We found this circuit in a Popular Electronics from the 90s. Its purpose is to monitor a power line. The circuit uses optical couplers of the time.
Found in a 1990s William Sheets, this automatic gain control for audio amplifiers uses...
The power supply shown can supply voltages of approximately 0 V to 12 V with a maximum current of 4.5 A,...
The consumption of this circuit in the standby condition is only 1 uA. The circuit must be...