A motion detector switch is a device used for home security. Once installed these sensors detect motion within an area, usually less than 100 feet. Most of the time, motion sensors trigger loud noises or lights to go off, alerting homeowners of a potential thief and scaring away burglars. A motion sensor can also be connected to a burglar alarm to signal a security company or feature an auto-dialer to automatically call preprogrammed phone numbers for assistance.
Generally, a motion detector switch uses infrared, sound or microwaves sensors to detect movement. Infrared switches measure infrared energy or heat radiation and are triggered when a heat signal within the range of the human body temperature is detected. Ultrasonic motion detectors use sound waves to detect motion. If movement is detected, the sound wave pattern is disrupted and alarm is signaled. Sound-based motion detectors can also use passive sensors and be triggered by the noise of breaking glass. Microwave sensors bounce microwave signals off of objects then measure the length of the returning wave to detect motion; these sensors can often penetrate through walls to detect motion.
There are drawbacks to the use of infrared, ultrasonic and microwave sensors. Infrared switches usually have a limited range of motion and can sometimes be tripped by pets within the home. Soundwave sensors could be accidentally triggered by sounds from animals passing or ringing telephones, while microwave motion sensors may be set off by motion from objects blowing in the wind and cannot penetrate through metal. To reduce the likelihood of false positive, a duel-technology motion detector switch can be used. Duel-technology motion detectors use both infrared and microwave technology to eliminate these gaps in the system.
Motion detector lights are typically used around the perimeter of the home to illuminate dark areas in large or side yards as well as around porches, driveways and garages. These lights make it difficult for a person to sneak up to a home without being detected. Motion detector alert systems can also beep to warn the homeowner of a car pulling into the driveway or alert to the presence of someone approaching the front door before they ring the alarm. Inside the home, these sensors are typically placed along interior doors, windows, stairs, and in the hallway — areas where an intruder is likely to pass.
For maintenance-free solutions, solar motion sensor devices are another option to consider. Solar security lights do not require any wires be installed and are powered by solar energy making these lights useful even when the power goes out. A solar motion detector switch can usually be applied in the interior or exterior of the home.
To increase overall home security, many individuals use a motion detector switch along with a camera. These motion-based cameras can be placed along the perimeter of a building as well as near the pool, kid play areas and at entry doors to provide home surveillance. Since these devices only record when motion is detected they can usually save data storage space.