This two-digit timer was found in the 1983 Special Projects issue of Radio Electronics magazine. The circuit uses components that can still be found today.
This is the patent for the zener diode regulator circuit by David B. Dean of Austin published in...
This simple 10-position roulette circuit with the 4017 found a 1987 documentation. The circuit can...
This circuit was found in a 1986 documentation. The circuit has a common configuration with the...