Burglar Alarm Basics

What is a burglar alarm?  Basically it is a system that is designed to alert you to a danger.  Sensors/devices are connected to a main panel either through wiring or they can also be done wireless using radio frequency signals.  The burglar alarm systems can also be used to detect fire in addition to intrusion protection.

 

One of the things that I noticed whenever someone called me about their home security system was that the customer actually spoke a different language than what my alarm system technicians spoke.  Since I want everyone to get off to a good start with their home security, I thought I would spend a little time talking about the different parts of a burglar alarm system and what each part does.  Don’t worry; I won’t get too technical here.  I just want to provide you with the basic parts of a burglar alarm and what they do.

 

Parts of a Burglar Alarm System

 

  • Control Panel – first up is the brains of the alarm system.  The control panel handles everything to do with the burglar alarm.  It tells; the siren to ring, the phone line to send a signal to the central station, how long to allow someone to come in and turn off the system.  It is also where all of the wiring for the alarm system devices go to and are managed and it also houses the backup battery.  Most alarm system panels are located in utility closets or laundry rooms.
  • Keypad –  the keypad is used to send to the control panel instructions.  This is where you arm and disarm the system, add additional user codes, bypass zones, etc.
  • Key Fob – a key fob does the same thing as a keypad but it is limited to just arming, disarming, and sending a panic signal.  It’s very similar to the kind people use to unlock and lock their cars.
  • Siren – a burglar alarm isn’t any good if no one hears it.  A siren is the noise maker. 
  • Motion Detector – this device is what it says it is.  It detects motion and when there is something that tells the detector that there is movement within it’s field of view, it sends a signal to the alarm system control panel.  Based on how the control panel is programmed it will; set off the system, ignore it, or delay a reaction.  There are four types of motion detectors used with burglar alarm systems today:
    • Passive infrared (PIR) – this is the most common and usually the least expensive.  This motion detector looks for a change in temperature (like body heat).
    •  Microwave detector – this motion detector sends out microwave pulses and measures the reflection off of a moving object.  Think of it like something that is throwing out bouncy balls and each ball takes a certain amount of time to return.  When the ball comes back sooner than expected, it triggers an alarm.
    • Dual-technology – this motion detector uses a combination of passive infrared and microwave technologies.  The benefit of using this time of motion detector with your alarm system is that false alarms are less likely to happen.
    • Pet PIR/Motion detector – the final motion detector that I want to tell you about is the one that is designed to ignore pets that weigh up to 80 pounds.  These motions are great for people with pets but they can trigger false alarms if your pet is a known jumper.  Cats or dogs jumping up or down from a couch, bed, counter, whatever, can sometime set off an alarm.
  • Window/Door Sensor – commonly known as contacts.  These sensors come in two parts that have to line up with each other.  When a door or window is opened and the two pieces are pulled apart, an alarm is activated.  These sensors can be wired to the control panel or they can be wireless using radio frequency.
  • Sound Discriminator –  this device is used to pick up the sound of breaking glass.  It is also known as a glass break detector.  When glass breaks, it generates a sound in a certain frequency range.  These detectors are usually mounted in within 30 feet of the glass.
  • Smoke Detector –  this one is pretty obvious.  A smoke detector is there to detect smoke.  The biggest benefit to having a smoke detector included with your burglar alarm system is that when your system is set off because of smoke, it can send a signal to the monitoring company and they in turn can call the fire department.
  • Heat Button –  a heat detector is a device that reacts to the changes in the temperature.  Once the temperature reaches a certain threshold, it signals the control panel to set off the alarm.  Heat detectors are usually located where smoke detectors shouldn’t go.  They are usually located in kitchens, laundry rooms, garages, and attics.
  • Battery Backup –  the battery backup is located inside of the control panel and it provides power to the system in cases of power failure.  How long the battery lasts depends on the size of the battery and whether or not the security system is using a lot of power.  If the alarm system is actually in alarm and the siren is ringing, then the battery may not last very long at all.

 

Well that’s it for this post.  I hope I didn’t lose anyone by being too technical.  I think that it is important to know the different parts of a burglar alarm system and what they are designed to do so that you can make an informed decision when it comes time to choosing an alarm system that is right for your needs.