A system configured to provide galvanic isolation of data or power signals between primary and secondary sides. In various forms, the system may provide galvanic isolation with primary side passive or active sensing of a secondary side load, and with secondary side control for dual data and power control over a single galvanic interface; with series capacitive, series capacitive and resistive, alternating series capacitive and resistive, or series and parallel capacitive galvanic isolation, or series and parallel capacitive galvanic isolation for multiple isolated ground planes; using Manchester encoding across the galvanic isolation region; using differential power and data across the galvanic isolation region; using an isolated common reference for data and power links across the galvanic isolation region; using controller area networking across the galvanic isolation region; or using a resonant configuration and having feedback between the galvanic interface, only on the primary side, or only on the secondary side.