The alarm is quite effective. Big one, let’s teach you how to make a simple alarm. First prepare a clip, two batteries, a buzzer, an IED light, two screws, and a driver.
Twist the screw on the clip , one on each side
Glue the battery to the clip
Glue on the buzzer
Adhere the IED lamp
Solder the circuit
Tie a small piece of paper last rope
Fix the entire alarm to the door, with small pieces of paper sandwiched between the screws for insulation. When someone opens the door and turns the door handle, the rope will be pulled, the paper will fall off, the circuit will be connected, and the buzzer will sound. If you think this gadget is good, make one!