An aircraft power supply system, comprising: a power source formed as an aircraft generator; a DC-AC / DC-DC dual-mode converter configured to receive power from the power source; a DC-DC converter configured to receive power from the power source and electrically interconnected with a DC output; a first isolation switch electrically interconnecting the DC-AC / DC-DC dual mode converter with DC-DC converter; a second isolation switch electrically interconnecting the DC-AC / DC-DC dual mode converter with an AC output; at least one steady state DC load, at least one transient DC load (107; 108), and at least one AC load; and a microcontroller in communication with the AC output and DC output and configured to control the first and second isolation switches (111; 112); wherein the microcontroller is configured to cause the power supply system to operate in a first mode of operation and a second mode of operation; wherein when in a first mode of operation the first isolation switch is open and the second isolation switch is closed and the DC-AC / DC-DC dual-mode converter is configured to provide AC power to the AC loads and the DC-DC converter is configured to provide DC operating power to the steady state DC loads and DC standby power to the transient DC loads (107; 108); wherein when in a second mode of operation the first isolation switch is closed and the second isolation switch is open and the DC-AC / DC-DC dual-mode converter is cross coupled with the DC-DC converter and are together configured to supply DC operating power to at least one of the transient DC loads (107; 108) and the steady state DC loads. a power source formed as an aircraft generator; a DC-AC / DC-DC dual-mode converter configured to receive power from the power source; a DC-DC converter configured to receive power from the power source and electrically interconnected with a DC output; a first isolation switch electrically interconnecting the DC-AC / DC-DC dual mode converter with DC-DC converter; a second isolation switch electrically interconnecting the DC-AC / DC-DC dual mode converter with an AC output; at least one steady state DC load, at least one transient DC load (107; 108), and at least one AC load; and a microcontroller in communication with the AC output and DC output and configured to control the first and second isolation switches (111; 112); wherein the microcontroller is configured to cause the power supply system to operate in a first mode of operation and a second mode of operation; wherein when in a first mode of operation the first isolation switch is open and the second isolation switch is closed and the DC-AC / DC-DC dual-mode converter is configured to provide AC power to the AC loads and the DC-DC converter is configured to provide DC operating power to the steady state DC loads and DC standby power to the transient DC loads (107; 108); wherein when in a second mode of operation the first isolation switch is closed and the second isolation switch is open and the DC-AC / DC-DC dual-mode converter is cross coupled with the DC-DC converter and are together configured to supply DC operating power to at least one of the transient DC loads (107; 108) and the steady state DC loads.