Security Systems Components- CCTV Systems
A home security system works in combination with different components to make it fully operational. These are devices directly connected to generate, transmit, display, and store video data.
The working of a typical home CCTV system may look very straight. You purchase a camera and connect it with a video monitor. Done; Simple as that.
However, an expansive security system represents a number of different functional units integrated into one overall security network.
Such a complex system consists of various devices including, cameras, Lenses, Housing and Mounts, Video monitors, Switchers and multiplexers, Video recorders etc.
Common Components of a Security System
Today, technology-enabled modern CCTV systems enjoy the benefits of digital technologies. They use electronic databases, sophisticated components, and wire-free transmission techniques to optimize performance.
In this article, we are going to discuss some of the major components in a home CCTV system.
This will help you with the selection of devices especially cameras and other essential applications for setting a security system for your home.
Cameras are an indispensable part of any security framework. The strength of the security system depends largely on the reliability of the cameras you are using.
First off, the camera should work smoothly with the operational environment of your home. Also, it should well integrate with other applications in the network.
The selection of the right camera is easy if you have an understanding of cameras and their basic characteristics.
Two Categories of Cameras
Generally, we can group cameras in two primary categories: Fixed and PTZ (pan-tilt-zoom) cameras.
Fixed cameras are stationary cameras, focusing on a single field of view (FOV) constantly.
PTZ cameras are designed to get a clear view of FOV or the captured image. They can pan sideways, tilt vertically, and zoom in or out to get more focus on the image.
When you have a pre-defined area to monitor, a fixed camera is the best choice. You can mount it facing the specific area like your gate or the main entrance or a doorway.
With a fixed camera, you don’t have any interest other than watching the visitor at a specific field of view. The main benefit of the fixed camera is that it is less expensive and easy to install and use.
PTZ cameras or pan-tilt-zoom cameras are designed to pan left -to- right and tilt up and down. It can also zoom in and out.
In the process, the camera lens can vary the focal length to the field of view (FOV) and get a clear view of the captured image live. Moreover, it is capable of remote direction and zoom control. The FOV is the area seen by the camera and lens.
The user can scan back and forth the FOV or the image of any suspicious object or a human face by zooming in and out remotely.
You can also program the camera to change its focus to different directions automatically at regular intervals. This will help to widen the area of your field of view, and you won’t miss any action around that spot.
Types of Cameras based on Connectivity
CCTV cameras can also be classified according to the type of connections, such as Network cameras and Analog cameras. Then we have other types of cameras designed for the different operational environment. This includes Day/Night Cameras, Low-Light or Night Vision Cameras, Thermal Imaging Cameras, Miniature or Covert Cameras and Optional Cameras.
The lens is the primary part of an imaging chain on a CCTV camera. It is responsible for delivering an image to the imaging sensor. The quality of the image will depend on the ability of the camera lens to deliver un-distorted, evenly focused, accurate images.
When you select the lens, check out the details such as its focal length, the field of view, size of the image sensor and lighting conditions.
There are three types of lens, namely fixed focal length, varifocal (variable focal length), and zoom.
The other parts of the transmission system include the camera, image management and analysis software and monitor.
3. Housing and Mounts
Camera housings and mounts are important for the proper installation of the system. However, the point is that they should conform to the environmental or architectural conditions of the location. It is equally important that they are adaptable to the conditions of other materials used as part of the network.
4. Video monitors
Video monitors are important as they display video images for viewing. The quality of images displayed will depend on the type of monitor to a great extend. And it should be able to show at least as many pixels of information as the cameras are capable of imaging.
Today, you have excellent choices, like those offering liquid crystal displays (LCDs) and LED display and other features.
Depending on the purpose, homes and businesses select various types of monitors for surveillance They include Televisions, PC Monitors, Monochrome Monitors, CCTV Monitors, CRT Monitors, LCD Monitors, OLED Monitors, and Plasma Monitors.
A switcher is the simplest device in a CCTV network. It is responsible for sending analog videos to a recorder or monitor. Some of the switchers are designed to transmit video or TV signals continuously from several cameras.
The role of switchers is crucial particularly in an expansive network with greater numbers of cameras and monitors. Microprocessor-based switchers are versatile with controls over other devices including camera and lens.
Unlike switchers, multiplexers can receive and convert analog video signals to digital and vice-versa. It is also equipped to analyse video signals such as motion detection, and record frames and images or fields.
In a large security network, you can also program a multiplexer to display the images from a particular camera always on the monitor. Simultaneously, it can record the images from other cameras.
7. Video recorders
Video recording is an essential process in a surveillance system. It facilitates assessment, investigation, and evidence collection of a crime.
In the traditional surveillance systems, videos were recorded by a VCR on the video cassette tapes. This had several limitations.
But today this system is out of use. The role of VCR is taken over by DVR ( digital video recorder) and NVR (network video recorder)