Possible uses for Power over Ethernet

jsailor writes "Power over Ethernet allows devices to draw power from the Ethernet cable they use for networking. Power is provided by the LAN switch (end-span) or an intermediary device (mid-span). The current spec. is 802.3af and was covered on slashdot before. It provides approximately 13W at the end of a 100 m cable and is commonly used for IP phones, wireless access points, and increasingly security cameras. The technology saves costs associated with running power to the odd locations access points find themselves in and allows IP phones to be moved around with out carrying a power brick. The industry is considering a new standard that would provide up to 39W to a network device. Bizarre uses include electric razors. "

the next USB

[wattersa]

I for one would like to have my ethernet hubs use the standard wiring for power rather than a brick and AC adapter that I have to find an outlet for. Since telephones already do this it's just the next step in the direction of USB everything. Which seems to be a good thing (tm). Now I know how to set up a LAN in an unwired munitions bunker...

13W could be dangerous...

[Sheetrock]

Depending on the voltage and amount of power involved.

There are a couple of drawbacks to this plan: first, the increased caution that will be necessary in working with network cable (everybody's used to them being safe as phone lines) and second the possibility of burning out devices that weren't built with this standard in mind. Who's to say that a cheapie network extender installed in a rat's nest of cabling five years ago wouldn't start a fire when you hook something like this up?

Re:Easy enough,

[Vectorferret]

Tesla (who worked with Edison on early electric devices) wanted to transmit electricity wirelessly. Edison ruled it out because you couldn't charge for it that way. It's a good thing Edison won out, as to get enough electricity to power anything useful into the air over any real distance would be a huge cancer risk.

DC power -- sad failure of standartization

[mi]

As much as the AC standard can be considered a success -- even if different regions use different voltage and connectors, the sorry state of the DC power is an outrage.

Why does every DC-using device come with its own adapter, and uses its own voltage? Why could not we standardize that?

Maybe, this "power over Ethernet" initiatives (together with the "power over USB") will spell the end of power-strips with curiously shaped "bricks" constantly falling out of them...

Re:13W could be dangerous...

[MORTAR_COMBAT!]

an excellent post. volts [computerhope.com] don't kill people, amperes [computerhope.com] do! and since watts [computerhope.com] are the product of voltage and amperage, and voltage will be likely low... this would lead me to believe that yes, these could be dangerous devices with a good amount of current going through... a physics professor of mine once said "it only takes a single amp to stop your heart"... oh yeah! now we can play flatliners without the need for a power outlet! sweet!

Re:13W could be dangerous...

[willpall]

Actually, there's a constant DC voltage of ~48v (less by the time it gets to your house). The ring voltage is AC and closer to 100. Yes, it does fucking hurt.

Electric razors?

[RealAlaskan]

Bizarre uses include electric razors.

I'm trying to think of places where I have seen an ethernet jack but no wall power. Hmmm .... zero. Never seen such a place.

Now I'm trying to think how many times I've wanted to shave in a room which contained an ethernet jack. Hmmmm .... zero.

So, come on, somebody, tell me why you would buy a power-over-ethernet razor. I'm stumped.

Re:Easy enough,

[Ignignot]

That's a tesla coil, completely different than what I'm talking about. However, you do have several in your house. Any CRT's use them, if my memory serves correctly. Not particularly dangerous. The most dangerous electric appliance in your house is probably the toaster or hair dryer.

Re:Easy enough,

[saider]

It's a good thing Edison won out, as to get enough electricity to power anything useful into the air over any real distance would be a huge cancer risk.

Please provide some references for this. I did a paper on this topic about 6 years ago and I could not find one study that provided a link between power and radio frequency radiation and cancer.

What I did find was a lot of people who wanted to blame someone for their ailments. I read several complaints and they all basically read "there were no carcinogens found in the soil/air/water. A percentage of the people all lived close to power lines. Therefore the power lines must be at fault." From what I understand not one of those arguments held up under scrutiny.

Re:Electric razors?

[Drishmung]

On the other hand, if you've every travelled outside North America, you've probably seen a wall socket into which your razor would not plug (without an adaptor). http://users.pandora.be/worldstandards/electricity .htm [pandora.be], http://www.powercords.co.uk/standard.htm [powercords.co.uk]

Now, imagine a universal, world-wide standard for low power devices. Would that be useful?

Re:Easy enough,

[timster]

As I recall the whole "power lines cause cancer" thing was an example of irrelevant correlation. Turns out that statistically it tends to be poor people living next to high-voltage power lines and poor people have higher cancer rates for all sorts of other reasons.

Re:the next USB

[Anynomous Coward]

I'm still angry at USB and FireWire for coming out with Yet Another Standard when Ethernet was already available, cheap and ubiquitous.

Think how great it would be to just plug in all the equipment into ethernet. Keyboards, mice, webcams, the lot. Just pair the devices with a button just like it is done with wireless mice.

But no, they really had to reinvent the wheel...