Simulation of Controlled Sources Using Operational Amplifiers

By using feedback around an infinite-gain controlled source four finite-gain controlled sources may be simulated. Cascading two of these yields other types of controlled sources. New configurations are obtained by compensating imperfect controlled sources and also by using a negative resistance in the feedback loop. By making use of the singular elements (nullator and norator), some alternative configurations are derived, raising interesting possibilities for network synthesis techniques which employ controlled sources. Finally, replacing infinite-gain controlled sources by operational amplifiers yields practical circuits.