Abstract: Reference voltages selectively calibrated to match electrolyte being processed, influence adjustment of current controllers through which plating voltages are applied to primary and secondary electrodes of a dual chamber tank assembly, the primary reference voltage being modified by feedback of sensed secondary plating current from the secondary cathode. The reference voltages are regulated and limited to enable transfer of information between cascaded tank assemblies.

Abstract: Ionic silver is extracted from photographic fixing solutions by electrolytic plating on a removably fixed cathode plate of an electrode assembly connected in series with a fixed resistor to a voltage source from which plating current is drawn. The plating current is correctively changed by detection logic in response to excessive variation in the electrolytic resistance of the liquid beyond a threshold limit established through a programmed reference voltage generator that is calibrated to match the chemistry of the particular liquid being electrolytically processed.