This circuit controls the passage of the signal from one speaker to another. The potentiometers must be of wire 50 to 100 ohms with dissipation according to the power of the sound system.
The phototransistor can be of any type and the adjustment potentiometer 4M7. This circuit was...
We found this circuit in a Popular Electronics from the 90s. Its purpose is to monitor a power...
This configuration can be made based on other operational amplifiers. For other frequencies, the...