coil 42a and the high-voltage coil 4
The distribution capacity between 2b becomes large. Therefore, a sufficient distributed capacitance corresponding to the primary-side resonance capacitor of the high-voltage generation circuit 40 can be formed. The dielectric constant of the silicon insulating resin 48 is positively used for the distributed capacitance. In addition, since the low-voltage coil 42a and the high-voltage coil 42b are wound around the low-voltage and high-pressure integrated bobbin 42c, it is possible to obtain a distributed capacity with less variation as compared with a coil wound around another bobbin.

Incidentally, as described above, the low-voltage coil 42
If a and the high-voltage coil 42b are loosely coupled, the leakage magnetic flux increases and the image quality deteriorates due to the occurrence of raster ringing or the like. Therefore, in this example, the number of turns of the first high-voltage coil 42b1 wound around the second slit is set to be equal to or greater than the number of turns of the second high-voltage coil 42b2 wound around the third slit. . Thereby, the leakage flux can be reduced, the influence of the leakage flux can be reduced, and the deterioration of the image quality can be suppressed. this
In this case, the connection between the low-voltage coil 42a and the high-voltage coil 42b
Leakage increases due to sparser connection, but low-voltage coils
Winding of the first high-voltage coil 42b1 on the side adjacent to 42b
The number should be equal to or greater than the number of turns of the second high voltage coil 42b2.
Higher pressure than when there is no such relationship
The number of magnetic fluxes linked to the coil 42b increases, and the degree of loose coupling is increased.
But the leakage flux is reduced as a result.
You.

[0047]

According to the first and third aspects of the present invention, a low-pressure coil
And a plurality of high-voltage coils
While dividing and winding into bottles,
In other words, the number of turns of the high-voltage coil adjacent to the low-voltage coil
Flyback tiger with more than the number of turns of high voltage coil
It has a sense. This flyback transformer
Is the connection between the low-voltage coil and the high-voltage coil loose?
The distribution capacity between the low-voltage coil and the high-voltage coil is large.
In addition, this distributed capacity has a small variation.
You. Therefore, a resonance circuit can be constituted only by the inductance and the internal distributed capacitance of the low-voltage coil of the flyback transformer . Therefore , it is not necessary to mount the resonance capacitor on the circuit board, and it is possible to prevent the occurrence of an abnormal state due to, for example, an opening of the resonance capacitor due to a work error or a cut pattern of the board. Thus, it is not necessary to lower the high pressure, and it is possible to prevent a reduction in resolution due to focusing deterioration. Further, there is no need for a protection circuit for protecting even if an abnormally high voltage is detected. Also, as described above, the low voltage coil and the high
High leakage magnetic flux due to poor coupling with the pressure coil
But adjacent to the low voltage coil of the flyback transformer
The number of turns of the high-voltage coil on the side is equal to or greater than the number of turns of the other high-voltage coil.
Therefore, when there is no such relationship of the number of windings,
In comparison, the number of magnetic fluxes linked to the high-voltage coil increases,
The degree of leakage is reduced, and as a result the leakage flux can be reduced,
The influence of the magnetic flux, for example, image quality deterioration can be suppressed.

According to the second aspect of the present invention, a low voltage coil ,
A plurality of high-voltage coils are divided and wound into an integral split-slit structure bobbin. Since the coupling between the low-voltage coil and the high-voltage coil is reduced, the distribution capacity between the low-voltage coil and the high-voltage coil is reduced. increases, also the volume of distribution that Do small ones variation. Also, as described above,
Leakage due to loose coupling between high-voltage coil and high-voltage coil
The number of bundles increases, but it is used for low-voltage coils in flyback transformers.
The number of turns of the high-voltage coil on the adjacent side is
Since the number of wires is more than
Magnetic flux linked to the high-voltage coil increases,
The degree of loose coupling is reduced, and as a result, leakage flux can be reduced.
Wear.

The number of windings of the first high-voltage coil wound adjacent to the low-voltage coil is equal to or greater than the number of windings of the second high-voltage coil wound adjacent to the first high-voltage coil. By doing so, the leakage flux can be reduced. Thereby, the influence of the leakage magnetic flux can be reduced, and the deterioration of the image quality can be suppressed.

[Brief description of the drawings]

FIG. 1 is a connection diagram showing one embodiment of a high voltage generating circuit according to the present invention.

FIG. 2 is a diagram illustrating characteristics of a MOS field-effect transistor.

FIG. 3 is a diagram showing waveforms at various points in the example of FIG.

FIG. 4 is a sectional view showing an internal structure of a flyback transformer.

FIG. 5 is a diagram for explaining a distributed capacitance of a flyback transformer.

FIG. 6 is a plan view and a side view showing a flat cathode ray tube (flat CRT).

FIG. 7 is a connection diagram showing a configuration of a conventional high-voltage generation circuit.

FIG. 8 is a diagram showing waveforms at various points in the example of FIG. 7;

FIG. 9 is a diagram showing the internal structure of a conventional flyback transformer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 flat cathode ray tube 20 horizontal deflection circuit 21, 41 MOS field effect transistor 22 choke coil 23, 44 power supply terminal 24 resonance capacitor 25 horizontal deflection coil 26 S-shaped correction capacitor 40 high voltage generation circuit 42 flyback transformer 42 a low voltage coil 42 b high voltage coil 42b1 First high voltage coil 42b2 Second high voltage coil 42c Bobbin 42d Core 43 Low pass filter 45 High voltage rectifier circuit 47 Shield case 48 Silicon insulating resin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-128407 (JP, A) JP-A-2-132707 (JP, A) JP-A-1-315110 (JP, A) 140013 (JP, U) JP-A 55-103914 (JP, U) JP-A 56-46223 (JP, U) JP 3-47312 (JP, Y2) JP-A 64-5863 (JP, Y2) (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 3/18 H01F 38/42

Claims (3)

(57) [Claims] A low-voltage coil and a plurality of high-voltage coils are connected together.
When split and wound into body-shaped split slit bobbin
Among the plurality of high-voltage coils, adjacent to the low-voltage coil.
The number of turns of the high-voltage coil on the contacting side is
A flyback transformer that is more than a few, comprising a resonance circuit consisting only of the inductance and internal distribution capacitance of the low voltage coil of the flyback transformer, and obtaining a resonance pulse voltage boosted from the high voltage coil of the flyback transformer. And a high voltage generating circuit. 2. A wound and a low pressure coil, and a plurality of high-pressure coil is divided into integral division slit structure bobbin Then co
Among the plurality of high-voltage coils, adjacent to the low-voltage coil.
The number of turns of the high-voltage coil on the contacting side is
A flyback transformer, wherein Rukoto such as a few more. 3. An anodized flat cathode ray tube from a high voltage generating circuit.
Flat cathode ray tube device adapted to supply high pressure
In location, the high voltage generating circuit includes a low pressure coil, integral dividing a plurality of high-pressure coil slit
And wound around the bobbin,
Among the high-voltage coils, the high-voltage coil on the side adjacent to the low-voltage coil
Make the number of turns of the coil more than the number of turns of other high-voltage coils
A flyback transformer, and the inductor of the low voltage coil of the flyback transformer.
And the internal distribution capacitance only, and the voltage is boosted by the high-voltage coil of the flyback transformer.
Flat type cathode ray tube characterized by obtaining resonance pulse voltage
apparatus.