Looking for Clean Way to Power Wall-Mounted USB Touchscreen

[mderoy]

I’ve got a drywall partition where I’ve mounted a USB-powered touchscreen at about eye level. The screen came with a wall mount that allows the USB cable to run directly through the wall, so I drilled behind it and fed the USB cable down the cavity inside the wall.

At the bottom of the same wall, I’ve got a standard double socket (on a drywall backbox) and, next to it, an old BT telephone socket mounted to a 1-gang backbox. The BT socket is completely unused and has been disconnected for years.

Right now, as a temporary setup, I’ve removed the BT faceplate and installed a brush plate so I can pass the USB cable through and plug it into a USB charger in the socket right next to it. It works, but it doesn’t look tidy.

I’m looking for a more permanent and cleaner solution. Ideally, I want to power the USB cable within the wall using that old 1-gang backbox space (where the BT socket was). I know there are wall sockets with integrated USB ports, but those still require the USB cable to be plugged in from the front, which I want to avoid.

Is there such a thing as a USB power supply or transformer that can be installed inside the wall/backbox (behind a blank plate or similar), so the cable can remain hidden?

Open to any ideas or suggestions.

Thanks in advance.

 

[Harry Bloomfield]

Is there such a thing as a USB power supply or transformer that can be installed inside the wall/backbox (behind a blank plate or similar), so the cable can remain hidden?

Fine until the USB PSU hidden in the wall failed, then you would have to dig it back out to replace it. You can buy 90 degree USB adaptors, that allow the plug to come out from a socket, pointing down to the floor, or up the wall.

 

[mderoy]

Fine until the USB PSU hidden in the wall failed, then you would have to dig it back out to replace it. You can buy 90 degree USB adaptors, that allow the plug to come out from a socket, pointing down to the floor, or up the wall.

But I was thinking to have something that potentially fits in that 1g backbox then can put a blank plate for service or replacement.

Out of curiosity, those 1g sockets that have usb on the front, can the usb bit be diverted to the back?

 

[Harry Bloomfield]

But I was thinking to have something that potentially fits in that 1g backbox then can put a blank plate for service or replacement.

Oh, OK!

Out of curiosity, those 1g sockets that have usb on the front, can the usb bit be diverted to the back?

Possibly, if it suitable, and you don't mind cannibalising one, and blanking the hole in the front. You would also be mixing the mains wiring, with the 5v, within the box, which is never a good idea.

I have a small USB powered touch screen, for my weather station display, on a wall, which has a cupboard behind it. I used a 90 degree USB adaptor, to get the cable straight through the wall, powered by plugging it into a RPi, located out of sight in the cupboard.

 

[mderoy]

Thanks. Just thinking out loud. What if I spur from the 2g socket below then up the wall and install something like this behind the screen mount but slightly recessed so it allows for space to connect the usb cable? https://www.screwfix.com/p/lap-modular-3-1a-15-5w-2-outlet-type-a-usb-socket-white/151CC

 

[morqthana]

https://the3droom.co.uk/product/angled-recessed-mounting-plate-single-euro-module/

Is the screen powered via the USB port, or does it have a battery charged via it?

 

[Sureitsoff?]

https://the3droom.co.uk/product/angled-recessed-mounting-plate-single-euro-module/

that's is clever. Bookmarked!

 

[Tigercubrider]

If the BT socket area is unused, how large is the USB PSU that is needed?

Is it possible to remove the dry lined BT box and enlarge the hole to either accommodate the PSU with a cover or use a larger dry line box?

I’d rather not try to run mains up to the screen but is it possible to install the PSU behind the screen?

 

[morqthana]

is it possible to install the PSU behind the screen?

That's what the OP was suggesting here:

Thanks. Just thinking out loud. What if I spur from the 2g socket below then up the wall and install something like this behind the screen mount but slightly recessed so it allows for space to connect the usb cable? https://www.screwfix.com/p/lap-modular-3-1a-15-5w-2-outlet-type-a-usb-socket-white/151CC

Which he could do without (too much) protrusion with an angled recessed plate [smug] like wot I showed [/smug]

 

[robinbanks]

Is there such a thing as a USB power supply or transformer that can be installed inside the wall/backbox

If you take a hammer/screwdriver/multitool etc to that usb power adapter you'll end up with a circuit board into which the live and neutral plug pins are soldered. Desolder them and solder in two short multi strand flexes

Get yourself a switch fuse and a deep back box, put the backbox where the BT socket is, put the PSU circuit board in the backbox, wire up the ac feed to the switched fuse load terminals and feed the switch fuse by spurring it off the adjacent ac socket

I'd also consider buying a big bit of heat shrink and shrinking it over the PSU board, to reduce any risk of inappropriate electrical interaction between the board and the terminals of the switch fuse

---

If that doesn't appeal, swap the AC socket face plate for one that has USB charging outlets, and use a USB A 90 degree cable to come out of the outlet and immediately turn and go into the wall. If you want super low profile, something like eBay item 226955573789 will give it but you may want to protect it with something like plasti-dip, to form your own insulated covering to the circuit paths. If you're happy with something that protrudes a little further you should be able to find some 90 degree usb cable already coated in some moulded plug that doesn't stick out much more than the switch on the double socket, like eBay item 232137195712

powered by plugging it into a RPi, located out of sight in the cupboard.

Does the RPi run the weather station software or do you literally use an RPi as a power supply for a USB device?

 

[mderoy]

The tablet does not have battery. It’s powered directly via usb. So the tablet is mounted on the wall with a supplied mounting plate. There is a big enough opening through the plate into the cavity wall. So what I’m thinking is to place a 1g 13a fused and switched spur in the location where the old bt box was. Since there is already a 2g mains socket that hasn’t been spurred from. The supply feed can come from there. Then run a cable straight up (literally just 80cm max) to the cavity right behind the touch screen mounted. The touch screen literally just hooks on and off so access behind is easy for serviceability. Then what I’m thinking is right behind this mount plate into the wall to mount one of these https://www.screwfix.com/p/british-...18w-2-outlet-type-a-c-usb-charger-white/867ch

From then usb c I can use a angled cable to connect to the tablet.

this way when I’m away for long periods of time I can switch off the switch on the spur which turns off the supply to the 1g switch in the wall. Essentially the in wall socket is not being sealed but merely covered by the touch screen in front which just hooks off if needed

 

[Tigercubrider]

Is it dot and dab? Or a timber frame?
Look out for noggins

 

[mderoy]

Is it dot and dab? Or a timber frame?
Look out for noggins

It’s a partition wall with drywall on each side and secured the the metal stud frames