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ReLik writes "The BBC has an article regarding power supply via networks. 'Instead of needing adapters, computer networks could soon be supplying the devices they interconnect with both data and power. Some makers of network equipment are already putting the power via data cable system into their products. The basic plugs for computer networks are the same all over the world, raising the possibility that powered data cables could become a universal back-up power supply.'" We've talked a little about specific 802.3 spec advances previously.
I admit I don't quite know the exact ins and outs of this technology, but a few things do come to mind:
Wouldn't supplying substantial amounts of power through network cable (lets say cat5) make enough EMI to scramble the data going through the other pairs?
Also, would this work in situations using coax cable, where there is no other pair?
Lastly, can you put 120VAC along wires that thin without causing lots of power loss and making a lovely fire hazard?
If you can't see the value in jet powered ants you should turn in your nerd card. - Dunbal (464142)
These guys make a GSM/GPRS base station that is powered over Ethernet.
Cool huh?
-- Mike
"The RJ45 connector is a universal outlet," he said. "It's the only one identical in Asia, Europe and the US."
The same is true for FireWire and USB, and those are far more widely available. In fact, USB is increasingly becoming the standard for recharging portable devices, with USB power cables for most PDAs and cell phones available. FireWire might be better for this than USB because it can deliver more power, but maybe the USB standard will catch up.
You can even get a USB toothbrush.
The RJ-45 connectors used with Ethernet really don't do it for me; I think both USB and FireWire connectors are far better designed. I think POE (Power over Ethernet) will remain a niche market.
Now this could be interesting. I worked on a system that toasted three Ethernet cards before we got a clue and stuck an isolating piece in the middle. It was on a long loop of thinnet cable which connected several buildings at a high school.
I suspect many of the buildings had separate power feeds and therefore different grounds due to being built gradually over the course of 40 years or so. The potential eventually got us, and cost us a few bucks and a lot of lost hair.
They had better be very careful with this stuff. Interconnecting building grounds over your network cables is a good way to fry equipment and unsuspecting people.
Not really, all a hacker is likely to be able to do is disrupt the data communications on the line, they probably wouldn't even be able to detect whether the line is carring power. Think xDSL over a phone line: hackers may be able to totally disrupt the xDSL connection, but they can't stop people making calls on the phone line.
Disclaimer: The above comment was made while under the influence of too much coding and not enough sleep.
Don't forget that the telco backbones are fiber optic..not the best media for power transmission. They're talking about using twisted pair.
I'm really surprised that they will try to do this, considering the voltage potential difference between buildings. I wonder if this will be limited to a small area. Even if confined to a small area, it will still be very effective. It would sure give somebody a reason to protect their network switches! I went to a college where the network switches got zapped at least once a year since they were not protected, and the building was a lightning magnet. This kind of thing used to fry a few network cards and would prove to be much more severe if power were carried over those twisted pair CAT-5 cables.
More than enough BS
To achieve reasonable distances and power, the voltage will need to be highish.
This reminds me of an incident that happened about 15 years ago. We had an ethernet cable between two buildings. The cable was terminated on computer chassis on each end. Unfortunately the two buildings were powered from different phases, so when I opened a connector I became part of the ground loop passing mains. This was not in USA, but was in a country with real (>200V) power.
Engineering is the art of compromise.
Umm, hello...
Can anyone please tell me what the point of putting real juice down Ethernet would be? Isn't Ethernet like 30 years old? Why don't we come up with a new FireWire/USB type plug with a configurable interface, set it up with +5V, +12V, Ground, Data Send and Data Check, set up generic, open hardware-level frames capable of wrapping all other protocols and a spankin' new cable/plug combo which would shield the voltage lines? I mean, Christ, let's move on. Why are people still talking about Ethernet? Oh, and a better endplug would be nice; one that releases with a sharp jerk, stays put with a slow tug and has a satisfying, soft "click" when engaged.
I realize I will get downmodded for this, but I am being quite serious.
+1 Informative? Sucker. It is obviously a joke! Even the name is part of the joke "u" = micro as in micro-wave!!! Man, only on slashdot!