Dynamic focusing circuit, picture display device and method of generating a dynamic focusing voltage

The invention relates to a dynamic focusing circuit comprising a transformer with a primary winding for receiving a line-frequency deflection current and a secondary winding for supplying a transformed deflection current, and an integrator, coupled to the secondary winding, for generating a line-frequency focusing voltage from the transformed deflection current. A dynamic focusing circuit includes a transformer with a primary winding for receiving a line-frequency deflection current and a secondary winding for supplying a transformed deflection current. An integrator, coupled to the secondary winding, generates a line-frequency focusing voltage from the transformed deflection current. A waveform generator coupled to the secondary winding generates an additional line-frequency focusing voltage and superimposes the additional line-frequency focusing voltage on the line-frequency focusing voltage.