Generator for producing a d.c. supply voltage in a television receiver comprising a vertical scanning circuit
AssigneeThomson-Brandt
InventorsJoseph Colineau, Gerard Rilly
Life of this patent
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Abstract
The current which passes through the vertical deflector of a transistorized color television receiver is produced by a circuit comprising an active switch controlled and modulated at the line frequency and supplied by line retrace pulses delivered by the secondary winding of a line transformer. The voltage at the terminals of an assembly compring a capacitor in series with the vertical deflector has a constant sign which is independent of the current passing through the deflector. The same secondary winding of the line transformer supplies both the vertical scanning circuit and a rectifier circuit for producing a d.c. voltage, in particular for the supply of video amplifiers.
Claims5
A generator for supplying a d.c. voltage, especially to the amplifiers of the video stage in a television receiver, comprising a vertical scanning circuit in which the power for producing the current which passes through the vertical deflector is drawn solely from a cicuit supplied by means of line retrace pulses delivered by the secondary winding of a transformer, a capacitor in series with the vertical deflector being such that the voltage at the terminals of the assembly comprising said deflector and said capacitor has a constant sign which is independent of the direction of the current flowing through said deflector, the circuit being provided with an active switch which comprises a diode mounted in parallel, but in the opposite direction, with respect to a thristor or a transistor, said active switch being controlled and modulated at the line frequency, and wherein a rectifier circuit comprising a diode in the same direction as the diode of the active switch is connected to and is powered by said secondary winding of said vertical scanning circuit in order to deliver said d.c. supply voltage.
Dependencies are inferred from the claim text.