Amplifier gain control device - changes its gain in series of discrete steps, and uses amplifier with feed-back to set gain level

摘要

The feed-back circuit contains several resistors which are connected in series and whose resistances are chosen to follow a binary series. There is a selector circuit which is connected to each resistor in order to disconnect it from the feed-back circuit; an operating device responding to control signals operates the selector circuits, changing the feed-back circuit resistance in discrete steps from zero to a maximum value. The feed-back circuit may be used in an aircraft control system in which an amplifier or a pilot control input (10, 16) is fed to a logic circuit and also to an appropriate digital mixing network.