High Power over DSL (Ethernet extender)

[propus]

Hi,

I've been looking around the Internet for some time now. Months, even years for a supplier who can help. I came across this forum and thought what the heck, I'll post up and see if anyone can help.

I'm looking for a Copper based Ethernet extender (twisted pair or coax) capable of operating on cables of around 5km in length. Downlink speeds should be as high as possible, but I'd like a minimum of 5Mbit/s. Uplink can be as low as 0.5-1Mbit/s. Fully rate adaptive with the option to manually set limits.

The hardware also has to be reasonably compact. Rack mount is not an option.

Now for the difficult part...
I also need to send power on the same twisted pair (or coax) cable. The power can be injected from a stand alone PSU which I can source easily enough so I'm not worried about integrated/onboard PSU. The thing is I'm looking for power in the region of 400Vdc @ 2amps.

Anyone got any ideas, pointers, suggestions, etc? Or if someone tell me where I could purchase such an extender that would be great!!!

Ideally I'm looking for a long range, HV over VDSL2 kinda product

 

[pitz]

Twisted pair/coax and 400VDC don't belong in the same sentence.

If you're putting in electrical cable, why not just run fibre along with it? Transceivers for fibre over those distances are dirt cheap.

What are you trying to do anyways? 400VDC circuits obviously have special protection requirements, and you really should be working with a professional (engineer) on this to ensure compliance with the relevant electrical codes and for personnel safety.

As you've probably figured out, this isn't exactly just off-the-shelf sort of gear.

 

[Fardringle]

The extremely tiny wires in twisted pair and coax cables simply won't be able to handle the 400 Volt/2 Amp current. With that much voltage/amps, you'd melt the copper before you even got a usable current at the other end.

 

[propus]

The coax I'm be using is 14AWG core and 12AWG screen contained within an 11mm double armoured steel cable. I have the HVdc PSU, power distribution, filtering and safety circuits already. DC-DC modules, filters and voltage reducers are all in place for stepping the 400Vdc down to usefull voltages at the other end. By using 400Vdc I can run the system at around 1amp which results in very little heat and minimal power loss over the cable. Getting the same wattage at the other end using say 24Vdc or 48Vdc would require dangerous currents!

At the moment I have a complete working system... Two versions actually. First system is based on ADSL and the second system is based on a VDSL2+ which will down grade to suite cable length.

Unlike a normal PoE setup I dont just have an IP camera or small monitor to power and control. I'm using up to around 720Watts. Yes this is not off the shelf, but that's why I'm here asking around. A few years ago PoE wasn't off the shelf

My current setups are bulky and required several custom circuits integrated in an imaginative way with off the shelf equipment.

To give an example I currently have a rack mount PSU, PC, Monitor and custom built interface box at one end of the cable. At the other end of the cable I have 8 high intensity LED lamps with about 1,400lm output each, each lamp is RS485 controlled, I have 2 video cameras streaming live video, both cameras with RS232 data/control, various other power relays, sensors, pan and tilts etc all with Ethernet, RS232 or RS485 serial data outputs constantly streaming. All data, video and control is continuously streamed up to the PC and recorded whilst the 400Vdc is injected down the cable to power everything. This all over a single coax. Basically I'm multiplexing VDSL ontop of a 400Vdc coax power line.

I'm looking for a way to simplify this setup by using off the shelf or built to spec items. The closets I've come is PoE, but the power is just not anywhere near enough and I need power over DSL? Has anyone seen anything like this anywhere?

 

[bobdole369]

The best you can handle at 10mbits over coax is roughly 300meters. Thats it. Period. Anything more you may as well move to a full docsis transceiver. http://www.gefen.com/gefentv/gtvproduct.jsp?prod_id=5275

Also it won't like 400VDC on the line so just forget about that. Use your coax to pull a fiber to lash to it and be done with it.

 

[drebo]

5km is way too far. Also, 400V over the same pair will fry any piece of equipment you put on there. The attenuation at 5km would make 2amps almost useless at the other end as well.

You can get the data to about half that using these: http://www.startech.com/Networking-I...it-2km~EOC110K

But, you're asking the impossible.

 

[propus]

Sorry guys but my current setups are working. As I said I have used a very imaginative setup. The above are not theoretical setups. They are actual working systems of which I have built around 30 similar systems over the last 5 years. The next step is to reduce the space required for all the hardware.

I have also built fibre based systems, but in some cases swapping the cable from coax to fibre is just not an option.

2amps doesn't sound a lot, but at 400Vdc it can be stepped down to 24Vdc 30amps!!

Imagine having an outpost 5km in the middle of nowhere and being able to lay a single cheap armoured coax cable and provide that outpost with high speed data and 700-800watts of power.

I need some out of the box thinking or directions to companies who may be able to help. Larger companies are not interested, but small independent companies have supplied a few odd ball things in the past.

Voltage drop on 5km cable is about 30Vdc at around 1.5amp draw which is fine as the DC-DC modules I use are spec'd for 320-400Vdc. The PSU is set to supply 400Vdc from the other end. I can even convert the dv voltage to 240vac at the far end if required.

This isn't pipedream stuff. This is working kit out in the field.

 

[bobdole369]

If you have a working system, then what the hell is the question?

Unlike a normal PoE setup I dont just have an IP camera or small monitor to power and control. I'm using up to around 720Watts. Yes this is not off the shelf, but that's why I'm here asking around. A few years ago PoE wasn't off the shelf

Nothing off the shelf exists, go file a patent and sell it to the few people to whom something like this makes sense.

Sorry guys but my current setups are working. As I said I have used a very imaginative setup. The above are not theoretical setups. They are actual working systems of which I have built around 30 similar systems over the last 5 years. The next step is to reduce the space required for all the hardware.

I have also built fibre based systems, but in some cases swapping the cable from coax to fibre is just not an option.

2amps doesn't sound a lot, but at 400Vdc it can be stepped down to 24Vdc 30amps!!

Imagine having an outpost 5km in the middle of nowhere and being able to lay a single cheap armoured coax cable and provide that outpost with high speed data and 700-800watts of power.

I need some out of the box thinking or directions to companies who may be able to help. Larger companies are not interested, but small independent companies have supplied a few odd ball things in the past.

Voltage drop on 5km cable is about 30Vdc at around 1.5amp draw which is fine as the DC-DC modules I use are spec'd for 320-400Vdc. The PSU is set to supply 400Vdc from the other end. I can even convert the dv voltage to 240vac at the far end if required.

This isn't pipedream stuff. This is working kit out in the field.

 

[propus]

Im looking for off the shelf or smaller electronics. A bit like PoE but PoDSL?! I haven't seen anything off the shelf, but it's almost like those ac power plug in Ethernet extenders you use in your home to create a network.

Currently I'm using a mix of off the shelf kit, stripped down, modified and interfaced with custom circuits. Messy and bulky. A single board which would allow me to inject HV into a DSL, ADSL, VDSL etc line would be ideal.

Question is has anyone ever came across this type of stuff? Any company, websites, independent developers details would be worth me looking at.

By the way the startech web site has some nice looking bits n bobs. Thanks.

The gefen stuff is sweet and has really come on over the last few years. Not what I'm looking for for this application, but I have considered using their kit on other projects including my own home

Cheers for the input guys. Anymore suggestions even mad ones are welcome.

 

[al ballantine]

old thread bump!

Hi,
I have some info about this topic and know of other kit out there that uses 400Vdc. I'm trying to put a similar system together myself (Power & DSL over 5km+ armored coax cables).

Anyone know of an off-the-shelf option yet?
Did the OP make any progress?
A lot can change in 5 years! (i'm hoping)