Let's take a look at Ikea's smallest USB power supply which is also called smart Hagel just like its triple Outlet brother or sister and uh, this. depending the country, you'll have either the connectors will come out the site or they'll come out the back. In the case of the UK, we've got our big chunky Square pin plug and it comes out the back. Now it's notable: this thing is only rated at this point I Have to say this does not fit in this rear.

I'm gonna have to turn it upside down. This thing is only rated about one amp at five volts because it's actually designed for powering low power devices. But Ikea say it's one of these things. just plug it in and leave it in all the time.

It's uh, perfectly safe to do that. So here is a suitable tester. Let's Zoom down on this so you can see the digital display better. So we're currently displaying seven milliamps holding 5.03 volts.

I'm turning it up. it's ready to finance. Maybe we'll just turn it right up to over one amp. It's still loading at five volts over one amp.

so let's keep going and I'll use the finer control 1.1 amp 1.11234 Five Stone five volts six and it cuts out so C 1.16 amps and then it cuts in an area. Okay, that's reasonable enough. It is just designed for things like little lights and things like that. I Shall Zoom back out again? Oh no I want some back out? I'll just stay where we are I'm not sure how easy this is going to be to open as my usual Brute Force approach of ramming something in here and then trying to force it apart.

Going to work I Don't think this is going to come apart in a controlled manner I Think it's going to be broken in the process I should be putting these in here and prizing apart. If it doesn't come apart easily and Ikea stuff doesn't come apart easily, not necessor the furniture, then I'll just pause. In fact, you know what at this point in time I mean I'll try this spider. Where is the spider? I've misplaced the spudger.

There's a spudger this is Samo Now let's try it in here. but is it? I Think it is really tightly sealed so I don't really hold up much hope for getting it open like this one moment, please. I'm about to get destructive I have correct the SIM and now it is open. Let's get it out.

Oh, look at the big isolation slot there. That's quite impressive. Um, things I'm seeing initially there's little inline fuse. There is a couple of input pastors with uh, filtering, a little inrush thermostat look of it.

That's quite surprising for a little power supply like this. I'll Zoom down a bit. Uh, there is the Transformer with super duper extra separation going out and this that could be one of those little polymer capacitors. This looks like a bootstrap past that looks like mosfet for it.

Where is the chip that controls this? It's probably that little dinky chip there, right? You know what happens now. I Shall take a picture and then we can explore the circuitry one moment. please. Reverse engineering is complete.

It's quite a nice design. It's got some nice features a particularly structurally because if you take a look at this case, it's got this big L plate in it that goes through the isolation slot in here to provide an extra barrier against well flashes. So it's got a decent lip round here and also tracking and that also is augmented from the other side of the connector. it's got this plastic plate covering the electrical connections.

Decent heavy gauge wire that is so unexpected in in these things you you get so used to the crappy Chinese ones. Let me Zoom down a bit that you expect super flimsy wire. This is wire rated uh for handling fault scenarios. There is also this little tab here and this tab presses down behind the USB socket to provide extra mechanical reinforcement.

So I'd Guess that's partly for plugging stuff in and out. Also, it's worth mentioning that the socket doesn't just have the tabs at the side, but it also has a central pin going down to provide extra strong rugged mounting for the plugging and plugging of stuff from that. Very good Uh, things worthy of node: I'll give you a brief summary of the suction, then go straight to the schematic. Uh, we've got the live command goes through a one amp, tenderly fuse with the neutral, comes in and goes through a 05d100 NTC Interest limiting thermistor.

What this does. It starts off with a slightly higher resistance, limits the inrush current disease. Capacitors charge up and then under load. It will warm up slightly in its resistance, will drop so it won't limit the current too much.

The number one is O5d100 that breaks down as O5. That's the diameter. D It's a disc and one zero zero. Just let a resistor color code.

one zero decimal multiplier, one zero and then zero is a multiplier. So effectively it's just 10. Uh ohm. I Measured it at 12 Ohms, but switch is fine.

Um, there are two capacitors, death beam capacitors, and an inductor between them, plus a little sneaky surface. Mountain Doctor in the back. a super well initiated Transformer with the secondary brought out on a separate port with that thick insulated winding and then a little capacitor Over here for the Um Bootstrap circuit. and on the other side, we've got the Uh, a polymer capacitor.

I think uh, 560 Microfarad 6.3 volts. that should be Sugar Sugar Super long life at circuitry wise. Biggest surprise here was this transistor here I Had to take it out of the test because I thought that was a mosfet. It's not.

It's an Npm transistor, one designed for switching Uh ballasts and so like the old fluorescent lamp bars are finding new uses for that transistor in neat little power supplies. We have a dedicated chip which is marked Uh 2i3, I or two by three one the usual stuff. It flies. We've got the filtering, We've got the snubber network across the primary, we've got the sense resistors, that little control chip, the transistor, and then the sort of feedback circuit, and the bootstrap and the secondary side.

We've got a traditional Schottkey diode with a snubber across it, which is good. Uh, that makes me think of Hive or was it Nest can I remember which was a Google one Anyway, the ones that, uh, the diode blew up all the time. Yeah, that the snubber would have prevented that. And then it's basically got that uh, polymer capacitor a little 5.1 K resistor across that as a passive load just for stability when it's not got a load plugged in and then a little.

add coupling, capacitor and the output to the most the USB port via two resistor dividers to provide a particular particular signal on the data pins. Let me bring in the schematic and then snickly well, nobody notices. draw in that extra one that I missed at 5.1 K Resistor 5.1 K Resistor 5.1 K That's that little extra shunt resistor that just provides a load that stops the voltage across this capacitor creeping up too high when there's no load and this unit is just pecking at the output just to keep it awake. Um, the incoming Supply Oh, let me Zoom down this.

I Really have to zoom down there. we go. make it fit. Uh, incoming Supply There's the one amp fuse.

There's the little NTC thermistor that is so cute. Uh Bridge rectifier and then a 4.7 megafide 400 volt capacitor through a tiny little surface. Mountain Doctor I wonder where that was initially? I'll show you it's uh, that little black thing there L2 uh, that is that little surface Mountain Doctor there is the main through-hole component inductor for filtering and then it initially. When you power up, it charges this capacitor, which is the power supply capacitor for this chip.

It charges it via this mosfet, which is by default turned on uh, naturally, and that charges via the 300K and 150k resistors. and once that has reached the Threshold at which that capacitor has reached the threshold voltage that the chip starts running and can therefore create its own power, It shun says it turns this uh mosfet off so that those resistors aren't active anymore. Quite interesting. That will reduce the power distribution slightly.

Also, it's supposed to have advantages of running High voltages cross resistors, but that's not such a huge thing. I Think it is purely this tiny little power saving that it adds to it. Once it's running, you've got a feedback winding that provides power via 2.2 Ohm resistor and diode to that capacity faster. and you've also got a little feedback network network and decoupling capacitor that then signals back to the chip so it can see a mirror of what's happening on the secondary side.

so it doesn't need any fancy feedback. It's all done through the windings. Here's that to hat: 4243 DM Npn transistor with a built-in reverse diode across it. Quite neat.

It's been driven directly, so this must have a current limited output. Normally with these circuits I Think it. I tend to think of it as being you know, a mosfet, but that's interesting I Have to keep an eye out of that future in case. I see other ones using a similar thing.

There are two 4.7 ohm resistors that when this transistor turns on, current flows through. the premium puts a magnetic charge into it. They sense the point at which the the current reaches a certain threshold and then this chip will sort of turn that off. Um, when it does, the Slate before this section can cut in, you sometimes get a spike across this inductor and it shunted via this diode.

a couple of resistors to that capacitor that just absorbs that. and then this resistor here gradually leaks that away so it's ready for the next. Spike It's the Snubber network. Um, there's a class Y capacitor between the two zero volt rails.

Zero volt, Zero volt. but they're completely separate zero volt rails. Here, this is about 350 volts ish. It's actually I Think this is universal voltage and it runs from Hold on? Where is it? Yeah? I Think it is 100 to looking looking all over for it.

Uh, 100 to 240 volts. So it is universal voltage. So that could be quite a wide range of voltages. but the current is covered across as the this turns off, the magnetic field collapses.

and that's the point that this little diode diverts it through to this polymer capacitor. There is a little snubber Network because, uh, Schottky diodes. Although they're very fast, which is a main advantage, are very bad at dealing with reverse voltage spikes. So they've got a little shunt across that a little bit snubber.

Network that just absorbs any sharp transient spikes. Uh, that is what killed those thermostats. There's a Google thermostat not having that. Um, there's another little decoupling capacitors.

Then there's that little shunt resistor. and then there are the two voltage dividers that feed the USB output. and that is it. Fundamentally, it's a very straightforward design, but a nice design.

It is exactly what you'd expect from Ikea It's Uh designed to hire standards. uh, particularly the Uh separation. the casing. It's nothing like those junk ones you get off eBay and Amazon that are just electrical death traps.

some I Always recommend if you're going to get a USB power supply, get it from somewhere like Ikea because then you're going to be any. they have a reputation to protect. They have standards to comply to, and uh, their standards are high and it's safe. It's a bit ideal for charging your electrical stuff, but there we go you USB stuff.

That is it. The Ikea small Hagel mini charger rated at one amp 5 volt output. It's a very nice power supply as expected from Ikea.