In an embodiment, a system may comprise at least two power supplies which may comprise a first power source, a first step-down converter, a first switching device, a first bus, a second power source, a second step-down converter, a second switching device, and a second bus, the first and second buses being electrically separate. An exemplary system may further comprise an alternate power supply comprising a third power source and an alternate step-down converter connected to at least the first and second buses via at least a third switching device, the alternate power supply acting as a backup power supply configured to be used after a failure of one or more of the at least two power supplies. In some embodiments, the first and second switching devices may be controlled by at least a first controller and the at least third switching device may be controlled by an alternate controller.