This circuit consists of two stages that each shift 180 degrees the signal. The circuit was proposed by Siliconix in a 1966 publication. Equivalent FETs can be used.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...