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Welcome to the "History of CCTV" Section | |||||||||||||||||||||||||||||||
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Dennard 350 housing on a 230 P/T head - circa 1976 | |||||||||||||||||||||||||||||||
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Unlike Dome cameras which appear to be sprouting on every piece of available wall space in the known universe (well almost!), the application of these discreet designs are surprisingly not a new phenomenon, but were actually already being used in the early '80’s. As cameras have become progressively smaller, so too have the ancillary items of equipment used to build a complete system. The first weatherproof camera housing that Doktor Jon used was not a lot smaller than a standard size golf bag, and the combined weight of this huge metal box, window wiper, camera and monster zoom lens, meant that the pan and tilt head also had to be ever so slightly impressive. Capable of carrying a 70Kgs. load in high winds, this leviathon of a motorised platform was possibly responsible for as many ‘slipped discs’, as it was for apprehending villains. Whilst the earliest control systems were lovingly built with ‘hard wired' hand tied wiring looms, the main techniques for “making things move” were either Direct Drive (i.e. sending the correct control voltage straight to the lens or Pan and Tilt head motors), or Relay Interface where a low level control voltage was sent to switch electrical relays located close to the camera itself. By the late ‘70’s, using ‘sophisticated’ 1 MHz (!) industrial micro computer control boards, digital Telemetry was starting to appear as the preferred method of building & controlling much larger and more elaborate systems. So much so, that by the end of the ‘80’s, Relay Interface had almost disappeared, and Direct Drive is now only ever used for the shortest of short range applications. Whilst we’ve already had a quick look at the development of cameras, it's actually the display part of a CCTV system which appears to have taken an absolute eternity to evolve. Forty years ago, Black & White (monochrome) monitors based on Cathode Ray Tube (CRT) technology , were the norm, and yet here we are all these years later, and you can still buy pretty much the same piece of equipment, but at around 1/4 of the equivalent price.
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