Gte Sylvania Incorporated

Jesse H L'Hommedieu

Martin Fischman

In a color cathode ray tube deflection apparatus having a deflection yoke with horizontal, vertical and quadrupole windings and affixed to a color cathode ray tube, a quadrupole convergence circuit includes a quadrupole winding coupled to a source of substantially parabolic-shaped horizontal and vertical frequency signals and coupled by a signal clamping circuit which is, in turn, shunted by an impedance varying in proportion and an opposite direction to variations in the impedance of the clamping circuit as determined by the value of the substantially parabolic-shaped vertical frequency signal whereby convergence at the corners of a cathode ray tube is enhanced.

Quadrupole convergence circuit

A horizontal deflection system with a transformer coupled driver including separate turn-on and turn-off drivers coupled to first and second input windings of the driver transformer is shown. The output winding of the driver transformer is loosely coupled to the first input winding to provide a sawtooth drive current to the horizontal output transistor sufficient to maintain the horizontal output transistor in saturation without wasting excessive power. The output winding is tightly coupled to the second input winding to provide a sharp turn-off pulse to the horizontal output transistor.

Horizontal deflection system

A horizontal deflection system with a transformer coupled driver including separate trace and retrace drivers coupled to an input winding or windings of the driver transformer is shown. A feedback or pulse forming means is connected from the transformer to the input of the retrace driver for providing a pulse to the retrace driver in response to termination of the trace drive signal by the trace driver.

A vertical deflection system including a driver circuit energized by a voltage source having a sufficient magnitude to provide a trace deflection signal to the vertical deflection winding and a retrace voltage source switched into the circuit with the vertical deflection winding to provide adequate voltage for effecting vertical retrace of the electron beam deflection in a cathode ray tube is disclosed.

Vertical deflection system

A self-regulating horizontal deflection system with feedback indicative of the magnitude of an unregulated voltage source and of load variations to pulse width modulate the output of the horizontal oscillator is shown. Separate turn-on and turn-off drivers are transformer coupled by separate primary windings to the horizontal output transistor to optimize the driver stage and conserve power.

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Waterloo, NY, United States of America

Jesse H L'Hommedieu