REDUNDANT DC INPUT POWER SUPPLIES HAVING BACK-FEED PROTECTION

An electric power supply comprises first and second input circuits for receiving first and second input DC voltages and a control circuit coupled to the first and second input circuits. The control circuit is configured to sense the first input DC voltage and the second input DC voltage and to enable the first input circuit and disable the second input circuit in response to the first input circuit having the highest input DC voltage to substantially prevent current from back feeding to the first input circuit from the second input circuit. The control circuit is also configured to enable the second input circuit and disable the first input circuit in response to the second input circuit having the highest input DC voltage to substantially prevent current from back feeding to the second input circuit from the first input circuit.