A dual power supply switching system for use in an electronic sign where independent suitably sized power supplies each capable of independently powering an entire plurality of LED display modules supply power on an alternating distributed basis to the plurality of LED display modules. A microcontroller having an odd or even address on each LED display module controls the connection of the respective LED display module to a particular power supply by controlling onboard solid state switches and, upon sensing an inadequate power source supply, switches to the other power supply to re-establish power to the LED display module.