Guest CCTVINSTALLER Posted May 26, 2004 Posted May 26, 2004 Hi all, Just been having problems recently with power supplies. Give you an example last week i done an installation for a house- 4 colour IR cameras (12V) with 250ma power consumption. I connected them to a DVR and used 2X 12V 2.5amp power supplies (plug). Thats 2 cameras to each 2.5A power supply! I used RG59 and alarm cable for power and video and the cable run for each camera was no longer than 20metres. I thought it might be the DVR so i connected the cameras straight to a monitor. You get a wave and line going through the picture and camera picture starts jumping up and down every now and then. Is there any specific power supplies anyone can recommend, or can anyone spot an error in my installation method. Thanks for your help Mathew clifford
CompostCORNER Posted May 26, 2004 Posted May 26, 2004 The installation seems sound enough. You mention it's in a house so this most certainly won't effect you unless it's like a massive stately home but i gotta ask. Are all your cameras, monitors, DVR's PSU's all connected to the same phase? Secondly, I'm not doubting your installation skills but are the PSU's regulated? You mention (plug) in your post as if they are the plug in transformer type of PSU's. If they are like over the counter units available to the masses, they may well be unregulated. If they are, your 12vdc power supply units could be sending as much as 17vdc to your cameras not only causing image problems but possibly damaging the cameras too. If the installation checks out, then maybe it's induced interference. Over 20 metres though, I would have thought any image problems would have been very minimal. After ruling out the above, I can only think of faulty PSU's but with power supply units, from new, they either work or they dont. Tony
Guest CCTVINSTALLER Posted May 26, 2004 Posted May 26, 2004 Tony, The PSU is a 12v regulated AC Adapter. Could you recommend any specific supplier to purchase PSUs, i have quite a few trade accounts, is there any model you've found robust? Mathew
CompostCORNER Posted May 26, 2004 Posted May 26, 2004 You'd be correct to reccoment Elmdede PSU's. Used them many a time. Also used Gardiner Tech's G100 psu. Only a 1amp unit but looking good with that Gardtech500 housing. Not had any probs with the Elmdene stuff. I've recently used a VCL PSU that was a 6 x 2amp psu. Basically a PSU with 4 seperate 2 amp outputs. This was used for 2 NRC's (numberplate recognition Cameras) that had IR LED's fitted. Only problem was it drew 3.1amps when powered up for about 5 seconds even though the cams plus LED's rated at 1.5 amps according to the specs. I guess it dragged a fair bit of load upon power-up. Always better to use a boxed battery backed-up power supply unit even though the battery is irrelevant on CCTV systems due to power fail cuts the DVR. It's easier for fault finding. Tony
Guest Andyp Posted May 27, 2004 Posted May 27, 2004 Have you tried referencing the negative on the PSU's to see if that has an effect? Another thing to check is the monitor(assuming that you have one fitted) Is there a termination switch (Hi/Lo or On/Off). If there is check the position of the switch. Not necessarily this causing the lines but can cause a dodgy picture. By the way what colour IR cameras are you using? Is there such a thing? Andy
Guest CCTVINSTALLER Posted May 27, 2004 Posted May 27, 2004 Andy, The IR cameras are basically a range of day/night bullet cameras with 12 IR Pieces with a range of about 10metres. We don't use them much anymore due to the short range, its difficult installing them in driveways, they don't illuminate very well, but they aint that bad for domestic purposes- 1/4" sony CCD with 420TVL. Does anyone use any IR cameras which have a better range- more than 10metres and found them reliable. I think we use AVTECH cameras if anyones heard of them and they only cost around £60-£70 trade. We also use a submergible bullet line fed camera (1/3" sony hyper HAD CCD) they're not bad because they come with 30metres of RG58cable, and a special power supply' no need to run extra alarm cable for power, but they cost around £30 more than the IR bullets.
Guest Andyp Posted May 27, 2004 Posted May 27, 2004 I take it that by day/night you mean colour/monochrome switchable? Any luck with the power supplies? Andy
Guest CCTVINSTALLER Posted May 27, 2004 Posted May 27, 2004 Nope not yet, ive ordered 20 Elmdede PSU hopefully they'll solve the problem, which PSUs do you usually use for 12V cameras?
TSS Posted May 27, 2004 Posted May 27, 2004 We had a similar problem with some Advanced Vision Cameras we installed in a resi. The cameras themselves were quite nice (a pleasant/refreshing change from Dennard Domes) but had problems ghosting and such. Spoke to their tech support (V helpful) they dont like Elmdene PSU's at all... Still we bought their regulated psu and it works fine now TSS Communication is "A question asked, and an Opinion given." I offer mine to help you with yours. Statements I make are my personal views only at the time they are posted, if I offend you sorry, must be taken in context and do not neccesarily represent those of my employer.
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