IR BURGLAR DETERRENT

A burglar alarm or deterrent takes care of the internal security of the house. The burglar alarms, also known as security alarms (Home security systems) are deliberately contrived to guard the house against break-ins. Today we can discern different kinds of alarms with different working principles.
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Fundamentally every alarm system has triggers. The triggers are set off whenever an intruder tries to enter the premises. Now, there are basically two major types of burglar alarms. One that sets of when some body breaks the electrical circuit, and the other, which gets tripped when it senses motion.

Electric Circuit – These are the most simple alarm systems that use electrical circuits. Generally, we can employ them to protect the borders of the house, that is the probably the entry points to the house that the burglar might use. These security systems are further divided into two types:-
a) Closed-circuit systems – In this system as long as the door is closed the electric circuit remains closed and whenever somebody opens the door, the circuit becomes discontinuous, and the alarm is set off.
b) Open-circuit systems – In an open circuit what happens is when somebody opens the door the open-circuit is completed and electricity starts flowing so the alarm is prompted.

Motion Detectors – These are the other type of security systems. They can detect burglars who have already entered the house. Their principle of working is to send out radio energy and observing the reflection pattern. Now when someone walking into the room obstructs the reflection pattern, the alarm gets active and sends a signal to the control box. Something warm moving across a cold room or something cold moving across a warm room will set off the motion detector.

For a full proof security system to protect the house, we can use the combination of the motion detectors and open or closed circuit alarms. The control unit of the system is connected with the sensors through either narrowband RF signal or low-voltage hardwire and these in turn are joined to a means, which announces the alarm, to extract response. The opening of a door or movement of a body sensed through passive infrared (PIR) is detected by these security sensors.