Abstract: Organ pipes distortions, caused by parasitic ringing in a horizontal deflection current are suppressed by forming a current pulse in a current injection arrangement. The current pulse is coupled to a junction terminal between a terminal of the horizontal deflection winding where a high retrace pulse voltage is developed and a low voltage terminal of a linearity correction inductance. A high voltage terminal of the linearity correction inductance is coupled to a horizontal output transistor. The current pulse begins prior to the end of retrace and ends during the trace interval. A modulation network is coupled across the linearity correction inductance for providing a low impedance current path to the current pulse.

Abstract: An East-West switching transistor is coupled between a flyback transformer primary winding and a horizontal deflection output transistor circuit to control retrace energy to obtain an East-West modulation of the deflection current amplitude as required for East-West pincushion raster correction. The East-West switching transistor isolates a retrace resonant circuit that includes a horizontal deflection winding from a flyback resonant circuit that includes the flyback transformer during a portion of retrace. The deflection winding is coupled to a common conductor to permit the use of a retrace voltage sample, developed in the deflection winding and coupled to the East-West switching transistor, to control the switching operation in a manner that bypasses the flyback transformer. A resistor coupled in series with the primary winding develops a voltage, during trace, that is indicative of beam current.

Abstract: An automatic beam current limiting arrangement of a television receiver or display monitor comprises an average beam current limiter coupled to the low side of the high voltage transformer for reducing the contrast of a reproduced image when the average beam current exceeds a threshold and a peak current limiter coupled to the cathodes of the picture tube for controlling a current source which determines the threshold of the average beam current limiter in response to the sum of the cathode currents of the picture tube. In one embodiment, the cathode current sensing circuits comprise the same cathode current sensing circuits utilized in an automatic black level setting arrangement. This beam limiting arrangement allows operation at high contrast levels while inhibiting excessive peak white areas.

Abstract: A selectable aspect ratio raster is generated on a CRT with a 16:9 aspect ratio screen by a deflection yoke and deflection amplifier. The deflection amplifier is coupled in a non-floating configuration to the deflection yoke. This permits a switching arrangement to control the horizontal deflection amplitude by the selectable addition of inductance in series, with the yoke. The switching arrangement also controls other deflection circuit parameters to provide optimum raster correction at the selected aspect ratio.

Abstract: In a television receiver, an ultor accelerating potential or high voltage for a picture tube is derived by rectifying a retrace pulse voltage developed in a high voltage winding of a flyback transformer. The retrace pulse voltage is developed by a horizontal deflection circuit output stage that is coupled to the high voltage winding via a primary winding of the flyback transformer. The horizontal deflection circuit output stage includes a horizontal deflection winding, a retrace capacitor and a trace switch. The trace switch includes a damper diode and a horizontal output transistor. An energy storage coil is coupled in parallel with a third winding of the flyback transformer during a controllable time interval beginning during the second half of horizontal trace and ending during retrace. The energy stored in the coil during the trace portion is transferred to the flyback transformer during retrace to enhance high voltage at high beam currents.

Abstract: Organ pipes distortions, caused by parasitic ringing in a horizontal deflection current are suppressed by forming a current pulse in a current injection arrangement. The current pulse is coupled to a junction terminal between a terminal of the horizontal deflection winding where a high retrace pulse voltage is developed and a low voltage terminal of a linearity correction inductance. A high voltage terminal of the linearity correction inductance is coupled to a horizontal output transistor. The current pulse begins prior to the end of retrace and ends during the trace interval.

Abstract: An East-West switching transistor is coupled between a flyback transformer primary winding and a horizontal deflection output transistor circuit to control retrace energy to obtain an East-West modulation of the deflection current amplitude as required for East-West pincushion raster correction. The East-West switching transistor isolates a retrace resonant circuit that includes a horizontal deflection winding from a flyback resonant circuit that includes the flyback transformer during a portion of retrace. The deflection winding is coupled to a common conductor to permit the use of a retrace voltage sample developed in the deflection winding as a feedback signal to synchronize the deflection current to the video signal. The arrangement reduces phase modulation of the deflection current as a function of beam current variations, that could be visible as a beam current dependent horizontal picture shift or a raster bending in a horizontal direction.

Abstract: Two windings of a flyback transformer in a horizontal deflection circuit are inductively coupled with opposite polarity to a source of horizontal rate retrace pulses. The windings have a common junction coupled to ground. A circuit energized by the retrace pulses generates modulated currents of opposite polarity. Conduction of each current is controlled by a switch circuit including a semiconductor switch and two diodes. The switch circuits are coupled to one another at a junction, and the junction is coupled to an energy storage capacitance. One of the diodes conducts positively valued portions of the respective current through the energy storage capacitance and the other of the diodes conducts negatively valued portions of the respective current through the semiconductor switch. Each semiconductor switch is a current discharge path.

Abstract: A nonlinear video signal processing system provides gamma correction to improve rendition of picture details near black. In addition, picture brilliance is improved using a brightness and frequency dependent enhancement circuit providing increased detail signal contrast in bright picture areas. In each color channel, the respective color signal is gradually separated into a low level amplitude signal portion and a higher level amplitude signal portion. The higher level amplitude portion is high-pass frequency filtered. The low level signal portion and the high-pass filtered higher amplitude signal portion are added to the original, linear video signal for producing a combined signal coupled to the kinescope. The low level signal portion is DC coupled to the linear signal and the high level signal portion is AC coupled to the linear signal.

Abstract: A deflection switch of a horizontal deflection circuit is coupled to a retrace resonant circuit that includes a horizontal deflection winding and a first retrace capacitance. A flyback transformer primary winding is coupled to a junction terminal of the deflection switch and the resonance circuit. An East-West modulation current is generated by a bidirectional second switch having a conduction time that is phase modulated during horizontal retrace at a vertical rate in a parabolic manner. The second switch is coupled in series with the first switch during the entire trace interval. To prevent an over-current condition when the current in the second switch exceeds a predetermined first level, the second switch is turned off and interrupts the flow of current through the deflection switch.

Abstract: A MOSFET power switching transistor in a DC-to-DC converter of a television apparatus has a drain electrode that is coupled via a primary winding of a chopper transformer to an input supply voltage. A first signal at a given frequency causes, during normal operation, alternate conduction and nonconduction in the transistor. A second signal is generated that is proportional to the voltage developed across the internal "on" resistance of the transistor when the transistor is conductive. The second signal is clamped when the MOSFET transistor is nonconductive. The second signal is coupled via a current sensing arrangement to the transistor gate. The second signal prevents the transistor from further conducting when the amplitude of the second signal exceeds a predetermined value that corresponds with a predetermined limiting threshold level of current in the transistor.

Abstract: A deflection switch of a horizontal deflection circuit is coupled to a retrace resonant circuit that includes a horizontal deflection winding and a first retrace capacitance. A flyback transformer primary winding is coupled at a junction terminal of the deflection switch and the retrace resonant circuit. A second winding of the transformer is coupled to an ultor voltage power supply. To provide side pincushion correction, a second switch, having a conduction time that is phase modulated during horizontal retrace at a vertical rate in parabolic manner, is coupled between ground and a terminal of the retrace resonant circuit remote from the flyback transformer primary winding. The second switch is conductive during the entire trace interval and is turned-off at a controllable instant during the first half of the retrace interval.

Abstract: A diode is coupled to a low voltage end terminal of a tertiary high voltage winding of a horizontal flyback transformer. The diode is back biased during trace and during a portion of the second half of retrace by a voltage that is coupled to the diode through a resistor from a B+ voltage source. When the diode is back biased, the resistor dampens parasitic ringing current in the tertiary winding caused by the leakage inductance of the transformer. During a portion of retrace, occuring prior to the time the diode is back biased, the diode is conductive and bypasses the resistor. This prevents the resistor from increasing the output impedance at the ultor terminal.

Abstract: A power supply includes a source of first and second switching signals that are at opposite phases. First and second MOS power transistors have main current conducting electrodes coupled to a transformer and have gate electrodes that are respectively coupled to the first and second signals to provide push-pull operation. When a transition occurs in a first one of the MOS transistors from a conductive state to a nonconductive state, a voltage is developed at its gate electrode due to its input Miller capacitance. The gate electrode voltage is coupled to a control terminal of a controllable attenuator that attenuates the switching signal that is coupled to the gate of the other MOS transistor. This delays the initiation of the conductive state in the other MOS transistor until immediately after the first transistor becomes nonconductive, thereby avoiding simultaneous conduction in the two transistors.

Abstract: A deflection circuit output stage generates in a deflection flyback resonant circuit a first flyback voltage at a horizontal frequency. A switch generates in a second flyback resonant circuit a second flyback voltage at the horizontal frequency having a phase relative to that of the first flyback voltage that is controllable. The first and second flyback voltages are summed and applied to a voltage tripler that produces an ultor voltage. A control circuit varies the phase of the second flyback voltage in a negative feedback manner that stabilizes the ultor voltage over a wide range of beam current variations.

Abstract: East-West modulated current that is generated in an East-West control circuit is coupled to a deflection circuit output stage via a Class A operated amplifier serving as a current source having a high output impedance during retrace. The current source prevents coupling of a signal at a retrace frequency during retrace between a high voltage winding of the flyback transformer and a retrace resonant circuit that includes the deflection winding. The high output impedance of the amplifier current source during retrace maintains the average value of the modulated current during retrace unaffected by an amplitude of a retrace voltage that is developed in the retrace resonant circuit. In this way ultor voltage loading variation is prevented from causing "mouseteeth" distortions.

Abstract: In a vertical sawtooth generator, first and second capacitors are coupled in series to a first terminal of a switch. When the switch is conductive, the two capacitors are discharged by the switch to form a sawtooth signal at the first terminal having a down-ramping portion that corresponds with a retrace interval. When the switch is nonconductive, the two capacitors are charged by a source of current to form an upramping portion of the sawtooth signal that corresponds with a trace interval. An S-shaping arrangement that is coupled to a junction terminal of the two capacitors includes a third capacitor two resistors and a clamping arrangement that provide S-shaping of the sawtooth signal at both ends of the trace interval and dc restoring prior to the beginning of each trace interval.

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 degaussing circuit for a cathode ray tube, of a video display apparatus includes a resonating capacitor that is charged prior to degaussing. A degaussing coil is disposed about the cathode ray tube. An SCR, responsive to an on/off control signal, is turned on by a control switch for coupling the resonating capacitor to the degaussing coil in order to generate an AC, degaussing current in the coil having an amplitude that diminishes to a low amplitude during a degaussing interval. Positive feedback is used for speeding up the turn-on time of the control switch. A series pass transistor switch couples a source of a supply voltage to a delay network. The series pass transistor switch is coupled in the current path of the current that is supplied by the power supply. An energizing voltage is developed at the output of the delay network.

Abstract: In a deflection apparatus which corrects for inside pincushion distortion, a deflection winding and a retrace capacitance form a retrace resonance 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 an inductance, is coupled to the trace capacitance during the trace interval to form a second resonant circuit with the trace capacitance 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, that is modulated in accordance with the modulated voltage, modulates the trace parabolic voltage across the trace capacitance in a manner to reduce inside pincushion distortion. The trace capacitance acts as a bypass capacitor around the inductance during retrace to prevent the inductance from affecting the retrace voltage.