Patent ID: 8817006

Claim:
A display adapter, comprising: an alternating current (AC) power plug to be inserted into an AC power socket to receive a first AC voltage; a video graphics array (VGA) interface to be connected to a display; a first conversion circuit comprising a digital to analog (D/A) converter, and a coupler connected between the D/A converter and the AC power plug; a second conversion circuit comprising an analog to digital (A/D) converter, and a decoupler connected between the A/D converter and the AC power plug; and a switch unit connected between the VGA interface and each of the first conversion circuit and the second conversion circuit, to connect either the first conversion circuit or the second conversion circuit to the VGA interface; wherein when the switch unit connects the first conversion circuit to the VGA interface, the D/A converter receives a first digital signal representing VGA data output by the display through the VGA interface, and converts the first digital signal representing VGA data into a first analog form data, the coupler couples the first analog form data to the first AC voltage, and outputs the first AC voltage coupled with the first analog form data to the AC power plug, the AC power plug transmits the first AC voltage coupled with the first analog form data to an AC power line connected to the AC power socket; and wherein when the switch unit connects the second conversion circuit to the VGA interface, the decoupler receives a second AC voltage coupled with a second analog form data through the AC power plug from the AC power line connected to the AC power socket, decouples and separates the second AC voltage coupled with the second analog form data into the second AC voltage and the second analog form data, and outputs the second analog form data to the A/D converter, the A/D converter converts the second analog form data into a second digital signal representing VGA data, and outputs the second digital signal representing VGA data to the display through the VGA interface.