A method of tuning an electrical liquid separator, comprising: providing a liquid mixture in the form of a water in oil emulsion to a vessel of a separator, the vessel having an inlet, a heavy component outlet and a lighter component outlet; electrically coupling a power unit to the liquid mixture inside the vessel, wherein the power unit includes a rectifier, modulator, and chopper, wherein power leads supply primary power to the rectifier via rectifier leads, which connect a primary power supply to the rectifier; applying a time-varying voltage from the power unit to the liquid mixture, wherein current flows through a power conduit to a power electrode of at least one electrode pair (28, 30) and/or through a return conduit from a reference electrode of the at least one electrode pair to the power unit, wherein the reference electrode comprises an electrode immersed in the liquid mixture in the vessel and coupled to a reference potential of the vessel or the vessel coupled to ground potential; increasing a voltage applied to the liquid mixture from the power unit from a first voltage to a second voltage; detecting an inflection point in a current from the power unit, wherein a current sensor is coupled to the return conduit, wherein a controller is operatively coupled to the current sensor to receive signals from the current sensor representing current flowing in the return conduit and to the power unit to control application of power to the electrodes, and/or wherein a current sensor is coupled to the power conduit and operatively coupled to the controller, wherein the controller receives signals from one or both of the current sensors (114, 116), wherein the current sensed in the power circuit is analyzed by the controller to find the inflection point, wherein the controller determines a rate of change of the current with the voltage by computing a first difference between successive current readings and a second difference between the corresponding voltages, and then computes the ratio of the first difference to the second difference, wherein the inflection point is the point at which the ratio begins to decline after increasing; setting a voltage output range within an operating window of the power unit to encompass a voltage at which the inflection point was detected; adjusting a modulation frequency of the time-varying voltage to minimize current flow through the liquid mixture; and adjusting a base frequency of the time-varying voltage to minimize current flow through the liquid mixture, wherein the chopper modulates application of voltage to the power conduit, providing an independent source of time variation, so that the base frequency applied to the power lead can be adjusted and the modulation frequency applied by the chopper can be independently adjusted. providing a liquid mixture in the form of a water in oil emulsion to a vessel of a separator, the vessel having an inlet, a heavy component outlet and a lighter component outlet; electrically coupling a power unit to the liquid mixture inside the vessel, wherein the power unit includes a rectifier, modulator, and chopper, wherein power leads supply primary power to the rectifier via rectifier leads, which connect a primary power supply to the rectifier; applying a time-varying voltage from the power unit to the liquid mixture, wherein current flows through a power conduit to a power electrode of at least one electrode pair (28, 30) and/or through a return conduit from a reference electrode of the at least one electrode pair to the power unit, wherein the reference electrode comprises an electrode immersed in the liquid mixture in the vessel and coupled to a reference potential of the vessel or the vessel coupled to ground potential; increasing a voltage applied to the liquid mixture from the power unit from a first voltage to a second voltage; detecting an inflection point in a current from the power unit, wherein a current sensor is coupled to the return conduit, wherein a controller is operatively coupled to the current sensor to receive signals from the current sensor representing current flowing in the return conduit and to the power unit to control application of power to the electrodes, and/or wherein a current sensor is coupled to the power conduit and operatively coupled to the controller, wherein the controller receives signals from one or both of the current sensors (114, 116), wherein the current sensed in the power circuit is analyzed by the controller to find the inflection point, wherein the controller determines a rate of change of the current with the voltage by computing a first difference between successive current readings and a second difference between the corresponding voltages, and then computes the ratio of the first difference to the second difference, wherein the inflection point is the point at which the ratio begins to decline after increasing; setting a voltage output range within an operating window of the power unit to encompass a voltage at which the inflection point was detected; adjusting a modulation frequency of the time-varying voltage to minimize current flow through the liquid mixture; and adjusting a base frequency of the time-varying voltage to minimize current flow through the liquid mixture, wherein the chopper modulates application of voltage to the power conduit, providing an independent source of time variation, so that the base frequency applied to the power lead can be adjusted and the modulation frequency applied by the chopper can be independently adjusted.