In the figure we have two circuits of limiters that provide the cut of the negative peaks of a signal. The circuit is from an 80's telecom documentation being adaptable on common receivers.
The component used in this regulator is not common today. The switching circuit is from an 80's...
This analog frequency meter for low frequencies was found in Radio Electronics magazine from July...
This circuit was obtained in a 1970 EEE and applies to almost any operational amplifier. The...