This circuit was found in a RE Experimenter Handbook from the 90's. The components are of the time, rare nowadays, except the 555 and 4017.
It can be obtained from Mouser Electronics, sensors (receivers) transmitters and benders for...
Suggested by General Electric in a 1965 documentation, this circuit can use the TIC106 as an SCR....
The circuit shown is from the 1994 Linear Applications Handbook from National Semiconductor. The...