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 circuit is from an Argentine publication from 1973 but can be assembled with BC558 and BC548...
This two-stage amplifier circuit with RC coupling was obtained in a 1977 Radio Handbook. The...
This control for motors up to 1 A was found in a Siliconix documentation using its own component....