This anti-bounce circuit was found in a 1967 US documentation. Modern transistors such as the 2N2222 can be used. The circuit acts as a shield.
The circuit illustrated in Figure allows external loads (8) to be driven from parallel port...
This circuit uses two transistors to simulate the action of an SCR on a regenerative switch....
The filter presented is from 1994 but can be implemented with a more modern equivalent. We found...