Video output stage using earth as black level - uses single polarity operating voltage to drive amplifier stage

摘要

The output stage has an amplifier stage (10, 140) for adapting a video signal power to the requirement of the appts. in which it is installed. The amplifier stage (10, 140) is supplied by an operating voltage of only a single polarity. The cold end of the outlet (80) of the output stage is at the voltage level of the black level of the video signal. The amplifier stage (10) may be a differential amplifier set at a reference value which is a proportion of the operating voltage so the synchronising voltage is kept at the reference level. ADVANTAGE - Reduces cost of power supply by using single working voltage.