HORIZONTAL POSITION AUTOMATIC CONTROL CIRCUIT OF MULTI-SYSTEM

摘要

This circuit fully automatically holds the horizontal position of the frame when various transmission systems are received. The retrace pulse of the retrace transformer is supplied to a sawtooth-wave integrator which is constructed of a resistor and two capacitors. A direct voltage of a 50/60-Hz discriminator is superimposed on the output of the integrator at a node via a diode and a resistor. The 50/60-Hz discriminator prevents the vertical synchronisation difference of the different radiated systems from changing the size of the vertical frame.