Video components measuring appts. esp. for black level - has auxiliary amplifier similar to main signal amplifier switched in parallel with regulating voltage fed to both from regulator circuit

摘要

Separate signal amplifiers, are connected to a common analyser (A). At least one of these amplifiers (V1) has a switch (S1) to disconnect it from the analyser (A). Parallel to this amplifier (V1), a similarly dimensioned auxiliary amplifer (H1) has an associated control circuit (R1) connected to a selected part of the video signal whose control voltage (U) is sent to the auxiliary amplifier (H1) as well as the associated signal amplifier (V1). USE/ADVANTAGE - Separately analysing components of video signals e.g. red, green and blue signals using simple and inexpensive structure reducing cross-talk between signal amplification and can be quickly switched between outputs of signal amplifiers.