JP2005117233A - Power supply, deflection and high voltage circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply and a deflection high voltage circuit in which high voltage applied to a CRT is affected less even when the variations in a high voltage load occurs and variations in high voltage pulses gives no effect on a deflection pulse although there is a general tendency that the high voltage load of the deflection high voltage circuit increases. <P>SOLUTION: DC voltage outputted from a diode 21 of a high voltage circuit part is given to one end of a first primary winding 2 for a high voltage output wound on a first core 51 of a transformer 1, the other end of the winding 2 is connected to the drain terminal of a FET6 being a first switching device of the high voltage circuit part, and the source terminal of the FET 6 is connected to the ground. The gate terminal of the FET 6 receives a signal outputted from a phase and pulse width control circuit 7 receiving a horizontal drive pulse (HD) signal. One end of a first secondary winding 4 wound on the same core of the first primary winding 2 is connected to the ground and the other end is connected to the anode of a diode 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a power source, a deflection, and a high voltage circuit used for a television receiver or the like.

  In recent years, high definition, such as high-definition television, and higher frequencies of computer monitors, displays, and the like have been advanced. In addition, in order to meet the demand for high image quality, there is an increasing demand for increasing high-voltage power in order to brighten the screen brightness. Further, it is desired to minimize the influence on the image by the high voltage current load. In order to avoid the problems as described above, the power supply circuit and the deflection / high voltage circuit have been separated from each other conventionally, resulting in an increase in occupied volume, an increase in the occupied area of the printed circuit board, and an increase in power consumption due to loss. .

  That is, conventionally, the power source and the deflection / high voltage circuit are generally configured separately, and the transformer is also generally configured separately. A method for stabilizing high-voltage output and reducing power loss has been proposed (see, for example, Patent Document 1), but the power source and the high-voltage transformer are configured as separate transformers. A method of extracting other voltages from the deflection high-voltage transformer is also widely used, but there are various methods for reducing the deflection output and other power sources due to the high-voltage current load.

  The conventional technology will be described below. FIG. 11 is a circuit diagram of a conventional power source and deflection / high voltage circuit, and shows an outline of a general circuit configuration in which a power source transformer and a deflection / high voltage transformer are separated. In FIG. 11, a DC voltage rectified by a rectification bridge 106 for converting a household AC voltage into a DC voltage is supplied to the primary winding 102 of the power supply switching transformer 101. The capacitor 105 is a DC voltage smoothing capacitor. The field effect transistor (hereinafter referred to as FET) 103 is switched by a signal from the control circuit 104 to which the outputs of the output voltage detection resistors 120 and 121 and the detection winding 119 are input, and a stable voltage is supplied. The winding 107 is for deflection / high voltage circuit drive voltage output, the diode 108 is its rectifier circuit, and the capacitor 109 is for smoothing.

  The windings 110, 111, and 112 are for other voltage (Low + B) output, and the diodes 113, 114, and 115, and the capacitors 116, 117, and 118 are for rectification and smoothing. Is. The DC voltage output from the winding 107 of the power supply output switching transformer 101 and rectified by the diode 108 is supplied to the primary winding 131 of the deflection / high voltage transformer 130. A resonance pulse and a deflection current are generated by switching based on a horizontal synchronizing signal supplied to the base of the horizontal output transistor 136, resonance of the primary winding 131 and the deflection yoke 132, and resonance by the resonance capacitor 134. The capacitor 133 is a capacitor for supplying power to the deflection yoke 132 and correcting linearity in the image, and the diode 135 is a damper diode. High voltage pulses are generated in the high voltage windings 137, 139, and 141 by the magnetic flux induced by the primary winding 131, and are rectified by the rectifier diodes 138, 140, and 142, and a high voltage (EHT) is supplied to the CRT.

Next, a circuit for outputting another power source using a deflection / high voltage transformer will be described. FIG. 12 is a conventional deflection / high voltage circuit diagram. 12, a DC voltage is supplied from the power source 152 to the primary winding 131, and the operations of the primary winding and the high-voltage winding are the same as those in FIG. Further, a voltage is induced by secondary windings 143, 144, and 145 provided in the same magnetic path, rectified by rectifier diodes 146, 147, and 148, and another voltage (Low + B) is supplied. The capacitors 149, 150, 151 are smooth. However, the configuration as described above has a problem that the influence on deflection and other voltages is large due to the high-voltage load fluctuation.
JP 2002-034245 A

  In recent television receivers, monitors, displays, etc., it is necessary to respond to an increase in the high voltage load accompanying an increase in screen brightness, which is a condition of high image quality. For this reason, conventional power supply circuits and deflection / high voltage circuits are separated. Therefore, there are problems that the occupied volume, the occupied area of the printed circuit board, the power consumption due to loss increase, and the high voltage output circuit exerts on the deflection circuit.

  The deflection high-voltage circuit of the present invention solves the conventional problems. Compared with a CRT that tends to increase the high-voltage load of the deflection high-voltage circuit, even if a fluctuation of the high-voltage load occurs, there is little influence on the high voltage, and the fluctuation of the high-voltage pulse An object of the present invention is to provide a power source, a deflection, and a high voltage circuit that do not affect the deflection pulse.

  In the present invention, a transformer having three axes magnetically coupled by a pair of ferrite cores having three legs is configured, and the first primary winding formed on the first axis and the horizontal operation A first switching element that performs switching in synchronization with a frequency; a first secondary winding that generates a voltage in synchronization with the first primary winding; and the first secondary winding. A high voltage circuit having a circuit for clamping the output of the power supply to a power source through a diode, a second primary winding formed on the second and third axes of the transformer having the same cross-sectional area, and a horizontal operating frequency. And the second primary winding is wound with the same number of windings around the second and third shafts, and the second and third shafts. Are connected in series, and the magnetic flux generated by the second primary winding is In a power transformer circuit having a second secondary winding that is adjusted to have a larger winding direction and that takes out an output voltage from the secondary winding, the first switching element is turned on. Depending on the period, the peak time of the current flowing in the first primary winding does not match the peak time of the current flowing in the second primary winding depending on the ON period of the second switching element.

  According to the present invention, a CRT that tends to increase the high-voltage load of the deflection high-voltage circuit has little influence on the high-voltage even if the fluctuation of the high-voltage load occurs, and the power supply that does not affect the deflection pulse. A deflection and high voltage circuit can be provided.

According to the first aspect of the present invention, a transformer having three axes magnetically coupled by a pair of ferrite cores having three legs is formed, and a first primary formed on the first axis. A first switching element that performs switching in synchronization with the winding and the horizontal operating frequency; a first secondary winding that generates a voltage in synchronization with the first primary winding; A high voltage circuit having a circuit for clamping the output of the secondary winding to a power source through a diode, a second primary winding formed on the second and third axes of the transformer having the same cross-sectional area, and a horizontal operating frequency. The second switching element has a second switching element that performs switching in synchronism, and the second primary winding is wound evenly around the second and third axes, and the second and third axes As each winding is connected in series, the magnetic flux generated by the second primary winding is increased. In a power supply transformer circuit that has a second secondary winding that is adjusted in line direction and has a wound winding and extracts an output voltage from the secondary winding, the first primary is controlled by the ON period of the first switching element. The peak time of the current flowing through the winding is not matched with the peak time of the current flowing due to the ON period of the second switching element, thereby preventing the influence of the magnetic flux of the power transformer and the high-voltage transformer. And the saturation tolerance of the ferrite core to be used can be ensured, and the shape of the transformer can be reduced in size.

  According to a second aspect of the present invention, a transformer having three axes magnetically coupled by a pair of ferrite cores having three legs is formed, and a first primary formed on the first axis. A first switching element that performs switching in synchronization with the winding and the horizontal operating frequency; and a first secondary winding that generates a voltage in synchronization with the first primary winding. A high voltage circuit having a circuit for clamping the output of the secondary winding to a power source through a diode, a second primary winding formed on the second and third axes of the transformer having the same cross-sectional area, and a horizontal operating frequency. The second primary winding includes a second switching element that performs switching synchronously, and the number of windings of the second primary winding is evenly wound around the second and third axes. As each winding is connected in series, the magnetic flux generated by the second primary winding is increased. A power transformer circuit that has a second secondary winding that is adjusted in line direction and is wound, and that extracts an output voltage from the secondary winding, and a third secondary that is wound around the first shaft of the transformer. A third switching element connected through a choke coil from one of the winding and the third secondary winding, and performing switching in synchronization with the horizontal operating frequency, and the other of the third secondary windings By connecting to the capacitor and grounding the other electrode of the capacitor, the voltage is supplied from the high voltage circuit to the deflection circuit side. The influence on the deflection circuit with respect to the fluctuation of the high-voltage load can be reduced as much as possible.

  According to a third aspect of the present invention, a transformer having three axes magnetically coupled by a pair of ferrite cores having three legs is formed, and a first primary formed on the first axis. A first switching element that performs switching in synchronization with the winding and the horizontal operating frequency; and a first secondary winding that generates a voltage in synchronization with the first primary winding. A high voltage circuit having a circuit for clamping the output of the secondary winding to a power source through a diode, a second primary winding formed on the second and third axes of the transformer having the same cross-sectional area, and a horizontal operating frequency. The second primary winding includes a second switching element that performs switching synchronously, and the number of windings of the second primary winding is evenly wound around the second and third axes. As each winding is connected in series, the magnetic flux generated by the second primary winding is increased. A power transformer circuit that has a second secondary winding that is adjusted in line direction and is wound, and that extracts an output voltage from the secondary winding, and a third secondary that is wound around the first shaft of the transformer. A third switching element connected through a choke coil from one of the winding and the third secondary winding, and performing switching in synchronization with the horizontal operating frequency, and the other of the third secondary windings By connecting to the capacitor and grounding the other electrode of the capacitor, it is a power supply, a deflection, and a high voltage circuit that supplies voltage from the high voltage circuit to the deflection circuit side, and the center of the pulse width of the resonance pulse of the deflection circuit On the other hand, a control circuit for delaying or advancing the rising phase of the high voltage pulse is provided to stabilize the deflection circuit, so that the power supply voltage is not changed with respect to high voltage fluctuations and horizontal frequency switching. It is possible to reduce the variation of the flat deflection circuit.

(Embodiment 1)
FIG. 1 is a power supply and high-voltage circuit diagram according to Embodiment 1 of the present invention, FIG. 2 is a voltage and current waveform diagram of the power supply and switching elements of the high-voltage circuit according to Embodiment 1 of the present invention, and FIG. FIG. 4 is a perspective view of a ferrite core according to the first embodiment of the present invention, and FIG. 5 is a perspective view of the ferrite core according to the first embodiment of the present invention.

1 is connected to the negative output side of the rectifier bridge 25, and the positive output side of the rectifier bridge 25 is grounded. The smoothing capacitor 24 is for smoothing the voltage from the rectifying bridge 25. The gate terminal of the FET 22 is connected to the output of the horizontal drive pulse (HD) and the output adjustment / pulse width control circuit 23 to which the output voltage detection voltage is input. The drain terminal of the FET 22 is connected to the primary winding 14 wound around the second shaft 52 of the three-axis transformer 1 that is magnetically coupled. The other end of the primary winding 14 is connected to the primary winding 15 wound around the third shaft 53, and the other end of the primary winding 15 is grounded. Here, the primary windings 14 and 15 are connected in the direction in which the magnetic flux generated by each increases.

  The drain of the FET 22 is connected to the anode of the diode 21 that rectifies the generated pulse, and the cathode side of the diode 21 is connected to the grounded smoothing capacitor 20, and the detection resistors 18 and 19 connected in series and the same. It is connected to the detection capacitors 16 and 17 connected in series. The other ends of the detection resistor 19 and the detection capacitor 17 are grounded. The midpoint of the detection resistors 18 and 19 and the midpoint of the detection capacitors 16 and 17 are input to the output adjustment and pulse width control circuit 23. On the second shaft 52 and the third shaft 53 of the transformer 1 wound with the primary windings 14 and 15, the secondary windings 26 and 27, 30 and 31, 34 and 35 wound in the same manner are provided. And connected to the anodes of rectifier diodes 28, 32, 36 of pulse voltage generated from the respective windings. The cathodes of the rectifier diodes 28, 32, and 36 are connected to the grounded smoothing capacitors 29, 33, and 37.

  Next, the high voltage circuit unit in FIG. 1 is connected to the first primary winding 2 for high voltage output in which the DC voltage output from the diode 21 is wound around the first shaft 51 of the transformer 1. The other end is connected to the drain terminal of the high-voltage switching FET 6 that is the first switching element of the high-voltage circuit section, and the source terminal of the high-voltage switching FET 6 is grounded. The gate terminal of the high-voltage switching FET 6 is supplied with the signal output from the pulse width control circuit 7 and the phase in which the horizontal drive pulse (HD) signal is input. One of the first secondary windings 4 wound on the same axis as the first primary winding 2 is grounded, and the other end is connected to the anode of the diode 3. The cathode side of the diode 3 is connected to the cathode side of the diode 21, and the pulse generated in the secondary winding 4 is clamped by the supplied DC voltage.

  The windings 62, 66, and 70 wound around the first shaft 51 are high-voltage generating windings. One of the windings 62 is connected to the cathode terminal of the diode 61 whose anode terminal is grounded, and the other is the capacitor 64. Connected to. The other end of the capacitor 64 is connected to the cathode terminal of the diode 63 whose anode terminal is connected to the cathode terminal of the diode 61, and the cathode terminal of the diode 63 is connected to the anode terminal of the diode 65. Similarly, diodes 67, 69, 71, 73 and capacitors 68, 72 are connected to the windings 66, 70, and the circuit configuration rectifies all the waves of the pulses generated in the windings 62, 66, 70. . A high voltage is output to the cathode side of the rectifier diode 73 and is connected to the anode electrode of the CRT. The basic operation of the power supply and high voltage circuit configured as described above will be described.

  In FIG. 1, when a signal synchronized with the horizontal drive pulse (HD) is input to the gate terminal of the FET 22 which is the second switching element, and an ON signal is input to the gate terminal, the second primary from GND. A current flows through the windings 14 and 15, and a current flows through the drain and source of the FET 22 to the negative side of the rectifier bridge 25. Next, when an OFF signal is input to the gate terminal of the FET 22, a positive voltage is generated on the drain terminal side of the FET 22 due to the back electromotive force generated in the primary windings 14 and 15. FIG. 3 shows a timing chart of the operating voltage and current. The positive voltage generated on the drain side of the FET 22 is rectified by the rectifier diode 21 and smoothed by the smoothing capacitor 20.

The rectified and smoothed DC output voltage is divided into low voltages by the detection resistors 18 and 19 and the detection capacitors 16 and 17 and sent to the output adjustment and pulse width control circuit 23. The pulse width of the ON signal sent to the gate terminal of the FET 22 is controlled depending on whether the DC output voltage value is higher or lower than the set value. If the DC output voltage is low, lengthen the ON signal, increase the DC output voltage,
When the DC output voltage is high, the signal is controlled so that the ON signal width is shortened and the DC output voltage is lowered. Further, a voltage similar to the drain voltage of the FET 22 is induced in the second secondary windings 26 and 27, 30 and 31, 34 and 35, which are wound in the same manner as the primary windings 14 and 15, and the rectifier diode 28. , 32, and 36, and the secondary voltage (Low + B) smoothed by the smoothing capacitors 29, 33, and 37 is supplied.

  Next, when the Hi period of the horizontal driving pulse is input to the gate terminal of the first high-voltage switching FET 6 in the high-voltage circuit section, the drain terminal is grounded. As a result, a current starts to flow in the first primary winding 2 for high voltage output of the transformer 1 due to the aforementioned DC output voltage. When the horizontal drive pulse is in the low period, the high voltage switching FET 6 is turned OFF. Then, a counter electromotive force is generated in the primary winding 2, and resonance is caused by the distributed capacitance generated between the high-voltage generating windings 62, 66, and 70 and the resonance capacitance 5, and a pulse is applied to the drain terminal of the high-voltage switching FET 6. Voltage is generated. At this time, a pulse voltage is similarly generated in the first secondary winding 4 in the high voltage circuit section. However, since the output of the winding 4 is clamped to the power supply voltage (DC output voltage), the peak portion has a waveform cut by the power supply voltage. Accordingly, the peak value of the drain voltage of the first high-voltage switching FET 6 is similarly cut, and a high-voltage pulse wider than the deflection resonance pulse can be obtained.

  This is because even when the high-voltage load fluctuates, the supply time of energy to the high-voltage side becomes long, and the high-voltage output can be stabilized with respect to the flyback pulse having the normal deflection pulse blanking period width. FIG. 3 shows a timing chart of the operating voltage and current. At this time, the peak time of the current flowing in the second primary windings 14 and 15 due to the ON period of the FET 22 as the second switching element and the ON period of the high-voltage switching FET 6 as the first switching element are first. It is considered that the peak time of the current flowing through the primary winding of the first winding does not match.

  Next, the movement of the transformer 1 will be described with reference to FIG. First, the magnetic flux induced by the current flowing through the second primary windings 14 and 15 during the ON period of the FET 22 as the second switching element is indicated by a solid arrow A. The second shaft 52 and the third shaft 53 of the transformer 1 around which the primary windings 14 and 15 are wound form a closed magnetic circuit, and the primary windings 14 and 15 are wound so that the magnetic flux increases. ing. The magnetic flux generated by the primary windings 14 and 15 induces and cancels out the magnetic flux in a direction opposite to the first shaft 51, and thus does not affect the winding wound around the first shaft. Further, a broken line arrow B indicates a magnetic flux induced by a current flowing in the first primary winding 2 during the ON period of the high-voltage switching FET 6 that is the first switching element. The magnetic flux B passes through the second primary windings 14 and 15, but the voltage induced by the magnetic flux B has a reverse polarity and cancels out so that no voltage is generated in the primary windings 14 and 15. FIG. 4 shows a perspective view of the triaxial ferrite core used in the present invention. In addition, the performance of the present invention can be obtained by applying the same windings to a triaxial ferrite core structure as shown in the perspective view of FIG.

  By using a three-axis transformer as described above, a power supply and a high-voltage transformer that are not affected by both the power supply and the high-voltage circuit are configured, and a stable circuit that is not affected by high-voltage load fluctuations is provided. By shifting the peak time of the current flowing through the first and second primary windings, the magnetic flux density excited in the ferrite core to be used can be reduced, and the transformer can be miniaturized.

(Embodiment 2)
FIG. 6 is a power supply, deflection, and high voltage circuit diagram according to the second embodiment of the present invention. The emitter of the horizontal output transistor 45 of the deflection circuit section is grounded, the choke coil 40 is connected to the collector, and the other end of the choke coil 40 is connected to the winding 38 wound around the first shaft 51 of the transformer 1. The The other end of the winding 38 is connected to a grounded capacitor 39. The collector of the horizontal output transistor 45 is connected to a damper diode 44, a resonance capacitor 43, and a horizontal winding 41 of a deflection yoke, and the other end of the deflection yoke 41 is connected in series with a grounded S-shaped correction capacitor 42. It is connected. The base of the horizontal output transistor 45 is connected to the output of the horizontal drive circuit 46 to which a horizontal drive pulse (HD) is input. The basic operation of the deflection circuit and the high voltage circuit configured as described above will be described.

  In FIG. 6, a signal having a duty ratio of 50% is input as the horizontal drive pulse (HD). A high voltage pulse is generated in the primary winding 2 of the high voltage circuit unit during the low period of the horizontal drive pulse, and an induced electromotive force is generated in the winding 38 on the deflection circuit side magnetically coupled through the first shaft 51. Is generated, and electric charge is accumulated in the capacitor 39. A negative polarity portion of the induced voltage generated in the winding 38 passes through the capacitor 39, passes through the anode electrode of the damper diode 44, and is rectified through the choke coil 40 and the winding 38. Since the high voltage pulse is clamped by the power supply voltage, a rectified DC voltage is generated at both ends of the capacitor 39, and the voltage value is determined by the number of windings of the high voltage primary winding 2 and the deflection circuit side winding. It is determined by the ratio with the line 38. With the configuration as described above, it is possible to arrange the drive power supply on the high voltage side and obtain the power supply voltage of the deflection circuit unit with the high voltage pulse generated on the high voltage circuit side.

  Next, the operation on the deflection circuit side will be described. FIG. 7 shows a voltage waveform diagram at each point in the second embodiment of the present invention. Point C is the horizontal drive pulse, point D is the base voltage of the horizontal output transistor 45, point E is the collector voltage of the horizontal output transistor 45, point F is the drain voltage of the high voltage circuit switching FET 6, and point G is the winding 38 and winding. The junction voltage of line 40 is shown.

  When the D point voltage becomes Hi, the horizontal output transistor 45 is turned ON, and the deflection current flows from the S-shaped correction capacitor 42 through the deflection yoke 41 to the collector of the horizontal output transistor 45. Further, during this period, a current flows from the capacitor 39 serving as the power source of the deflection circuit to the collector of the horizontal output transistor 45 through the winding 38 and the choke coil 40. Next, when the base voltage of the horizontal output transistor 45 becomes Low, the horizontal output transistor 45 is turned OFF and a blanking period starts. When the horizontal output transistor 45 is turned OFF, resonance starts at a frequency determined by the inductance value of the winding 38 and choke coil 40 of the deflection circuit unit, the inductance value of the deflection yoke horizontal winding 41 and the capacitance value of the resonance capacitor 43. At the same time, a high voltage pulse is generated in the primary winding 2 of the transformer of the high voltage circuit section, and an inverted voltage of the voltage generated in the primary winding 2 is generated at point G via the core.

  At the start of the resonance period, the continuation current of the deflection yoke 41 flows into the resonance capacitor 43, and when a certain time has elapsed, current flows from the resonance capacitor 43 into the deflection yoke horizontal winding 41. Thereafter, the continuation current of the deflection yoke 41 flows as a deflection current through the S-shaped correction capacitor 42 and the damper diode 44. Further, the G point voltage generated at this time is rectified on the negative side by a rectifier circuit including a capacitor 39 and a damper diode 44, and operates as a driving power source for the deflection circuit. Here, if a phase difference is provided during the OFF period of the high voltage switching FET 6 and the horizontal output transistor 45 on the high voltage circuit side, the voltage stored in the capacitor 39 can be varied.

  Here, recent television receivers, monitors, and displays are systems in which input signals are varied and the horizontal drive frequency is switched according to the signals.

  The relationship between the horizontal drive frequency fH and the current flowing through the deflection yoke is expressed by (Equation 1). IDYPP is a horizontal deflection current, V is a power supply voltage, LDY is an inductance value, and Ts is a horizontal scanning period. In the above formula, V and LDY are fixed and Ts changes, so IDYPP changes and horizontal amplitude changes. Therefore, the horizontal amplitude is adjusted with V being variable. As means for varying V, a method of controlling using a chopper circuit is used.

IDYPP = (V / LDY) × Ts (Equation 1)
In the chopper circuit, the output voltage is given by (Equation 2).

Vo = (Ton / T) × Vin (Expression 2)
Vo represents the output voltage of the chopper power supply, T represents the switching frequency, Ton represents the switching ON period, and Vin represents the input voltage. The output voltage is adjusted by controlling the Ton width.

  The pulse width of the high voltage circuit unit of the present invention is fixed at the resonance frequency by the primary winding 2, the distributed capacitance, and the resonance capacitance 43. Therefore, when the horizontal drive frequency changes, T in (Expression 2) changes and Vo changes. Therefore, the high-voltage circuit unit of the present invention can operate as a high-voltage power source, and can also operate as a chopper power source by the transformer and the choke coil 40. For example, the horizontal drive frequency is set to about 45 KHz and the drive is performed with a duty ratio of 50%. When the horizontal drive frequency is changed to 32 KHz, IDYPP in Formula 1 is about 1.4 times higher, but the high voltage circuit section can cancel out with Vo of about 1 / 1.4. As a result, the power source of the deflection circuit is fed back according to the horizontal drive frequency, and the change in horizontal amplitude can be reduced.

  FIG. 8 shows an equivalent circuit diagram of the high-voltage transformer unit according to the second embodiment of the present invention. The primary winding 2 of the high-voltage circuit unit is wound with the secondary winding 4 in a state where the degree of coupling is close to 1. One of the primary windings is connected to the anode of the power supply voltage 70 and the other is connected to the drain terminal of the high-voltage switching FET 6. One end of the secondary winding 4 is grounded, the other end is connected to the anode terminal of the diode 3, and the cathode terminal is connected to the anode of the power supply voltage 70.

  When the high voltage switching FET 6 is turned OFF, resonance is started by the primary winding 2, the distributed capacitor C and the resonant capacitor 5. The resonance frequency at this time is set according to the maximum horizontal drive frequency. That is, in a television receiver or the like in which the horizontal drive frequency is switched, a 50% duty ratio is selected for a state with the highest frequency. On the other hand, the secondary winding 4 has approximately the same number of windings as the primary winding, and the degree of coupling is set to be close to 1. Therefore, an induced voltage similar to the voltage generated in the primary winding 2 is generated. However, since the secondary winding 4 is clamped to the power supply voltage by the diode 3, the peak of the resonance pulse cannot be higher than the power supply voltage. Further, since the other end of the secondary winding 4 is grounded, an AC voltage with both positive and negative polarities is generated with respect to the ground point as the voltage across the secondary winding 4 as viewed from the grounding portion. At this time, if the ON / OFF duty ratio of the switching FET is set to a state close to 50% and the resonance frequency of the resonance pulse is set to a state close to the horizontal drive frequency, the voltage across the secondary winding 4 is based on the ground point. An AC voltage waveform having a power supply voltage 70 on the positive side and a power supply voltage 70 on the negative side can be obtained.

  As a result, it is possible to obtain a high-voltage pulse that is about a half of the horizontal period, and it is possible to stably supply a high-voltage load, and a high-voltage circuit that is hardly affected by fluctuations in the high-voltage load. Can be.

  In FIG. 6, the control circuit 7 connected to the gate terminal of the switching FET 6 in the high voltage circuit section is provided with a phase control circuit, and its operation will be described. The emitter of the switching transistor 45 in the deflection circuit section of FIG. 6 is grounded, the collector is connected to the transformer winding 38 via the choke coil 40, and the other end of the winding 38 is connected to the grounded capacitor 39. A damper diode 44, a resonant capacitor 43, and a deflection yoke horizontal winding 41 are connected to the collector of the switching transistor 45, and the other end of the deflection yoke is connected in series with a grounded S-shaped correction capacitor 42. Yes. On the other hand, the base of the switching transistor 45 is connected to a horizontal drive circuit 46 to which a horizontal drive pulse is input.

  Next, in the high voltage circuit section in FIG. 5, the DC voltage output supplied from the power supply circuit section through the diode 21 is connected to the high voltage primary winding 2 of the transformer, and the other end of the high voltage primary winding 2 is the high voltage circuit section. The first switching element is connected to the drain terminal of the high-voltage switching FET 6, and the source terminal of the high-voltage switching FET 6 is grounded. The gate terminal of the high-voltage switching FET 6, which is the second switching element, is connected to the phase and pulse width control circuit unit 7 to which the horizontal drive pulse is input. One of the transformer windings 4 is grounded, and the other is connected to the anode terminal of the diode 3. The cathode terminal of the diode 3 is connected to the cathode terminal of the diode 21 and clamps the generated pulse with the supplied DC voltage.

  The windings 62, 66, and 70 wound around the first shaft 51 are high-voltage generating windings. One of the windings 62 is connected to the cathode terminal of the diode 61 whose anode terminal is grounded, and the other is the capacitor 64. Connected to. The other end of the capacitor 64 is connected to the cathode terminal of the diode 63 whose anode terminal is connected to the cathode terminal of the diode 61, and the cathode terminal of the diode 63 is connected to the anode terminal of the diode 65. Similarly, diodes 67, 69, 71, 73 and capacitors 68, 72 are connected to the windings 66, 70, and the circuit configuration rectifies all the waves of the pulses generated in the windings 62, 66, 70. . A high voltage is output to the cathode side of the rectifier diode 73 and is connected to the anode electrode of the CRT.

  With the configuration as described above, as shown in the second embodiment, the phase and pulse width control circuit 7 can be utilized by utilizing the characteristic that the voltage stored in the capacitor 39 of the deflection circuit can be controlled by controlling the phase of the deflection pulse. Thus, it is possible to apply feedback control to the deflection pulse by controlling the phase of the pulse input to the gate terminal of the FET 6 of the switching element of the high voltage circuit. As a result, it is possible to realize a circuit in which the horizontal amplitude does not change with respect to fluctuations in the high-voltage load or changes in the horizontal drive frequency.

  FIG. 9 is a voltage waveform diagram at each point according to the second embodiment of the present invention, and FIG. 10 is a deflection pulse change characteristic diagram when the phase is variable according to the second embodiment of the present invention. The amount of change of the deflection pulse when the phase of the rising of the high voltage pulse is changed is shown. In FIG. 10, the fact that the deflection pulse becomes smaller indicates that the horizontal size becomes equivalently smaller, and that the deflection pulse can be controlled by performing phase control.

  As described above, according to the present invention, the power source, the deflection, and the high voltage circuit are configured by the same transformer, and the influence of the power source and the deflection high voltage circuit can be reduced as much as possible, and a circuit that can be operated by a small transformer is supplied. it can. In addition, the high voltage load of the deflection high voltage circuit tends to increase, the high voltage is stably supplied, the high voltage fluctuation is reduced as much as possible, and the fluctuation of the high voltage load affects the deflection circuit. Therefore, it is possible to provide a deflection high voltage circuit in which phase control is performed so as to eliminate the fluctuation of the deflection circuit.

Power supply and high-voltage circuit diagram in Embodiment 1 of the present invention Voltage and current waveform diagram of power supply, switching element of high-voltage circuit in Embodiment 1 of the present invention 1 is a basic configuration diagram of a three-axis transformer in Embodiment 1 of the present invention. The perspective view of the ferrite core in Embodiment 1 of this invention The perspective view of the ferrite core in Embodiment 1 of this invention Power supply, deflection, and high-voltage circuit diagram in Embodiment 2 of the present invention Voltage waveform diagram of each point in Embodiment 2 of the present invention Equivalent circuit diagram of high-voltage transformer section in Embodiment 2 of the present invention Voltage waveform diagram of each point in Embodiment 2 of the present invention Deflection pulse change characteristic diagram at the time of phase variation in Embodiment 2 of the present invention Conventional power supply, deflection / high voltage circuit diagram Conventional deflection / high voltage circuit diagram

Explanation of symbols

1 Transformer 2, 4, 14, 15, 26, 27, 30, 31, 34, 35, 38, 62, 66, 70
Winding 6 FET
7 Phase, pulse width control circuit 18, 19 Resistance 22 FET
23 Pulse width control circuit 25 Rectifier bridge 40 Choke coil 41 Deflection yoke horizontal winding 42 S-shaped correction capacitor 43 Resonance capacitor 44 Damper diode 45 Horizontal output transistor 46 Horizontal drive circuit 51 First axis 52 Second axis 53 Third axis axis

Claims (3)

A pair of ferrite cores having three legs constitutes a magnetically coupled transformer having three axes, and is synchronized with the first primary winding formed on the first axis and the horizontal operating frequency. A first switching element that performs switching, and a first secondary winding that generates a voltage in synchronization with the first primary winding, and the output of the first secondary winding is a diode. The high voltage circuit having a circuit for clamping to the power source through the second primary winding formed on the second and third axes of the transformer having the same cross-sectional area and switching in synchronization with the horizontal operating frequency are performed. A second switching element, wherein the second primary winding has the same number of windings around the second and third shafts, and each of the second and third shafts is wound; As the wires are connected in series, the magnetic flux generated by the second primary winding increases. In a power transformer circuit that has a second secondary winding that is adjusted in winding direction and takes out an output voltage from the secondary winding, the first switching element is turned on by the ON period of the first switching element. A power source, a deflection circuit, and a high voltage circuit, characterized in that the peak time of the current flowing through the first primary winding does not match the peak time of the current flowing through the second primary winding due to the ON period of the second switching element. . A pair of ferrite cores having three legs constitutes a magnetically coupled transformer having three axes, and is synchronized with the first primary winding formed on the first axis and the horizontal operating frequency. A first switching element that performs switching, and a first secondary winding that generates a voltage in synchronization with the first primary winding, and the output of the first secondary winding is a diode. The high voltage circuit having a circuit for clamping to the power source through the second primary winding formed on the second and third axes of the transformer having the same cross-sectional area and switching in synchronization with the horizontal operating frequency are performed. A second switching element, wherein the second primary winding has the same number of windings around the second and third shafts, and each of the second and third shafts is wound; As the wires are connected in series, the magnetic flux generated by the second primary winding increases. The winding direction is adjusted and the second secondary winding is wound, and the power transformer circuit for extracting the output voltage from the secondary winding and the first winding of the transformer are wound on the first shaft. A third switching element connected via a choke coil from one of the third secondary winding and the third secondary winding, and performing switching in synchronization with a horizontal operating frequency; A power supply, a deflection, and a high voltage circuit, characterized in that a voltage is supplied from the high voltage circuit to the deflection circuit side by connecting the other secondary winding to a capacitor and grounding the other electrode of the capacitor. A pair of ferrite cores having three legs constitutes a magnetically coupled transformer having three axes, and is synchronized with the first primary winding formed on the first axis and the horizontal operating frequency. A first switching element that performs switching, and a first secondary winding that generates a voltage in synchronization with the first primary winding, and the output of the first secondary winding is a diode. The high voltage circuit having a circuit for clamping to the power source through the second primary winding formed on the second and third axes of the transformer having the same cross-sectional area and switching in synchronization with the horizontal operating frequency are performed. A second switching element, wherein the second primary winding has the same number of windings around the second and third shafts, and each of the second and third shafts is wound; As the wires are connected in series, the magnetic flux generated by the second primary winding increases. The winding direction is adjusted and the second secondary winding is wound, and the power transformer circuit for extracting the output voltage from the secondary winding and the first winding of the transformer are wound on the first shaft. A third switching element connected via a choke coil from one of the third secondary winding and the third secondary winding, and performing switching in synchronization with a horizontal operating frequency; A power supply, a deflection, and a high voltage circuit for supplying a voltage from the high voltage circuit to the deflection circuit side by connecting the other end of the secondary winding to the capacitor and grounding the other electrode of the capacitor. A power supply, a deflection, and a high voltage circuit characterized by providing a control circuit for delaying or advancing the rising phase of the high voltage pulse with respect to the center of the pulse width of the resonance pulse, and stabilizing the deflection circuit.

Images