How Home Security Systems Work
monitor the home environment and provide alarms or alerts when something is amiss. A home alarm can provide great peace of mind whether you (or your kids) are home alone or when you’re away and no one is at home. The “something amiss” that is monitored by your home alarm can be almost anything you might care to know. These days there are monitors, alarms and detectors for almost everything that might go on, in or around your house and your property–including break-ins or vandalism by criminals, trespassers or thieves.
Monitoring Methods and Options for Your Home Security SystemYou can monitor and protect your home outside and inside with one or several of the following as part of your home security system:
- Motion detectors (many of these react to temperature signals to determine if someone has moved into a room)
- Smoke alarms
- Carbon monoxide detectors
- Video surveillance cameras (also referred to as CCTV or closed circuit television)
- Driveway alarms (activated when a car passes a motion detector/sensor or when a car drives over a specially equipped hose on the ground)
- Personal alarms (panic transmitters can be carried in the pocket or worn around the neck or wrist so you can summon help quickly)
- Panic buttons (can be installed in certain rooms so that help is alerted when you press the button)
- Intercoms (allow you to talk to and/or see a visitor who has approached your door or rung your doorbell)
- Window sensors (to detect when a window or door is opened)
- Glass break sensors
- Flood or water level sensors
- Dummy video surveillance systems are also an option and as an effective theft deterrent
- Alarm signage can also act as a deterrent whether or not you have a security system installed in your home
Alert Methods for Home Security AlarmsHome burglar alarms offer a number of options for alerting you of an intruder, trespasser or movement. Options to consider include:
- Audio alarms in the home that the intruder, you and neighbors can hear
- Silent alarms
- Visual alarms such as a light that flashes (good as an aid to the hearing impaired or for use in loud environments)
- Alerts sent to your email or smartphone whether you are in the house, out in the back yard, in the garage or out of town
- Alerts sent directly to a professional security company or home security monitoring service. (These services will usually investigate by contacting your and/or sending police or fire department as needed.)
Home Burglar Alarm Systems: Choosing Hard-Wired or WirelessThe installation and functional details of your system depend upon which of, and how many of, the above types of Monitoring Methods (listed above) you choose to have in your house, driveway, garage and other areas of your property. You can also opt for an entirely wireless system, where all components run on batteries or are plugged into the wall. Or you can instead choose a hard-wired home security system where each component is wired into your home’s electrical supply with a battery backup. You can also choose a hybrid system as well, that has hard-wired and wireless components.
How Wireless Home Security Alarms WorkWireless home alarm systems generally consist of three basic components: Sensors/transmitters: These are listed under the Monitoring Methods above, such as a window sensor or motion sensor. These devices are placed strategically around and inside the home to detect and alert you to signs of trouble. Different sensors are designed to “look out” for different things and trigger the alarm if it happens. For example, some alarm sensors are triggered if a door or window is opened, alarms triggered if glass is broken, if there’s movement in the room, or if carbon monoxide or smoke is detected. When triggered, the sensor acts as a transmitter and sends an alert signal to the receiver(s). Indoor, plug-in receivers: The sensor/transmitters in a wireless system typically send alarm signals to indoor receivers plugged into an electrical wall outlet in your home, placed within range of the transmitters (cameras, motion detectors, etc.). The alarm must be set loudly enough that you can hear it throughout the house–or pick up the alert on your portable receiver if you’re in the back yard, for example. Most systems give you the option to add extra receivers (if you need the alert sound to travel further in a larger home.) You would then install (or plug in) additional receivers in more than one location of the house. Control Panel: This is the nerve center of the home security system, which manages sensor activity and sends an alert to you via the method you’ve chosen–and may also notify an alarm monitoring company. You use the Control Panel to arm or disarm the alarm system, as well as to customize your settings. You would likely arm and disarm it with an alarm code entered into the keypad. Many home alarms have settings for “staying at home” and “away.” The stay at home mode might not activate motion sensors, for example, but would still keep glass break sensors armed. You might also have a remote control or be able to control the alarm on your smartphone or laptop.
How Hard-Wired Home Security Systems WorkHard-wired home alarm systems usually operate on a closed circuit. When the electrical circuit is broken (when a window is opened and its sensor is tripped, for example) it triggers the alarm to sound.
- The window sensor consists of two parts (one on the window casing and one on the window frame or sill). The two parts are lined up when the window is closed. One half contains a magnet and the other contains the actual switch. This window sensor is part of the closed-circuit system connected to a key switch/control panel, alarm buzzer/bell and battery.
- When magnet and switch are pulled apart when the window is opened — the switch/circuit is opened, triggering the alarm. Simply closing the window does not restore the circuit and doesn’t stop the alarm sound–until either the battery runs down or someone switches off the circuit with a key or by using a keypad code.
- The electronic switch built into the alarm sounder is turned on by breaking the window sensor’s magnetic-switch loop. A key-operated switch in the sounder circuit (or a keypad with a code) is the only way to silence the alarm sounder. A physical key (or keypad code) also allows you to turn the alarm system off when it’s not needed.
- The electronic parts that makeup the alarm’s sounder are mounted on a circuit board. Underneath the circuit board are a coil and plunger that strike the bell or activate an electronic sounder. Below the coil are “breaker points” that cause the plunger to vibrate rapidly, striking the bell to make the alarm/buzzer sound.
How to Choose Best Home Security AlarmThings to consider when selecting a home alarm system:
- Transmission distance (for wireless components): What is the distance from where the transmitter(s) will be installed to the receiver? Make sure to purchase a wireless system with enough range.
- Signal interference (for wireless): Test to be sure there is no interference or signal transmission problems cause by walls or large furnishings between sensors and receiver.
- Type of notification: You may want to choose an alarm sophisticated enough to provide unique alarm sounds for each different area you are monitoring with window sensors, driveway, front door video, etc.
- Number of receivers and transmitters needed: How many driveways, windows, doors and other entry points do you want to monitor?
- Mobility: Choose a home alarm system that offers a portable wireless alarm receiver if you need to move around a large home or spend lots of time outdoors.
- Battery life: Check the battery life of your wireless alarm or any wireless components in your system.
- Durability/versatility: Check to see if the transmitter is waterproof and if your video camera will work in the dark. (Infrared motion detectors should work in the dark.) Make sure to choose durable components for the best long-term performance, especially on any components that you will be installing outdoors.
- Integration: If you add any components to your security system later, make sure they are compatible with your already-installed system.