Lectrician Posted December 7, 2004 Posted December 7, 2004 OK, i am new to CCTV really, I have installed some systems supplied by the wholesaler, but have a question. What type of signal does the standard CCTV give via the BNC connector?? Can this be conected to a standard TV via the composite input?? How do you calculate possible volt drop on the 12vDC feed to cameras?? and what cable to poeple regularly use to feed them (I have seen flex, alarm cables 'doubled' up, and speaker cabel.) Email : martin@askthetrades.co.uk
Lectrician Posted December 7, 2004 Author Posted December 7, 2004 God, reading that, I have realised I need to slow down when typing....and drink less for any response Email : martin@askthetrades.co.uk
Rich Posted December 7, 2004 Posted December 7, 2004 What type of signal does the standard CCTV give via the BNC connector?? Can this be conected to a standard TV via the composite input?? 1Volt P-P composite video which indeed can be connected to a standard video input. How do you calculate possible volt drop on the 12vDC feed to cameras?? and what cable to poeple regularly use to feed them (I have seen flex, alarm cables 'doubled' up, and speaker cabel.) 33979[/snapback] I usually use .5mm round twin flex up to 100 meters without problems.
ian.cant Posted December 7, 2004 Posted December 7, 2004 What type of signal does the standard CCTV give via the BNC connector?? Can this be conected to a standard TV via the composite input?? Any cctv camera will not connect direct to a tv ariel in, you either need a modulator to turn it into a tv type signal (VHF i believe) so you can find it with the tuner. Or you can connect it via AV leads and then pick it up as an AV channel, likewise with a BNC/Scart connector. Hope that makes more sense? As for power cable, i prefer to use .75mm 3 core flex, mainly because i get it for free basically. However you can use whatever cable you like as i am sure you know, the normal is the type cables you have already mentioned. As for calculating voltage drop, its been like 25 years since i had to that so being honest, you connect the power and meter it at the other end I find 12vdc/24vac down a .75mm flex goes a long long way, 200mtrs is no problem.
Brian c Posted December 7, 2004 Posted December 7, 2004 As for power cable, i prefer to use .75mm 3 core flex, mainly because i get it for free basically. 33998[/snapback] Send me the details of your supplier!! If you don't know......ask.
Guest Posted December 7, 2004 Posted December 7, 2004 Any cctv camera will not connect direct to a tv ariel in, you either need a modulator to turn it into a tv type signal (VHF i believe) so you can find it with the tuner. Or you can connect it via AV leads and then pick it up as an AV channel, likewise with a BNC/Scart connector. Hope that makes more sense? 33998[/snapback] Not sure who's confused here but I think someone is, (could be me)! Pretty much any camera will connect to a TV's composite in. For a TV with no AV\scart\composite in then the above is true.
Brian c Posted December 7, 2004 Posted December 7, 2004 What Ian said is correct. The Tv will not display CCTV camera images through the TV Aerial (VHF) input. Most ,if not all, modern TV's have a scart/AV/composite input aswell, though, that CCTV camera's can connect to. If you don't know......ask.
Rich Posted December 7, 2004 Posted December 7, 2004 What type of signal does the standard CCTV give via the BNC connector?? Can this be conected to a standard TV via the composite input?? 33979[/snapback] Just to clear things up, Composite Video is the signal cameras send out and what TV's use on the Video inputs/outputs and scart (standard 1 volt peak to peak video signal) You cant connect a composite signal to a tv tuner (rf modulator).
Guest cctvman Posted December 8, 2004 Posted December 8, 2004 Camera output = composite signal 1volt Tv antenna input = rf signal as it has an antenna (rf signal pickup) Three ways to put a composite video signal over to a standard tv 1 use an rf modulater about £15-£35 out of maplin cpc ect 2 use the av input on the tv(if it has one) was used for the old camcorders 3 use a standard household vcr av input all do it ! ( pins 1 & 3 stick in my mind but dont quote me on that). Agree with brian on 3-core mains flex also handy if your using a 12volt cam then want to change to a mains camera ect although i have to pay for mine Oh & tv today is UHF not vhf been the 60's since it was there although spain ect still use vhf along with france ect ect for the tech heads out there ULTRA HIGH FREQUENCEY normal audio output is around 468-480mhz & video signal just above Regards Al
norman Posted December 8, 2004 Posted December 8, 2004 These are the connections for a 21 pin scart to comp video, I have highlighted the ones most commonly used. 1 Audio right out 2 Audio right in 3 Audio left (or mono) out 4 Audio return 4 Audio return 6 Audio left (or mono) in 8 Video status out 8 Video status in 19 Composite video out 20 Composite video in 17 Composite video return 18 Composite video return 21 Shield Nothing is foolproof to a sufficiently talented fool.
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