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.
In the figure we show how to use an LM324 as a voltage comparator the reference voltage is...
We found this circuit in a 1964 Electronic Design. It provides 0.5 V signals from 4 kHz...
This circuit is from a 1992 documentation, but the components used can still be easily assembled. The...