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.
The operational amplifier used in this circuit is not common today, but it can be implemented with...
This circuit is used to test triacs. It can be connected in series with a resistive load such as...
In the figure we have the configuration of a transistor as a temperature sensor. The circuit is...