USB powered switch?

casper_uk · 25 Jul 2021 at 19:02

Hiya,

Does anyone know if there is such a thing as a 1000 Mbps switch that can be powered by usb? I think usb-c can push 15w at 5 volts (3 amps)? which seems like it should be enough in theory, but am struggling to find anyone that has done it before.

https://www.overclockers.co.uk/tp-l...rts-plastic-case-tl-sg1005d-v9-nw-174-tp.html

This item uses a power supply that has an output of 9V 0.6A for example. Has anyone tried this before?

Cheers

whitecrook · 25 Jul 2021 at 19:12

Sorry no but unifi do a nice little poe powered switch that seems like a neat solution

KompuKare · 25 Jul 2021 at 19:28

casper_uk said:
Hiya,

Does anyone know if there is such a thing as a 1000 Mbps switch that can be powered by usb? I think usb-c can push 15w at 5 volts (3 amps)? which seems like it should be enough in theory, but am struggling to find anyone that has done it before.

https://www.overclockers.co.uk/tp-l...rts-plastic-case-tl-sg1005d-v9-nw-174-tp.html

This item uses a power supply that has an output of 9V 0.6A for example. Has anyone tried this before?

Cheers

I think the specs are actually a lot more complex than that.
3A is in there but both at 5V and 20V (60W) for PD.
Looking at the summary of the specs on the WikiPedia
https://en.wikipedia.org/wiki/USB-C#Power_issues_with_cables
it might be a while until anyone releases a switch powered solely by USB-C, especially since PoE is a well established standard.

PiKe · 25 Jul 2021 at 19:34

I've only ever seen 10/100 switches which can be USB powered.

whitecrook · 25 Jul 2021 at 19:50

Actually the switch i mentioned above is the flex mini and it also can be usb c powered. So there you go

USW Flex MiniBuild and expand your network with the UniFi Switch, part of the Ubiquiti Networks UniFi Enterprise System. The UniFi Switch, model USW-Flex-Mini, is a smart managed Gigabit switch. It offers 5 RJ45 Ethernet ports, providing 1 Gigabit links to your devices. Power up the USW-Flex-Mini with the included USB Type-C power adapter or with 802.3af PoE Ethernet in port 1.

casper_uk · 25 Jul 2021 at 20:03

whitecrook said:
Actually the switch i mentioned above is the flex mini and it also can be usb c powered. So there you go

USW Flex MiniBuild and expand your network with the UniFi Switch, part of the Ubiquiti Networks UniFi Enterprise System. The UniFi Switch, model USW-Flex-Mini, is a smart managed Gigabit switch. It offers 5 RJ45 Ethernet ports, providing 1 Gigabit links to your devices. Power up the USW-Flex-Mini with the included USB Type-C power adapter or with 802.3af PoE Ethernet in port 1.

Excellent news, thanks! Also I think I know what 802.3af means now

There is a network cable already in the location I want to put the switch. If i plug that into the first slot, it should have enough power to run any other ethernet cables I plug in yes?

whitecrook · 25 Jul 2021 at 20:17

casper_uk said:
Excellent news, thanks! Also I think I know what 802.3af means now There is a network cable already in the location I want to put the switch. If i plug that into the first slot, it should have enough power to run any other ethernet cables I plug in yes?

To avoid any doubt this switch only can BE powered via poe. It does not pass through or power any devices itself

to power this
via poe you will meed a poe injector or a poe switch upstream

the point is you dont need to plug this in to a wall or a usb , only the network, which you were gonna do anyway, right

.

casper_uk · 26 Jul 2021 at 04:57

whitecrook said:
To avoid any doubt this switch only can BE powered via poe. It does not pass through or power any devices itself

to power this
via poe you will meed a poe injector or a poe switch upstream

the point is you dont need to plug this in to a wall or a usb , only the network, which you were gonna do anyway, right .

Bad choice of words from myself. I blame working nights and being half asleep when posting

I was planning to plug a normal ethernet cable from my virgin router, to this switch. Then two other cables to my server and a mesh WiFi disc. The two other cables just need to connect to the network, no poe power required. Does this sound feasible? Or do I need a Poe injector (what ever one is) from the router to switch to power the switch?

Maybe a usb cable would be easier after all

Rroff · 26 Jul 2021 at 05:05

Depending on requirements of the switch you can always use a step-up/boost device to take 5V from USB and/or USB-C and output 9 or 12v regulated with a barrel jack output - usually they are capable of ~10 watt (probably a little less with conversion efficiency losses) but some up to 15 watt.

Most of my gigabit switches (4 to 10 port) are rated for 9v 1amp or 12v 0.5-0.7 amp.

the-evaluator · 26 Jul 2021 at 07:40

casper_uk said:
I was planning to plug a normal ethernet cable from my virgin router, to this switch. Then two other cables to my server and a mesh WiFi disc. The two other cables just need to connect to the network, no poe power required. Does this sound feasible?

That won't work unless you're planning to power the switch from a standard plug outlet.

casper_uk said:
Or do I need a Poe injector (what ever one is) from the router to switch to power the switch?

A PoE injector is a device that would sit inline between your VM router and the switch and would inject power into the network cable meaning that if your switch were PoE powered then it be powered up just by plugging in the network cable. The injector needs power so it would need to be plugged into the mains.

This is an example of a PoE injector. Note how there are 2 ethernet interfaces - one would connect to your VM router and the other would be the output which would connect to your new switch and provide data & power to it. There's a mains input socket too.

whitecrook · 26 Jul 2021 at 07:51

casper_uk said:
Maybe a usb cable would be easier after all

what are you planning to plug the usb cable into?

casper_uk · 26 Jul 2021 at 10:55

whitecrook said:
what are you planning to plug the usb cable into?

Back of the server, usb-c port. Thanks for all the information everyone, learnt a bit more which is always good

whitecrook · 26 Jul 2021 at 11:08

casper_uk said:
Back of the server, usb-c port. Thanks for all the information everyone, learnt a bit more which is always good

if your server reboots / goes down you will lose power to your switch...

Your server presumably is plugged in to the wall, so wouldn't it just make more sense to plug any switch into the same power socket ?

casper_uk · 26 Jul 2021 at 12:26

whitecrook said:
if your server reboots / goes down you will lose power to your switch...

Your server presumably is plugged in to the wall, so wouldn't it just make more sense to plug any switch into the same power socket ?

What's with all this common sense and logic? Am i really still on planet earth?

A very good point that is. I won't have a spare socket but I could always try and get something sorted i suppose

whitecrook · 26 Jul 2021 at 12:39

maybe https://www.ebay.co.uk/itm/183768826486 or similar ?

or get the poe injector linked above, get the infi flex mini, plug the poe injector in near your modem (you do have a spare socket, there ? ) then you don't need to plug anything in to electric at the server end, since the uplink network cable will supply the required power to drive the switch..

OR

since you already have presumably a network cable going from your modem to this new swtitch/server/area, why don't you just run another 2 or 3 cat5e cables, since the VM router has a built in switch anyway.

Caged · 26 Jul 2021 at 14:36

Just get a power strip, why make it so complicated