This circuit is used in transceivers, enabling input selection by diode switching through polarity reversal. The circuit is from an old American documentation on telecommunications.
This basic configuration can be found in a lot of articles on this site. In this case, the relay...
This clipper or limiter circuit limits the amplitude of AM or FM audio signals. The diodes are...
We find this circuit in an old documentation, but it can be made using modern transistors. The circuit...