Hi welcome to Tear down Tuesday Now as part of the recent tear down for this sink dude medical pacemaker monitoring system. it came with one of these up medical grade power supplies and everyone wanted me to tear this down. tear down this plug pack this wall wart and see what's inside a proper made in Germany There we go Beauty Hi to all my German viewers made in Germany medical grade which it would come under certain art type standards. Basically it's going to have increased our clearance and you know I've sent.

you know much better build quality than your one hung low one from China so everyone wanted to take a look at it. So let's go. and these medical devices as I explained in the previous are tear down. Everything is medical grade isolation in here.

from the clearance on the ground planes to the Type Approval used on the transformer there were y'all actually tore out that medical grade transformer. you know, the high value resistors, all that sort of jazz and a medical grade optocouplers warfare are transferring the data and of course to power the whole thing at the top. You need this medical grade plug pack for the isolation part of it. So that's going to be the big difference.

Your suit should see a big difference in build and both Claridge and our creepage distances. yes they are are different things. Cleary's clearance and creepage as I'll explain no doubt when we open it up, but yet that's going to be difference between this made in Germany medical grade plug pack. it's just a five volt, you know, five watt plug pack and a 100 and you know, just off the shelf consumer plug pack.

So here we go. and for reference, here's all the stuff on the back and it's from a company called Fry Row if I'm pronouncing that correctly. Yes, it is made in Germany any any way up Fry Row specialize in like up, you know, medical grade up plug packs just like this, power supplies and things like that, so that's probably one of the most reputable ones you can get. and you know is going to be a pretty good example of a good medical grade power supply.

In this case, it doesn't have it on here, but this is going to be designed to meet the IAC medical equipment requirements which is 6:06 Oh 1-1 And so it's going to meet those requirements you I don't know, Even if you can download that, you usually got to pay for these IEC standards. But anyway, in this particular one I think I found some data on ER and this particular one has an MTBF a mean time between fire over 200,000 hours. I'm not sure if that's part of the standard or whether or not it's just a you know, an internal thing from my Frye robe and of course you can see all the type approvals on it. and yet these things aren't just you know slapped on by the manufacturer.

these would have been now you know, fully tested and not fully complied? Absolutely no doubt. And I Do like these plug packs with the sleeve I can get it off. Usually they're not that bit easier to get off, but anyway. um this isn't particular to these medical wild ones.

A lot of plug packs these days which are supplied with consumer products have now have these plug in are replaceable plugs. So instead of giving you you know five plug packs with every product or different leads and things like that, it's much cheap, no or different leads. anyway with different plugs, they just give you this these little adapters and include all five in the package and you can see the pads on the PCB down in there. There we go.

so they just make direct contact down in there so there's probably just one single piece you're being taught inside this entire thing. So let's crack it open, have a look. Unfortunately, this looks like it's a ultrasonically world and so may have to get the Dremel out for this. You usually can try not crack them open from the outside by banging on them and stuff like that, but yeah, this one doesn't seem to our budget also.

Yep, Dremel time. First of all, most start out on the case here and look at the huge amount of overlap on this case, how it slides all the way on like that. Wow, that's a lot of overlap I'm not sure and I think that's part Of the requirements, probably just their particular type. but geez, you know if that thing explodes inside, it's probably not going to way you know, come apart in a hurry or explode out.

Very nice. And look at the bottom-side The first thing that strikes you is the clear delineation between a primary side over here, secondary side, massive isolation slot down in there. not only just the isolation slot but the physical are creepage distance there and these big long optocoupler packages like this for extra voltage isolation. The reason why they're that long is because there probably are four kilovolt a ratable I have to look at the parts on that so don't quote me.

but I believe that the specs for these things is that for Kilovolts clearance between primary and secondary I could be wrong there. But anyway, it's You know it's much higher than usual and just look at that delineation. Absolutely enormous. So they've got the slot cut out in here.

They've got a slot all the way in here and the traces are all the way back. They haven't just run them over auto rather than willy-nilly over here and stuff like that. So really, absolutely incredible. And if we take a look at the top side there, yes, of course it's not.

If I fall board at some class board. it's a you know, a phenolic base type board, but nothing wrong with that. Very common in that low-cost Once again, they still have to, you know, shave cost on these things. But look at that transformer that looks beautifully wrapped that looks so you know, looks like it's worth every cent.

They've got a little heatsink that's actually a heat sink down in there. You can see the package mounted surface mount our package actually mounted onto that. It's not bolted, it's actually soldered or welded onto there. but they've used that right angle bracket.

They've got a thicker one over here for the secondary side heatsink. We'll take a closer look at that. But yeah, look at that. That's just beautiful.

Ah, so I mentioned before the turns, clearance and creepage. And yes, they are different and they do get confused a lot. Here's what the main clearance is. the physical err distance between two points.

So you know if I got this point here and this point here, then it's the difference in free err between those two items. That is the clearance. But creepage is not the air-gap creepage is the physical distance along the surface from that point. So from this surface all the way across the shortest path on the surface, across over to there for example, or yeah, from there, over to there, that would be the creepage distance.

So in terms of art like a board, contamination and stuff like that, there's two different terms there and two different requirements: clearance and creepy. so just keep that in mind so that's what you get in with the slot there. you're getting the clearance, Others are the same. So if you had a pin there and a pin there, the clearance is exactly the same.

So any high voltage across those two points can just arc over like that, arc over air at a certain voltage. But then your creepage might be different because your board might be contaminated, could have dust on it, could have residue left over for the soldering process, manufacturing people's fingerprints, whatever it happens to be, or a bug, or I don't know, you know, dirt and grime, and all sorts of stuff driven by fans and equipment. Things like that that builds up on the board. So if you've got a physical slot on there, then that increases your creepage distance like that.

so you don't have to worry about surface contamination. your clearance remains the same, but then your clearance becomes the minimum specification for your board instead of the creepage becoming the minimum specification for the board. And often it's the the clearance you control and is going to be fixed in your design and manufacturing process between two points. But the creepage distance wall is the same.

You can actually get contamination, so that's why your creepage distance can actually dominate your effect. So that's why they put those slots in there. Now if this was me and I was doing a real built and braces design like gilding the lily then I would have actually routed out another slot underneath those operate optocouplers. But in this case now you can see that they haven't the board, so the creepage distance is going to be across the board under those packages.

So you know in theory you could get up moisture under those packages and then you know, degrade your isolation there. But you know they're obviously still doing it, yet still got a massive isolation there between the pins on either side of those optocouplers there. And I'm sure more than meets the specification. I'm You know there's a difference between meeting the specification and meeting it comfortably and really gilding the lily.

Now one thing you may have noticed here is your typical primary secondary suppression capacitor which you know is normally a you know, an X-class capacitor to go between your primary and secondary their. They haven't fitted that at all. and of course they've put a slot under that, to you know, eliminate your creepage but distance between there and there. So how they're actually keeping their EMC compliance in check there without the suppression cap between primary and secondary? I Don't know.

And yeah, it might be interesting to go into the details on not something like that. but yeah, anyway, obviously they aren't deem isolation to be I guess more important than I am see in this particular case. or maybe they've tested and they just didn't need it. But yeah it's it.

was certainly designed to be in there, But they decided not to fit it and they a couple of no surprise for finding a V-shape hard in there. They're the best in the business of course at TC LT one double O five. let's go to the datasheet and here it is the TC LT 100 series. and here we go here it is creepage distance.

Look at this eight millimeter greater than eight millimeters. hence the wide package there. specifically. look at all the type approvals of course and applications are switch mode power supplies and look at.

this has got more agency approvals that you can poke a multimeter probe out. Unbelievable. And there's an agency tabled somewhere in the datasheet as well. And if we have a look down here, what are we talking about in terms of isolation? Look, isolation, coupler, isolation, Test Voltage.

Ah, sorry about the selection things really. The ice. Oh look. five thousand Volts RMS Beauty.

That's what you want so you know. absolutely enormous creepage distance on this thing. And in terms of the opto cup of itself. Well, five thousand Volts.

RMS You know that's just absolutely enormous. and that's why they've chosen this thing because it because of its isolation characteristics and its art type approvals as well. And look you know and they really go to town on this Optocouplers as you'll see in the a a cheap one then you know they just use some crap in a one hunger and optocoupler and it's just you know, absolutely useless. So yeah, if you want to do it right, you've got to use a proper branded part like this with all the agency approvals and everything else.

Otherwise, you know when you submit if you design your plug pack and go and submit it for all those approvals. unless you want to fake it, you know your crap manufacturing. You fake those sort of things. but nobody's going to buy.

No reputable company is going to buy your product, especially medical stuff. They're not going to take the risk. So when you go and submitted for approval to the agencies they're going to look at, they'll look at this datasheet. what optocoupler have you used? Show us the you know manufacturing information on your isolation, transformer, everything else.

So all that stuff and once they see is this, you know, tick, tick tick. It's already got all these agent agency approvals. Yep, awesome. And the controller there is a th two, oh five, nine, four and I wasn't able to get any immediate data on that.

That's a switch mode controller for the primary side there and well, it's you know. One of these are Chinese jobs I don't know what brand or or whatever and datasheet seems to be a bit hard to come by, but if I can't find it, I'll link it in down below. I'm surprised that they didn't use a name-brand one. they're actually now if we have a look at the input here, it goes around to a series protection resistor here and straight over to the Diode bridge over there.

and then the Diode bridge is. well, there we go. There's our inline fuse if you're wondering where the fuse was. no, that's not a capacitor.

that's an 800 million year but fuse once again, with all the requisite type approvals on it. Yes, they haven't just bummed in anything there. They fused a top round I dot off hand I Don't know who the manufacturer it is, but yeah, VD you our underwriters like you know the whole work so they haven't just like whacked in an M 205 on its ass. you know from some you know one, huh? No vendor in the you know, the Shenzhen market there, but you know they've really gone to town to choose the fuse properly and that's probably part of all the type approval as well.

And that common mode choke on the input there. look at that have really got to town. They're a bit messy on the winding there, but hey, you know, look at the shroud on it. Beautiful.

Now at first glance, these main electrolytic caps here JH Brand CD 263. They look like you know one hung low Chinese ones a 105 degrees C I rated I've never heard of them before but I believe they are from actually a German company called Shanghai which yet sounds Chinese but hey it's Jiang hai Europe they're a German I'm maybe made in Germany and interestingly, the other brand in here is a Rubicon. There we go. No problems with a Rubicon whatsoever.

Once again, that's the Y X series I think 105 degrees C rated. No problems with Rubicon but it's interesting that they combine the two manufacturers there. Then there, that's 400 volt. So they're all 400 volt caps.

so the JH ones are there and over here as well. Exactly the same. Unfortunately, on the second side, they haven't exactly are gone with the best. They're gone for a Samsung there, which you know isn't exactly our No.1 for the best quality, but you know they're okay.

so they've cut a little bit of cost. they're not sure why. Oh, and by the way, the other electrolytic cap in here is that JH brand as well. You can see a nicely heat shrunk vertical inductor there.

Nice attention to detail. They haven't just left the wires hanging out willy-nilly Now, the heatsink for the diode here is interesting because it's at not screwed in its pop riveted in. Yes, they do have heat sink compound behind that and then it's sad designed to press fit into the board. so rather rather unusual.

but I'm sure quite effective. It looks like we have some sort of PCB base to spark up there I Haven't seen that design before. It's a rather unusual but they've removed the solder mask and they've done deliberately sharp points on it so it's got to be some sort of a spark up. I Tell you what I'm not that keen on though is the creepage distance in here and the clearance.

This is a 400 volt rated captain as you saw soldered on the other side here and I got the trace and this resistors very close to it and well I don't know I got a presume that they've done their homework there, but yeah, geez. I don't know that spark gap up there. By the way, there's the other high voltage cap across there. that's the other 400 voltage HH brand one.

So once again, not a huge amount of creepage distance between those two traces in there. So yeah, but they've probably done their homework I don't know offhand. I'd have to give them the benefit of the doubt and you know otherwise you need the schematic to run through and compare everything now. I've gone and sucked the transformer out of this thing so that we can unwind that and see what it's like.

But anyway I it bought up what's happening on this site on the secondary side of the circuit. I Don't really care much for the primary side, but this secondary side here is rather interesting. and I've done a little bit of reverse engineering not complete and here it is. Here's a Dave CAD drawing of it and it's a rather unusual look at the output rectifier diode.

it's actually between the two coils on here. there's two coils between one between the outer pins like that and one between the inner pins like that on this secondary side. and they've actually got the rectifier diode between the two. Like that.

It's really quite weird. And then they've got another rat see down here. and this is one of the optocouplers here. This is this first optocoupler and that's directly across the transformer output.

Now there's some more circuitry around here, which I Haven't bothered because I'm lazy to actually our decode that you can do that yourself if you're really keen. But yeah, it's once again, it's across the fire, the transformer output and it's going to a second optocoupler there, which is then coupled back to the primary side. So we're going to. so there's two up there couplers and a rather unusual diode in between the two coils there.

Hmm. Oops. I Actually forgot the big-ass filter cap there. Of course you've got to have that because it it's just a basically a single wave rectified with the filter cap across there.

And of course, the opto. A couple of feedback to ensure the 5 volt regulation on the output, and they've got some extra filter in here with that vertical heat shrunk output inductor, which we saw there. And of course, a good majority of our power dissipation is inside that rectifier diode. And of course, that's why it's on a heatsink.

there. There we go. It's an MBR one, double six. Oh, and for those playing along at home, there's the markings on the ferrite core if you know what they mean.

And by the way, the primary side has three windings on it. one between there and there, another between the two inner ones, and another one between there and there as well. So let's unwrap this sucker and see what's inside. You can see that interestingly on the outside.

it looks like they got a winding on the outside of the ferrite. Just a couple of turns there. Nothing huge. So you've got a wonder.

do you wrap this sucker first? You can see that winding around there is not enamel coated. There you go, that's interesting looked and I will code it under the wrap there. but no, it's certainly not. so that is very curious.

And no, that's not actually a winding because both our strands of course go back to the one point down here. and if it was a winding, it would be enamel coated wire of course. so it doesn't, you know, short out at that point. So they've just from that point there that just wrapped a couple turns around there as yeah, I don't know.

Hmm, not as 100% sure of the why they've actually gone to the effort to do that. If anyone's got any definitive answers, please let us know. So taking that winding off and we've got a what looks like an E core, Our transformer here. Why is it called a an E core? Well, you can see the split there and there, and there's almost certainly one going through the center as well.

So it's actually, if you take just that one half and imagine that, we'll probably see it when we take it apart is shaped like a letter E hence the name Ecore and equals like this are extremely popular because they're They're really easy to wind, and they're cheap, so you know, but they don't. They do form a closed magnetic system, but they don't offer any inherent shielding. you can start to see inside this. Look at this big spongy stuff.

I Originally thought that that was a right under separating the primary and the secondary, but it's not. You can see it. sort of like just like an end stop there, so like it's just a, you know, a like a spacer on the end of that there and you can see there's the primary winding under there you can see, but some of the primary winding is also on top, actually wrapped over. If I can take more of that mylar tape off, you can clearly see it.

It's wrapped over the top of that secondary right winding. so that's got to be the feedback loop there wrapped over the secondary. so the primary side is tucked to right on the bottom. There secondary is outside that with this huge insulation on these are wires.

so There we go. That's how we get in. You know, it's not just in an enamel coating with a mylar wrap. they're You know, really going to tell on the insulation on the secondary windings there and then clearly the feedback coil wrapped.

You know, it's not a huge number of turns, only small number of turns, but that's wrapped over the top of the secondary. and that sense winding is not just wrapped on top of that. By the way, it's sort of sandwiched in between I've that peeled off a little bit there. Turn that off.

but it's sandwiched in between two mylar wraps like that. So they've really gone to town on the insulation there. as you'd expect, because that's the big requirement for these are medical transformers and medical power supplies is the isolation. That's everything.

And I don't really need to go much further than this because we can see pretty much everything. There's the primary winding in there and then look at you. don't get my knife here. Look at that layer of insulation there.

It's not just it does. It kind of looks like mylar tape from the top, but it's a it's not. It's some other, you know, hugely thick compared to mylar tape wrapping on there. And it's It's almost.

It's almost spongy. like it's a Yeah, it's rather unusual, but that's where they're getting all their isolation right there between primary and secondary. And yep, yeah, they haven't skimped. Come to think of it, this spongy stuff on the top is probably too.

You know, ensure that the secondary winding here doesn't, sort of. You know, stray across to the slide over to the side here and get close to like a a gap. So it's almost like it's a creepage distance between the primary, the primary down in here. it has to get around the edge, under that tape the creepage all the way, and then through this thick insulation on the secondary, winding right through.

So I think that's what it's doing is increasing the creepage distance there. Ah, beautiful. That rubber stuff is really quite quite thick. I'm very impressed with that, and there looks like they've probably got another mylar wrap under that as well.

Jeez, talk about gilding the lily. And just as a very quick comparison, let's take a quick look inside another one which is not a medical gray one, but you know, hey, it's ul listed. It's got all the requisite you know, Tuv approvals, all that sort of stuff. Once again, 5 volts.

It's a bit higher current than the other one which is our two and a half ounce. but let's take a quick look inside and there you go. check out that The first thing that strikes you was the caps on cap. oh man.

one hung low all the way. I'm bigger. Heat sinking of course because this is a higher current one, but still a 5 volt output our supply and it just looks pretty crusty doesn't it? And so let me whip the board out and I have a look on the underside and here we go. check it out.

You can see that the here is the primary art side over here. Yeah, they got nice isolated slots there between the here we go between the diode bridge between the individual wires, so you know that's all nicely. you know, laid out and spaced. And here is the primary of the transformer, the secondary of the transformer.

Huge gap in there. No problems. Got another isolation slot down in here. Here's our opto coupler across here.

and there's our suppression cap across there because this one does actually have a suppression cap. and there's the opto coupler tucked away down in there. Looks a bit dodgy, but I mean I've seen worse than that, so that's a relatively I Guess you could call that a reasonable example of a cheap one. Opto coupler down in there doesn't instill a lot of confidence.

Lo4 5 - well yeah, I couldn't even get data on that sucker at a quick check, but you notice the Y Class suppression cap between that primary and secondary. there? There we go there, it is across there and there's our up to a couple of there. You know it's ok. I mean it's You know it's alright for just a regular consumer grade supply, but this one simply wouldn't cut it as a medical grade isolation.

Not a chance in this transformer. Well, it's not instilling a lot of confidence in me, that's for sure. So yeah, let's save and won't fully tear it apart. but let's have a look.

This is the secondary side over here. You can tell by the thicker wires of course, the higher current and the primary side over here looks like it's got a couple of windings and we've got a similar thing happenin' here. We've got the outer sense wire wedge between -, well, this isn't my large, some other sort of tie and just wedge between that on the outside of the secondary. So you'd have your sense winding here, then your secondary, then your primary in the core and we've got the secondary winding.

Come in here and then there's another wrap for the secondary winding going in there. But what it's all about is the insulation in there between the primary which you can see which is the red color enamel coated wire and the secondary which is in there. So there probably is going to have more wraps of this say yellow tape and yeah, you can see it there. There we go.

I Won't bother taking it apart any further means. see, there's just a wrap or two of that yellow tape plus the enamel on the two windings of course and they see there's nothing stopping it. sort of like you know, creeping over the you know, right to the edge here. and you know how you wind that tape, it might be a bit thinner on the edge or it might not be it there there.

It all depends on how you can control your wrapping during production and stuff like that. so there's no creepage distance like we saw on the you know or with with this sponge tape here. No creepage, didn't Large creepage distance like that around the edge of the tape and back over between primary and secondary. So yeah, no contest there in terms of primary secondary isolation.

And of course the medical one had this really thick rubber insulation there between the primary and the secondary, let alone the the sponge creepage thing. So none of that you find on this consumer one. Chalk and cheese? really? Yep, if I'm going to trust my life to something, it's going to be this one. And of course you do with these medical things.

That's the whole point. So it's not that these are you know, inherently more reliable. Although that might be part of the spec, it's all about the isolation between primary and secondary and you can see it in spades inside the construction of the transformer which is where it's all that and the very nice site you know quality brand are traded and meet the standard Vishay Optocouplers in the isolation slots and that's what it's all about. And that's why this has been given medical type approval and is you know, approved for use with medical appliances and you know that cheap thing like this just isn't going to cut the mustard.

So if you enjoyed that, please give the video a big thumbs up. That would be really appreciated. And please comment and subscribe. And you know all that jazz that I serve video bloggers So at the end of any video and as always our data sheets will be linked down below if you want to check out the data sheets for our parts used in this thing and also a link to the Eevee blog forum discussion as well.

but you're welcome to leave comments on the blog or on YouTube I Do read them all I attempt to anyway and reply where possible. Catch you next time you you.