Abstract: A time-limited power supply system for providing power to an electronic device includes a first input module, a controlling module, a switch module, a display module, and an alarm module. The first input module inputs a power on time signal in the controlling module. The controlling module receives the power on time signal and outputs a power on control signal accordingly. The switch module receives the power on control signal and provides an AC voltage to the electronic device for a set time. The display module displays the time for which the power on state will continue. The controlling module outputs an alarm signal when a remaining power on time is less than a certain period of time. The alarm module issues an audible warning to remind the user that the power on time of the electronic device may need to be extended.