Abstract: A power supply according to the principles of the inventions comprises two stages. The first stage is a power factor corrector stage. This stage provides the required line regulation, including greater than 95% power factor correction, and provides a range of outputs from approximately 5 volts to 200 volts with good load regulation at low voltages. The second stage is a soft switching power supply having good load regulation from approximately 40 to approximately 175 volts. An intermediate high voltage of the first stage supplies the input to the second stage, thereby achieving extremely good line regulation and low regulation.

Abstract: A switched-mode power supply with a control loop and a microprocessor has a normal mode and a low-power mode with a burst mode. The microprocessor is connected via an output to the control loop and uses this to control the burst mode of the switched-mode power supply directly. The control loop of the switched-mode power supply monitors, in particular, a secondary output voltage, so that the output of the microprocessor is connected to the control loop, for example via a simple resistor network or a transistor stage. The clock frequency and the duty cycle of the burst mode are permanently stored in the microprocessor and can be defined for the switched-mode power supply directly, for example using TTL logic.

Abstract: A deflection apparatus capable of generating a stable deflection pulse in a deflection output circuit even when turning on the power source or changing over the frequency of horizontal synchronizing signal is disclosed. A pulse width modulation (PWM) controlled power supply circuit generates a supply voltage for obtaining a desired horizontal amplitude depending on the frequency of horizontal synchronizing signal. The PWM voltage controller discriminates the frequency of horizontal synchronizing signal, and controls the output voltage of the PWM controlled power supply circuit. An oscillation frequency switching controller discriminates the frequency of horizontal synchronizing signal, and outputs a frequency changeover signal to an oscillator so as to be an optimum oscillation frequency depending on the output voltage of the PWM controlled power supply circuit.

Abstract: The invention is intended to enable the easy measurement of the amount of color purity at each of many measured points. An adjusting coil (9) is provided at a neck portion of a color cathode ray tube (1). Also, color image pickup means (4) for photographing the screen of the color cathode ray tube (1) is provided. A monochrome signal of any one of red, green, and blue colors is input to this color cathode ray tube (1). Thereafter, while varying the electric current made to flow through the adjusting coil (9), the image pickup signal obtained by the color pickup means (4) is decomposed into red, green, and blue color signal components. And the intensity of each of them is measured. Then, using the values of the electric currents that are supplied to the coil adjusting (9) and the location distances between the luminous regions of the red, green, and blue colors on the color cathode ray tube (1) there is determined the following.

Abstract: A cathode ray tube protection system for protecting a cathode ray tube from maintenance of high voltage residual occurring when power is turned on or off or due to abnormal operation in a projection-type television is provided.

Abstract: The invention relates to a display device comprising a cathode ray tube including an electron source and an electron beam guidance cavity having an entrance aperture and an exit aperture for concentrating electrons emitted from the cathode in an electron beam. Furthermore, the cathode ray tube comprises a first electrode which is connectable to a first power supply for applying, in operation, an electric field with a first field strength E1 between the cathode and the exit aperture. &dgr;1 and E1 have values, which allow electron transport through the electron beam guidance cavity. Furthermore, a modulating means positioned between the cathode and the exit aperture is present for modulating a beam current to the display screen. According to the invention, the display device is provided with switching means for preventing the electron beam from passing through the exit aperture in a blanking period and for passing the electron beam through the exit aperture in a display period.

Abstract: An electron gun according to the present invention is provided with a grid having a beam aperture with a small diameter. In addition, the electron gun of the present invention is such that a second grid thereof is comprised of a plurality of grid plates each having the beam aperture. The electron gun of the present invention is such that a required grid comprising the electron gun is comprised of the grid plates each having the beam apertures. At least one grid plate among the plurality of grid plates has a beam aperture with an aperture diameter of less than 80% or less of an overall pseudo plate thickness. When compared with the case of comprising the grid with one sheet of metal, it becomes possible to provide a beam aperture with a small diameter.

Abstract: The invention relates to a compact and cost-effective diode-split high-voltage transformer for high voltages of, in particular, above 20 kV, in which the high-voltage winding lies in chambers of a coil former underneath the primary winding and which contains elements by which the electric field between the coil former and the core is reduced in order to avoid corona effects. These elements include, for example, a conductive coating of the surface of the inner cavity of the coil former, which coating preferably comprises colloidal graphite. The conductive coating may also be realized by a metallized plastic film which is wound between the core and the coil former. Alternatively, the cavity between the core and the coil former may be filled with a material whose relative permittivity ∈r is distinctly greater than that of air. The use of a larger number of diodes is also possible for reducing the electric field.

Abstract: An appartus for adjusting the correction amount of a horizontal linearity and suppressing the amplitude of a horizontal deflection current in an image display device. A switching element 11 is provided between both ends of an S-curve correction capacitor 5 connected in series to a horizontal deflection coil 4, and by turning on this switching element 11 during a horizontal retrace period to discharge the S-curve correction capacitor 5, and controlling also the ON time of this switching element 11, the linearity in the horizontal period is corrected.

Abstract: A horizontal drive circuit for a video display device includes a switching device for switching according to a horizontal oscillation frequency generated by a horizontal oscillator and a surge protector, and a method therefor. A driving transformer has a primary winding connected to the switching means and a secondary winding. The secondary winding provides an amplified current according to the status of the switching device. A diode serves as the surge protection connected between the switching device and the primary winding of the driving transformer.

Abstract: Discharge current limiting resistors are provided in respective high-voltage supply lines for distributing high voltages produced by a high-voltage distributor to the anodes of respective CRTs. As a result, a discharge current coming from a high-voltage capacitor that is part of a total discharge current flowing into a CRT where an abnormal discharge has occurred can be reduced to ½ of that in the conventional case and discharge currents coming from coating capacitances of the remaining CRTs that is another part of the total discharge current can be inhibited.

Abstract: A circuit for regulating an anode voltage in an information display apparatus. A horizontal deflection circuit has trace and retrace modes of operation. The horizontal deflection circuit further has a fixed retrace capacitance; and a series combination of a switched retrace capacitance and a switch element, which combination is coupled in parallel with the fixed retrace capacitance. The switch element is in a closed position as the horizontal deflection circuit enters the retrace mode of operation. A voltage divider network samples the anode voltage. A control circuit is responsive to the sample voltage for controlling the switch element, such that the control circuit effects regulation of the anode voltage by selecting a time during the retrace period at which to place the switch element in an open position. The control circuit may also provide a raster width compensation voltage for an east-west pincushion correction circuit.

Abstract: The present invention relates to an apparatus and a method for saving electric power in a display system in which, when the display system is turned to an off mode, a total electric power consumption is reduced to a range for the display system to be operated through a reduction of an on-duty time period of a PWM pulse by using a charging/discharging device of a large capacitance. The present invention provides an ultra electric power-saving mode for a display system when the display system is turned into an off mode with no input of the horizontal and vertical synchronization signals from a video card of the computer main body to the display system. It accomplishes this by reducing the total electric power consumption by approximately half compared to the existing off mode performance through a remarkable reduction of the on-duty time of a PWM pulse to a range of supplying an operational voltage of the microcomputer with the use of a charging/discharging device of large capacitance.

Abstract: A deflection current/high voltage integration type power supply has a flyback transformer having a primary winding and a secondary winding; a series circuit of a deflection coil and a first capacitor, connected in series to the primary winding of the flyback transformer; a resonance capacitor connected in parallel to the series circuit of the deflection coil and the first capacitor; a first switching element, connected in parallel with the series circuit of the deflection coil and the first capacitor, to be turned on/turned off by a drive signal so that a high voltage is generated at the secondary winding of the flyback transformer and a deflection current flows in the deflection coil; a parallel connection circuit of a second switching element and a second capacitor, connected in series to the primary winding of the flyback transformer; and a switching control means to control the deflection current flowing in the deflection coil and the high voltage generated at the secondary winding of the flyback transfor

Abstract: A display apparatus of multi-mode cathode ray tube is disclosed which is capable of enlarging a horizontal screen size by adjusting a size of the horizontal screen by employing a step-up type without occurrence of additional power consumption or a double trigger phenomenon.

Abstract: A resistor-capacitor-diode clamp is coupled to an S-capacitance of a horizontal deflection circuit output stage for reducing ringing by causing critical damping. The supply voltage of the output stage varies at a vertical rate parabolic manner for modulating the horizontal deflection current to provide East-West correction. A clamp capacitor of the clamp has a terminal that is direct current coupled to the supply voltage. Therefore, each terminal of the clamp capacitor has the same vertical rate parabola component. Consequently, the DC voltage difference developed between the terminals of the clamp capacitor does not include any vertical rate parabola component, the result is that the sensitivity of the damping to the supply voltage vertical rate variations is, advantageously, eliminated or reduced.

Abstract: A wide band horizontal size regulation circuit of a display, is selectively switched according to input frequency, to control the amount of current transmitted to a current sensing port of a PWM IC. This circuit includes a microcomputer for generating a signal for regulating the horizontal size of a picture, a PWM-IC for generating a PWM signal for controlling the amount of current which flows through a horizontal deflection coil according to the control signal of the microcomputer, a current sensor for feeding back a current corresponding to a picture state to the PWM-IC in order to maintain a specific horizontal size, and a current controller which is selectively switched according to the control signal of the microcomputer, to control the amount of current fed back to the current sensor of the PWM-IC.

Abstract: The constitution comprises a circuit for feeding the blanking pulse winding voltage floating from a deflecting transformer 8 or a deflecting yoke 5 of a deflecting circuit 15 into a converter circuit composed of inductor 21, capacitor, diode, and resistance, and obtaining a comparative wave suited to a horizontal operation frequency, and means for changing the DC bias voltage value of comparative wave, controlling the drive pulse width of switching element 27, and controlling the high voltage output depending on changes of current flowing time width at the primary side of a high voltage generating transformer. It further comprises a power source winding 29 for controlling the oscillating voltage generated in switching OFF period of the high voltage generating transformer, or a regenerative winding 37 to power source, or both windings, and also means for adding a capacitor for preventing oscillation.

Abstract: An ultor voltage switching power supply for a cathode ray tube is energized by a low voltage switching power supply. A switching transistor of the ultor voltage switching power supply is disabled when a screen of the cathode ray tube is blanked. An anode capacitance of the cathode ray tube that develops the ultor voltage discharges via a bleeder resistor, when the switching transistor is disabled. As a result, a transient decrease occurs in the ultor voltage. The decreased ultor voltage tends to maintain the screen blanked.

Abstract: A dynamic focus circuit enables ideal focusing characteristics to be obtained across the entire screen of a wide-angled cathode ray tube, by generating a dynamic focus voltage having a flat-bottomed waveform through the addition of a simple circuit to a conventional analog circuit. If an S-shaping voltage method is used, the voltage of a signal induced in a secondary coil of a step-up transformer for raising the voltage of a parabolic waveform signal having a horizontal deflection period switches the gain for converting the parabolic waveform signal to a dynamic focus voltage, according to whether the induced voltage exceeds a specified reference value. If the induced voltage does not exceed the specified reference value, the parabolic waveform signal is converted to the dynamic focus voltage at a gain of less than one.

Abstract: A CRT driving circuit includes a cathode control circuit for controlling a cathode voltage of a CRT on the basis of a video signal created by a video circuit, a power supply circuit for creating a power supply voltage for each of the cathode control circuit and the video circuit, a switch circuit provided between the power supply circuit and the cathode control circuit, and a monitor control circuit for on/off controlling the switch circuit and the power supply circuit on the basis of a power-on/off externally inputted signal. In response to the power-on/off signal, when the monitor control circuit switches the switch circuit and the power supply circuit into an off-state, it turns off the power supply circuit later than the switch circuit. Even after a power-switch is turned off, the video signal is supplied to the cathode control circuit so that the cathode control circuit continues its on-state.

Abstract: A high-voltage generator includes a high-voltage unit (1) and a further voltage generating unit (2) for generating DC high voltages (UF1, UF2), the voltage generating unit (2) including an adjustment unit (3) for adjusting a DC high-voltage (UF1, UF2) in an adjusting range between a lower and an upper limit voltage. In order to enable an as low as possible electric strength of the adjustment unit (3) and to reduce the impedance of the voltage generating unit (2), a DC voltage of between 100% and 200% of the upper limit voltage is applied to one connection point of the adjustment unit (3) whereas a DC voltage of between 50% and 100% of the lower limit voltage is applied to the other connection point of the adjustment unit (3).

Abstract: An apparatus using a double focusing type fly-back transformer is disclosed. A top bleeder type is adopted in drawing the focus voltage of the fly-back transformer instead of the conventional neutral point type, and the double patterns of the focus resistors are separated from each other instead of the conventional common connections to the ground on the substrate FUB of the focus unit part. Further, one or more of the separately installed focus resistor patterns is used as a feedback line together with the bleeder resistor, thereby drastically reducing the size of the bleeder resistor. The anode voltage output terminal is connected to the initial voltage setting part 12 and the high voltage stabilizing circuit part 11, so that one or more of the patterned resistors of the focus unit part together with the bleeder resistor BR2 can share in serving as feedback lines.

Abstract: A compensation control circuit of horizontal scanning size suitable to be used in a general monitor to compensate the variation amount of horizontal scanning size due to the influence of the anode load current. The compensation control circuit includes two parts: One is the horizontal scanning size compensation circuit and the other is the horizontal scanning size control circuit. The horizontal scanning size compensation circuit is coupled to the coil of the fly-back transformer to generate a corresponding compensation signal according to the variation of the anode load current. The compensation signal is far lower than the level of the anode voltage. Therefore, it can be processed by the general electric circuits. The horizontal scanning size control circuit is coupled to the horizontal scanning size compensation circuit to receive the compensation signal. The compensation signal can combine with the shift regulation signal sent by the microprocessor to be a D.C. modulation signal. Then the D.C.

Abstract: A control grid voltage generating circuit comprises a high voltage source, a low voltage source and an amplifier biased by the high/low voltage sources. The high voltage source is coupled to the ground through a low-impedance path. The amplifier receives an input signal and generates a control grid voltage in response to the input signal. When the CRT is powered off, the amplifier can be rapidly discharged via the low-impedance path, thereby speedily turning off the amplifier. The control grid voltage is then driven to be the low reference voltage, thereby cutting off the electron beam and protecting the CRT.

Abstract: The disclosure is a stepped rectification high-voltage transformer including a secondary step-up winding in which at least two output diodes connected to two different stages of this secondary winding are located in a same axial level and perpendicular to the potentiometer block forming part of the insulating casing. The invention is applicable notably to the power supply of television cathode ray tubes.

Abstract: A television apparatus set has the capability of selectively displaying picture information obtained from a broadcast television signal and a display monitor data signal. A zero voltage switching switch mode power supply generates a higher voltage B+ supply voltage for a horizontal deflection circuit output stage, when the deflection circuit output stage operates at a rate greater than or equal to approximately 32 KHz. A series-pass regulator power supply generates at a common supply terminal a lower voltage B+ supply voltage, when the deflection circuit output stage operates at a lower rate equal to approximately 16 KHz. During a start-up interval, the horizontal scanning output stage is supplied with the lower B+ supply voltage regardless of the scan frequency for reducing excessive stress in the horizontal output stage switching transistor to improve reliability.

Abstract: A speed-up circuit 10 is connected to a detection line 6 for feeding back the high voltage detection value of a high voltage detection circuit 5 to a high voltage stabilizing circuit 1. When a power supply switch is turned on, since a PNP transistor 12 of the speed-up circuit 10 is turned on, a resistor 11 is connected to the detection line 6, so that the high voltage detection value is reduced forcedly. Accordingly, the high voltage stabilizing circuit 1 increases the peak value of a flyback pulse generated by a resonance-type power supply circuit 2 to output higher high voltage thereby to shorten the rising time of the high voltage output supplied to the anode of a CRT. After the lapse of the predetermined time from the turning-on of the power supply switch, since the terminal voltage of a capacitor 13 having been charged through a resistor 14 exceeds almost the voltage at a point A, the PNP transistor 12 is turned off, so that the resistor 11 is separeted from the detection line.

Abstract: A method and apparatus for testing the horizontal drive stage of a cathode ray tube display where the horizontal drive stage has a drive output which is directed to the base of a horizontal output transistor. In the method and apparatus, the output from the horizontal drive circuit is disconnected from the base of the horizontal output transistor and is connected to the apparatus of the present invention. The apparatus includes a load which simulates the load normally provided by the base of the horizontal output transistor. A meter differential amplifier is connected across the load and readings therefrom are projected on a display. The horizontal drive stage is then energized and readings from the display are compared to known operating requirements of the base of the horizontal output transistor.

Abstract: A supply is disclosed that develops a high dc voltage that may be applied to the anode of a cathode ray tube (CRT) of a display system. The supply provides the high dc voltage without the need for any high voltage flyback transformers and without the need of any power transistors. In one embodiment, the circuit of the invention is interposed between a subsystem of a power source of a horizontal deflection system, and the anode of the CRT.

Abstract: A monitor protection system comprise a display power management signaling (DPMS) operating unit for performing a predetermined power control; a horizontal deflection detecting circuit for detecting a horizontal deflection signal from a horizontal deflection circuit; a vertical deflection detecting circuit for detecting a vertical deflection signal from a vertical deflection circuit; and a control circuit for determining whether the horizontal deflection signal and the vertical deflection signal are normal, and generating a predetermine control signal to run the DPMS operating unit in order to observe the conditions of horizontal/vertical synchronization signals continuously, and protect a CRT monitor independently from the horizontal/vertical synchronization input conditions.

Abstract: A method is provided for reducing a residual spot on a cathode ray tube when a power supply is turned off. The method is executed by applying a holding voltage being no less than the value of the voltage enabling to enhance the back raster luminance and a cut-off voltage, or a voltage of a lower value, to a second grid electrode while the anode voltage is lowered to a predetermined voltage value when the main power supply is turned off.

Abstract: The power output of a static DC--DC converter employing a current mode PWM controller is controlled upon the varying of the switching frequency, by detecting the sawtooth signal produced by the local oscillator generating a DC signal with an amplitude inversely proportional to the frequency. The power output is controlled by alternatively clamping the output voltage of the error amplifier of the PWM controller at a voltage proportional to the amplitude of the DC signal, or by offsetting the signal present on the current sensing resistor by a voltage corresponding to the difference between a constant voltage and the DC signal.

Abstract: A wide band high voltage stabilizing circuit supplies optimum voltage to a fly back transformer (FBT) according to the change of horizontal frequency or high voltage by connecting a charge storage unit and switching element to a primary coil of the FBT, the switching element being turned on or off according to a switching signal which a microcomputer recognizing a horizontal sync frequency signal applies corresponding to a frequency band.

Abstract: A high-voltage power supply of a video display apparatus provides an ultor voltage and a focus voltage to a cathode ray tube. A low-voltage power supply provides a variable voltage to a primary winding of a flyback transformer of the high-voltage power supply. The magnitude of the variable voltage is responsive to first and second feedback signals provided by first and second negative feedback paths. The first feedback signal is derived from the ultor voltage and is used to regulate the ultor voltage. The second feedback signal is provided by the low-voltage power supply via a path that bypasses the high-voltage power supply, and is summed with the first feedback signal to ensure that the focus voltage remains at or above a predetermined minimum voltage.

Abstract: A high voltage generation circuit incorporates the horizontal circuit of a cathode ray tube (CRT) monitor. The horizontal circuit comprises a horizontal output transistor, a retrace capacitor coupled in parallel with the horizontal output transistor, a damping diode which clamps the minimum voltage at the drain of the transistor to approximately ground potential, and a flyback transformer. The primary winding of the flyback transformer is coupled between a terminal where a DC power supply B+ is applied and the drain of the horizontal output transistor. A second transformer is provided between the retrace capacitor and the ground for producing a voltage at the secondary winding thereof each time a free oscillation occurs between the damping interval Td of the damper diode and the conduction interval Ton of the horizontal output transistor.

Abstract: A sample of the high voltage retrace pulse is modeled across the series connection of a coil and low voltage winding of the flyback transformer. The AC current of the high voltage winding is fed through the coil in order to obtain the same retrace voltage shape as across the high voltage winding. Thus in this manner modeled high voltage retrace pulse is rectified by a diode and a charge capacitor. The rectified voltage is loaded by the beam current by a load resistor. The loading produces excellent tracking between the high voltage and the high voltage sample.

Abstract: A display device having a set protecting function upon generation of an abnormal voltage includes a horizontal deflection circuit for providing a horizontal signal to a deflection yoke connector, a high voltage output circuit for supplying a high voltage to an anode in accordance with an oscillating signal applied from the horizontal deflection circuit, a power supply circuit for supplying power to the horizontal deflection circuit, and an abnormal voltage detector disposed between the deflection yoke connector, and the high voltage output circuit and the power supply circuit, for detecting whether the deflection yoke connector is connected and whether a part of the high voltage output circuit is damaged, to thereby control a power output of the power supply circuit in accordance with a detected result.

Abstract: A picture display apparatus includes a non-synchronized self-oscillating switched-mode power supply (SMPS) associated with a line output stage (35) which generates power supply voltages for other elements of the apparatus, the standby state being obtained by stopping the line scan. The switch (1) of the SMPS is a MOS-type field effect transistor, and it is turned on by a winding (6) which is magnetically coupled to a ballast inductance (5), this winding (6) having one end connected to the connection point (50) between the switch and the ballast inductance, and generates, at its other end (51), a control voltage which is in phase opposition with the voltage generated in the ballast inductance, the control voltage being transmitted to the gate of the field-effect transistor (1). A capacitor (42) is arranged as a shunt across the drain-source path of the FET and creates an oscillating circuit together with the ballast inductance (5).

Abstract: A high-frequency horizontal deflection/high-voltage generation apparatus capable of setting inductance of a deflecting yoke without being affected by a collector voltage of a horizontal switching transistor and suppressing power loss while increasing a deflecting pulse voltage so that amplitude adjustment and side-pin correction can be effectuated without incurring any appreciable power loss. A voltage which is higher than the collector voltage V.sub.CP of the switching transistor is applied to the deflecting yoke. A resonant circuit is provided for applying to the deflecting yoke a voltage pulse of positive polarity and that of negative polarity, i.e., the voltage pulses bearing opposite phase relation to each other, for increasing equivalently the voltage applied across the deflecting yoke. The switching waveform outputted from the resonant circuit is synchronized with a switching operation of a high-speed switching element driven by a voltage induced in a winding of the deflecting transformer.

Abstract: A picture stabilizing circuit for a semiwide-screen television receiver capable of preventing vertical lines of the picture from being bent by detecting and compensating for a high-voltage variation caused by a picture brightness variation.

Abstract: The most popular method for reducing stray emission effects in a cathode ray tube is to install a bleeder resistor at the flyback transformer of the tube. Such a bleeder resistor is, however, quite expensive. Therefore, the stray emission reduction circuit according to the invention differentiates the H pulse when the TV set is switched from "on" to "standby" which results in a higher duty cycle of the control transistor, implying a lower duty cycle of the horizontal output transistor HOT. This results in a lower voltage at the tuning capacitor and hence lowers the flyback peak voltage at the anode. This results in a drop of the EHT voltage.

Abstract: An apparatus for controlling a switching frequency of a switching mode power supply (SMPS) for a video display appliance which can remove a switching noise generated during the switching-on and switching-off operations of an SMPS transformer by controlling the switching frequency of the SMPS transformer so that the duty of the SMPS transformer is kept in a predetermined range.

Abstract: A CRT protective circuit capable of eliminating spots during a mode conversion operation includes a microprocessor for generating a mute signal according to externally-provided horizontal and vertical sync signals, and a high voltage generating section for generating a high voltage according to an operation of a flyback transformer. A first switching section is switched according to the mute signal for supplying the high voltage of the high voltage generating section to a grid terminal, and a high voltage dropping section divides the output voltage of the high voltage generating section according to the switching status of the first switching section and supplies the dividing voltage to the grid terminal to control brightness of the spots.

Abstract: A display device includes a capacitor which charges or discharges, and an oscillation voltage stabilizing circuit, which prevents an abnormal oscillation by constantly maintaining the oscillation voltage of a pulse width modulation circuit which oscillates according to a time constant of a resistor.

Abstract: A high-voltage transformer for a television receiver is known to be tuned to a specific harmonic of the frequency of the flyback oscillation in order to reduce the internal resistance of the high-voltage source. In certain cases such as, for example, a channel change, a particularly high beam current of the order of magnitude of 3 to 5 mA briefly occurs. As a result of such a current surge, overshoots are produced at the transformer which may increase the flyback voltage at the switching transistor by approximately 150 V and thus endanger the transistor. The object is to design the transformer in such a way that overshoots of this type are reduced. According to the invention, the number of partial windings (W2-W5) is greater than the number of diodes (3-5), and separate partial windings (W2-W5) are tuned to different harmonics. This tuning causes the quality factor to be reduced and the attenuation and the bandwidth to be increased in the system.

Abstract: A flyback transformer which comprises: a primary-side coil; a secondary-side high-voltage coil divided into a predetermined number of coil pieces; high-voltage rectifier diodes connected, in the same polarity, in series with the coil pieces respectively so as to form a series circuit as a whole; a high-voltage capacitor connected to a cathode side of one of the high-voltage rectifier diodes located in a final stage of the series circuit; and an in-phase high-voltage coil reversely connected to the one high-voltage rectifier diode in the final stage of the series circuit so that a reverse pulse generated by the in-phase high-voltage coil is superimposed on the cathode side of the one high-voltage rectifier diode.

Abstract: The control performance of a controlled power supply (14, 13, 1, 6, 8) which specifically feeds the line output stage (35) is deliberately degraded so as to produce the same effect as in the case where a resistor of about ten ohms would be arranged in its power supply connection (5). This is realized by causing the current feeding the line output stage (35) to flow through a part of a resistor (8) of the divider.

Abstract: A high voltage stabilizing circuit includes: an error amplifier for receiving a flyback pulse rectified from one secondary side coil of a flyback transformer at an inverting terminal thereof and for receiving a reference voltage at a non-inverting terminal thereof, and for comparing the received inputs; a pulse width modulator for implementing a modulating operation in accordance with an output signal of the error amplifier and for simultaneously generating an output signal which is synchronous with the flyback pulse; a switching unit for performing a switching operation in accordance with the output signal of the pulse width modulator; and an auxiliary transformer having a primary side coil to which an output signal of the switching unit is supplied and a secondary side coil which is connected in parallel to another secondary side coil of the flyback transformer, for producing an output pulse corresponding to the flyback pulse outputted from the flyback transformer.

Abstract: A power supply system has a switching element to be turned on and off for d.c. to d.c. conversion of a unidirectional supply voltage in synchronism with horizontal synchronizing pulses used for line by line synchronization in a computer display. Since commercial computer systems commonly make selective use of horizontal synchronizing pulses at two different repetition rates, one of which is too high for driving the switching element, the horizontal synchronizing pulses generated at either rate are directed into an amplitude modulator circuit where the pulses are modulated to have either of two different predetermined amplitudes according to their repetition rates. The repetition rate of the horizontal synchronizing pulses being generated is determined from the amplitude of the amplitude modulated horizontal synchronizing pulses, and the switching element is driven at the lower rate even if the horizontal synchronizing pulses are being generated at the higher rate.