You can use this Simple Alarm to protect your door or window . It emits a loud beeping sound and turns on the room light when an intruder/thief tries to pick the door lock. The alarm only works after 5 minutes to confuse the intruder.
Operation of this burglar alarm circuit is simple. IC1 is used to trigger the SCR after a delay of 5 minutes and a Reed (Normally Open) switch is used to control the operation of IC1. The CD4060 oscillates and provides high output only when its reset pin 12 is grounded. When the door is closed, the magnet comes close to the reed switch and closes. The reset pin of IC1 now goes high through R1 and remains off. When the door opens, the magnet moves away from the reed switch and IC1 begins to oscillate with components C1 and R3. After 5 minutes, its Q8 output goes high and triggers the SCR. The relay and buzzer are activated. The relay can be used to drive an AC load such as ambient light or AC doorbell. The SCR remains latched until the anode voltage is removed by pressing S2 (normally closed switch).
Fig. 1: Image of the normally open reading switch
Fig. 2: Image of the magnet and Reed switch arrangement
The red LED flashes and indicates circuit activation. Attach the Reed switch to the door frame and the magnet to the door with exact positioning so that when the door closes the Reed switch makes contact.
SCR 2P4M 
Fig. 3: Image showing SCR 2P4M
Circuit diagrams
| Door_0 alarm circuit |  |