DIY Alarms

Control Box

• A do-it-yourself alarm system is usually based around a control box, which activates the alarm in case of a breach and allows you to turn the system on and off (usually via a keypad). Depending on the model you purchase, it may need access to a power source such as an electrical outlet. Beyond that, you need to select a location for it based on safety and convenience. Wireless alarm systems have a specific range for all their components; any sensor beyond the range of the control box may not be able to function. Take careful measurement of your entire house and look for a control box location that allows you to cover the whole space with its range. If possible, you should place it near the main entryway, so you can turn it on and off easily before you leave the house and when you return. You may also wish to place it in some out-of-the-way spot like a closet, which keeps it hidden from burglars.

Door and Window Alarms

• In order for an alarm system to work effectively, it needs to cover every entryway on the ground floor of your house. Take a count of all the doors and windows in your home and make sure your alarm system has enough sensors to cover all of them. DIY alarm sensors are usually based on a simple trigger mechanism. One half of the sensor is placed on the door or window itself, while the other is placed on the nearby frame. When the door or window is closed, the two halves are in contact with each other, forming a circuit which prevents the alarm from going off. When the alarm is activated and the door or window opens, the circuit is broken and loud noises ensue.

Motion Sensors

• Motion sensors use sonar signals, infrared detectors or other technology to monitor a wide space such as a room. Most DIY alarms don't have enough detectors to cover the whole house, so you should select your locations carefully. Pick rooms which contain valuables you want to protect or rooms in a centralized locale which a burglar will have to pass through in order to reach the rest of the house. (Hallways and stairways work well in this regard too.) Place the motion sensor in a high place with a good view of the entire area--corners work well--and unobstructed by any mountings or furniture.