The circuit transistors, found in a 1974 documentation, may be the BC548. The circuit is used in quadriphonic systems to combine signals.
This circuit safely replaces common locks, since, instead of the key, the opening is made with the...
Based on operational amplifiers of the time, this circuit from the 1980s has high input impedance. The...
Sine signals are converted into square signals by this simple circuit. The maximum frequency is...