In the figure we have a circuit that uses unusual components, being indicated for low frequency applications. The circuit signal is generated by a unijunction transistor that oscillates at 8 kHz.
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...