New utility of an existing class of DC galvanically isolated current sourcing circuit topologies for power conversion simultaneously allows improvement in its secondary circuit(s) to power conversion efficiency and reduction in working voltage magnitudes, or simply reduction in working voltage magnitudes, with resulting benefits for reduction in manufacturing cost, reduction in size and weight, and increase in market acceptance, or may simply allow secondary circuit(s) to enable easier provisioning of safety, improvement in reliability, or improvement in efficiency. The magnitude of DC output voltage is optimized at higher value for greater efficiency, while simultaneously optimizing the secondary circuit's working voltage maximum magnitude at a lower value for greater safety. The method requires full cycle current-compliant input impedance of the secondary power source whereby the secondary of the DC galvanically isolating device behaves in a mode of being a full cycle voltage-compliant current source.