March 21, 2023
CCTV cameras have become a common sight in public places and workplaces, but how exactly do they work? In this article, we will explore technology behind CCTV cameras and how they capture and transmit video footage.
CCTV stands for closed-circuit television. A CCTV camera captures video footage and sends it to a recording device or a monitor for live viewing. A CCTV system typically consists of a camera, a cable, a recording device, and a monitor.
The Camera
CCTV cameras come in different shapes and sizes, from dome cameras to bullet cameras. The most common type of camera is dome camera, which is mounted on ceiling and can be easily adjusted to capture different angles. The camera captures video footage using a sensor and a lens. The sensor converts light into electrical signals, which are then processed by camera's electronics to create a video image. The lens focuses light onto sensor, controlling angle and depth of image.
The Cable
The camera is connected to recording device or monitor via a cable. The cable carries video signal from camera to recording device or monitor. There are two types of cable commonly used in CCTV systems: coaxial cable and twisted pair cable.
Coaxial cable is a type of cable that has a copper conductor surrounded by a layer of insulation, a braided shield, and an outer jacket. It is most commonly used type of cable in CCTV systems. Twisted pair cable is a type of cable that has two insulated wires twisted together. It is less common than coaxial cable, but is used in some CCTV systems.
The Recording Device
The video footage captured by CCTV camera is sent to a recording device, which stores footage for later viewing. The recording device can be a digital video recorder (DVR) or a network video recorder (NVR). The DVR records video footage onto a hard drive, while NVR records footage onto a network-attached storage (NAS) device.
The Monitor
CCTV monitors are used to view live or recorded video footage from CCTV camera. The monitor can be a dedicated monitor or a computer monitor. The CCTV system can also be connected to a network, allowing users to view footage remotely using a smartphone or computer.
In conclusion, CCTV cameras work by capturing video footage using a sensor and lens, transmitting footage through a cable, recording footage onto a recording device, and displaying footage on a monitor. CCTV systems have become an important tool for improving security and safety in public places and workplaces. By understanding how CCTV cameras work, we can appreciate technology that makes them effective in preventing crime and protecting people.
