The document discusses burglar alarm systems and their components. It explains that burglar alarms consist of sensors to detect intruders, a control panel to power the sensors and provide alerts, and connections between these components. Some common sensor types mentioned are door and window contacts, motion detectors, light dependent resistors, and magnetic contacts. The control panel monitors the sensor circuits and sounds an alarm until someone enters a security code at the keypad. The control panel is usually hidden away for added security so intruders cannot disable it.

2. INTRODUCTION:
Burglar alarm is the one of the
security system which is use to
prevent our home, office, banks, etc.
In our project burglar alarm is
mainly used to find out the theft and
it can also give the signal to the user
or owner by using of the mobile
phones. So the theft can be avoided
and the thief also will be caught.

3. The concept of burglar alarms was
introduced to the world by
. Holmes made these alarms
an important component of business
and residential security. In 1905,
after enjoying several years of
successful business, Holmes sold the
concept of burglar alarms and his
company to American Telephone and
Telegraph Company (AT&T). AT&T
then went a step further and
connected burglar alarms to
emergency call systems at both fire
and police departments.

4. . Burglar alarms are systems designed to detect unauthorized entry into a
building or area.
They consist of an array of sensors, a control panel and alerting system,
and interconnections
 Sensors detect intruders by many methods such as monitoring door
and window contacts by
Sensors may be directly wired to a control panel that provides sensor
power, or may communicate wirelessly.

5. LET’S GET THE BASIC
STRAIGHT.
(BEFORE “THEY “ DO)

7. Step 1: Try and
catch the burglar
at the door step it
self,

9. A BASIC MAGNETIC SENSOR :

11. o The burglar only needs to close the door again to turn the buzzer off. That's why
most modern burglar alarms incorporate another piece into the circuit -- the
control box.
oThe control box is hooked up to one or more alarm circuits, but it also
has its own power supply.
oBut once the alarm is triggered, the control box won't cut it off until somebody
enters a security code at a connected keypad.
oIt monitors the circuits and sounds the alarm when they are closed or opened
(depending on the design).
oFor added security, the control box is usually positioned in an out-of-the-way spot,
so the intruder can't find it and attempt to destroy it..

14. Passive infrared (PIR) motion detectors:

17. Time Delay:

22. I n this basic circuit, the alarm will be
switched on under the following four
different conditions:
1. When light falls on LDR1 (at the
entry to the premises).
2. When light falling on LDR2 is
obstructed.
3. When door switches are opened or a
wire is broken.
4. When a handle is touched.

23. short circuits these spikes before they can do any damage. >To avoid this adjust potentiometer VR3 properly.