GB1421988A - Toroidal deflection yoke having conductors wound in flyback manner - Google Patents

Abstract

1421988 Deflection coils for cathode-ray tubes RCA CORPORATION 21 Feb 1973 [28 Feb 1972] 8453/73 Heading H1D A toroidal deflection yoke, e.g. for a colour cathode-ray tube comprises a pair of horizontal and a pair of vertical deflection coils wound on a hollow flared core, the turns being applied so that they occupy a single layer at the wider end of the core and a double layer at the narrow end, the coils being wound by taking a conductor around the core with the turns close together at the narrow end and spaced apart at the wider end, this being done for several turns and then the conductor is taken back in a fly-back manner on the outside of the core and further turns are applied to fill in the spaces between the conductors at the wide end and on top of the earlier turns at the narrow end. A typical winding pattern is shown in Fig. 3. The turns of coil 1 are indicated by lines between the numbered circles and those of coil 2 by lines between numbered triangles. Solid lines are portions of turns on the outside of the core and a few internal portions are shown as dotted lines, it being understood that all circles or triangles of like number are connected by such internal turn portions. In this Figure, the flyback turn is made after alternate turns but in Fig. 4 (not shown) seven turns are made before the fly-back. After turn 15, Fig. 3, a gap is left in coil 1 to accommodate coil 2 to obtain the required turn distribution, coil 2 being wound in a pattern similar to coil 1, i.e. with fly-back turns after alternate turns. This method of winding deflection yokes is said to require less operations in the winding machine than the conventional method of winding continuously around the core and cutting the wire to form the separate coils.