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Posted by ryuzaki0 on from the net-comes-with-free-juice dept.

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.

4 of 182 comments (clear)

  1. Power causes interference? by NeoSkandranon · · Score: 4, Interesting

    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)
  2. FireWire, USB by 73939133 · · Score: 4, Interesting

    "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.

  3. Ground loops and differences by EmbeddedJanitor · · Score: 4, Interesting
    One of the reasons ethernet is AC coupled (transformers etc) is to break direct current paths. It scares me somewhat that people are thinking of reintroducing these by power down the wire.

    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.
  4. It's a bird! It's a plane! It's Legacyman! by MerryGoByeBye · · Score: 4, Interesting

    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.