Abstract: A sync regenerator is provided which regenerates synchronizing information signals having a varying amplitude and width by comparing the sync signals in a comparator circuit to which a source of reference potential is applied. The comparator output signal of fixed amplitude is pulse width detected and the value of the detector output voltage is coupled by a feedback circuit to the reference potential source to vary the reference potential so as to maintain the width of the comparator output signal constant. The regenerated sync output signal is of constant amplitude and constant width.

Abstract: A video blanking circuit is provided which inserts a system blanking interval signal having controlled leading and trailing edges into a video signal. The blanking signal is combined with a clamped video signal in a first non-additive mixer which also provides a white clip level. The output of the first non-additive mixer is further coupled to a second non-additive mixer in which black level excursions are clipped so as to provide an output video signal having a proper system blanking interval into which synchronizing information may be added to complete the composite video waveform.