Charging an iPad with PoE

js.dk

macrumors newbie
Original poster
Jan 17, 2012
2
0
Hi,

I need your help, i want to charge my iPad with PoE (power over ethernet) from the switch. Do you know if i can get a kit for that?

Jonas
 

takeshi74

macrumors 601
Feb 9, 2011
4,974
68
I would be surprised if Apple would allow charging via PoE.
It's pretty clear that they don't since the iPad doesn't have an RJ45 jack. If the adapter can properly convert I don't see why not. Whether Apple supports it or not isn't really relevant.
 

miles01110

macrumors Core
Jul 24, 2006
19,261
31
The Ivory Tower (I'm not coming down)
This is true. I think he just assumes if a current is flowing, then it'll charge. Devices are a little more technologically advanced nowadays. :p
Shrug. Even old Apple Firewire adapters don't charge modern iDevices. Learn what you're talking about and things make a lot more sense. If a device doesn't support a protocol, it won't work the way you want it to.
 

jeremyshaw

macrumors 6502
Oct 29, 2011
340
0
Shrug. Even old Apple Firewire adapters don't charge modern iDevices. Learn what you're talking about and things make a lot more sense. If a device doesn't support a protocol, it won't work the way you want it to.
Not that easy, as long as there is 5V, and above 150mA (blank out the two data pins), the iPad will accept it as a charging circuit. Of course, 150mA may not charge anything fast enough at all...
 

Lagranger

macrumors member
Jun 22, 2010
45
0
A question that seems simple in theory, but in practice is a bit complicated to answer. To recap comments in previous posts: yes, there is a specific sensing protocol iGadgets use to determine if they're plugged in to a compatible power source, particularly iPads which require more current to charge properly in a decent amount of time. (Also mentioned, much of this 'protocol' is implemented using pullup/down resistors on certain connector pins)

But also remember that PoE (802.3af) uses a sensing protocol as well and isn't entirely as simple as a DC power supply tapped into a network cable. So the PoE endpoint will require more than just a DC-to-DC conv. to give you the 5v to plug the iPad cable in to. There *are* a few companies selling PoE splitters that will break out 5vdc (and something like 2A) off of a PoE connection, so it is possible you could cobble something together, but that's already veering into some basic hardware hacking and most may not want to risk that level of experimentation on their iPads.

Another (probably non-practical) suggestion. I've seen a few PoE enabled VOIP phones that have USB ports on them. Granted these are probably low-power ports since they're likely for things like flash drives and headsets, but some may provide enough juice to charge your iPad, albeit slowly. (With the proliferation devices that are charged through USB, I wouldn't be surprised if some VOIP handset makers already design for this)

Gotta learn to write shorter responses. Sorry.
 
Last edited:

Amazing Iceman

macrumors 68040
Nov 8, 2008
3,949
1,538
Florida, U.S.A.
According to specs, PoE delivers power ranging between 44 to 57 volts DC, with the powered device receiving between 37 to 57 volts DC.

Check the pin config at this link: http://en.wikipedia.org/wiki/Power_over_Ethernet

It may be a little risky to try to make something like this without the proper knowledge and components. You would need at least a DC transformer, voltage regulator, RJ-45 plugs and connectors.

It would definitely be much easier to just use a wall charger; even a Solar charger may be more affordable.
 

BiggAW

macrumors 68030
Jun 19, 2010
2,542
171
Connecticut
You could probably figure out how to hack something together... but this just sounds like a terrible idea... and WHY on earth would you want to do that?
 

nostresshere

macrumors 68030
Dec 30, 2010
2,675
268
Hi,

I need your help, i want to charge my iPad with PoE (power over ethernet) from the switch. Do you know if i can get a kit for that?

Jonas
Why would you want to this.

There is no ethernet port.

Regular power adapters are dirt cheap. They work.

Huh??????
 

AllieNeko

macrumors 65816
Sep 25, 2003
1,004
57
Wow people on here are rude and there's some dangerous advice. You short data pins together and give it a 150mA rated supply and you'll kill the supply and hopefully not the iPad. Shorted data pins indicate 1000mA is available. If it isn't that's bad news.

Why PoE? Simple - PoE let's you use legacy installed CAT5 cabling for power up to 100m from the switch (802.3af). PoE is a great solution for wireless access points, wall clocks, VoIP phones, etc. Obviously being power-only is a stinky limitation for the iPad but oh well, it's still potentially very useful for embedded/kiosk type uses of an iPad.
 

BiggAW

macrumors 68030
Jun 19, 2010
2,542
171
Connecticut
Wow people on here are rude and there's some dangerous advice. You short data pins together and give it a 150mA rated supply and you'll kill the supply and hopefully not the iPad. Shorted data pins indicate 1000mA is available. If it isn't that's bad news.

Why PoE? Simple - PoE let's you use legacy installed CAT5 cabling for power up to 100m from the switch (802.3af). PoE is a great solution for wireless access points, wall clocks, VoIP phones, etc. Obviously being power-only is a stinky limitation for the iPad but oh well, it's still potentially very useful for embedded/kiosk type uses of an iPad.
Just run USB. Yeah, PoE is great for Wifi, Voip and security cameras, but it makes NO SENSE for an iPad.
 

AllieNeko

macrumors 65816
Sep 25, 2003
1,004
57
BiggAW, I can guess what the AW stands for. Why are Mac-heads so dang rude? Just because you can't see the reasoning doesn't mean others can't. The world is changed by people who are constantly being told "Why?" in such a rude way. I bet Steve Jobs was asked the same a lot, especially early on. Mac-heads just do not get it. Crazy ideas change the world.

Sure, it'd be dang nice if the iPad could do Ethernet on the dock connector, but even without it, PoE has a lot more potential than USB. USB runs at a very low voltage (5V). Sustaining the iPad's current draw at that voltage over any distance needs very thick cable. It's much better to run at a higher voltage (802.3af PoE is 48V) and convert it down right before you need it. Also, many buildings have Ethernet already ran. So an embedded iPad, such as a wall mount controller, could use existing cable and power supply (PoE switch) infrastructure, over very long distances, with a PoE to USB adapter.

For the right embedded application, it's a fantastic potential solution. Running 5V (USB standard power) a long distance in walls with new cabling is not. So, just because you don't have a use for it, quit being a jerk and putting down the people who do.
 

BiggAW

macrumors 68030
Jun 19, 2010
2,542
171
Connecticut
BiggAW, I can guess what the AW stands for. Why are Mac-heads so dang rude? Just because you can't see the reasoning doesn't mean others can't. The world is changed by people who are constantly being told "Why?" in such a rude way. I bet Steve Jobs was asked the same a lot, especially early on. Mac-heads just do not get it. Crazy ideas change the world.

Sure, it'd be dang nice if the iPad could do Ethernet on the dock connector, but even without it, PoE has a lot more potential than USB. USB runs at a very low voltage (5V). Sustaining the iPad's current draw at that voltage over any distance needs very thick cable. It's much better to run at a higher voltage (802.3af PoE is 48V) and convert it down right before you need it. Also, many buildings have Ethernet already ran. So an embedded iPad, such as a wall mount controller, could use existing cable and power supply (PoE switch) infrastructure, over very long distances, with a PoE to USB adapter.

For the right embedded application, it's a fantastic potential solution. Running 5V (USB standard power) a long distance in walls with new cabling is not. So, just because you don't have a use for it, quit being a jerk and putting down the people who do.
You do realize an iPad is made to be mobile right?
 

AllieNeko

macrumors 65816
Sep 25, 2003
1,004
57
You do realize an iPad is made to be mobile right?
Sure I do. I also realize it's a $499 slab-of-high-resolution-touchscreen-goodness with an established developer platform, an application market, and some real advantages over Android tablets (especially the ability to go full screen, which Android tablets do not have).

If people didn't do things that items weren't "made to do" there would never be any new technology. The world you love is shaped by people who think outside the box and put existing items to unintended uses.

A self-contained 10" high-res touchscreen computer has a lot of potential embedded applications, as shown by the fact that someone already has a wall mount and PoE adapter available.

And the pricing isn't as bad on that as everyone thinks. It's a tad pricey but not terrible. 802.3af isn't the cheapest thing to implement - the exact voltage isn't guaranteed and it has to be negotiated with the switch to have power. I'd say $50-$80 is more reasonable, but charging a premium is the benefit of being the only one to market so far. Their whole solution (wall dock + PoE adapter) will set you back $540 - $640 for the secure version. I'd rather build the bracket myself, but I'd probably spring for their PoE adapter rather than risk frying an iPad in my own experiments.

So basically, why do you put down the most creative people - the ones thinking outside the box - the ones who ultimately change expectations and lead to the creation of the nice pre-packaged technologies you love?
 
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