Abstract: A power supply system may include a target device and an adapter. The target device may include an adapter connection switch that receives adapter recognition information to form a connection with the adapter, a voltage detection unit that receives an output voltage from an adapter, and a voltage-change-requesting unit that outputs a voltage to request a voltage change based on information on the output voltage from the adapter. The adapter may include a device information recognition unit that receives the voltage to request a voltage change, and an output-voltage-changing unit that changes the output voltage based on the voltage to request a voltage change.

Abstract: The present invention relates to a pillow, which aids a user to sleep soundly when the user is lying on the back, and makes breathing easier and helps stimulate the acupuncture points on the face when the user is lying on the stomach and rests the face on the pillow. To this end, the present invention comprises: a main body; a neck support part, which is formed in the longitudinal direction at the front side of the main body and has a height higher than the height of the main body; a ventilation hole, which penetrates the center of the neck support part into the center of the main body; an incline support part, which is provided on the main body in contact with the ventilation hole, and has a gradual decline towards the ventilation hole; and an acupuncture point stimulation part provided in a protruding manner on the ventilation hole side of the neck support part.

Abstract: The present invention relates to a pillow, which aids a user to sleep soundly when the user is lying on the back, and makes breathing easier and helps stimulate the acupuncture points on the face when the user is lying on the stomach and rests the face on the pillow. To this end, the present invention comprises: a main body; a neck support part, which is formed in the longitudinal direction at the front side of the main body and has a height higher than the height of the main body; a ventilation hole, which penetrates the center of the neck support part into the center of the main body; an incline support part, which is provided on the main body in contact with the ventilation hole, and has a gradual decline towards the ventilation hole; and an acupuncture point stimulation part provided in a protruding manner on the ventilation hole side of the neck support part.