In the figure we have a good rectangular signals generator with several frequency bands. The circuit is based on old logic but can be implemented with modern equivalents.
Found in old documentation, this circuit uses special discharge lamps (neon) of the time. The...
This 1968 Texas Instruments circuit uses diacs of the era. SCRs can be modern equivalents according...
This circuit is designed to measure very weak currents, in the order of picoamperes. We found it...