Unit level isolated bus transfer device

An apparatus for high-speed switching between a plurality of power sources, the apparatus comprising:

• a switch-mode isolation transformer comprising:
• a plurality of isolated primary windings, each of the plurality of isolated primary windings being electrically isolated from each other and selectively couplable to a power source of the plurality of power sources, and
• a secondary winding coupled to a load;
• and
• a controller operatively coupled to the switch-mode isolation transformer and configured to selectively couple one of the power sources of the plurality of power sources through a corresponding isolated primary winding, responsive to detecting an adverse condition in another power source of the plurality of power sources, wherein the controller is configured to provide power to gate drives of respective switching elements, and wherein, responsive to detecting the adverse condition, power is removed from a gate drive of a switching element coupled to a first primary winding of the plurality of primary windings concurrently with providing power to a gate drive of a switching element coupled to a second primary winding of the plurality of primary windings.