This video is going to be something a bit larger than normal for this bench. It's not going to fit that well, but it doesn't really matter because i'll open it up and take it to bits and then it'll be smaller. So this is one of these air conditioning units. It's got a fan in the back and it's got a little pull-out drawer in the front and it's got wicks in here and there is a water reservoir.

But it doesn't rely on that as the main thing for the water when you use this or you're. Partly supposed to soak this with water so that it does evaporate of cooling and then you're supposed to lift the lid off and there's an ultrasonic atomizer down here, the ultrasonic atomizer fires water down into this little v down here, which is uh, probably just to let It blow down to a certain level before the fan catches it, and that then throws it through and that will keep these wet to a degree, but it'll also blow a mist of water out the front. So i'm going to pour some water into this. Oh, incidentally, this thing has oh, very exciting, uvc sterilization, as in it doesn't look right and next press.

That button shows a red led which, after a while, goes green and then goes blue color changing led it's just one of those gimmicks that they just throw in so that's uh, three settings, uh, uvc, color, changing and off the fan has three speed. Sets i'll show. You that in a moment, because i'm going to pour the water in first and then i'll show you the mist coming out of it. If i can show you the miscommunity, so i'm going to put the water in like this, and it has the three fan speed settings for what appears to be 12 volt fan, which is odd, because it's a 5 volt supply when i turn it on i'll turn.

On the low setting i'm going to try and set this up now, i don't think you're going to see that fog coming out right. Tell you what one moment please! Now you can see it! That's a fog of water! That's blowing out the front of the unit that produces quite a good coverage. Uh, there's probably other uses for this okay right time to take it apart. One moment please: i've poured the water out, let's begin the destruction, so the construction of this is well there's a fan in the back um.

The power comes straight onto this. We've got a cable coming out to the little uh ultrasonic atomizer and i don't see any obvious screws. There's some screws holding the back panel on, but i think these little clips here may give access. We shall find out shortly.

Oh yeah. That was easy! Oh! Oh! That's very modular! Oh look at that! Just really because the cable's coming onto this, it's just these two cables, one going down to the fan and one going to the ultrasonic transducer, that's very convenient the little inductor. That's the ultrasonic transducer inductor! It's a little step up transformer excellent. Let's take a look at those leds.

First i'll get this out the way. Let's bring this down to a more sensible height, i shall bring in just a random lamp box focus down to there. Okay right, that's perfect! Give it something to look at, let's plug this in and zap ourselves, see if we can blind ourselves with dangerous ultraviolet light, so the uvc they're just standard uh near uv leds, that is it! It's not ultraviolet uh, germicidal ultraviolet at all and there's the color changing led. Oh joy, right here.

Let's whip this circuit board out, i can see a use for that case. Powerful fan 5 volt input, even a 12 volt little boost circuit. If that's uh accessible for bypassing um could be useful for other things, based on recent projects involving room air uh, what do we got? There's the boost circuit for the fan, but i tell you what i'm going to take a picture of this and then we shall reverse engineer it and see what we can find. The reverse engineering is done.

It's an interesting little circuit this little chip here. This microcontroller is doing quite a lot, so i shall zoom down this, so we can get a closer look at it. The back of the circuit board is the top section of the picture here and it's flipped. So, let's say, for instance, this inductor here this three pin inductor matches to the front of the circuit board.

The microcontroller couples to it's got is a double sided board, but the back is really just used for the ground, plane and also random tracks from the microcontroller to the separate modules on the circuit board. The modules are as follows: there is the piezoelectric crystal driver, the little water atomizer, which basically has an s10 mosfet. There are three mosfets in this board and s10s two s10s driving inductors and an a2shb for the fan. The reason they've used.

The s10s is because they've got a higher voltage, they're rated for 60 volts instead of 20.. The microcontroller drives them with this exact same circuitry, a 330 ohm resistor and then there's a 10k resistor across mosfet to keep. It turned off then from the gate to the ground, but it's got no transformer and when it wants to actually atomize the water, the microcontroller supplies a stream of policies to this mosfet, which pulses this little inductor here, which uh applies, the appropriate voltage and frequency to The uh, the crystal the fan is just plain weird: it's got two sections, there's a mosfet that switches the fan on off and there's a mosfet uh that is used to actually boost the voltage up from five volts. I was looking for the boost converter chip.

It's done by the microcontroller again when the microcontroller wants to actually turn on the fan. It turns the a2shb on, and then it also starts pulsing this and the frequency it pulses at will determine the voltage that's developed across this circuitry. I shall show you that in a moment, uh the leds, the amazing ultraviolet, the uvc germicidal fakers - are just in parallel with just one single resistor for both them. The rgb led has its own resistor and then three white leds for the different power settings.

Just have one resistor for them all, it's very straightforward. The other thing worth noting here is that the microturn here's, the incoming supply there is a decoupling capacitor close to the microcontroller, but then also a resistor and capacitor just to create more isolation, because there's two very nasty inductive loads in this circuit board. I shall expose the circuit board for you to take a look at and then i shall bring in the schematic. It looks fairly cluttered it's not as cluttered as it looks.

It's all modern. Here's the usb supply command the decoupling capacitor, a 20 ohm resistor, leading down to another capacitor which just provides that isolated supply. That just means that the spikes and glitches happening with five volt rail from these pulsed inductors are less likely to crash the microcontroller, which would be a very bad thing. You don't want these mosfets staying on all the time, because if they do, it will cause problems with high current, because these inductors will just saturate and then pass a lot of current uh.

There's the leds clustered as the one rgb led the two ultraviolet leds and the three white leds each with their own one 100 ohm resistor. The two push buttons are just pulling down to the zero volt rail the ground. Here each mosfet has the 330 ohm resistor feeding. I don't know why i wrote 330 of them up there as well, but then i don't know why i wrote the fan twice as well.

It's just uh. I drew the fan symbol in afterwards and then just wrote fan above it, even though i'd done it before, but that's, okay, we'll get back back to that in a minute. So the gates of the mosfets are pulled to the zero volt rail with a 10k resistor. Just to make sure that when this system is powered up and the microcontroller isn't stable, it defaults if the output's just floating it makes sure these mosfets are off.

This is kind of important, mainly with these two. When it wants to power the atomizer, it starts feeding a stream pulses to this one which energizes this inductor, and this is the way the inductor is showing the drawing. But i thought that there'd be a fairly heavy primary section. Then the atomizer would be over a sort of higher voltage section.

I don't know if they're actually using a low voltage higher current, i would have thought it would be higher voltage lower current, like in piezo sounders um. So i'm not sure why they've drawn it that way. One day i'm going to clearly have to unwind one of those transformers. The fan is interesting.

Here's the boost circuit for the fan, which is the inductor and that's round about 4.7 micro, henry 4.7 micro henry. They drop drop is 4 7, like 4.7 ohms. It's not it's very strange. I don't know why they do that.

The circuitry, when it wants to set the output, will switch. The output under load between 7.8 volts for low 9 volts for medium and 10 volts for height, so decisive and so accurate that it's almost like they said all right, so 8, 9 and 10 volts, roughly it's quite clever, but to step the voltage up. It provides the appropriate number of pulses to this inductor when this inductor is pulled to the zero volt rail. It builds up a magnetic field in it and then, when this turns off that field collapses and it diverts the so say.

For instance, this is positive and then this is negative. It builds up that field and then it turns off. This goes negative. This goes positive and then that means that the current flows through this uh shortcut diode to this capacitor.

There is a zener diode across that the only time exceeds the zener. Diode is, if you do, i do and power the circuit up. The fan disconnect to see what voltage it goes up to. It went up to 15 volts, but it depended on the power setting.

I think it was really struggling at the end, so it's probably more like a 12 volt zener diode, so that provides the plus volt supply to the fan. Then the negative side gets switched and you think well, why don't they just when they want to run the fan? Why don't they just pulse this to step the voltage up in reality, even if this isn't running, if you connected the other side, the fan negative. Without this mosfet here, current would flow through the inductor through that diode and it would uh feed the fan, and i tested that i turned the fan off. But then i bridged the uh mosfet here and the fan ran at a fair lick.

Just on the five volts. It was five volts minus a short shortcut drop uh. I measured 4.5 volts across it when i was running it like that. So when the processor wants to turn on the fan, it just enables this transistor to activate, in the first place, to pull the negative connection to the zero volt rail, and then it starts pulsing this inductor to step the voltage up.

It's quite neat that is it. It has other functions apparently built in after a certain length of time. It will turn off the atomizer um. I also mentioned turning the uvc lights off the sterilization lights.

I'm just thinking. That's a gimmick, though strange uh, but there we go. It's very modular. It's a neat unit.

Uh, it's got potential. The fact the fan runs happily at five volts suggested. If you wanted to make some sort of uh air handling unit for other reasons, ozone generator, then it would be quite an interesting unit if you just disregarded the ultrasonic atomizer and you just fed 5 volts straight to the fan. You'd get a good airflow through it, and you could also then use that to power a 5 volt module of your choice in here, but as it is, it works really.

Well, it's very modular, just it clips together very decisively and uh the way the the circuitry here is just basically two connections just plugged onto that circuit board. Well, let me just plug them on right now plugged on to i could get a job in the factory kind of. I don't think they would employ me, though. So here's the one that just goes on here, two identical connects.

I wonder if they ever get in the wrong way round: two identical connectors stuff. The wiring in here i've already pointed leds that way and then just slot it down like oh hold on it. Hooks in like that and clicks. Am i i'm gon na burst this now? If i get the wiring in the way, i don't think so.

I think i'm just not. Oh there we go. Maybe i won't get a job in the factory, but it all clips together very sensibly and this uh, the deflector here in the front of the atomizer. The two screws are also holding this sort of like the chromatin that secures the atomizer in place.

It's very interesting unit quite well built it wasn't that expensive, i think it was about. I think it was about 10 pounds, so i'm going to go and check that one moment please. So i paid 13 pounds. Apparently, it was like something like 11 pounds, plus 2 pounds, processing or vat or whatever um, but it's now gone up to thirteen pounds.

Ninety nine, presumably with v80, on top of that as well free delivery that came from a seller called very catchy name rage. Man, rage dash man, mini air conditioner, portable cooling fan, led cold water travel, cooler unit. Uk. I think the main identifier for these is the fact they've got the two buttons and the three leds, but um.

It's a neat enough unit. The case is nice, it's nice and robust. It does spare that haze of watch out the front and it's running, it's not mega noisy and it has a potential if you just want a case with a fairly powerful little fan. That will run from 5 to 12 volts and you get a bonus atomizer as well, but there we go interesting, not too bad.