5v USB feeds in ceiling space for mmWave sensors

Hardware
1

Hello everyone. I am looking at putting some mmWave sensors in the house to detect presence and feed some Node Red routines I have. I dont know if we have any sparkies on the forum but wondered what the best route is to have 5v USB feeds in the ceiling space (the sensors will be ceiling mounted). Do I put a traditional 240V plug with USB socket in a backbox in the ceiling void, do I use a transformer of sorts, if so any recommendations or something else? Any help appreciated but looking for what would be the ‘right and safe’ way of doing this rather than ‘it will work but may be subject to safety issues’ way of doing it :wink:
Thanks for any help.

2

If you’d put the wall plug somewhere else, be aware that the typical 5V wires are thin and suffer from voltage drop.

If you’d put the adapter in the ceiling void I recommended using a proper brand one to avoid fire risks.

3

Personally - I would wire a 12V or 24V bus from a reasonably central spot and use a DC-DC 5V converter at each position. Most of these handle voltage drops pretty well and if you get too far out just run another bus.

Unless you’re a sparky stay away from adding 240V sockets everywhere.

4

Thanks @JeeCee, I wanted to avoid putting adapters in the closed ceiling space if possible, branded or otherwise as i wont have visibility of them if something goes wrong with them. What I meant about putting a socket in the ceiling space was to use one of the 3 pin plug sockets with integrated usb socket as part of the fitting, I think i would trust that more but may be wrong?

5

Thanks @zoogara for the advice. Given that i am looking to put these in each room eventually, pulling cables could be a real challenge for the entire house. I was hoping i could spur off an existing ring to feed whatever device i needed that would limit the amount of disruption. Am competent in the wiring side of things but was wondering what others were using to bring the 240 down to 5 in terms of trusted transformers or otherwise given the device wont be visible once closed up etc. thanks

6

I would consider using Power over Ethernet (POE). You could either use a splitter to just take the voltage, or use a build your controller so that it can be wired to the network.

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