This circuit was found in documentation from the 1970s. However, it can be implemented with modern transistors such as 2N2222 for Q1 and BF494 for Q2. The crystal depends on the desired frequency.
This is a circuit that should not be used for readers interested in a fair game. The circuit...
This interesting idea was obtained in a 1982 documentation and can be used for special effects in...
We found this circuit in an old publication from Argentina. The relay must be of the sensitive type,...