Home Projection Television: Part III. Deflection Circuits

High-efficiency magnetic deflection circuits which are equally adaptable to projection and direct-viewing television receivers, and a method of obtaining perfect interlace by utilizing the first serration in the vertical synchronizing signal, are described. The horizontal output stage comprises a power-output tube and an "efficiency diode." It is shown that the latter can be used in such a way that it effectively improves the power economy, suppresses spurious oscillations, and improves the sweep linearity. The vertical output stage is coupled to the deflection coils by means of a transformer, which, for reasons of power and space economy, is allowed to introduce considerable distortion of the sawtooth current wave shape. This distortion is compensated by a phase-correcting network in the grid circuit of the output tube. The deflection coils are wound in a flat layer with tapered cross section, and are afterwards bent to shape. A newly developed low-loss magnetic ferrite material has been advantageously utilized in the horizontal-deflection circuit.