1513181 Cathode-ray tube circuits LICENTIA PATENT-VERWALTUNGS GmbH 4 July 1975 [10 July 1974] 28220/75 Heading H4T In a known EAST-WEST pincushion distortion correction circuit employing a diode modulator including diodes 8, 9 (Fig. 1) connected in a bridge circuit including (auto) transformer 11, impedance 12, the magnitude of which is varied by a field frequency waveform 14 and a winding 15 on the line transformer 4, correct operation requires that, to prevent the diodes effecting peak rectification, a D.C. consuming load (e.g. load 19) be connected to terminal 18. The present invention connects this terminal via resistor 20 to the operating voltage terminal 21 of the line output stage which, when U 2 is arranged to be higher than U, (by suitable selection of tapping 17 or the transformer 11), acts as the consuming load which thus receives a boost voltage. Fig. 2 shows a first modification in which the (auto) transformer 11 of Fig. I is replaced by a double wound transformer and Fig. 3 shows a modification in which the resistor 20 is connected via a diode 24 to a suitable tap 25 on the line transformer 16. The operating voltage for the video output stage of the television may also be supplied from terminal 18.
展开▼
