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How Burglar Alarms Work


Sounding the Alarm

There are several things a security system might do when it detects an intruder. In an advanced system, the control box will be wired to several different components. Typically, it will activate:

  • a siren or other loud alarm noise
  • flashing outdoor lights
  • a telephone auto-dialer

The siren and lights serve three functions:

  • They alert occupants and neighbors that someone has broken into the house.
  • They drive the intruder away.
  • They signal to police which house has been broken into.

The telephone auto-dialer can:

  • Dial the police directly, and play a pre-recorded message giving the address of the house and any other relevant information. This message will usually play over and over so that the police will still hear it even if the call is put on hold for some time.
  • Dial the security company that installed the equipment. In this case, the control box can feed specific information about the intrusion -- which circuits or motion detectors were activated, etc. The security company then relays this information to the police.

Home security is a rapidly growing field, and there are new and improved burglar alarms popping up all the time. For the most part, these systems are all built around the same basic structure. A central control box monitors several motion detectors and perimeter guards and sounds an alarm when any of them are triggered.

To find out about specific alarm devices and new installation techniques, check out the sites listed on the next page, or talk to a security system installer in your area.


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