Generally, a security system is a network of controls, wires, and sensors configured to alert the user and/or a central station of unwanted intrusion and/or fire. Brands and specific configurations vary widely as do types of sensors and communication for the control panel. Most modern alarm models offer very competitive features and, though they operate differently, easy-to-use interfaces.
For example, a basic hard-wired system includes three door sensors and a motion detector in addition to the control panel and siren. The control panel is where the brain of the system is located. All wiring must connect to the control panel. AC power, keypad, siren, phone line, and any sensors connect here. The panel is often installed in a closet or utility room. It is a white or tan metal box with a hinged lid varying in size, normally a bit bigger than one foot by one foot.
Door sensors can be either recessed, meaning hidden in the door jam, or surface mount, meaning mounted on the frame or edge of the door. Door and window sensors detect whether a door or window is opened or closed. Motion sensors use the infrared spectrum to detect body heat moving within its view area.
Most brands also offer wireless security systems. Generally, this refers to the sensors themselves being wireless. A wireless door sensor is a small white box mounted at the door which transmits a radio signal to communicate with the control panel instead of using a wire.
Once the alarm detects an intrusion, it communicates to the central station. Many forms of communication for alarms exist and, as technology advances, new possibilities are becoming available.
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