This circuit was found in the July 1969 Radio Electronics magazine. The circuit controls resistive loads and universal motors with power according to the SCR used.
We found this circuit, which appears with variations on this site, in a European documentation from the...
This circuit that drives an electromechanical counter of the time was found in Radio Electronics magazine...
Found in a Hands On Electronics of the 80s, this circuit makes use of a gas sensor of the time....