Using an ultrasound module to reduce the standby power consumption of a PC monitor

In this paper we present a design using an ultrasound module to reduce the standby power consumption of a personal computer (PC) monitor. Although a PC monitor enters standby status by means of the power management of the operating system (OS) after a preset idle time and awakens when the keyboard is hit or the mouse is moved, this way of entering standby status is not efficient for the monitor which still consumes 0.3-1 W of power in standby status. Our design features a socket to plug-in the PC monitor, which enters standby status more efficiently, consuming 0.008 W. This socket supplies the monitor with power when a user is detected by the ultrasound module; when the user leaves it turns the monitor off without using an idle timer, and the electric power is cut off by the solid state relay (SSR) controlled by the micro control unit (MCU) to reduce the standby power.