JPH089183A - High pressure generator - Google Patents

Abstract

PURPOSE:To make a high voltage output constant by inserting a saturable transformer for resonance in series with a primary and a secondary winding of a flyback transformer respectively so as to control a resonance state depending on a high voltage load. CONSTITUTION:A circuit comprising a 1st saturable transformer 12, a 2nd saturable transformer 12' at the primary winding and the secondary winding of a flyback transformer 6 respectively, and inductive components of the transformers 12, 12', capacitors 8, 8' and resistors 9, 9' is resonated by plural odd number multiple harmonics of a horizontal synchronizing signal frequency when a high voltage load current is low. The high impedance phenomenon due to the resonance and the loss by the resistors 9, 9' reduce the harmonic component of the flyback transformer and a peak level is decreased as shown in dotted lines in waveform diagram. When the high voltage load is increased, the primary current of the transformers 12, 12' increases, the secondary inductive component is reduced to reduce the resonance effect. The harmonic component of the flyback transformer is not attenuated and a peak level of the output waveform is extended as shown in solid lines in the waveform diagram. Since the waveform is obtained by using a diode 10, the high voltage regulation characteristic is improved.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure generator,
Especially, it relates to improvement of flyback transformer high voltage regulation. 2. Description of the Prior Art One of the prior art examples is Japanese Patent Laid-Open No. 52-6.
There is a technique described in Japanese Patent Publication No. 9522. This is shown in FIG.
In this conventional technique, a resonance circuit composed of a coil 7, a capacitor 8 and a resistor 9 is inserted in series with a primary winding of a flyback transformer 6, and a harmonic component of a high voltage output waveform is attenuated by the resistor 9, This is intended to improve the high voltage regulation by making the back transformer output waveform head substantially flat as shown by the dotted line in FIG. 3 to widen the conduction range of the high voltage diode 10. However, even in this circuit, it is inevitable that the high-voltage output is reduced by the amount of the high-voltage load. As another conventional example, there is a method in which a saturable transformer is inserted in parallel with the primary winding of a flyback transformer, the inductance is changed by a high voltage load, and the high voltage is stabilized by changing the pulse width of the flyback period. But in this case,
Inductance changes reach several hundreds μH to several mH, which makes the transformer large and expensive, and also causes ringing due to the inductance to easily disturb the screen. The above-mentioned prior art has a problem that the high-voltage output decreases as the high-voltage load increases. Further, in the method of varying the inductance of the saturable transformer, the size of the transformer is increased and the cost becomes high. further,
The ringing due to the inductance appears in the output waveform of the flyback transformer, and it is easy for the screen to be disturbed. An object of the present invention is to improve the above-mentioned drawbacks of the prior art, to reduce the ringing component of the output waveform of the flyback transformer at a low cost, in a small size and with a simple structure, and to suppress the influence of load fluctuations to achieve high voltage. It is to realize the technology that can make the output constant. In order to achieve the above-mentioned object, the present invention is connected to the primary side of a flyback transformer (corresponding embodiment reference numeral 6) and has a resistor (corresponding to the embodiment) connected to the secondary side. The first resonance transformer (corresponding embodiment reference numeral 1) in which the inductance value is changed by the current corresponding to the load current of the flyback transformer connected to the primary side
2) and the load current value is low (first state)
Then, the first resonance circuit configured to resonate with a plurality of odd harmonics of the horizontal frequency of the flyback transformer and the secondary side of the flyback transformer are connected to the secondary side with a resistor (corresponding to embodiment 9 ′) Is connected and has a second resonance transformer (corresponding embodiment reference numeral 12 ′) whose inductance value is changed by a current corresponding to the load current of the flyback transformer supplied to the primary side, and the load current value is A second resonance circuit configured to resonate with a plurality of odd harmonics of the horizontal frequency of the flyback transformer in a low state (first state), and at least a flyback pulse on the secondary side of the flyback transformer. A rectifier configured to rectify the peak portion on the positive electrode side, wherein the first and second resonance circuits reduce harmonic components by the resonance and the resistance in the first state, and A second flow increasing above the first condition
In the state (1), the resonance is deviated to reduce the reduction of the harmonic component, and the high voltage value of the flyback transformer is made substantially constant in the first and second states. In the first and second resonance circuits, harmonic components are reduced in the first state due to high impedance due to resonance and loss due to resistance, and in the second state, reduction of the above harmonic components. When the load current is increased in the first state and the second state, the high voltage value is kept substantially constant. That is, the reduction of the peak value of the pulse is adjusted by reducing the proportion of harmonics contained in the primary side pulse of the flyback transformer as the load current value increases. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 1 to 6 are explanatory views of the principle of the present invention. 1 is a horizontal output transistor, 2 is a damper diode, 3 is a resonance capacitor, 4 is a horizontal deflection coil, and 5 is an S
Letter correction capacitor, 6 is a flyback transformer, 8 is a capacitor, 9 is a resistor, 10 is a high voltage rectifier diode, 11
Is a power supply capacitor, and 12 is a saturable transformer. The capacitor 8, the resistor 9, and the secondary winding of the saturable transformer 12 form a resonance circuit that attenuates the harmonic component of the flyback transformer output. A characteristic diagram of the saturable transformer 12 is shown in FIG. As the primary winding current increases, the secondary inductance decreases as shown in the figure. In this structure, when the high voltage load increases, the power supply current flowing from the point B increases. As a result, the secondary inductance of the transformer 12 is reduced, and this winding is connected in parallel with the capacitor 8 and the resistor 9.
The resonance effect due to the series circuit of is reduced. Therefore, the harmonic component is not attenuated, and the peak value of the output waveform has the extended characteristic as shown by the solid line in FIG. On the contrary, when the high-voltage load decreases, the power supply current flowing from the point B decreases, the secondary inductance of the transformer 12 increases, the resonance becomes active, and the resonance effect increases. As a result, the harmonic component is attenuated and the peak value is lowered and the characteristic becomes flat as shown by the dotted line in FIG. Since the high voltage is obtained by rectifying the waveform shown in FIG. 3 by the high voltage rectifying diode 10, the high voltage regulation characteristic is improved by the principle described above. This characteristic is shown in FIG. In the experiment, a capacitor 0.01 μF, a resistance 27 Ω, a saturable transformer, a secondary winding inductance 68
The change in μH to 20 μH was an improvement in high-voltage regulation of 1.5 KV. Since the primary winding current of the saturable transformer 12 may be a current corresponding to a high voltage load, the A.V. B. You may drive using L (automatic brightness limitation) detection voltage. The resistor 9 may be composed of a semiconductor element, and the internal impedance may be changed according to a high voltage load. Further, in the circuit of FIG. 1, the saturable transformer 12 may be omitted and a self-saturation type coil depending on the current may be used. FIG. 4 shows a screen distortion prevention circuit. The drawing distortion is a phenomenon in which the high voltage is lowered in a bright portion of the screen, the deflection sensitivity is increased, and the screen size is expanded. From the above description, it is clear that the screen distortion can be corrected by applying a high voltage to the primary winding of the saturable transformer 12 according to the screen brightness to perform high voltage correction. When the present invention is applied to flyback transformers of different high-order tuning, since the harmonic frequency is high, the resonant circuit frequency also needs to be high. For this reason,
Capacitor capacity must be small. In reality, the saturable transformer winding has a distributed capacitance, so that it is not necessary to connect a capacitor. That is, a saturable transformer and a parallel circuit of a resistor can also be used. This is shown in FIG. In this circuit, the pulse applied to the primary winding of the flyback transformer is obtained by dividing the inductance of the primary winding of the flyback transformer and the inductance of the saturable transformer. Inductance is reduced, the pulse of the primary winding of the flyback transformer is increased, and high voltage regulation is improved. In this configuration, a variable resonance circuit including a resistor is connected to the primary winding of the flyback transformer, but since the flyback transformer has a transformer configuration, the resonance circuit is provided on the high voltage winding side. It may be inserted, and the configuration in this case is shown in FIG. FIG. 7 shows the configuration of an embodiment of the present invention. That is, a resonant circuit including a transformer is inserted in both of the primary winding and the secondary winding, which further increases the high voltage regulation effect. According to the present invention, the high voltage output can be easily made constant even under a low cost, small size, and simple circuit configuration, and at the same time, the occurrence of linking during the horizontal scanning period can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of the principle of a high pressure generator of the present invention. FIG. 2 is a characteristic diagram of a saturable transformer used in the circuit of FIG. FIG. 3 is a waveform diagram of high voltage output. FIG. 4 is a circuit example of a screen distortion correction circuit. FIG. 5 is a circuit diagram of a harmonic attenuating circuit including a saturable transformer and a resistor. FIG. 6 is an explanatory view of the principle of the high pressure generator of the present invention. FIG. 7 is a circuit diagram showing an embodiment of the present invention. FIG. 8 is a characteristic diagram of voltage drop. FIG. 9 is a diagram illustrating a conventional example. [Explanation of Codes] 1 ... Horizontal output transistor, 2 ... Damper diode, 3 ... Resonance capacitor, 4 ... Horizontal deflection coil, 5 ... S-shaped correction capacitor, 6 ... Flyback transformer, 7 ... Coil, 8 ... Capacitor, 9 ... Resistance, 10 ... High-voltage rectifier diode, 11 ... Power supply capacitor, 12 ... Saturable transformer.

Claims (1)

[Claims] 1. Connected to the primary side of the flyback transformer (6),
A first resonance transformer (1) whose inductance value is changed by a current corresponding to the load current of the flyback transformer which is connected to the secondary side and is supplied to the primary side is connected to the resistor (9).
2) and the load current value is low (first state)
And a first resonance circuit configured to resonate with a plurality of odd harmonics of the horizontal frequency of the flyback transformer, and connected to the secondary side of the flyback transformer (6),
A second resonance transformer (1) whose inductance value is changed by a current corresponding to the load current of the flyback transformer, which is connected to the secondary side and which is supplied to the primary side, has a resistor (9 ′).
2 '), and a second resonance circuit configured to resonate with harmonics of a plurality of odd multiples of the horizontal frequency of the flyback transformer in a state where the load current value is low (first state); A rectifier configured to rectify at least the positive-side peak portion of the flyback pulse on the secondary side of the transformer; and the first and second resonance circuits, in the first state, by the resonance and the resistance. In the second state in which the harmonic component is reduced and the load current is higher than in the first state, the resonance is deviated and the reduction of the harmonic component is reduced to reduce the first and second states.
A high voltage generator characterized in that the high voltage value of the flyback transformer is made substantially constant in the second state.