The experimental circuits used for this work were constructed from three operational amplifiers, having differing adjustable gains, and with output ranges restricted to a certain amount, feeding a summing amplifier. This generated the transfer function for the system including the various Features. Control of the transfer function parameters was achieved using ten turn precision potentiometers.
A two-stage sample-and-hold circuit was used to transfer the output of the transfer function generator back to the input, on a clock pulse provided by an external generator.
Two copies of these circuits were constructed; they could be used together with a matrix rotation circuit to investigate two-dimensional systems.