Current control circuit for horizontal deflection coil of television

Abstract

In a circuit for controlling the current flow through a coil, such as, the horizontal deflection coil of a television receiver, a first switching circuit including a first switching transistor and a first damper diode is connected in parallel with a first resonant circuit including a first capacitor and a first coil which is the coil through which the current flow is to be controlled, a second switching circuit including a second switching transistor and a second damper diode is connected in parallel with a second resonant circuit including a second capacitor and a second coil, a charging capacitor is connected in a common current path for the first and second resonant circuits, and switching signals of the same frequency, for example, the horizontal frequency of a video signal, are applied to the first and second switching transistors with the phase difference between such signals being controlled to vary the voltage across the charging capacitor and hence the current flowing through the first coil. The phase difference between the switching signals is varied or modulated by a parabolic correcting signal having the vertical rate or frequency of a video signal in the case where a side pin-cushion distortion of the raster of a cathode ray tube is to be corrected, or the phase difference can be modulated by a correcting signal corresponding to the electron beam current or anode voltage in the cathode ray tube so as to stabilize the horizontal dimension of the raster.