Self -made experts use clothes to teach everyone to make a simple version of alarm.

First prepare two batteries, stick to the clothes clip in different directions

Then find a welding point on the clothes clip, and press the screw on the two ends of the clip

Then welded a bee lumator between the screws and the battery

Then use the wire to connect each part, and a simple alarm is completed

Install it on the door and stick to the side of the door frame with one end of a line, and pinch one end with a clip!As long as someone pushes the door, it will touch the alarm device