This circuit was obtained in a 1967 Electronics World. The components are still common today, the SCRs can be replaced by equivalents and the unijunction transistors the 2N2646.
This circuit simulates an inductor. Or operational amplifier of old type, but a configuration is...
This very high input impedance JFET circuit was found in the 1995 Encyclopedia of Electronic...
Found in a 90’s 303 Circuits, this circuit uses components that are still common and has a common...