Burglar alarms are perhaps the single most commonly utilized security equipment available in the world today. Business premises have been using them long before sophisticated video surveillance
systems were invented. Their effectiveness has won the hearts of private home owners too. The options available are far and varied ranging from simple to highly sophisticated kits that require professional installation. What will surprise you, however, is that most burglar alarm systems have the same design. On the other hand, did you know that the simplest alarm systems are also the
most effective? No matter how surprising this sounds, it is the truth.

Simple Circuit Mechanism

To understand how a burglar alarm works, think of a basic electric circuit. In such a circuit, electricity flows by virtue of having a path where it can move between two oppositely charged points. If you want to turn it on, all you have to do is keep the circuit path open or closed. Burglar alarms are examples of such circuits only that they are fitted along entry ways. Whenever the entry point is intruded into, say by opening the door while the alarm is on, its switch will detect this and trigger a siren. There are two categories of such alarms: closed and open circuit alarm systems.

Closed and open circuit systems

In closed circuit systems, when you close the door and it remains that way, electric current can flow uninterruptedly from one end to the other. However, if you or an intruder opens the door, the act opens the circuit hindering the flow of electricity which triggers the alarm. Open circuit systems work in the opposite manner. The circuit closes when the door is opened hence creating an electric flow. Soon as the electric circuit is completed, the alarm goes off. Out of the two, the best choice is the alarm system working on a closed circuit. Open circuit alarms are easily deactivated hence the reason they are not highly encouraged.

Components of a closed circuit alarm system

A basic alarm system uses batteries to power the circuit, metal switch, magnet and a buzzer. Once you
close the door, the magnet, which is normally embedded in the door’s structure, pulls the switch and closes it to complete the circuit. Any time the door is opened, the magnet moves making the spring to go back to an open position. This, effectively, means that the current is cut off. The relay-driven switch closes and sounds the alarm. This system also works so well on windows such that whenever an intruder pens the window, the current is cut off, the magnet and the switch misaligned which in turn activates the buzzer.

As criminals become cleverer, the need for sophisticated burglar alarm systems has also arisen. From a security point of view, your choice of alarm system will largely depend on areas intruders are likely to try and gain access through. Apart from doors and windows, you can also have burglar alarms that are carefully concealed beneath doormats or carpets.


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