Abstract: A first voltage-to-current converter responsive to a picture height adjustment control signal generates a first current in a capacitor for producing a trace portion of a sawtooth signal in the capacitor having a rate of change that is adjustable in accordance with an adjustment of the control signal. A second voltage-to-current converter responsive to the control signal generates a second current in a resistor for producing a third signal that is adjustable in accordance with the control signal. The sawtooth and third signals are coupled via a differential amplifier to a vertical deflection winding to produce a vertical deflection current in accordance with a difference between the sawtooth and third signals such that picture height adjustment does not affect vertical centering.

Abstract: In a vertical sawtooth generator of a vertical deflection circuit, a first comparator generates an output signal when a retrace portion of a sawtooth signal is at a first magnitude to initiate a vertical trace portion of the sawtooth signal. An amplifier responsive to the sawtooth signal generates a feedback current at a time that occurs more than one-half of the length of vertical trace portion after vertical trace is initiated. The feedback current is coupled to a capacitor to develop a capacitor voltage. The capacitor voltage is applied via a voltage-to-current converter to an integrating capacitor to develop in the integrating capacitor the trace portion of the sawtooth signal.

Abstract: In a vertical sawtooth generator of a D.C. coupled vertical deflection circuit, a vertical deflection amplifier generates a sawtooth signal. Magnitudes of the sawtooth signal in first and second instants of its trace period are determined in accordance with first and second D.C. signals, respectively. The first and second D.C. signals are adjusted during service to control the raster height and the raster centering such that while the raster height is adjusted, raster centering is not significantly affected, and vice versa.

Abstract: A system for adjusting the position and size of a picture generated by deflecting a light source in response to a deflection current and displayed in a picture area larger than the picture includes sensors for sensing the picture arranged outside the picture and within the picture area. First and second differential amplifier both have an inverting and noninverting input terminal. A deflection voltage proportional to the deflection current is applied to the noninverting input terminal of the first differential amplifier and to inverting input terminal of the second differential amplifier. A first reference voltage is applied to the inverting input terminal of the first differential amplifier to produce a positive correction pulse in accordance with the difference between the deflection voltage and the first reference voltage.

Abstract: Vertical deflection circuitry for substantially eliminating rolling and bouncing in a video monitor, where, for example, the video monitor successively displays images produced by each of one of a plurality of non-synchronized video cameras and an incoming vertical synchronization (synch) signal to the monitor is merely a composite of the individual vertical synch signals generated by each of these cameras. Specifically, the vertical deflection circuitry generates the appropriate vertical sweep signal for a current one of these cameras from this composite synch signal so as to properly locate the corresponding video image generated by this camera on a display screen of the monitor.

Abstract: A saw-tooth wave signal is supplied to the non-inverting input terminal of a first power amplifier constituting a first negative feedback amplifier. The output terminal of the first power amplifier is connected to one terminal of a deflection coil. A signal output from the other terminal of the deflection coil is supplied to the inverting input terminal of the first power amplifier. The other terminal of the deflection coil is connected, through a resistor, to the output terminal of a second power amplifier constituting a second negative feedback amplifier. The output terminal of the second power amplifier is connected to the inverting input terminal of the second power amplifier. The DC voltage appearing at the output terminal of the second power amplifier in the non-signal state is set to be equal to that of the first negative feedback amplifier.

Abstract: In a beam scan velocity modulation (SVM) system for a television receiver, a video signal is applied to a differentiator followed by a limiting differential amplifier. A driver amplifier coupled to the limiting amplifier drives an output stage that supplies current to an SVM coil. Certain video signals with large high frequency content may tend to produce excessive dissipation in the devices of the output stage. To prevent this, a current source for the differential amplifier is controlled by a voltage which is a measure of the average current through the output stage. The magnitude of the current source is varied to thereby vary the peak-to-peak signal output from the limiting amplifier to prevent overdissipation of the output devices. The driver amplifier performs a coring operation that is unaffected by the variable limiting.

Abstract: A vertical amplifier of a vertical deflection circuit has an output transistor operating as a conductive switch that couples a boosted supply voltage to a vertical deflection winding during vertical retrace. A feedback network that bypasses the deflection winding is coupled between an output terminal and an input terminal of the amplifier to provide a phase lead. A clamping diode is coupled to the feedback network. The clamping diode reduces a magnitude of a feedback signal, during vertical retrace, in a manner to delay an instant in which the output transistor begins operating as an amplifier stage. The lengthening of vertical retrace due to the feedback signal is thereby reduced.

Abstract: A display monitor includes a conventional cathode ray tube display and display drive. A conventional horizontal deflection system and high voltage system are operable to provide horizontal scan of the cathode ray tube and a high voltage potential therefor. A vertical deflection system suitable for multiple frequency and normal or expanded modes of operation includes a vertical oscillator and vertical amplifier driving a vertical deflection yoke. A sample of the vertical deflection signal is detected by an amplitude detector and compared to a reference amplitude to produce an error signal operative upon the vertical scan system. Individual reference voltages corresponding to normal and expanded modes of operation are selectively coupleable to the reference voltage portion of the system by a selector switch.

Abstract: A parabola generator for geometric correction of a television raster, comprises: a resettable circuit for generating a repetitive ramp signal and a resettable integrator for generating a repetitive parabola signal from said repetitive ramp signal. A first resetting circuit initializes the ramp circuit at a frequency related to a scanning frequency. An auxiliary resetting circuit initializes the integrator prior to integrating each repetitive ramp. The auxiliary resetting circuit minimizes timing errors from variations of the ramp signal due to transient conditions. In one embodiment, the scanning period is a horizontal scanning period and the ramp and parabola circuits are reset at the end of each horizontal scanning interval. In this case, the first and auxiliary resetting circuits are responsive to horizontal retrace pulses, for example the leading edges of the horizontal retrace pulses. A further circuit modulates the periodically reset parabolic signal at a vertical scanning rate.

Abstract: A horizontal deflection circuit for a multiple-scanning type television receiver that receives a video signal that can have a number of horizontal frequencies is comprised of a detecting circuit for detecting a deflection width of the input video signal, a comparator for comparing a detected deflection width with a signal proportional to the picture size of the input video signal in the horizontal direction, an adder for adding an output of the comparator and the picture size signal, a voltage signal generating circuit for generating a voltage signal proportional to the horizontal frequency of the input video signal, and a multiplying circuit for multiplying an output signal of the adder and an output signal of the voltage signal generating circuit, wherein a horizontal output circuit is controlled on the basis of the output signal of the multiplying circuit.

Abstract: A vertical deflection circuit for a CRT display device comprises a first negative feedback circuit for detecting a vertical deflection current flowing through a vertical deflection coil feeding it back to a ramp wave generator to thereby stabilize a vertical size of the display image on the CRT screen, second negative feedback circuit connected between the deflection coil to an input of the output circuit for detecting a mean vertical deflection current which is fedback to an output circuit to thereby stabilize a vertical position of the display image on the CRT screen and a controlling circuit for controlling feedback amount of the first and second negative feedback circuits to thereby regulate a vertical size and a vertical position of the display image on the CRT screen variably.

Abstract: A deflection system comprises: a signal generator, an amplifier stage, a negative feedback path and a vertical rate waveform generator. The signal generator is coupled to a source of flyback pulses for developing from energy in the flyback pulses a horizontal rate drive signal having a predetermined and substantially constant DC voltage reference level. The amplifier has a first input coupled for receiving the horizontal rate drive signal and an output coupled to a deflection coil. The amplifier output has a DC voltage reference level corresponding to the DC reference level of the horizonatl rate drive signal. A DC feedback signal on the negative feedback path is related to deflection current. The feedback path is coupled between the coil and a second input of the amplifier. The vertical rate waveform is also coupled to the second input of the amplifier for modulating the horizontal rate drive signal.

Abstract: The present invention relates to a vertical deflection circuit of a picture display unit which is capable of displaying pictures against variety of scanning frequencies. There are provided: a vertical oscillation means which generates a deflection voltage (V.sub.SAW) synchronizing with a vertical synchronizing signal (VD), includes a constant current source and is capable of varying the amplitude value of said deflection voltage (V.sub.

Abstract: Disclosed herein is a linear deflection amplifier which is suitable for processing horizontal sweep signals for driving a magnetic deflection yoke of a radar CRT PPI (Plan Position Indicator) display. The amplifier features a transadmittance feedback where output current follows input voltage. Flyback resonance is derived by a shunt capacitor coupled to an FET switch. Low cross-over distortion and temperature compensation of components within the system is achieved by use of a modified class B power MOSFET push-pull configuration.

Abstract: A horizontal deflection circuit for a multiple scan display, capable of controlling the horizontal deflection voltage for a plurality of horizontal scanning frequencies. The output power of the amplifier is controlled on the basis of the result of detection of the data of horizontal size of the image plane so that the horizontal size of the image plane is adjusted to a predetermined size. The data of horizontal size of the image plane is obtained through the detection of the amplitude of a flyback pulse signal. The amplitude of a sawtooth signal for horizontal scanning is controlled according to the deviation of the detected amplitude of the flyback pulse signal from a predetermined value. The horizontal deflection circuit is very simple in construction and is capable of carrying out continuous horizontal deflection according to the horizontal scanning frequency varying in a plurality of levels.

Abstract: An object of the present invention is to provide a ramp generator which makes the scan start level by the sawtooth constant so as to obtain a proper interlace characteristic on the television picture plane. The present invention includes a clamping circuit which prevents the voltage from rising or falling so that a predetermined voltage value varies corresponding to the supply voltage.

Abstract: A signal generator which generates an amplified yoke signal for application to a vertical yoke of a cathode ray tube monitor is presented. The signal generator includes a linear ramp generator and a correction generator. The linear ramp generator has an output on which is placed a ramp signal. The linear ramp generator also has a first input which receives a clock signal. The frequency of oscillation of the clock signal determines the frequency of oscillation of the ramp signal. The linear ramp generator additionally has a second input for receiving a height adjustment signal. The linear ramp generator varies the maximum voltage range of the ramp signal responsive to the height adjustment signal. The maximum voltage range is varied independent of the frequency of oscillation of the ramp signal. The correction generator receives the ramp signal from the linear ramp generator and generates an "S" correction signal.

Abstract: A base drive circuit for a flyback output transistor has an inductive element having series connected coils for generating a linear ramping current to the base electrode of the output transistor in response to an input pulse. A high, almost instantaneous reverse current is produced through a discharge coil that receives inductively coupled energy from the current generating coils. The ratio of the maximum input current to the discharge current is established by the number of coils generating the input current versus the number of coils in the discharge circuit. Linearity of the base drive current is maintained by dissipating any excess energy in the inductive element to ground prior to each input pulse.

Abstract: A timebase circuit for use in the vertical timebase of a television receiver in which a linearity control current fed to the ramp capacitor is derived by multiplying a current proportional to the difference between the instantaneous and average ramp voltages by a reference current which may be adjusted to control linearity.

Abstract: A picture display device for displaying a picture by means of a line raster consisting of a plurality of lines which are successively scanned in the opposite direction includes a video signal processing circuit for receiving an incoming video signal comprising video information and synchronizing signals and for supplying the video information of a line in one direction and the video information of the subsequent line in the opposite direction, and a line deflection circuit for generating a line deflection current through a line deflection coil. To minimize the power which is dissipated in the line deflection circuit, this circuit constitutes a self-oscillating stage with its natural frequency which is determined by a resonant network comprising the line deflection coil and which is independent of the frequency of the line synchronizing signal in the incoming video signal.

Abstract: A memory control for use with a digital oscilloscope having a display and a digital memory storing a sequence of signal samples. The sequence of signal samples is cyclically read from memory and displayed. The memory control adjusts the memory access operation to provide a controlled signal flow to the display at a rate within the slew-rate limits of the graphic display. In the memory control, the point slew, or distance over which the display beam moves from the present data point to the next point, is measured. If the point slew relative to the time interval between displayed signal samples exceeds the slew-rate capability of the display, the signal flow from the memory for subsequent data points is reduced or inhibited for a time sufficient to allow the display to reach a coordinate position corresponding to the desired data point.

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: An amplifier stage with variable gain dependent on the anode voltage is interposed between a ramp generator having constant amplitude ramp output voltage and the vertical deflection stage in such a manner as to vary the input voltage of said vertical deflection stage in accordance with anode voltage variations. In such a manner the vertical deflection current varies correspondingly.

Abstract: A top/bottom pincushion correction transformer injects a horizontal rate correction signal in series with a vertical yoke that is driven from a vertical amplifier that has a non-inverting and an inverting terminal. A feedback arrangement includes a voltage sensing resistor for supplying a voltage indicative of the current flow in the yoke to the non-inverting terminal of the amplifier. The primary winding of a pincushion transformer is connected in series with a current limiting resistor and their junction is connected by a bridging resistor to the voltage sensing resistor. The voltage developed across the voltage developing resistor is of opposite polarity to the voltage developed across the current limiting resistor for offsetting the same.

Abstract: A circuit arrangement for generating a sawtooth-shaped signal for the field deflection in a picture display device with an amplitude which is substantially independent of the field frequency is disclosed. The value of the sawtooth-shaped signal during the occurrence of a sampling pulse is compared with a reference value for generating a control signal controlling the slope of the sawtooth-shaped signal. To eliminate instability in amplitude, which might result from phase jitter of the incoming field synchronizing signal and might cause an interlace error, sampling pulses are applied whose repetition frequency is substantially equal to the nth part of the field frequency, where n is an integer which is larger than 1, preferably a small multiple of 2.

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: A linear high power amplifier suitable for low voltage operation comprising a push-pull output stage (Q1, Q2) arranged to control the voltage supplied to a load (Z.sub.L) in dependence on an input signal (V.sub.IN) applied to the amplifier. Means (L.sub.S, S) is provided for separately supplying to said load (.sub.Z L) a current (I.sub.S) which changes at a rate faster than the maximum rate of change of current (I.sub.L) in the load (Z.sub.L) required by the input signal (V.sub.IN) thereby to produce a corresponding change in the current (I.sub.A) required to be supplied by the output stage (Q1, Q2) to the load (Z.sub.L) in order to maintain the voltage across the load (Z.sub.L) at the value required by said input signal (V.sub.IN). Switching means (Q3, Q4, C) operated in dependence on the value of the current (I.sub.A) supplied to the load (Z.sub.L) by the output stage (Q1, Q2) causes the sense in which said changing current (I.sub.S) changes to reverse when said current (I.sub.

Abstract: A process for avoiding non-linearities and brightening on the television picture tube includes the generating of an additional signal of a higher frequency than that of the deflections signals, the separating of the additional signal into signal parts of opposite polarity, and the addition of the two additional signal parts to the deflection signals during time intervals immediately before and after the return movement period.

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: An electron beam magnetic deflection system capable of raster and stroke deflection and providing minimum power dissipation in raster mode. Automatic switching of the voltage demanded in raster mode is obtained by continuously sampling the yoke current, the power supply voltage being switched in magnitude and polarity corresponding to the direction of change and polarity of the yoke current. By returning energy stored in the yoke to the power supply during portions of the raster cycle, power efficiency is substantially enhanced.

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 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: A vertical compensation circuit for a digital TV receiver having a vertical drive signal that is insensitive to changes in CRT beam current includes a variable gain amplifier and means for sensing changes in B+ operating potential that track changes in CRT high voltage which is related to CRT beam current. The voltage sensing means detects a change in B+ operating potential and applies a voltage indicative of that change to a feedback circuit for changing the feedback level on a variable gain amplifier to which the vertical drive signal is applied.

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: The output of a deflection operational amplifier is coupled through a dissipation circuit to a deflection yoke coil of a stroke written cathode ray tube for deflecting an electron beam on the tube screen. A feedback circuit is coupled between the coil and the inverting input of the amplifier to control the current through the coil. The dissipation circuit comprises a dissipative resistor, such as an incandescent lamp, and a shunt connected bypass capacitor. The dissipation circuit dissipates power during coil steady current conditions such as exist during slow movement or hold of the electron beam on the screen when voltage across the coil is low but coil current may be high. Thus the power otherwise dissipated in the amplifier output transistors is dissipated in the dissipation circuit. The bypass capacitor passes high frequency deflection signals to the coil during coil high instantaneous current conditions corresponding to fast movement or slewing of the electron beam on the tube screen.

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: 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: The initiation of the flyback interval of a variable format CRT display system is controlled by a frequency independent closed loop compensation circuit. The termination point of a sawtooth pulse, which is initiated at the start of the horizontal sync for the CRT display system, determines the point for the initiation of the flyback interval. The termination point of the sawtooth is compared with the center of the flyback interval. So long as the flyback pulse is perfectly centered on the termination point, the timing is proper. However, if it is off-centered, circuitry results in delaying or advancing the turning off of the horizontal yoke driver to modify the initiation of the flyback interval in a manner to compensate for the change in delay.

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 circuit for generating a deflection current through the field deflection coil of a picture display device having a sawtooth generator, a combining stage, a multiplying circuit and an amplifier. Applied to the combining stage is a sawtooth signal generated by the sawtooth generator and a sawtooth signal originating from feedback. The combining stage generates three linear combinations of these input signals. Two linear combinations are applied to the multiplying circuit for obtaining a parabolic signal which is applied to a signal input terminal of the amplifier, whereas the third linear combination is applied to the feedback input terminal of the amplifier. The series arrangement of the deflection coil and a separating capacitor is coupled to the output terminal of the amplifier, a feedback network being included between the said series network and the combining stage.

Abstract: A Raster and Stroke Writing Deflection Amplifier Arrangement for a cathode ray tube (CRT) is disclosed which uses a conventional vertical oscillator and vertical deflection amplifier and a conventional horizontal oscillator and synchronous horizontal deflection amplifier, both driving deflection coils for providing vertical and low power horizontal scan operation for raster scan writing of data, and a flyback transformer and rectifier for providing the high D.C. voltage required by the CRT anode by rectification of high surge voltages created during horizontal retrace periods.

Abstract: A ramp generator comprises an integrating capacitor and a current source connected to the capacitor to charge the capacitor and thereby generate a ramp signal. A switching device is connected to the capacitor and is operative to discharge the capacitor periodically in response to a periodic control signal applied to a control terminal of the switching device. A comparator has a first input terminal connected to a peak detector, which detects the peak value of the ramp signal, and a second input terminal connected to receive a reference voltage. The comparator compares the peak value of the ramp signal and the reference voltage and is connected to the current source to control the rate of supply of current to the capacitor in response to the comparison result so as to maintain a predetermined relationship between the amplitude of the ramp signal and the reference voltage, independently of the frequency of the control signal.

Abstract: Selected additional voltages are utilized to modify the respective horizontal and vertical sawtooth waveforms which generate the horizontal and vertical electron beam scans in a photoelectric tube. The added voltages are selectively applied during the respective horizontal and vertical blanking intervals, whereby the speed of the scan is doubled, tripled, etc., during the blanking intervals. Since the time available during blanking is still the same, increasing the speed of the beam scan causes the beam to scan correspondingly further into the non-scanned target portion. Thus, corresponding greater distances into the surrounding target are discharged which, in turn, circumvents charge bleeding into the active picture area, thereby precluding edge hooking.

Abstract: The magnetic deflection sweep amplifier includes a first switch, such as a MOSFET in series with a deflection yoke. The switch is controlled by a second switch, such as a bipolar transistor, and the second switch is able to selectively control the first switch, whereby the yoke current can be reversed, to provide complete flyback, or can be truncated part way through flyback to stop the retrace at an intermediate position. The flyback amplifier also has provision for linear operation without flyback. The present invention accomplishes the foregoing with very few parts and with very little power consumption.

Abstract: Electronic apparatus and method is disclosed for generating a linearity correction signal for use in or with a CRT electron beam deflection circuit. In a preferred embodiment, transistor is used to vary the parameters of a multiple feedback infinite gain bandpass filter such that the filter is essentially on the point of oscillation during trace, but is highly damped during retrace.

Abstract: A vertical frequency deflection signal generator includes a comparator whose output is coupled to a capacitor the voltage across which constitutes the vertical deflection voltage. The capacitor is charged from a voltage source in the vertical trace interval and discharged when the comparator output switches to ground potential, i.e. when the voltage at the inverting input of the comparator is greater than the voltage at the direct input. To synchronize such a vertical deflection signal generator to vertical synchronization pulses derived from an incoming television signal, the vertical synchronization signals are applied to the base of a transistor whose emitter-collector circuit is connected to the comparator output through a resistor. Each received vertical synchronization signal therefore causes a slight decrease in the output voltage of the comparator and, because of a feedback resistor, a corresponding decrease at the direct input of the comparator.

Abstract: A deflection coil driver includes a current driver stage comprising three power transistors, a first power transistor being caused to turn on via a class B transistor stage when an input signal of a first polarity is input to the class B stage, second and third power transistors being caused to turn on via said class B stage when the input signal has an opposite polarity. When turned on, the first power transistor couples current from a positive voltage source to the deflection coil, the second power transistor couples current from a negative voltage source to said coil, and the third power transistor couples said coil to ground. A transistor switch determines whether the second or the third power transistor is on, as a function of the voltage across the deflection coil. The current through the coil is also sensed and provides negative feedback to an input amplifier to ensure that the shape of such current matches the shape of the input signal.

Abstract: A circuit for increasing the stability of a sawtooth signal in regard to thermal drift comprises a conventional generator whose output is controlled by a loop circuit constituted by a switch controlled in opposition with respect to a switch connected in shunt on an integration capacitor, a low-pass filter having a cut-off frequency determined to select substantially the d.c. component and an operational amplifier network for determining the gain of the loop circuit which consequently produces a voltage corresponding to the mean value of the signal. The direct-current voltages and the passive components are so determined that the mean value of the sawtooth signal preferably corresponds to the reference zero potential.