Rca Inc.

Thomson Consumer Electronics Inc.

Thomson Licensing S.a.

Thomson Licensing

Rca Licensing Corporation

Robert Joseph Gries

James A Wilber

Ronald E Fernsler

Wolfgang F Dietz

Kevin Michael Williams

Jeffery B Lendaro

David Ross Jackson

Leroy W Nero

John Charles Peer

Frank S Wendt

William Benjamin Aaron

Marvin N Norman

Robert Goah Watson, Iii

Snehali Choksi

Babah Shahbender

Irwin Gordon

Sandor Miko

Calvin E Conn

A video display includes a scanner operable at a first frequency and a higher second frequency. A switch mode power supply drives a transformer with three secondaries. First and second rectifiers & filters are associated with the first and second secondaries. A rectifier is coupled to the third secondary and by way of a switch to the first filter. Feedback from the first filter controls the SMPS. In a first operating mode, the scanner is operated at the first frequency, the switch is open, the scanner supply is a first voltage from the first filter, and ancillary equipment is supplied with a third voltage by the second filter. In a second operating mode, the scanner is operated at the second frequency, the switch is closed, the scanner supply is a second voltage, higher than the first, from the first filter, and ancillary equipment is supplied with the same third voltage.

Deflection supply voltage feedback control in conjunction with frequency change

An autotransformer steps up the output of a high voltage amplifier for applying a drive signal to the focus electrode of a CRT. A parabolic signal is obtained or generated at a deflection frequency such as the horizontal scanning frequency and is applied as an input to the amplifier. The amplifier output is coupled to a center tap of the autotransformer. One winding is serially coupled to the focus electrode and the other winding is AC coupled by a capacitor to ground, in parallel with the amplifier output. The transformer steps up the amplifier output voltage and can reduce the voltage rating required of transistors in the amplifier.

Dynamic focus amplifier output with step-up autotransformer

A dynamic focus voltage generator includes a source of a flyback input signal at a horizontal deflection frequency. A double integrator is responsive to the input signal for generating a parabolic periodic signal. An amplitude detector is responsive to the parabolic periodic signal for generating a control signal that is indicative of an amplitude of the parabolic periodic signal. A comparator is responsive to a signal at a reference level and to the control signal and coupled to the double integrator for regulating an amplitude of the parabolic periodic signal in a gain control negative feedback manner. A non-linear network is responsive to the parabolic periodic signal for producing a bathtub shaped output signal that is coupled to a focus electrode of a cathode ray tube.

Dynamic focus voltage amplitude controller

A horizontal oscillator, responsive to an on/off control signal, generates an output signal that is coupled via a driver stage to a control terminal of a horizontal deflection output transistor. During a transition interval that follows a standby mode of operation, the duty cycle of the oscillator output signal is reduced relative to when a run mode of operation occurs to provide soft-start operation.

Slow turn-on in a deflection circuit

A boost capacitor has a first terminal that is coupled to a retrace capacitor of a horizontal deflection circuit. A diode couples a trace voltage in an S-shaping capacitor to the boost capacitor to charge the boost capacitor during trace. A second diode rectifies a voltage that is equal to the sum of the boost capacitor voltage and a retrace voltage developed in the retrace capacitor for generating a screen grid voltage for a cathode ray tube.

Voltage booster for CRT electrode supply

A horizontal deflection system comprises a horizontal deflection yoke and a resonant retrace circuit coupled to the yoke and to a switched energy source for generating a horizontal deflection current in the yoke. A diode modulator is coupled to the resonant retrace circuit. A control circuit operable in a switched mode supplies a control signal to the diode modulator for modifying the deflection current to correct for side pincushion distortion. A transformer has a first winding coupled to the diode modulator and to the control circuit for recovering energy from the diode modulator. The transformer has a second winding for receiving the recovered energy from the first winding. A diode clamp is coupled to the second winding and to a load driven by a voltage source at a first voltage level, for transferring the recovered energy from the second winding to the load. The energy is transferred from the first winding to the second winding at a second voltage level across the first winding determined by the first voltage level and the turns ratio of the transformer. The second voltage level defines an effective voltage clamping level and is related to the operating range of the diode modulator. The second voltage level can be adjusted to levels different from the first voltage level by changing the turns ratio of the transformer.

Transformer coupled voltage clamp for pincushion correction circuit

An on-screen character display system includes a tri-state character generator for generating a tri-state character signal having black portions corresponding to the leading and trailing edging portions of the character and a white portion corresponding to the body of the character and an inactive level when no character is to be displayed. To prevent the shielded cable used for coupling the tri-state character signals to video signal processing circuit from remaining charged to the black level corresponding to the trailing edging portion too long thereby creating a disturbing inequality between the widths of the edging portions, an auxiliary driver circuit is enabled to drive the shielded cable toward the inactive level when the character is supposed to end.

Tri-state on-screen display system

A ferroresonant power supply having a relatively temperature stable output voltage includes a saturating magnetic element having a magnetizable core and a winding located thereon. A magnetizing current is developed in the winding by a high frequency source of alternating input voltage for generating an alternating magnetic flux in the magnetizable core that links the winding so as to develop an alternating polarity output voltage. A capacitor develops a circulating current that generates a magnetic flux in a core section associated with the winding that aids in magnetically saturating the core section to provide regulation of the alternating polarity output voltage by means of ferroresonant action. In order to temperature stabilize the output voltage, the magnetically saturating core section of the magnetic element is formed of a ferrospinel comprising a lithium ferrite or a substituted lithium ferrite. The lithium cation containing ferrospinels have desirable magnetic properties of a relatively small change in saturation flux density with temperature and, when properly manufactured, a low coercivity which results in a relatively small temperature rise above ambient temperature in the saturating element. When the ferroresonant power supply is used to generate an ultor voltage for the picture tube of a television receiver, the regulated alternating polarity output voltage may be stepped up and rectified to provide a regulated DC ultor voltage that is relatively temperature stable.

Television receiver ferroresonant high voltage power supply using

A source of high frequency alternating input voltage is coupled to the primary winding of a high frequency low voltage ferroresonant transformer of a television receiver power supply. A capacitor is coupled across the secondary output winding of the ferroresonant transformer, and generates a circulating current that magnetically saturates the secondary core portion of the transformer to regulate the alternating polarity output voltage developed across the secondary output winding. A step-up high voltage transformer includes a primary winding and a high voltage secondary winding tightly coupled to the step-up transformer primary winding. The regulated alternating polarity output voltage developed by the low voltage ferroresonant transformer is coupled to the primary winding of the step-up high voltage transformer without prior DC rectification of the ferroresonant transformer output voltage. The applied, regulated ferroresonant transformer output voltage develops a regulated high voltage across the step-up transformer high voltage secondary winding. A high voltage rectifier arrangement develops an ultor voltage from the regulated high voltage.

Television receiver high frequency regulated power supply including a

An electronic regulator produces a regulated direct voltage less than the raw direct voltage input. The load on the regulated output is the primary winding of the horizontal output transformer of a television horizontal deflection circuit. A secondary winding of the output transformer is connected in series with the source of raw direct voltage. An energy storage capacitor is coupled across the secondary winding, and charged therefrom by a gated rectifier. The regulated output voltage is taken across the raw direct voltage source and capacitor. An overvoltage protection circuit for protecting against fault conditions is provided. The protection circuit includes a diode coupled between the regulated output voltage terminal and the raw input voltage terminal. The diode is normally back-biased and becomes conductive when a fault condition makes the regulated voltage exceed the raw input voltage. A resistor in series with the secondary winding controls circulating currents in the event of an overvoltage fault.

Overvoltage protected de-boost regulator

In a television deflection system employing a first SCR for coupling a deflection winding across a source of energy during a trace interval of each deflection cycle and a second SCR for replenishing energy to the source of energy during a commutation interval of each deflection cycle, a gating circuit for triggering the first SCR. The gating circuit employs a voltage divider coupled in parallel with the second SCR which develops gating signals proportional to the voltage across the second SCR.

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Indianapolis, IN, United States of America

Robert Joseph Gries