Tecwisen

The second type of CCTV system is NVR (Network Video Recorder) based CCTV system which is a network-based system.  Firstly let's recognize the main components of the NVR-based CCTV system.   Now let's see what are the basics of this system. Let's see more details later 1. IP Cameras As DVR-based CCTV systems, there are various types of cameras used in an NVR-based CCTV system depending on the purpose. But those CCTV cameras are called IP cameras as all cameras in an NVR CCTV system have an IP address. Unlike a DVR CCTV system resolution of the cameras in an NVR system is measured by megapixals. The picture quality of this system is mostly higher than a NVR based system 2. Network  Video Recorder (NVR)  Similar to the DVR in a DVR-based CCTV system. But unlike DVR cameras and NVR communicate by IP network in this system. The NVR only has one RJ-45 network slot to connect all the cameras. Communication between cameras and NVR is not done directly in this system. T...

1. Selecting a cable Selecting a good cable is essential for a reliable CCTV system. As there a several options Let's find out the advantages and disadvantages of each.   1. Coaxial cables Coaxial cable is the default cable that has been used to transfer video signals between the camera and video recorder since the very beginning of the introduction of CCTV systems. But using this cable has some disadvantages as well as advantages. Advantages  The loss of the cable is very low compared to other cables. Strength is relatively good Disadvantages Heavy and Bulky therefore difficult to install Need a separate way for camera power Cost is relatively high 2. CAT 5/CAT 6 network cables    Cat 5 or Cat 6 cables can be used for CCTV using passive video Baluns which convert a UTP cable near characteristics of a Coaxial cable. This cable also has its own advantages and disadvantages. Advantages Not heavy and is easy to install Both video signal and power can be sent throug...

 CCTV camera power supplies A separate 12V DC power supply is needed for CCTV cameras. Mainly there are two options in the market today. 1. Combined power supply  Can power number of cameras. Available in a number of current ratings. (eg- 10A,20A,30A etc). Can choose the current rating according to the number of cameras and the rated current provided by the camera manufacturer.  Advantages Easy to install Relatively low in cost Disadvantages If the power supply breaks down whole camera system stops functioning As some of these have fans these power supplies may be noisy  2. Single power supply   Used to power one camera. Separate units are needed to power each camera. Some units may equipped with backup batteries. Mostly installed near CCTV cameras.  Advantages Only one camera will stop working if one unit failed Disadvantages Cost is higher because several units needed  A separate AC power line is needed if installed near the camera 

 CCTV Monitors and Cables There were dedicated monitors for CCTV systems earlier and most of today's DVRs can use computer monitors, originally CRT-type monitors were used for this purpose. But nowadays LCD/LED monitors are widely used. CRT CCTV monitor LCD/LED monitor Cables used for CCTV Co-axial cables are generally used for DVR-based CCTV, but Cat 5 or Cat 6 cables can also be used. Cat 5, 5e, or Cat 6 cables are now commonly used due to convenience and low cost. When using Cat 5,6 cables, a device called Video Balun is used. This makes the Cat 5, 5e, or 6 cables a cable with the same properties as a Co-axial cable. This Video Balun is two types of Video Balun Active Video Balun and Passive Video Balun. Power should be provided for Active Video Balun and power should not be provided for Passive Video Balun. BNC connectors Coaxial cable Other types of cables that can be used  Passive Video Baluns

 Video Recorder A video recorder is an essential device in a CCTV system. Initially, analog video recorders with VHS tapes were used for this, and with the advancement of technology, digital video recorders are used today. Well, let's see what a Digital Video Recorder (DVR) is. Video in a DVR is recorded on a hard disk. DVRs are manufactured according to the number of cameras they can fit. (eg - 4 Channel DVR, 8-channel, 16-channel, 32-channel). And there are mainly 2 types of DVR. 1. PC-based DVR 2. Stand-alone DVR Any desktop computer can easily be turned into a PC-based DVR. But PC-based DVR is not very popular. Therefore stand-alone DVR is widely used. Stand alone DVR  Front view of a stand-alone DVR Rear view of a DVR and accessories    DVRs have many different features and below are some of them. 1. Remote viewing - This allows the DVR to be accessed remotely via the Internet (Remote logging). It can be viewed and controlled remotely from the cameras in this DV...

CCTV cameras Cameras are one of the components that directly affect the quality of a CCTV system. That's why you have to pay more attention when choosing a camera. Let us now see the types of CCTV cameras and how they are used.  1. Dome Cameras These cameras are installed on the roof or ceiling.  Mostly used as indoor cameras. But can be used as outdoor cameras if equipped with IP protection.  2. Bullet Cameras  The name is given because the shape is similar to a gun bullet. Widely used as outdoor cameras but can be used in indoors as well. Most of these are equipped with IP protection and are mostly built with a metal frame. Has an adjustable cap that prevents falling water droplets onto to front glass.  3. Pan,Tilt and Zoom Cameras (PTZ Cameras) This type of camera can be rotated horizontally (Pan) and vertically (Tilt) and zoom in on distant objects. Because of that, these cameras can cover a wide range. And some of these cameras have the ability to operate a...

Well, let us now know what is CCTV. CCTV stands for Closed Circuit Television. That means closed-circuit television. It got this name because it provides frames to only a few TV screens from the respective cameras. That is because it does not transmit the image frames outside like normal television transmission. This field, which has quite a history, has made great progress today. There are two main CCTV technologies in use today 1. DVR CCTV systems 2. NVR CCTV systems Let's talk about DVR CCTV systems first DVR CCTV systems Now let's see what are the basics of this system. Let's see more details later 1. Cameras There are various types of cameras used in a CCTV system depending on the purpose. Camera types will be discussed in a later post.   2. Video Recorder Used to record input from the cameras. In the early stages, video cassettes(VCRs) were used to record the videos. In modern days Hard disks are used to record the videos and the unit is called Digital Video Recorder(...