This lockable two-position servo control system was found in documentation from the 1990s. The error amplifier can be an operational amplifier and the sensors are phototransistors.
The correct connection of speakers and tweeters in a speaker to obtain better sound quality,...
This circuit with germanium transistors was found in a Mullard manual from 1960. The components depend...
This circuit was found in a Popular Electronics from the 90s. The components admit equivalents and the...