Circuit for Transient-Free Current-Potential Control Conversion

A general technique for switching a closed loop control circuit from one function, to another is described. A closed loop exists at all times, even during the switching operation. A potentiostat that can be switched to a galvanostat and vice versa in less than 10 fisec was built. No spurious potential or current transients were observed on test or real cells. This potentio-galvanostat has been tested with a conventional three electrode cell, with a ring-disk electrode, and as a potentiostatic interrupter.