This simple SCR control was found in the December 1987 issue of Radio Electronics magazine. The circuit uses a well-known C106 but can be used in equivalents of the same series.
In the figure we have a bistable multivibrator using an operational one. The circuit is from old...
This is another of the Star Trek red alert circuit that you can find on this site. We took this...
This circuit for testing zener diodes by lifting their curve on an oscilloscope was presented in...