In the early eighties cameras, which were as large and as heavy as bricks and consumed a great deal of power, used tube technology from the days of early electronics. These tubes had to be changed every few years, or if very sensitive, every few months, resulting in high maintenance costs.
In the late eighties, solid state technology started to appear and the buzz word became CCD (charge coupled device). This one inch piece of silicon was light-sensitive and its face was etched with 250,000 fine light sensitive transistors, each of which switched on and off as photons of light energy hit the surface. These 'pixels' could be scanned and arranged into a picture and so the chip camera became a reality.
These new devices and support circuits reduced the size of camera to less than a third of the size of its tubed cousins. It was however three times the price. Since then, a number of factors have contrived to bring down the costs to a point at which they are affordable to the masses.
The image sensor size came down to about a ninth of the area of the first chip cameras, and the associated cost savings were accordingly passed on.
Sensitivity and pixel count has soared so now true twilight cameras with 600 line resolution from 600,000 pixels are available.
Size has diminished with the use of SMT (surface-mount technology). This has resulted in some cameras having board sizes of less than 32mm sq.
Here in South Africa, because of the alarming levels of crime within industrial sectors, both manufacturing and retail, the rapid growth of the CCTV industry comes as no surprise. With CCTV becoming affordable, even to the smaller operator, more and more installers are turning to CCTV technology in addition to the more conventional intruder detection methods such as burglar alarm systems, access control and gate automation in order to protect their customers' businesses. The widespread use of cameras, both covert and overt, in retail stores, factories, warehouses and offices is now commonplace, reducing both customer and employee theft.
GKB - a CCTV specialist
Always mindful of needs and demands within the security industry, Sesco Security, in association with its overseas supplier GKB, distributes an ever expanding range of CCTV products to many customers country-wide.
Established in 1985, GKB specialises in the manufacture and export of cameras, monitors, video switchers, quad systems, scanners, multiplexers, controls and other accessories for CCTV systems.
Peter Jen, GKB's sales manager, says that more than 13 years' experience and numerous successful projects has ensured GKB a reputation in the market for its high-quality and cost-effective products. GKB has a 660-square metre factory with more than 40 workers to handle its production, which has increased dramatically over the years.
High-quality B/W, CCD cameras are available through sole SA distributors, Sesco. Employing a 1/3" image sensor, the cameras feature excellent resolution of 450 TV lines, and minimum illumination of 0.02 lux . They offer BLC (back light compensation) and a DC drive, with current consumption approximately 200 mA at 12 Volts.
GKB mini CCD cameras are also of the highest quality, featuring auto-shutter control, AGC-control circuit, and built-in wide-angle lens.
A popular addition to the range is the durable weatherproof camera with high resolution (420 TV lines). The low-light (0.02 lux), 1/3' B/W camera features a built-in lens and bracket for easy installation. It's ideal for outdoor applications. Its supplied with the transformer and needs no outdoor housing as its casing is durable metal and is completely weatherproof.
Dummy cameras are also available, comprising an empty camera case with dummy lens, and an LED which flashes for authenticity.
Covert pinhole cameras are amongst the smallest on the market and easily fit into an ornaments, PIR casings, etc.
Dome cameras with built-in lenses are also available, as are a full range of sophisticated colour cameras.
Both B/W and colour monitors are reliable and feature clear, sharp, stable images.
GKB's video switchers feature smooth switching without picture roll or flutter while using a VCR to record. Models SW-604/608 allow one or two monitors to connect up to four or eight video cameras. The unit's display camera outputs in automatic sequence and permits other switchers or video devices at different locations to operate independently.
Jen says that GKB constantly invests in procuring advanced facilities, upgrading technology and developing new products. He adds, "We have obtained CE and FCC approvals and are proud that our products are known for their reliability and cost-effectiveness." Major markets include America, Europe and Africa.
For details contact Sesco at: Durban 031 3034022, Johannesburg 011 4556234, Cape Town 021 4486333, Port Elizabeth 041 581 3122, East London 043 7420327, Pretoria 012 3481560, Windhoek 0926461 220830, or e-mail: sales@sesco.co.za.
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