A power supply system. The power supply system may have a power circuit having a switch and adapted to generate a first output voltage and a second output voltage, depending on the state of the switch. It also includes an output connector coupled to the power circuit, where the output connector includes a plurality of electrical contacts including a first electrical contact and a second electrical contact. A voltage output indicator device is coupled to the first and second electrical contacts. The voltage output indicator device indicates that the power circuit is producing the first output voltage or the second output voltage, so that the user is aware of the voltage being output by the power supply system.