When entering the rooms, the guests have to insert the room card into the Energy Saving Switch to turn on the illumination system. While leaving the room, the guest draw the room card; then the power supply will be shut off by the Energy Saving Switch about 15 seconds later. The delay function is very important in the Energy Saving Switch, without it, the guests have to leave the room in the dark. The consumption of the illumination system in each room in the hotel is about 2000 watt. If the guests forget to turn off all the electric appliances when they leave the room, which will be a great waste and it"s very insecure. While their leaving, it is difficult for the waiter to know whether the lamps are turned on or not in the rooms. So we specially developed the Energy Saving Switch for the hotel to save the substantive regrettable consumption