Monday, January 21, 2013

CCTV Camera Monitor Type

B/W Monitor and Color Monitor

  In the past, 9 to 12 inch (diagonal) B/W CCTV cameras monitors were very popular in the field. Nowadays, more and more people are looking for high inches and color monitors. As it known to us, 3 different color dots can produce one pixel of information, so, color monitor  usually has lower resolution than B/W monitor.

Single Monitor, Quad Monitor and 4-Channel Monitor

  Single Monitor is usually professional monitor with one video input of BNC jack.In order to combine multiple cameras, we should use Quad splittervideo switcher or multiplexer. Quad monitor has built-in quad splitter and usually has 4 DIN jacks for video inputs. 4-Channel Monitor contains 4 channel video switcher inside and usually has 4 DIN jacks for video inputs. Quad Monitor or 4-Channel Monitor is usually a part of packaged observation system and does not match other manufacturer's camera or cable.

Saturday, January 19, 2013

Video Switcher Introduction

Video Switcher is a device which can show multiple CCTV cameras on one monitor screen, manually or automatically. When it runs on automatic sequential mode, the dwelling time on each camera can be changed from 1 second to 30 or 60 seconds. When video switchers have BNC jacks and your cameras have RCA connections, you will need BNC/RCA adapters. you can buy it at any electronic shop like Radio Shack or Best Buy, etc. The equipment supplier should provide adapter or you can buy it at any electronic shop like Radio Shack or Best Buy, etc. Most commercialized video switchers have 4 channels or 8 channels, that is, we can connect 4 or 8 cameras. Video Switcher works for both B/W and color cameras. A Video Switcher can be connected to a CCTV monitor, TV or VCR.

Thursday, January 17, 2013

Quad Splitter

  Quad Splitter is device which can combine 4 cameras and show them on one monitor screen at the same time. A built-in switcher can display the pictures one by one. There are two types for video inputs to choose, BNC jacks or RCA jacks. You can select one based on camera's video connection type. But, if the video input jack does not match your camera's type, a BNC/RCA converter is needed, you can buy it at any electronic shop like Radio Shack or Best Buy, etc. B/W splitter works with B/W cameras and color splitter with color cameras. A quad splitter can be connected to a CCTV monitor, TV or VCR.

Wednesday, January 16, 2013

Network Lines for CCTV Transmission

Nowadays, we use the Internet or intranet line as a video transmission method. DSL and T-1 are used for the Internet and LAN (or WAN) is for intranet. 

  DSL (Digital Subscriber Line) speed is from 144 Kbps to 1.1 Mbps. (More than 1.5 Mbps speed is called T-1), you need use a router with RJ45 jack to connect a web camera to a DSL, DSL supplier provides the router. If you need to connect several web cameras, you need a hub with multiple RJ45 jacks. You will have static and public IP address(es) (provided by the DSL supplier) assigned to the 
web camera(s). This IP address will act as a web site address on the Internet. 

  SDSL(Symmetric DSL) is strongly recommended. SDSL has same upstream and downstream bandwidth, while downstream bandwidth of other DSL (IDSL or ADSL) is larger than upstream bandwidth. We should upload web camera's video data to the Internet, so a SDSL is more suitable for the web camera. To see the pictures from the camera, a residential DSL or even Cable TV line will be fine. (Refer to 
the bandwidth and the speed of a web camera for detail) 

  LAN (Local Area Network) or WAN (Wide Area Network) has intranet network in a limited area or organization and has several computers connected to the network. Web camera servers acting as computers can be connected to LAN or WAN so that each computer can share the video data. The jacks between
Web camera servers and LAN or WAN is RJ45.

What is Web Camera

Network IP camera
Web Camera
  Web Camera (Network Camera) consists of a CCTV Camera and built-in network video server so that it can be connected to a network line such as DSL or T-1 for the Internet or LAN. When the camera is assigned an IP address, you can view the camera's video no matter where the network line is available.

  One of the important features of web camera is the speed. The image compression technology for Web camera is very pivotal. For now, the Wavelet is the most competitive compression algorithm with compression rate 30% to 300% higher than other technology such as JPEG or MPEG.

  Another excellent ability of web camera is programmable, when detecting movement by web camera, the maximum 5 pictures can be send to your email 

Monday, January 14, 2013

Coax Cables for CCTV Camera

  RG means military specs Radio Guide and the numbers of RG are kind of arbitrary. Nowadays, the most popular RG designations are RG-6, RG-8, RG-11, RG-58 and RG-59. RG-58 and RG-8 are 50 ohm coaxes which is unsuited for video work. RG-6, RG-59 and RG-11 are 75 ohm cable types, RG-59 is the smallest (20 AWG centre conductor), RG-11 is the largest (14 AWG), between RG-59 and RG-11 is RG-6 which is 18 AWG.

About Wireless Transmitter and Receive

Wireless transmission is considered When it is difficult for camera to use a cable to transmit video signals to the monitor. But, heavy metal walls, high voltage power lines, microwave equipment can attenuate or block the wireless signals.

FCC strictly controls the wireless transceiver system. Manufacturers initialize the commercialized models and you don't need to get a separate FCC approval. When you want to change or modify the model specification, you need to get prior approval from the FCC. Each manufacturer has unique bandwidths of frequency derived from the FCC and cannot be compatible with other manufacturer's models. 

  Most commercialized wireless systems have 4 or 10 channels, given conflicts of the overlapped channel(s), it is impossible to use more than 4 or 10 transmitters in one area. But you can increase wireless receivers as far as they are within the range.