Abstract: A horizontal deflection high-voltage circuit using the diode modulation horizontal deflection circuit is provided with a means detecting the high voltage output from the flyback transformer for supplying the input terminal of the flyback transformer with a control signal which controls the high voltage to be kept constant and a means detecting a variation in the control signal for supplying one end of a modulation coil with a control signal which controls the horizontal deflection current to be kept constant, whereby a horizontal deflection high-voltage circuit practically free from irregularity of adjustment and deterioration due to aging is provided.

Abstract: The oscilloscope sweeping circuit includes a first D/A converter which converts sweep rate step digital data into a charge current under the weighting of a reference current applied thereto. The charge current charges a capacitor and the amount of the charge determines the sweep rate. The reference current is produced by a second D/A converter which converts fine step digital data into an analog current.

Abstract: In a deflection apparatus which corrects for inside pincushion distortion, a deflection winding and a retrace capacitance form a retrace circuit during a retrace interval. A trace capacitance forms a trace resonant circuit with the deflection winding during the trace interval. A circuit branch that includes a second capacitance and a modulation inductance is coupled to the trace capacitance during the trace interval to form with the trace capacitance a second resonant circuit having a resonance frequency that is substantially higher during the trace interval than that of the trace resonant circuit. A current in the circuit branch modulates the trace parabolic voltage across the trace capacitance in a manner to reduce inside pincushion distortion. A supply current is coupled to an intermediate terminal of the modulation inductance for reducing "mouseteeth" raster distortions.

Abstract: A television line output circuit includes a first sawtooth network with a diode (D), a trace capacitor (Ct), a retrace capacitor (Cr) and a line deflection coil (Ly), and a second sawtooth network with a diode (D'), a trace capacitor (C't), a retrace capacitor (C'r) and a coil (L'). The diodes (D, D') are connected in series and the two sawtooth networks connected across a line output transistor (Tr). A first modulation source (M1) is connected across the trace capacitor (C't) in the second sawtooth network to modulate the line deflection current to overcome East-West pin-cushion distortion. A resistor (R) of low ohmic value is connected between the anode of the diode (D') in the second sawtooth network and earth and a second modulation source (M2) is connected across this resistor (R). The second modulation source (M2) provides a signal dependent on beam current to correct for display errors at line frequency rate as they occur.

Abstract: A horizontal deflection stage for a raster scan device (e.g. a television receiver or a monitor) comprises a deflection generator, a d.c. supply regulator for the deflection generator, a voltage controlled oscillator providing drive pulses to the deflection generator, a phase detecting circuit for locking the oscillator to applied horizontal synchronizing pulses, and a sweep circuit for sweeping the oscillator through a range of frequencies until it achieves phase and frequency lock with the applied horizontal synchronizing pulses. An input to the regulator serves to control the output voltage of the regulator in accordance with the frequency to which the oscillator is locked. Thus the horizontal deflection stage automatically adjusts the horizontal timebase, and the regulated voltage supply of the deflection generator, in accordance with the frequency of the applied horizontal synchronizing pulses, without any operator adjustment being required.

Abstract: A deflection circuit for a video apparatus that operates at multiple line rate deflection frequencies includes an S-shaping correction circuit that provides proper S-shaping of the line deflection current at any of the video apparatus line rate operating frequencies. A first S-shaping capacitor is in series with the deflection winding and also in series with a transformer primary winding. The transformer secondary winding is coupled to one or more capacitors. The secondary winding side capacitors are coupled to the secondary winding circuit in response to a line rate frequency indicative signal in order to form a series combination of the primary and secondary side capacitors. The effective capacitance of the secondary side capacitor is then equal to the actual capacitance value increased by a factor determined by the transformer secondary to primary winding turns ratio.

Abstract: A deflection circuit for a video apparatus is capable of operating at different horizontal rate frequencies in response to the incoming video information rate. In one embodiment, the deflection oscillator input voltage is varied in a cyclical manner to vary the oscillator frequency. When the oscillator frequency corresponds to the frequency of the incoming video information, the input voltage is maintained to maintain the desired oscillator frequency. In an alternate embodiment, a frequency to voltage converter generates the desired oscillator input voltage in response to the incoming video information rate.

Abstract: A field deflection circuit for use in a picture display device, comprising an amplifier to whose output the series network of a field deflection coil, a separated capacitor and a negative feedback resistor is disclosed. A circuit is provided in parallel with the separating capacitor for fixing the d.c. component of the voltage across the capacitor at a more less constant value. Frequency-dependent negative feedback networks may therefore be omitted.

Abstract: A variable-gain rectifier-amplifier with regulated voltage converts the output ramp of a ramp generator with regulating resistance of ramp amplitude into a triangular wave form with adjustable linearity which a feedback circuit brings back to said regulating resistance in the form of alternating current superimposing it on the direct current regulated through said resistance. This provides an S correction of the output ramp which depends on the gain regulation voltage of the rectifier-amplifier circuit.

Abstract: In a horizontal output circuit for a cathode ray tube, there is included a second resonant circuit combining in parallel a transistor, a damper diode, a resonant capacitor and a series connection of a capacitor and a coil serially connected to a horizontal deflection resonant circuit having a horizontal output transistor, a damper diode, a resonant capacitor, a series connection of an S-shape capacitor and a horizontal deflection coil and a flyback transformer. The constants of the circuits are set so that waveforms of resonant pulses generated by the two resonant circuits becomes similar. A parabolic correction voltage for vertical synchoronization is also applied to the second resonant circuit and the resonant pulse is amplitude-modulated parabolically by the vertical synchronization signal. Therefore, the resonant pulse of the first resonant circuit is amplitude-modulated parabolically with a reverse polarity.

Abstract: In a horizontal deflection circuit having a series circuit of a horizontal deflection coil and S-shape capacitor and a parallel circuit of a switching element and a second capacitor connected in series with said series circuit, there is provided a resonation circuit having a resonating frequency with the second capacitor that is substantially equal to the horizontal deflection frequency or a little lower than that for purposes of regulation of the high voltage of the cathode ray tube.

Abstract: A deflection circuit generates a deflection current at a scan frequency selected from any one of at least two ranges of frequencies. When the scan frequency is selected from the first range, only a first S-capacitor provides S-correction. When the scan frequency is selected from a lower second range, a series connected FET switch couples a second S-capacitor across the first S-capacitor. A DC average voltage is developed at a junction between the first and second S-capacitors. A resistor coupled to the second S-capacitor causes the second S-capacitor to be charged to the average DC voltage to prevent the average DC voltage from developing across the main current conducting electrodes of the FET switch when the FET switch is nonconductive. The FET switch is controlled by an output voltage of a comparator. The comparator is responsive to a signal that is indicative of the frequency range from which the scan frequency is selected.

Abstract: A horizontal deflection output circuit, such as used in a TV receiver or a display device, includes a series circuit composed of a ringing preventing resistor and a one-way switching element connected in parallel with a linearity correcting coil. That one-way switching element is turned on at the beginning of a horizontal scanning period to feed a current to the ringing preventing resistor but is turned off in the vicinity of a fly-back period to block the flow of the current to the ringing preventing resistor. Thus, the power loss due to the current flowing through the ringing preventing resistor for the fly-back period can be reduced according to the present invention.

Abstract: A horizontal deflection circuit comprises an oscillator responsive to a horizontal sync pulse applied thereto for generating a first oscillation at the frequency of the sync pulse. A first switching device is responsive to a first half cycle of the first oscillation to cause a ramp current to be generated in a resonant circuit. The resonant circuit comprises a deflection coil and a first capacitor to produce a second, half-cycle oscillation immediately following a complete cycle of the first oscillation to define the retrace period of the circuit. A second switching device when enabled is responsive to a second half cycle of the first oscillation. The second switching device is enabled by operating a manually controlled switch. The enabled second switching device intermittently couples a second capacitor to the first capacitor of the resonant circuit to vary the retrace period.

Abstract: A power amplifier circuit for driving an inductive load comprises a capacitor coupled between first and second circuit nodes, a first unidirectionally-conductive device having a first terminal coupled to the first circuit node, and a transistor having its collector coupled to the second terminal of the first unidirectionally-conductive device and having its emitter coupled to the second circuit node. The direction of conduction of the first unidirectionally-conductive device is the same as the direction of conduction through the collector-emitter path of the transistor. The circuit also comprises a second unidirectionally-conductive device connected in parallel with the first unidirectionally-conductive device for conducting current in the opposite direction from the direction of conduction of the first unidirectionally-conductive device.

Abstract: A line output circuit has a transistor (TR) whose collector is connected through the primary winding (P) of a transformer (T) to a direct voltage supply terminal (2), the secondary winding (S) of the transformer (T) being connected through a diode (D1) to a terminal (3) at which an EHT supply appears. A diode (D2) shunts the collector-emitter path of transistor (TR) to provide a path for negative going sawtooth current. Two serially connected flyback capacitors (Cf1, Cf2) also shunt the transistor (TR), one capacitor (Cf2) being shunted by a switch (S1). The series arrangement of a linearity correction inductor (L1), a deflection coil (Ly), a further inductor (L2) and a trace capacitor (Ct1) also shunt the transistor (TR), the inductor (L2) and trace capacitor (Ct1) also being shunted by the series arrangement of a further trace capacitor (Ct2), a linearity correction resistor (R) and a switch (S2).

Abstract: In a video display apparatus having a service mode of operation, a vertical deflection circuit includes a vertical deflection winding coupled to a DC blocking capacitor. An output stage includes first and second output amplifiers coupled to the vertical deflection winding in a push-pull arrangement at an output terminal. A vertical sawtooth voltage generator is coupled to a driver stage via an error amplifier that provides both AC and DC negative feedback for driving the output stage at a vertical rate in a sawtooth manner to generate a sawtooth deflection current in the deflection winding and for establishing a DC operating voltage level at the output terminal that charges the DC blocking capacitor. A service mode switching circuit is coupled to the driver stage for asserting the service mode of operation by maintaining the first output amplifier in cutoff and the second output amplifier in conduction to discharge the DC blocking capacitor and disable the generation of the sawtooth deflection current.

Abstract: A vertical deflection circuit for a CRT tube, with a so-called Mirror integration circuit, has an integration arrangement with a resistor and a capacitor, and a first amplifier for amplifying saw-tooth wave by the integration arrangement with a deflection coil coupled with output of the amplifier. A first feedback path is located between the deflection coil and the capacitor has been improved by a second feedback path between the deflection coil and input of the first amplifier. The second feedback path provides the sum of the parabolic voltage at the end of the deflection coil which is grounded through a second capacitor and a second resistor, and the saw-tooth wave voltage responsive to the current in the deflection coil to the first amplifier. The second feedback path provides the so-called S-shaped compensation on a screen so that a picture distortion, due to a non-arc face of a screen at peripheral portions, is compensated.

Abstract: A line deflection circuit in which a transistor (TR) conducts during the scan period to produce a sawtooth current though the line deflection coil (Ly), transistor (TR) being rendered non-conducting at the scan period to initiate the flyback period which may be required to be short (of the order of 6 microseconds). During flyback the circuit is tuned to produce a half sinewave which determines the flyback period and to an odd harmonic (3rd or 5th) of the fundamental for the flyback period. A change in inductance of the width control inductor (L1) will produce a change in the flyback period while a simultaneous change in the inductance of the inductor (L2) will produce a change in the leakage inductance of the transformer (T) to change the frequency of the desired odd harmonic to ensure that the odd harmonic has the desired relationship with the flyback period. Overcomes display modulation that would otherwise be produced.

Abstract: A voltage of a sawtooth generator is present at a capacitor. This voltage is compared to a reference voltage. In case of a deviation, a controllable current source is connected in parallel to a constant current source charging the capacitor. This allows the position of the picture to be maintained fixed by keeping the center of the picture at a preset level. A counter circuit counts lines of a screen picture and produces a control signal. An electronic switch is connected to the counter circuit and to the capacitor for periodically discharging the capacitor after a vertical deflection period triggered by the control signal of the counter circuit. A first comparator circuit is connected to the counter circuit and activated by a signal from the counter circuit and further connected to the capacitor for comparing the actual voltage applied at the capacitor to a reference voltage. A vertical deflection output stage has an input connected to the capacitor.

Abstract: A field effect transistor (FET) quadrature switch for the control of multi mode microwave phase shifters provides bi-directional random mode switching while using only one power supply. The switch apparatus provides high speed, high voltage, and high-current switching while reducing the stand off voltage requirement of the linear driver, the number of switching elements which are required for mechanization, and reducing the size, weight and the complexity of the apparatus.

Abstract: A deflection drive circuit (15) for an inductive yoke (11) used with a raster scanned cathode ray tube rapidly interrupts current then reverses voltage applied to the yoke (11) during flyback. MOSFETs (Q32, Q47) are used to control current flow to the yoke. The current is interrupted by one MOSFET (Q32) being gated "OFF", after which current is permitted to flow to a capacitor (C51). At a preselected time, a second MOSFET (Q47) is gated on to admit reverse flow of current from the capacitor (C51) to the yoke (11). The second MOSFET (Q47) is gated "ON" by a circuit which includes a third MOSFET (Q57) and a pulse transformer (T59).Advantages include an ability to rapidly effect flyback without interfering with the forward scanning ability of the deflection drive circuit 15.

Abstract: A high-speed power amplifier for driving inductive loads is capable of operating at frequencies of at least 270 kHz. The drive amplifier includes an oscillator that develops a continuous square-wave signal having relatively short transition times and a regulated 50% duty cycle. The oscillator output signal is applied to a filar-wound impedance transformer whose response time characteristics do not change substantially the transition time characteristics of the oscillator output signal. The impedance transformer circuit includes a pair of transistors operating in a push-pull configuration simultaneously to maintain the relatively short transition times of the oscillator output signal and to develop the high-current transformer output signal needed to drive a power transistor switch. The power amplifier is designed to provide a base current signal that promotes better dissipation of the power generated in the power transistor as it operates at high switching speeds.

Abstract: A field deflection amplifier generates a field deflection current in a field deflection winding. An LC resonant circuit is coupled to the deflection winding and to an output switching amplifier. A control circuit switches conductive states of the amplifier at a line rate, with a 50% duty cycle, to excite the LC resonant circuit into providing a line rate correction current for the field deflection winding. The control circuit varies the modulation envelope of the field deflection current at a field rate in a generally sawtooth manner to provide north-south pincushion correction. When used in conjunction with raster scanning in a square-planar picture tube, the modulation envelope is nonlinearly waveshaped to take into account the aspherical nature of the picture tube faceplate.

Abstract: In picture-reproducing equipment with higher scanning frequencies (e.g., flicker-free television, visual display unit), the generation of the horizontal-deflection current is separated in frequency from the generation of the operating voltages by supplying the horizontal-deflection circuit from a DC voltage source which is part of the voltage power supply providing the operating voltages. The supply circuit is preferably connected to the grounded deflection capacitor. This makes it possible to influence the picture geometry in a simple manner, particularly to perform horizontal pincushion correction.

Abstract: A television deflection apparatus includes a deflection winding coupled to a retrace capacitance to form a retrace resonant circuit. A power transistor switch is coupled to the retrace resonant circuit for generating alternating current in the retrace resonant circuit. The power transistor switch energizes a primary winding of a flyback transformer that supplies a first voltage across a secondary winding of the flyback transformer. The first voltage is coupled to an inductance for forming an upramping current in the inductance. The upramping current in the inductance is coupled to the base electrode of the power transistor switch, causing the power transistor switch to be conductive during the second half of trace. A second switch, that is responsive to a deflection rate input signal, couples to the base electrode of the power transistor switch a negative supply voltage that turns off the power transistor to initiate the retrace interval.

Abstract: A video display apparatus operates at two or more horizontal scan rates. In order to prevent excessive collector voltage from being applied to the horizontal output transistor, a transition circuit turns off the horizontal output transistor when switching between horizontal scan frequencies occurs. The horizontal output transistor is maintained nonconductive until the correct oscillator frequency and supply voltage is coupled to the horizontal output circuit.

Abstract: A horizontal deflection circuit output stage is coupled to a first end terminal of a primary winding of a flyback transformer for developing at that terminal a retrace voltage. A second end terminal of the primary winding is coupled to a switched mode power supply that provides at the second end terminal a combined voltage that is the sum of a DC B+ scanning voltage component and a horizontal rate rectangular-wave voltage component. The difference voltage between the retrace voltage and the rectangular-wave voltage component is developed between the end terminals of the primary winding of the flyback transformer and is coupled by transformer action to a high voltage secondary winding for generating an ultor accelerating potential. The phase of the rectangular-wave voltage component relative to the retrace voltage determines the level of the ultor accelerating potential.

Abstract: A circuit for providing input power to the horizontal deflection coil or yoke for a raster scan type of cathode ray tube. The circuit includes a closed loop current sensor which uses an operational amplifier to compare the sensed current with an adjustable reference voltage to provide a control for the current, thereby providing a constant current power source for a resonant deflection yoke flyback circuit. The current drive and S shaping capacitor are directly coupled to the deflection coil, omitting a coupling transformer and a linearity coil.

Abstract: A capacitively coupled square wave generator provides a steady state sinusoidal current flow in a deflection winding of a cathode ray tube. The deflection winding, the capacitive coupling and an additional capacitor form a tank circuit which filters out the odd harmonics of the square wave generator to provide a sinusoidal current in the deflection winding to produce bidirectional scanning.

Abstract: In a deflection circuit, a flyback transformer and a retrace resonant circuit that includes a deflection winding are mutually coupled by a relatively small capacitor during the retrace interval so as to reduce transient distortions that may be caused by a sudden high beam current change. East-west modulation is provided to the deflection circuit output stage via an impedance having a relatively large value at the retrace frequency. A resonant circuit that includes the deflection winding and the flyback transformer is tuned to the retrace frequency. Synchronization information of the current through the deflection winding may be derived from a winding of the flyback transformer.

Abstract: A drive circuit for a horizontal deflection circuit that is operable at a number of horizontal scan rates includes a pair of transistors coupled in a push-pull arrangement. The voltage supplies for the drive circuit transistors, which provide the forward and reverse drive for the horizontal output transistor, produce voltage levels that are dependent upon the horizontal scanning rate that is selected in order to minimize power dissipation during switching of the horizontal output transistor.

Abstract: A quasi-resonant random access deflection system includes a biresonant, bidirectional deflection circuit connected to the deflection yoke of a display monitor picture tube and a control circuit connected to the deflection circuit and being operable to generate signals to actuate the deflection circuit so as to cause, via the magnetic fields of the deflection yoke, selected movement of the electron beam of the picture tube along a bidirectional path and stopping of the beam at any position along the bidirectional path.

Abstract: An apparatus for generating a periodic resonant pulse voltage across an inductance includes first and second switches coupled together in a series cascode arrangement. The cascode arrangement applies a first voltage to an inductance for storing energy therein. A periodic switching signal is coupled to the second switch. Each cycle of the switching signal includes a turn-on portion and a turn-off portion. The initiation of the turn-off portion makes the second switch nonconductive to enable the inductance and a resonating capacitance to form a resonant circuit that generates a resonant pulse voltage at a terminal of the resonant circuit. A damper switch is coupled to the inductance for terminating the generation of the resonant pulse voltage at the end of the first interval, prior to the initiation of the turn-on portion of the switching signal.

Abstract: A linearity correction circuit for high speed horizontal scanning is disclosed. The correction circuit uses high speed, fast recovery components capable of operating in the fifty to one hundred kilohertz range. A variable inductor is tapped directly to the flyback transformer, the variable nature of the inductor giving a range of correction for linearity. The inductor is connected to a capacitor and a damper diode with a diode so that the voltage built up across the capacitor, which is connected to the deflection coil, causes the damper diode to conduct early, thus correcting linearity of the circuit. Using a minimum number of components a highly efficient circuit is provided both in operation and cost of construction.

Abstract: A power supply and scanning line deflection circuit for a picture display device. The power supply circuit comprises an inductance and a switch which switches at line frequency, the inductance forming part of a resonant network during the cut-off period of the switch. The line deflection circuit comprises another switch which also switches at line frequency and a line deflection coil which during the cut-off period of the switch, which substantially coincides with the retrace period, forms part of a resonant network which also comprises an inductance. A transformer winding is coupled to one of the inductances. During the cut-off period of the switch pulses are developed across this transformer winding which are rectified for generating a supply voltage for a variable load.

Abstract: A deflection circuit is coupled to a horizontal deflection winding for generating scanning current in the winding. A retrace pulse voltage is developed across the deflection winding during the retrace interval. A flyback transformer is coupled to the deflection circuit and has retraced pulse voltages developed across windings thereof. A source of supply energy is coupled to a first winding of the flyback transformer and a load circuit, such as a high power audio circuit, is coupled to a second winding of the transformer and draws load current therefrom. A switched mode power supply is coupled to the source of supply energy and to the flyback transformer for controlling the transfer of energy between the source and the load circuit. A compensation circuit responsive to the operation of the switched mode power supply produces variations in current in an inductance coupled to the flyback transformer. These variations are indicative of variations in load current drawn by the load circuit.

Abstract: A raster generator circuit is disclosed for a cathode ray tube display having a fixed efficiency at any desired raster scan rate. eliminating external clock dependency for synchronization ahd having a fixed efficiency. The circuit generates a raster signal having a self-adjusting line density corresponding to the time allowed for rastering a complete screen.

Abstract: A horizontal deflection circuit with raster distortion correction includes a horizontal deflection winding coupled to a first retrace capacitor and an input inductance such as the primary winding of a flyback transformer coupled to a second retrace capacitor. Horizontal switching elements are operated at a horizontal deflection rate for generating current in the inductance and a horizontal scanning current in the deflection winding. During retrace, the horizontal deflection winding and the first retrace capacitor form a first resonant circuit and the input inductance and the second retrace capacitor form a second resonant circuit. One of the switching elements decouples the resonant circuits from each other to minimize the interaction therebetween. A source of raster distortion correction current is coupled to the deflection winding to provide the required scanning current modulation.

Abstract: In a dual mode CRT deflection circuit, a capacitor for effecting rapid retrace of the CRT beam by means of resonant nonlinear operation is selectively shunted such that beam deflection may be linearly controlled. A bidirectional switch preferably comprising a field effect transistor (FET) is connected in parallel with the capacitor which in turn is connected in series with the deflection coil of the CRT with the series combination being driven by an amplifier in response to beam positioning signals. When the bidirectional switch is activated to shunt the capacitor, the deflection control circuit operates in a linear mode; and when the switch is deactivated, the deflection coil of the CRT interacts with the capacitor for resonant nonlinear operation. A comparator circuit is connected to the output of the amplifier and coupled to the bidirectional switch through an optical coupler to activate and deactivate the switch in response to conditions within the deflection control circuit.

Abstract: A hybrid CRT display includes vector generated portions for alpha-numeric data and normal raster scan portions for symbol data. A deflection yoke for a CRT is driven by a single horizontal amplifier having switching means which operate the amplifier in three modes necessary to achieve the hybrid display, enhanced by resonant retrace during raster scanning.

Abstract: A CRT video display includes a horizontal oscillator for producing a variable rate horizontal scan control signal in response to different resolution modes of operation. A horizontal output signal is produced in response to the variable rate horizontal scan control signal and a B+ voltage. The pulse amplitude of the horizontal output signal is maintained constant in response to changes in the rate of the horizontal scan control signal by appropriately adjusting the B+ voltage, whereby the high voltage and horizontal raster size of the display are maintained constant despite variations in the horizontal scan control signal which accommodate different resolution modes of operation.

Abstract: An energizing voltage is series coupled with a diode, an inductor, a flyback transformer primary winding and an input terminal of a deflection circuit. During trace, the diode is forward biased causing a voltage to be developed across and an input current to flow in the inductor. During retrace, opposite polarity retrace voltage commutates off the diode and decouples the input terminal from the energizing voltage at a varied instant within retrace, in accordance with the amplitude of the input current. The amplitude of the input current is related to the ultor load current. A voltage that is indicative of the input current is developed across a capacitor. A DC voltage between one plate of the capacitor and a reference conductor controls the deflection current in the deflection winding such that variations in the ultor voltage produce the same sense variations in the DC voltage that is supplied by the capacitor for maintaining a substantially constant raster width.

Abstract: A circuit arrangement for a picture display device for generating a sawtooth line deflection current. The arrangement comprises a power supply transformer having a primary winding and a secondary winding. One end of the primary winding is connected to a terminal of a supply voltage source and the other end to a controllable supply switch whose other side is connected to the other terminal of the source. The secondary winding is connected in series with a line deflection coil, a trace capacitor, and a deflection switch. A retrace capacitor is connected to the line deflection coil. During the retrace period the line deflection coil, the trace and the retrace capacitors are part of a resonant network the elements of which determine the duration of the retrace period.

Abstract: A deflection circuit for a television includes two semiconductor switching elements connected in series. Separate control circuits are provided for each semiconductor switching element to control the operation of the respective switching element. Each control circuit receives a control signal and is connected to a voltage source. For the control circuit associated with the switching element which receives the highest voltage, connection to the voltage source and the control signal is through diodes which provide common mode isolation. This control circuit includes a capacitor which provides energy for the control circuit when the diode connecting it to the voltage source is reverse biased.

Abstract: A step waveform generator includes a cup and bucket circuit in which charging and discharging a cup capacitor (C1) with predetermined units of charge is achieved, in response to a train of pulses supplied to its input terminal (1), by means of an operational amplifier (2) continuously monitoring the voltage across the cup capacitor and alternately supplying charging current and discharging current from a first and second constant current source (I1 and I2) respectively via separate feedback loops (T3, T2 and T4, T7, T6) of the amplifier. The constant currents, or multiples or sub-multiples of the constant currents, providing each individual unit of charge, are generated by current mirrors (T8, T9, T10) and added sequentially to a bucket capacitor C2. The size of each individual step of the resultant voltage waveform derived from the bucket capacitor and appearing at output terminal 4 depends upon the combination of mirrored increments of current selected by switch (S1, S2) and added to the bucket capacitor.

Abstract: A first regulating amplifier (7) provides a linearly increasing current to the horizontal deflection coil during the forward trace sweep and the amplifier is disconnected from the deflection coil and its parallel capacitor (2) during the retrace period to provide flyback by free reaction of the oscillating circuit. In order to shorten the retrace period an auxiliary coil (17) is energized with a regulated current during the forward trace sweep with the help of a second regulating amplifier (8) gated on during a preliminary portion of the line interval and a controllable voltage source (14) set thereby. During a first portion of the retrace interval currents flowing respectively in the auxiliary coil and in the horizontal deflection coil are stored in the capacitor (2), which discharges during the remainder of the retrace period only through the deflection coil.

Abstract: A switched vertical deflection circuit derives vertical deflection current from horizontal deflection energy. A single switching element operates during both horizontal trace and retrace intervals. Conduction of the switching element is controlled by a vertical control circuit to provide the desired vertical deflection current. Feedback to the control circuit is referenced to ground potential to eliminate nonlinearity caused by voltage supply variations. The vertical circuit voltage supply is adapted to sink as well as supply current, thereby stabilizing the supply.

Abstract: A video display system operates at a plurality of horizontal scanning rates. A voltage source produces different voltage levels, one of which is selected in response to the horizontal rate selected. A horizontal deflection circuit produces retrace pulses having amplitudes dependent on the scanning rate. A high voltage transformer has a primary winding with a number of taps. The voltage source is connected to one of the taps in response to the horizontal deflection rate selected so that the high voltage level developed across the transformer secondary winding remains substantially constant independent of changes in retrace pulse amplitude.

Abstract: An S-correction circuit for a video display apparatus provides switchable amounts of correction in a given line deflection interval in order to satisfy the requirements of cathode ray tubes having large deflection angles or complex curvature faceplates. A second S-shaping capacitor is coupled in parallel with the main S-shaping capacitor by action of a switching transistor. The time at which the transistor is switched may be controlled, for example, by modulating the switching point at a vertical rate, in order to increase the flexibility of the correction circuit.