This circuit is from a documentation from the 70s. The circuit uses logic gates of the time, which in many cases were arrays of transistors allowing use as audio amplifiers, as in this case.
The circuit in the Multisim Blue simulation sources a regulated voltage to loads up to 50 mA. The...
This circuit was found in a PC documentation from 1996. It can be used as a shield with modern...
Based on 74HC digital circuits, this circuit generates signals in three phases. The frequency...