Compensated linearity regulator for TV line sweep - uses additional winding to modify inductance of regulator coil in dependence of display frequency current

摘要

A linearity regulating stage for line sweep control in television receivers, compensates for the residual error at the top and bottom edges of the screen. The line stage (1) generates a saw tooth waveform signal to a line sweep stage (2) line sweep coil (3) and the coil (Sp) of a linearity regulator (4). The core is pre-magnetised with the aid of a permanent magnet (M). An additional winding (W) providing the necessary compensating effect is coupled to the output of two complementary transistors (T1, T2) in a vertical sweep stage (5). The coupling is effected over two chokes (Dr1, Dr2). The triangular sweep current to the vertical coil (7) exhibits a steep front for fast return and a slow linear sweep.