Integrated signal generator appeared in Radio Electronics magazine in January 1968. The integrated circuits are from the time and the generator produces signals from 5 Hz to 50 kHz.
Found in na 1970 EDN this circuit has a parallel regulation providing a symmetrical output of 15 V....
This configuration found in a 1976 publication can be elaborated with more modern operational...
This ultra-simple meter uses an output transformer and a small speaker as a microphone. The...