GB1253475A - Wide angle deflection yoke for a colour television tube - Google Patents

Abstract

1,253,475. Election beam deflecting apparatus. GENERAL ELECTRIC CO. 6 Jan., 1970, [15 Jan., 1969], No. 682/70. Heading H1D. A wide angle deflection yoke for use with a colour television tube using three co-planar beams and adapted to scan the beams over similar pin-cushion shaped rasters on the screen, comprises a generally cylindrical ferrite core on which are wound toroidal main and additional horizontal and vertical deflection coils which are wound in two layers over most of the circumference of the core. Viewed in section, Fig. 1 (not shown), the main horizontal deflection coil is wound anti-clockwise round the core from about 11 o'clock to about 7 o'clock and is connected in series with an additional winding extending anti-clockwise from 10 o'clock to 8 o'clock; similar windings are provided on the other half of the core. The main vertical deflection coil is wound clockwise from 10 o'clock to 2 o'clock and the additional winding is wound from 9 o'clock to 3 o'clock. The turns distribution of a quadrant of the horizontal deflection coil may follow the equation where Y H is the total number of turns and # the angle measured from 6 o'clock. The equation for the vertical deflection coil may be measured from 9 o'clock. There may be 52 turns/quadrant in the horizontal deflection coil and 66 turns/quadrant in the vertical coil, and 85% of the core may be covered by a double layer of windings. The mid-points of the horizontal and vertical winding systems may be connected together and connected to earth via a capacitor (Figs. 5 and 6, not shown).