I have a few projects that run on ESP’s. Some are easy to use a standard UK plug to USB power supply (eg, an old phone charger), but I also have some that are not. These are things that are tucked away in the attic, in walls or outdoor IP rated project boxes. Currently, I have a number of ways of dealing with them, none of which I’m really satisfied with. Ideally, I’d like to use a small unit that’s simple to connect 230 in, 5v out) that’s trustworthy. By that, I’ve seen a lot of low-cost devices that I don’t know if I could trust buried away.
So the question really: What do you use/what would you recommend?
I never found anything small; the component Ali-express type transformers tend to have open/exposed mains connectors. In the UK all 230v exposed mains connections require an electrical box. By the time you do all that, they are 3 x larger than a stubby mains socket transformer. Alternatively some UK mains sockets do have a 5v UBS type transformer already built in. Perhaps a bit of DIY to use that?
I’d considered this type of thing, but wanted to avoid soldering etc so it’s goods to hear that size is another nail in the coffin for the idea.
I’ve considered them - in the attic, it’s fine where there’s loads of space (and seems like a front runner, well actually what @Holdestmade suggested) but in walls, they’re too big.
Yeah, I was looking at the single euro module versions of these. That seem like they might be the best thing - tested & approved complete units that take a couple of wires.
Here is one I have in testing for my in wall tablet power supply.
I have 3D printed a faceplate with a fan as I read on Amazon reviews the PSU got hot but I have found that is not the case, at least with just charging a tablet wirelessly so might remove it
I’ll be adding a fused spur to the box with the Shelly1
I bought one of these to test. it seems almost perfect for some of my needs. However when I’ve powered it up to test it, it ‘smells’ - You know that solder heavy smell that cheap electronics give off? hence, I don’t trust it in a confined space with no easy access.
I have just realised today though that the term ‘driver’ seems to turn out more options than ‘transformer’ does, so also might try some of these from RS
They look good, is it ok to use LED drivers as a PSU, are they the same thing ?
EDIT: Apparently, as long as its a constant voltage driver and not a constant current driver you’re good to use LED drivers as a PSU if the current and voltage matches your requirements
Just in case anyone else is interested, the smallest units seem to be single USB charger euromodules, like this:, most are 1a, but they seem to max out at 2.4a-ish The trade-off is that thery’re more expensive than the other options but the benefits are speed of implementation (2 screw terminals, one usb socket) and half the size of the smallest LED driver I could find.
Recom got some nice and tiny power supplies - alone from the price I would pack that in your category “trustworthy”
But I’m actually very happy with my cheap (probably not “trustworthy”) Hi-Link based solutions where I pay about $2 for the psu itself and spend another 50 cents on a thermal self reset-able fuse for peace of mind
Did anybody do an analysis of those boards, is there any clear difference? For me it is like “one version has two horizontal green capacitors, the other versuinn two vertical silver ones”… but no idea which to prefer.
I have purchased some of these Hi-Link units - some 3.3v and 5v
Question for you: I notice the pitch of the pins doesn’t match up with perf / proto board - either you put the High Voltage size through the holes or the low voltage size but they both don’t match up. Understandable as I’m sure this wasn’t their first concern.
Aside from drilling larges holes through the perf board and making it work what strategy did you take in terms of mounting?
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- It needs to be CV not CC
power supplies - alone from the price I would pack that in your category “trustworthy” 
