An electronic power source for use in selective electrolysis or as a low voltage regulated supply is described. Its output is dc continuously controllable from zero to five volts at two amperes. Among its features are ripple content of 0.1 percent, and an output resistance of 0.01 ohm. The input impedance of the regulator circuit itself is in the order of 10 megohms, permitting control from high resistance electrodes.The instrument uses a variable‐amplitude two‐kilocycle carrier which is amplified by a power stage and fed to a dry‐disk rectifier. The output is then automatically controlled for equality to a self‐contained adjustable reference voltage. With modifications in the high level stages, the circuit is adaptable to a wide range of output capabilities.