I have thoroughly researched PoE splitters that can be installed into a European standard socket (68 mm in diameter and approximately 45–60 mm in depth) to neatly mount a tablet. I have found one suitable option: Flush-mounted power supply unit for tablets TabLines TNT003. Unfortunately, the price is disproportionate – higher than the price of the tablet itself. Perhaps someone has managed to find something similar, but at a reasonable price (I see that typically a USB-C splitter costs around $15-20).
If all you need is POE injection then you can look into something like this:
I need RJ45 → USB-C like this.
I am surprised that the price on Aliexpress is also so high. It’s not like the in-wall is much smaller than any standard splitter.
They’re expensive because they’re not just simple power adapters; they also convert Ethernet into a USB 2.0 tethered data connection which is something almost nobody wants to do (well, maybe people with really bad WiFi, but for that price they could get a quite good WiFi 6 AP instead), making them extremely niche products.
Curious about the rationale for desiring PoE for this scenario. I see it often on this forum and, as a network engineer, find it baffling. PoE works best for high-traffic or critical load (UPS-powered) devices, and a wall tablet console doesn’t really meet either criteria.
Standard PoE splitter that doesn’t fit into a mounting box costs $12, while a slightly smaller one costs $80. The difference doesn’t seem reasonable.
What would be your optimal solution if you need to provide power and network connection for a wall-mounted tablet, where only a CAT5 cable is available? The cable would provide only power, and the rest would be via WiFi? Is there an adapter that converts 48V to 5V, with an RJ45 input and a USB-C output?
But yes, in general I try to design the system so that each device is less dependent on other devices, thus reducing the likelihood that a number of things will not work due to a “hang” of one device.