 Hello friends, myself, Eryia Arsandane, assistant professor from the Department of Electronics, Walsh and Institute of Technology, Sulapur. Today, we are going to see the topic Close Circuit Television from the subject Audio-Video Engineering. So, what are the learning outcomes from this topic? At the end of this topic, students are able to explain the modification done in standard television system to achieve close circuit television system and also the working principle of close circuit television system. So, what is CCTV? The CCTV is known as close circuit television and introduction of CCTV. So, CCTV, it is a special application in which camera signals are made available only to a limited number of monitors or receivers. Hence, in this, there are different links used. The links used generally depend on first, distance between the two locations, second, the number and dispersion of receivers, third, mobility of either camera or receiver. Hence, the simplest link used in CCTVs where video signal from camera is connected directly through a cable to the receiver. This type of link is generally called as a simplest link. Introduction to CCTV, here you can see the block diagram for two different links. First link generally here, as you can see, direct camera is connected to the receiver or to the monitor. This is the simplest link and here you can see that there is a camera which is connected to several receivers or several monitors. As you can see here camera, then there is a video amplifier. The output of the video amplifier is carried through a RF cable and which is then given to the monitor. The basic difference between these two diagrams is that after the camera we are using equalizer and then the output of equalizer is given to the distribution amplifier where the amplifier amplifies the signals and then it gives to the different monitors or to the different receivers depending upon its receiving capacity. So working of CCTV, a television monitor which is also known as a receiver which uses or which does not use RF and IF circuits, here it is used only for the reception, hence it is known as the simplest link. Here one volt peak to peak signal is required for the monitor. Since the video signal is normally delivered through cables and even when it is transmitted it is over a limited region and for restricted use only. CCTV need not follow the television broadcast standards. As we know there are different television broadcast standards which include NTSC and PAL system which these are the two basic standards which are used in India. So as you can see here you will get an idea how a CCTV works, here there are different cameras or types of cameras used and then the output of these cameras is given to a DVR unit which includes a RAM of a high end RAM which stores the data and it also gives the output to the monitor. The output of DVR can also be given to a router through which the video signals can be given to the internet so that a remote client or remote storage can be done of these video signals. Hence in CCTV we can access the or we can see the video recording on a monitor as well as on the internet that is by using a proper remote client and we can store those videos hence by using a router unit. The CCTV uses components that are directly connected to generate, transmit, display and store video data. Many features exist within each of these categories that can satisfy any agency's operational requirements in the most challenging environment. So the most new CCTV systems maximizes the advantage of digital technologies by utilizing electronic database, compact components and wireless transmission techniques. So now we are going to see the different applications of CCTV. There are n number of applications of CCTV televisions. First one generally includes education where an instructor can give a lecture to large number of students sitting at different locations similarly close-ups of demonstration experiments and other aids can be shown on monitors during these lectures. So nowadays this kind of system is used in education where we can see the demonstrated experiments live when it is being performed and this can be seen from the different remote locations. Secondly, medicine. Several monitors and camera units can be installed to observe seriously ill patients in intensive care units that is ICU, in medical institutions, in medical institutions where operations are performed and these major operations can be shown to the medical students without their actual gathering around the operation table. So nowadays in India we are using CCTVs for this kind of application or major application in medicines. For businesses, television cameras can be installed at different locations in big departmental stores to keep an eye over customers and sales personnel. So nowadays when we go for shopping you can see in every departmental store or in every mall there is an CCTV which keeps an eye on the customer and also on the sales personnel. Surveillance in bank, railway yard ports, traffic points and several other similar locations closed circuit televisions can be effectively used for the surveillance purpose. In industry, CCTV has application in remote inspection of materials, observation of one of the major application is observation of nuclear reactions and other such phenomenon would have been impossible without these televisions. Similarly, televisions play a great role in scanning of earth's surface and probing of other planets. Probing means analysis of other planets. So these are the references for you people. Most of the CCTV part is covered in monochrome and colour television systems by R. R. Gulati. Thank you for watching the video.