This circuit was found in a 1970 IEEE publication. The circuit functions as a voltage controlled variable resistor and can be used with audio signals. Transistors admit current equivalents.
This circuit can gerenate square signals and be comanded by na external control. When the input...
This circuit is from an American 1967 documentation and can be implemented with modern equivalent...
This circuit was found in 1968 General Electric documentation. The circuit uses components from the era...