Using spare telephone wires for voltage + video?!

[Multiplex]

This might be a strange one...!

I've just bought a CCTV Doorbell that operates essentially a push button doorbell with a covert pin hole camera.

http://www.visibellsystems.com/specs.html#instruction

The camera plugs into a control box that operates the chime and sends the signal on to the TV through a scart lead.

What I would like to do though, is use the spare wires in my telephone extension for the doorbell camera. This would save me from having to drill holes through ceilings and floors, which would be a last resort.

And the doorbell camera requires only four wires:

red positive
black negative
yellow video output
blue switch

I have three wires spare in my extension, but because it's only used for the Sky box I intend to remove the wire that provides the ring ring (pin 3).

So that would give me four wires running from downstairs to upstairs.

Since the camera itself is wired using a telephone style cable with an RJ22 plug on the end, would there be any problem using my telephone extension to run voltage down it, as well as the camera signal and the switch wire? The voltage is only 12v 120ma.

I do obviously need the extension to keep working for the sky box to dial out, but that's all!

Any thoughts would be great.

Simon.

 

[breezer]

its not allowed, you would obviously be mixing the camera with the phone

phone lines ar 50 v if anything goes wrong your camera may go, worse still if you put 12v down the phone line goodness knows what you could do at the exchange end, and it will not be hard to trace where it came from

you may also get interfearance on either or both

 

[plugwash]

can't really see how its any worse than runnign two phone lines down the same cable or running phone and ethernet down the same cable both of which are done frequenty

and all the wires are insulated to the highest voltage present

 

[Multiplex]

It wouldn't go down the exchange end, because this is an extension cable (that I wired myself) from the master socket downstairs to the upstairs extension socket. The cable is a six wire cable, and three are needed for the extension. The only wires I'd use are the wires in the extension cable that are currently free and unconnected.

All I really need to know, is if the voltage and video signal will disturb the telephone extension. And if it's okay to run some voltage next to the wires carrying the telephone extension.

Thanks,

Simon.

 

[ryanj]

As long as you own the cable, and the pairs are actually free, and the cables are rated for the highest voltage present, you should be fine, and interference free.

 

[breezer]

it may be an extension, i am concerned if the cable gets damaged then the two can cross, also as i said you are mixing something that isnt telephone into a telephone cable.

if you really want to do it then go ahead, but dont say i didn't warn you

 

[Multiplex]

I'll let you know how I get on then!

Thanks for the quick replies.

Simon.

 

[AdamW]

When running home networks over phone lines (isn't actually ethernet, is a different standard called HPNA) you are running signals over the same conductors as the phone signals. So you have devices built to handle these voltages, and with protection in case they are connected to incorrectly wired phone-lines.

You are planning to use separate conductors, so provided you are careful to connect the correct wires (as you would be) then I can't see any technical problems with it. You may get interference on the picture coming from the camera if the Sky box is connected at the time.

Sky boxes only ever dial out, they are never dialed into so the ringer conductor is, as you have worked out, not required.

 

[plugwash]

When running home networks over phone lines (isn't actually ethernet, is a different standard called HPNA) you are running signals over the same conductors as the phone signals. So you have devices built to handle these voltages, and with protection in case they are connected to incorrectly wired phone-lines.

i was refering to runnign phone and ethernet down different pairs of the same 4 pair cat5

i've seen splitters availible commercially that do the wiring for this (the sort of thing used when they rearange offices slightly and don't want to go to the trouble of running in a new cat5)

 

[AdamW]

i was refering to runnign phone and ethernet down different pairs of the same 4 pair cat5

Yes, sorry . I thought you were talking about running ethernet down phone cable, but re-reading your post you were talking about phone down cat5.

Cat-5... is there anything it can't do?

 

[Lectrician]

I have recently used the said splitters to run network and PBX down one cat5e cable. Works a treat, and saved a lead trailing around the room

 

[Multiplex]

Well I got it working ok. In the end I didn't have to run any voltage, only the video signal, the ground for the video, and the pin 8 scart switching.

Using the standard telephone cable in my house I get a great picture! I can't actually believe how well it's working.

Simon.

 

[ban-all-sheds]

Cat-5... is there anything it can't do?

10Gbit.