June 2, 2021, 6:33am
I have a setup with ethernet cables at different places in my rooms that I want to use to charge tablets that will be placed on the wall (Covering essentially holes on the walls)
I am looking for the correct cable that I can use to transform Ethernet to USB-C with power to charge the tablet
I thought that this was straightforward, so I bought a couple of cables blindly but they did not work.
Does anyone know the specs for these cables that will be able to charge the tablet (Ethernet to USC-C with charging)
June 2, 2021, 6:55am
The technology you’re looking for is called Power over Ethernet - or PoE. It requires special PoE switches or PoE injectors that provide power which can then in turn be used by PoE splitters or in some cases devices that can use PoE standard power.
In short you’d need to figure out what wattage is required to drive your tablet and refer to the chart in the link below to make sure your power source (switch / injector) can provide it and your PoE splitter can provide power in the format you need (There’s plenty of splitters that provide USB standard up to 5A)
Here’s a good reference -
Power Over Ethernet (POE) ( Beginners Guide) (stevessmarthomeguide.com)
June 2, 2021, 11:51am
Thanks Nathan for the well thought reply and the link - very useful,
I have the relevant infrastructure:
Ubiquiti switch, that powers over POE ubiquiti unifi & other devices
Cat 6 Cabling
Thus, I thought that buying an ethernet to USB transformer would do the trick (
This is the one I tried recently)
I have read the guide but couldn’t find the answer so i`ll try to explain further.
I am focusing on the cable because as I said I am powering a lot of devices with the same ethernet cable - even some demanding HDMI to ethernet boxes.
Should the above cable work (Maybe I am connecting it somehow wrong?) . If not - what are the specs for the cable to do that
No, that cable will not work. It is designed to add an Ethernet port to a laptop/desktop that has USB-C ports.
You’ll want something like the following, a POE Splitter…
Descriptions:PoE splitter can save USB adapter wall plugs, extend powerline to where your Ethernet cable reaches, and make full use of extra PoE ports by converting them to micro USB. It's a good companion for micro USB...
June 2, 2021, 12:38pm
Thank you so much! Ordered
keep in mind that when doing POE the power part uses 2 of the 8 wires in an Ethernet cable. Thus, Gig speed over Ethernet needs 8 wires. So, the fastest is only 100Mb/s as it only uses 6 wires.
use 1 to inject the power over the Ethernet at the router/switch and a second to extract the power at the tablet.
pay attention to the power barrel plugs as you might need short adapter cables. this is were I had to ‘adapt’ things.
@nathancu said, you will need to find out what wattage adapter you need to plug into the injector for the table. distance could be a factor too.
I have many Gigabit POE Splitters that work perfectly.
Amazon.com: UCTRONICS PoE Splitter Gigabit 5V - Micro USB Power and Ethernet to Raspberry Pi 3B+, Work with Echo Dot, Most Micro USB Security Camera and Tablet - IEEE 802.3af Compliant: Computers & Accessories
Also, all of my Ubiquiti Access Points are POE powered, and are connected at 1Gbps.
There is no 100Mbps limitation when using POE.
ah, so i see that you have to use a specific power injector box that has the circuitry in it and not just a ‘dumb’ injector that ‘steals’ 2 of the 8 wires.
example of ‘dumb’ injector that ‘steals’ 2 wires: