This circuit appears on this site from different sources. This is from documentation from the 1980s. The operating system used is uncommon and can be replaced by a more modern equivalent.
This circuit is from an old European documentation, already influencing the unijunction oscillator that...
This circuit for cars of the time was found in a Popular Electronics magazine from the 90s. The...
Found in a Maxim documentation, this 1980s circuit drives 4 LEDs on a bar scale. The circuit does...