This circuit with unijunction transistors was found in a documentation from the 80's. The trigger times of the SCRs depend on the capacitors and are adjusted in the 5M (4M7) potentiometers.
This non-inverter circuit was found in a Radio Electronics. It shows the basic configuration of a...
Found in a Popular Electronics from the 1990s, this circuit monitors the voltage of a power supply...
This circuit has more historical value than practical, unless the reader find all the components...