This circuit was found in the February 1980 issue of Radio Electronics magazine. The digital circuit was shown in two parts, using 20 LEDs in a configuration with the LM3914.
The frequency of this Pierce oscillator, found in 1969 documentation, depends on the crystal. The...
This simple timer with unijunction transistor was found in an old American technical...
Found in documentation from the 1960s, this power supply employs germanium diodes from the time....