Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.