This circuit, with printed circuit board included, is from a Radio Electronics magazine from July 1971. The SCR can be any equivalent of the 106 series.
This circuit was obtained in a documentation of the 80s, using operational of the time. The...
In the figure we have a third fast adder that we found in an 80's Electronic Engineering. The circuit can...
We found this simple music box circuit that can also be used in a musical bell in a 1991...