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.
This circuit is from a 1977 publication, serving to produce sound effects in games, as it is...
This circuit measures the RF power of oscillators and small transmitters in the range of 0.05 to...
This ring circuit was found in the April 1959 Radio Electronics magazine. The capacitors are...