Circuit arrangement for a picture display device for generating a

Abstract

A circuit arrangement for a picture display device for generating a sawtooth-shaped line deflection current, at least two controllable deflection switches which are switched at line frequency and are arranged in series. As a result thereof the line deflection coil is connected to a trace capacitor during the trace period. During the retrace period the two switches are rendered non-conductive substantially simultaneously and the coil, the trace capacitor and a retrace capacitance form a resonant network the elements of which determine the duration of the retrace period. Supply energy is supplied from a supply voltage source by means of a supply winding which is divided in at least two winding portions which are each connected by means of one end through a supply diode to the resonant network and by means of the other end to a deflection switch and are coupled to the source via a controllable supply switch, which switches at the line frequency. During at least a portion of the trace period the supply switch is in the conducting state while the supply diodes are non-conducting and are non-conducting during the remaining portion of the line period while the supply diodes conduct. The conduction period of the supply switch may be adjustable to adjust the amplitude of the deflection current and also to stabilize this current versus fluctuations of the supply voltage. The said amplitude does not depend on the line frequency.