This circuit uses IC 556 which have timer 2 the group in one. First group is moto stable and second group does in front is in a state of a signal goes out work to is unfinished although signal. From detect disappear already. But output a pin 9 still have voltage the tall when encourage from detect , which might be switch the door is model usual close the circuit, or be strip sticks at sheet window glass by detect every jigsaw serial puzzle all. When detect any one open the circuit. The circuit will encourage signal to warn immediately and will work unfinished through the fire until press S1 for reset give the circuit stops to work. When feed power supply the circuit will still don’t work immediately, Because motostable delay keep 22 S. For S2 be switch at for stop the work of by don’t discharge power supply go out.