What can replace the room card to get electricity?

Cardboard. Because there is a chip in the room card, there is no induction in the card without the chip, and all the appliances in the room can't work. But if the room card in the hotel has no chip and is insensitive, then find a piece of cardboard and insert it into the card slot to have electricity. The working principle of this switch is to control the power supply of the room by controlling the on-off of the live wire. It is reduced to DC by rectification, and provided to the identification part and the output part by low-voltage power supply.