US Patent 8436749 Failsafe LED control system

A display system comprises first and second LED panels for displaying first and second priority aviation data, a power supply, a modulator, a processor and a logic gate. The modulator generates a modulated voltage for the second LED panel, where the second priority data are displayed at a modulated brightness. The processor controls the modulator, and generates a status signal indicating a failure condition of the modulated voltage. The logic gate switches the first LED panel from the modulated voltage to the unmodulated voltage based on the status signal, where the first priority data default from the modulated brightness level to full brightness based on the failure condition.