Patent ID: 8636878

Claim:
A device to generate an alternating current and to provide an electrical current to an electrowinning or electrorefining load, the device comprising: a direct component that provides a direct current to the load; and an alternating component that generates the alternating current and provides the alternating current to the load, wherein the direct component and the alternating component are connected in parallel with the load, wherein the alternating component generates the alternating current by subtracting a portion of the electrical current from the load during a first period of time, by accumulating the subtracted electrical current in the alternating component during a second period of time, by returning the accumulated electrical current to the load during a third period of time, and by repeating the subtracting, accumulating, and returning periodically or semi-periodically to produce and provide the electrical current to the load without changing an average value of the direct current from the direct component, and wherein the electrical current to the load is equal to a sum of the direct current from the direct component and the alternating component from the alternating component.