Vertical deflection waveform generator

Claim 1

A circuit for producing vertical deflection current for driving tHe vertical deflection coils of a cathode ray tube in which the radius of curvature of the screen is greater than the distance between the screen and the deflection center, said circuit including in combination: a source of sawtooth signals at the desired frequency of operation of said vertical deflection coil; first and second product multipliers each comprising first and second differential switching circuits, each differential switching circuit having first and second transistors with collector, base and emitter electrodes, the emitters of the first and second transistors of each of the differential switching circuits being interconnected, the bases of the first transistor of said first differential switching circuit and the second transistor of said second differential switching circuit in each of said product multipliers being interconnected, the bases of the second transistor of said first differential switching circuit and the first transistor of said second differential switching circuit in each of said product multipliers being interconnected, the collectors of the first transistors of each of said differential switching circuits in each of said product multipliers being interconnected, and the collectors of each of the second transistors in each of said differential switching circuits in each of said product multipliers being interconnected; first and second input transistors in each of said product multipliers, each of said input transistors having collector, base and emitter electrodes, with the collector-emitter paths thereof being coupled respectively in common with the emitters of the transistors in said differential switching circuits; first circuit means coupling said source of sawtooth signals with the bases of at least one of the input transistors of each of said first and second product multipliers; second circuit means coupling said source of sawtooth signals with the bases of the first transistor of said first differential switching circuit and the second transistor of said second differential switching circuit of said first product multiplier; third circuit means coupling the collectors of the second transistors of said differential switching circuits of said first product multiplier with the base of the first transistor of said first differential switching circuit in said second product multiplier and the base of the second transistor of said second differential switching circuit in said second product multiplier; and fourth circuit means coupling the output of said second product multiplier, obtained from the interconnected collectors of the transistors in said first and second differential switching circuits of said second product multiplier, with said vertical deflection coils for supplying deflection current thereto.