Vertical deflection frame sweep circuit - has reverse counter filled with successive binary words which triggers each sweep at end of count down to zero from each number

摘要

The switched mode sweep circuit has a saw-tooth waveform generator (2) which derives the saw-tooth waveform from the linesweep return signal at a line transformer secondary and applied it to a vertical deflection coil load (1). The generator includes a parallel diode and thyristor (D,TH,) opposition and in series with the secondary. The thyristor is triggered immediately before the start of each line sweep return by a signal from a flip flop (D) triggered by a control signal (S) from a reverse counter. The control signal is generated when the counter counts down to zero from a preset binary number fed into the counter. The binary numbers are successively fed at the rate of the line return pulses from a dead memory which is programmable by a calculator and image sensor to provide an improved image.