Line deflection circuit for a television receiver

In a television receiver, for a linear picture representation in the horizontal direction, the sawtooth-waveform line deflection current is flattened in the sense of S correction by a so-called S capacitor at the beginning and at the end of the line trace period. In the event of a change of the picture aspect ratio, for example for reproduction of a picture with 4:3 on a screen with 16:9 and the greatest possible filling of the screen in the horizontal direction, it is desirable for this S correction to be reduced or completely switched off in order that stretching deliberately occurs at the left-hand and right-hand edges of the picture. The value of the S capacitor would have to be increased for this purpose. Enlarging the S capacitor by supplementarily connecting a further capacitor is difficult to realize owing to the high values of these capacitors. It is an object to provide a simple circuit for changing over the linearity, which operates without changing over the S capacitor and in the case of which the inner pincushion equalization is not impaired. This is achieved by virtue of the fact that a frequency-dependent network tuned approximately to the line trace period, the said network being in the form, in particular, of a series resonant circuit having an inductance (L1) and a capacitance (C1), can be connected in parallel with the S capacitor (CS1). This network changes the voltage (UC) across the S capacitor (CS1) in such a way that the S correction appreciably decreases and desirable line stretching occurs at the left-hand and right-hand edges of the picture.