Input system with voltage transmission function and input device thereof

An input system with a voltage transmission function, the input system comprising plural input devices, each of the plural input devices comprising:

• a main body;
• a first connecting port installed on the main body;
• at least two second connecting ports installed on the main body;
• a power switching circuit electrically connected with the first connecting port and the at least two second connecting ports;
• and
• a control unit electrically connected with the power switching circuit, the first connecting port and the at least two second connecting ports,
• wherein the plural input devices comprise a first input device and a second input device,
• wherein when the control unit of the first input device detects that the first connecting port of the first input device is connected with an external power source, the control unit of the first input device issues a first switching signal to the power switching circuit of the first input device, so that the first connecting port of the first input device is enabled to receive a first voltage from the external power source,
• wherein when the control unit of the first input device detects that a selected second connecting port of the at least two second connecting ports of the first input device is connected with a selected second connecting port of the at least two second connecting ports of the second input device, the control unit of the first input device issues a second switching signal to the power switching circuit of the first input device, wherein in response to the second switching signal, the first voltage is converted into a second voltage by the power switching circuit of the first input device, and the selected second connecting port of the first input device is enabled to transmit the second voltage to the second input device.