POWER SUPPLY DEVICE AND POWER SUPPLY SYSTEM

Embodiments of this application disclose a power supply apparatus and a power supply system, to reduce a volume and costs of the power supply apparatus. The power supply apparatus includes a switching circuit, where the switching circuit includes a switcher, a first input terminal, a second input terminal, and an output terminal, the first input terminal of the switching circuit is configured to receive a first voltage provided by a first power supply, the second input terminal of the switching circuit is configured to receive a second voltage provided by a second power supply, and the switcher is configured to control the output terminal of the switching circuit to be connected to the first input terminal or control the output terminal of the switching circuit to be connected to the second input terminal; and a converting circuit, where the converting circuit includes an input terminal and an output terminal, the input terminal of the converting circuit is connected to the output terminal of the switching circuit, the output terminal of the converting circuit is connected to an electrical device, and the converting circuit is configured to receive the first voltage or the second voltage, convert the received first voltage or the received second voltage into a third voltage, and output the third voltage through the output terminal of the converting circuit.