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Beginner schematic and PCB layout analysis.
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Arduino Inventors Guide Book
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Radiosonde car tracking:
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Psion II PDA
BK Precision Binding Post Adaptor
The Choculator
MPEG4 USB TV/DAB dongle teardown
Forrest Mimms Circuit Classics
https://www.crowdsupply.com/star-simpson/circuit-classics
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Hi Welcome! Everyone's favorite segment Mailbag Yes, we haven't done one in a while, so let's get to it. This one is from No Starch Press. They've had several sucks of the South here on the EUV blog. I Don't need this because it's got a full time.

Um, yes, so we know what's in here from No Starts Press now. I'm gonna use this Alright, thick. Yes, this is the envelope stuff. Really tough stuff.

Anyways, the Arduino Inventors Guide Luanne Le Thomas By making ten awesome projects, let's have a quick check. All right, let's have a look at the Arduino Inventors Guide. It's actually by our Spark Fund. So I Seen that Brian and Derek work for Spark Fun and there you go.

Brian was a our school physics teacher are with the finish robotics Derek is a middle school technology teacher obsessed with pushing the limits, etc. And there you go. let's have his squares. It's basically a a project-based book.

so they go through ten different projects and by the way, the book is twenty nine, ninety five Yankee bucks and includes the digital one as well. and the index is quite comprehensive. Each individual project well. I mean it's You know it's three hundred and thirty yards.

three hundred and ten pages long. So let's take a look. I Mean we'll just show you we just jump through the project. ten, shall we? They're all gonna be very similar materials and stuff like that.

Lots of very good photos. What is a membrane potential I might look at that piezo buzzers building the circuit? we've got our requisite breadboard interface to Arduino type thing program in testing. We've got some code there we go got some Arduino code what you get in the console and some creative specific no it's not a huge amount of detail on like it's just mainly you know programming with the Arduino bid on solder in things like that. so flicking through it's like you know, yeah there's some Arduino code and stuff like that.

They do mention a couple of you know like electronic concepts and things like that but basically just how to wire up the pre-programmed the pre-made kits and stuff like that and getting them going step by step. which is fine but it's not something that you would want if you want to learn electronics or something like that. it's just you know how to build this particular project. so there's not a huge amount of value in there unless you're actually building the projects.

So there you go. It's a fine book that put a lot of work in towards very nicely produced as you expect from Martin No starch press but yeah it's not you know and yeah, but you've got a pony. you can't just buy the book, it's pretty useless on its own. You've got to our pony up for the projects as well but that's another quality art.

no start to press a book and if you want to check it out, link down below. thank you very much Lee See ya saying I'm silent I may be from Singapore I'd almost Singaporean viewers I Love Singapore So probably it's my favorite Asian stopover destination on the way because if you go, there's only two directions out of Australia and if you go one way I'm you got to go um Ava Basically, well if you're heading to Europe, you probably go I'm Asian so thank you very much I Like the feel of this cuz it's obviously going to be a PCB and yes it is. Ah, programmable timer switch. Jeez that's sizable isn't it? So Lee is from Malaysia Big fan! Thank you very much working on our small projects.
Involving some pics it acts as a timer switch. Just finished the PCB which I wish we could take a look at. This is the first time designing Circus Norrish off the selected components and their values are suitable. Especially the decoupling is switch decoupling capacitors correct.

If you find any mistakes on the layout, let's check it out. All right. First up, your power supply section. You've got a series diode in there and no worries, it's better than like a back to back diet across here which shorts out your supply if you get the polarity backwards.

If you can afford the voltage drop are than 0.6 volts across. they're all one volt. You know it's like an airport ever. Um then it's better to have it in series because if you plug in in backwards that just you get no Karen oil rather than just shorted out 680 Micah's problem quite high for the input.

Um, you generally don't need that for just input stability on a regulator like this. Then yeah, you don't. You don't really need that. Now, as for the regulator, here, the LD Trip 175.

This is a low dropout regulator and these are less stable than your regular like 7805 ones. for example, you need a specific type and size of output capacitors to, uh, you know you make it work. It's not a problem, but it's just that when you've got a nine to twelve volt input, I wouldn't be using an audio here. Once again, it's still going to work just fine.

but I would be just be using big as five volts out. Just a traditional 7805. No worries whatsoever. And as I said, you don't need that bigger input capacitance.

And the Apple Kappa you've got the hundred N Ten, Mike and 4.7 Mike and I can see on the well, there's no plus Mike on there. so these are all going to be a ceramic caps. and really, there's no point to doing that. Especially like something like the Four Point Seven and the ten next to each other the so near to each other.

Then they're not like an order of magnitude a decade apart. You don't really need that. So yeah, you I don't know whether or not you got that from the datasheet or not. But I doubt it now.

these could be spread across the board. Of course it's typical to put the your multi bypass caps just on the output of here instead of I don't recommend it, but a lot of people do that are guilty of it myself occasionally. but they're not spread out across the board Here it is. Um, they just threw all three in parallel like that right on the output of the regulator and there's just no point to that.
It would have been fine with just say a ten. Mike if it's an L do it needs you know one Mike minimum output capacitance or something like that all the single four point seven. you didn't really need the other ones. And also notice the really large loop area here that I've highlighted in green the ground of those three capacitors to get back to where it actually needs to be which is the ground pin pin number one of the U1 voltage regulator.

There it's to loop all the way around, see one like that, go right back through the input, go through that little slither there, go through D6 and then up to the pin. Like that and loop area is one of the big traps for young players in terms of PCB layout and you know EMC and the whole electromagnetic conformity thing. Now I Won't go into the technical details of loop area but is one of the worst things you can do in PCB layout is to have large loop areas like this and it's something that beginners get wrong all the time because they don't know about this sort of thing. and if you read the layout, application notes, especially for switching regulators, are really good.

If you look at a good, any almost any good datasheet for a switching regulator will talk about loop area and show you example PCB layouts how the ground return of your bypass caps must be as close as physically possible to the ground pin of your regulated device. In this case, we've gotta learn L Do so. Those three capacitors should have been like flipped over so that the grounds are on the bottom and then it just returned. it returns straight over to the pin number one a view one there or as I'm going to mention later, you can do our via stitching in there like heavy duty via stitch II but in this case you didn't really need to do that.

so it's important to put in this case at least one that 110 Mike is in the example application note across pins directly across, as close as possible pins one and two of you, one voltage regulator especially for these LDOS They can be quite susceptible to oscillation and things like that, so having a large loop area like this may cause a regular light this to be unstable. but in this particular case, we don't have heavy loads. we're just driving a microcontroller and it you know it's not high frequency switching stuff, so it's most likely with 95 percent. Certainly gonna work.

but hey, they'll be from that 5% of time when you're coming out sir and the thing isolates or you get some other issue. So yeah, loop area, look into it and we'll go over to the microcontroller schematic here. The next thing I'm going to check is like the bypass caps on the micro to see if you've actually got them. And yes, you do.

There we go. We've got to 100 ends there. That's fine because we do actually have two different power pins here. and if we have a look over on the board, are they close? Yep, see 10 and yep.
So yep, that's fine and dandy. Having those reasonably close to the power pins, you've got them a little bit away. but for this, it's not going to matter at all. The other thing I notice about your board here is that you've used what looks like oh Six, oh, three parts everywhere.

Why you do that on such a well? Otherwise, quite largely through whole board. There's lots of other through-hole stuff, but like I don't buy personally I know some people are different, but I don't like going to Oh Six Oh Three unless I need to On a board like this, you'd be using much better off using a 805, even 1206 S. But oh wait, Oh Five is generally the go. but I know a lot of people is just like their go-to thing is.

the is the Oh 603 and well. okay. but on a board like this I would have used larger parts. Here's something that I noticed on your layout just then.

Um, your input cap is all the way over here. You've got your power coming in like this, going off to your input cap and then tapping off down here to your input. That's not what your import cap is for. Your input cap needs to be close to your input pin and not just branching off like this.

You don't want to go in over to here and then coming back if you had it over here for legitimate for space reasons or whatever. That's fine, but then have this trace coming off here and going back to the pin like that. But as I said, you should have a dart closer. Otherwise, you've just got the inductor in series and that's not that great and it's going to work in this particular case.

But you know little traps like that could ruin your day later on down the track when you get something more advanced. The other thing with this board. Geez. I don't know if I can get in there and measure it but your your via holes there are absolutely tiny.

What are they like? No point. four millimeters tops, not point three. Something like that really don't need your RV is that small because you I am may may pay a penalty in terms of manufacturing costs because you might have to go to another manufacturing process to get the smaller holes and to it makes them not easy to like solder wires and hack and mod and things like that. And the other thing is the board.

Well I do like the layout, which I'll talk about in a sec. but stuff. Yeah, it is physically very large so you would have paid a lot. You know, much and a lot extra for a board that big.

it could have been shrunk down and made small, but maybe there's a reason physical reason to make it that big. In which case, that's fine. But yeah, otherwise I would have tried to get the size down on that. Now as I said, your layouts actually quite neat.

I You know the traces are reasonably short to the point I like I don't know why you chose the locations you did, but okay, that's part of layout. You choose your locations for your parts first and then you route everything and all of your traces. Oh, quite nicely your flow around like this around into there. there's just some short ones.
I Mean you've got multiple directions on here, but you've got to do that on double sided layout. You've got your flood fill plane all over. I Don't necessarily see any veer stitching like joining these ones together. So like you know, it's sneaking through here like this.

It once again, it's not going to matter on just a timer thing like this. there's no high current staff, there's no you know, high frequency stuff or anything like that. it's going to work fine, but on generally speaking yeah, you would have added. you know V is in here to, you know, stitch these and keep the ground planes short.

rather than create huge loops like going all the way around here like this and coming back like that you would. You know how stitching join in both sides, but as I said, it's not going to matter on a board like this. But otherwise I look for a first design, a first layout and he's excellent. Well done.

As for some of your other component varies like 8.06 k. You've obviously used the 96 range there. There's no need have such our precision in a simple base resistor like that, you know. So you use like E 12 like an 8 K to something like that would have been fine and your crystals are correct like this.

with your tracers coming in and kept short and then your caps going down to ground. no worries. and then for your microchip MCP 7940 real time clock chip I Don't know why you've got a Diode in series with the battery here. You really don't need that.

The coin cell holders like. if you put them in backwards they're going to be okay. You don't need the 1k in series or the diet there, but can see what you've tried to do in actually protecting the battery putting in. but generally you just you don't really need those.

You can hook your battery straight on to there. no worries. the reason you can do that is because the internal resistance of the coin cell is actually quite high and you know it can't deliver like a you know, a huge amount of our current to damage anything. Even if you were able to shove it in the the holder back to front, its you're generally not going to damage out these types of chips.

And as for your various switches here, I'm not sure where the switcher they on there are yeah up down Menu: Okay, all that sort of jazz. Yeah, you don't need these. I Don't know why you've got the 1k protection resistors in here and you're probably Eisley why you've done the RC debounce here. But generally you shouldn't need to do the RC debounce.

so pretty much all those components will be redundant. And as for the pull-up resistor? Well, we can just use the pull up resistor inside the chip, no worries. And for your relays? excellent, You've got your our back. EMF Protection Diodes Nice.
So yep for a first star design that is a bloody Ripper Good on you Lee sir David Jones Thank you very much indeed. our person and no one from Parts unknown I Just killed the stamp I Don't know what on earth it is a chocolate bar calculator. a bit in shock you later what? that's gold Thank You Nick spot of this Chocula at the boot sale without you. If anyone would mind lifting the skirt on this old four banger like to know the source of its unique aroma.

Yeah it does have an aroma of kind of cross between plastic and chocolate is all I can say mm-hmm Palm in Prague Thank you very much Nick it's a chocolate calculator Wow point over here one for oh I Heard that creak that wasn't good was it anyway? um it works. It's fake solar cell. There's actually a battery in there. hey well it could be dual power but like yeah hmm weird, it's crooked Oh All right, get in and yeah there's our battery and uh huh, looks like a real solar cell is actually hooked up.

but yeah, we'll just cut the membrane keypad. that's it. and do we have this is weird Oh oh no right, it's just a like it's gonna be a chip on board on the back of there. hmm yeah well yep that's all she wrote.

hmm well you know, chip on board and a membrane keypad? Whoop! did you know I Was gonna guess that the chocolate smell of this thing. actually maybe because they bundled this with some chocolate in the same packet and it's like seeped into the plastic or whatnot. But I Googled it and apparently they actually sold this as a chocolate scented and shaped calculator. so like they've actually may have infused it with a chocolate smell.

like why do these things exist? What is like wrong with this planet like I I don't maybe someone wants it, then you can get me and oh, you can get fake dog poo and farting novelty gnomes and spanker meters and oh geez I don't want my German viewers and thank you very much Alex hack Hawk Hou CK from which part of jou Rothenberg having bitten a Rothenburg? So let's check out see what's in here. We got a postcard from one of your latest videos. Seriously? Yes, the the problem with the the stupid binding posts on all these looks like it's plagued all of these damn electronic modes. Awesome! Thank you very much.

Ah, Beautiful. There you go. Binding post to banana plug attachment. Beautiful! Now you've seen this BK position electronic load before and the annoying binding posts on it.

Yeah, they're great if you've got the huge lugs to put on there. but if you just wanna plug some banana plugs in like they got no hole in there on the end to plug the banana plugs in, they've got no hole in the side of the thread so that you can put your wire through and then screw it on. No, it's just got the stupid lugs so thank you very much. Alex umm I think somebody else was going to send me one of these too, but they never actually got around with it and it's just a simple board which goes over the terminals.
There we go, look at that. They've taken off some of the code in there just to get some extra current handling capability. Not that it's going to make a huge amount of difference, but that is very, very nice. A very nice solid insulated binding to that banana plugs and it just goes over there like that.

Beautiful. It makes contact on the top side and the bottom side of course. Fantastic. So that is an absolute winner.

and I'm going to leave that permanently connected because I'll probably use at 95% of the time instead of the binding posts. and they've got the banana plugs coming out the right way. She want the cables coming out this way instead of if they were coming out this way then it would be over the buttons. if you came ahead and coming out the top.

added, get in the way of that, you could have them coming out the front. I guess. but then they did get in one way of turning these so that's ideal. Perfect.

Unfortunately, it's not the same for the Rye goal one which has the same issue with these stupid things. anyway. I should be able to fix that by just drilling another hole in the side there and scraping off some of the solder mask there and on the bottom and that'll work a treat. So yeah, what do they do? like copy each others like crap design binding posts are they get it Another cyclist A from Germany I'm from person Unknowing thank you very much Person: Unknown: it's chopped.

The notes certainly knew what it's a switch. Why do we have a PCB mount switch? Hi Dave I've had this for some years but never got around to sending in one of your videos. You mentioned you broke the power switch of your eye Goldie's are 1052 I did the same or changing the fairnie mine. Oh thank you very much I Tracked down the supplier in China well done and got a few replacement switches so have one.

Awesome! Thank you very much. Yes I did break my um busted my my goal to here. Original Roy Go Diaz 1052 Ii That's at home now so I won't be able to show you that that's like Sagan's oscilloscope. he plays with that and great thanks Replacements Which we don't know drugs because well yeah we do have pretty strict customs here of Lakeway muck around Arbiter did no drugs, only an electronic USB chip to the value of 0.1 cents.

Thank you very much from somebody from Laos In no way I don't want my Norwegian viewers how's it hanging in Norway Oh grid paper Nice. We've got a tiny look in the microscope. Okay, we've got a tiny little board. thank you very much.

Still person on no one with beautiful penmanship. Good Bad: Yeah. Fantastic. Like it's not.

You know it like I Just like it. It's not your classic penmanship, but it's almost. It's beautiful. They're all the correct.
Excellent. Um, unfortunately stops decoding an Mpeg-4 world's smallest TV dongle from Sanborns dot IT Italian Hmm. Okay, we'll have a quick squeeze microscope. So there you go.

The world's smallest TV dab FM receiver that plugs into the USB No, it doesn't but it used to have a USB plug on it I think um but yeah, it's tiny. just antenna connector on input. and yeah, let's check it out. I'll get the macro lens and there's the top side.

It looks like we've just got mostly regulator stuff. you can tell just by the bypass caps and the typical five pins suck 23. So to do the business and why don't we got a couple of chippies on the bottom. That's it.

Jesus not much doing is there. and that puppy there is a real tech RTL 28 32 and that's just a USB input DV receiver. It's like all the magic smokers in one chip and the other one right next to the antenna dead giveaway is the RF tuner. It's an Elan exert a 4000 and apparently are these were the Ducks guts in the SDR community.

the software-defined radio community. Apparently, this combination of chipsets was apparently highly regarded, but Ilanics uh, apparently folded and you can't get the E 4000 chipset anymore. So yeah, this is an old older design, but apparently I'm a lot of people were use these things for software-defined radio stuff. Cool.

As for heat building up inside the rubber? I'm not sure what the case in it was, but the chipsets wouldn't take much at all. I mean these are Belinda These are linear regulators on here, but like you know, 79 millionaires at 1.5 volts for the tuna I Don't know the real tech chipset PDF doesn't seem to be easy to come by, probably under little bloody NDA or some crap like that, but you know I don't think it would have consumed a huge amount so I don't think that would have been an issue. Thank you very much Steve Fazzio or is it fuzzy I think it's fuzzy Oh I'm from Geneva in New York USA Once again I double my New York viewers. Is there anyone else in Geneva I've never heard of Geneva New York I've been to Geneva Switzerland been there but I haven't been to Geneva New York that I'm aware of anyway tissue or we have aa nice look at that beautiful handcrafted.

so I'm it's a it's a solid soda dispenser wheel. Fantastic. There you go, Scan me thank you very much Fez Who's a youngster and works on Nardo restoring scopes among other things. These are some scope of various size scope.

C's favorite is the 78 34. Awesome analog storage fancy-pantsy um and design this little I won't built this the handcrafted little um soda dispenser. Perfect. I've only got the one here and I've got multiple rolls of solder so that one's going straight to the pool room.

Thank you very much. It's gonna work a treat thank you very much. Steve Kepler from Leo Indiana Yes, it's a Yankee fest so I'm just picking these randomly off that hope it's not fragile right? Is there anyone from Leo? right? Circuit Classics A stepped tone generator. Sweet.
it's got to be a kid we have. Note: we have a blink board and nice oh it's the old Forest memes circuits bought back to low F um boy um I didn't know it was Steve Kepler of its it's star Simpson Um, who sells these on that crowd supply? so I'm not sure if Steve is related in some way to that, but uh or whether or not he just randomly sent me a kid anyway. um they bought back the first memens. There's like a how to solder in the forest.

mims I kid if you don't know where, head Forest on the Air Power podcast which I'll link in down below. Fantastic. A couple of hours. The guy's brilliant.

so yeah, let's check it out. Yes, so this is the Forest MEMS The third arm who have had on the amp our fantastic multi our interview I'll have to were linked in and this is basically he's our projects recreated complete with his original hand-drawn our schematics straight out of the book look at that and the various art notes or whatnot from the engineers many notebooks, the triple five timer IC circuit page 22 and obviously there's a coin cell battery that goes on the side there and these were done by our star Simpson So I still don't know what Steve has to do with it. but anyway, thank you very much and it comes with a little the original white hand printed. There were hand done forest memes, how to get how to solder think and this is the circuit classics.

There's a whole collection of these which I'll link in down below I think it is cute Anyway, came with all the parts. that'll be a kick that Sagan and I can assemble together. Brilliant! thank you very much Steve thank you Chris Cochran with a K from Northumberland in the UK the old does so have a look I've from the description on this, we've had plenty of these so I hope it's something of for Dave it's purple. Oh I thought I had the open-source Hardware thing it's not, it's not the key, so retro.

Yeah, Well let's check it out first. Here we go: Yep, Sion um we have done that mating the old art people. Probably haven't seen all my mail banks, but we've had Saiyans at least two or three times. Cool.

It's the Zion to modern cm so unfortunately. so yep, we've definitely seen one of these. This is the model ICM made in the old dot of course. fantastic.

The Sion organizer too. and yes, it was one of the first usable PDAs and these things were massively popular I Remember I lusted after these, but we haven't done a teardown and an extensive comparison. I think of the various PDAs back in the day but yet got a processor in there? We've just got some SRAM none of that modern DRAM rubbish this would. and of course the ER program packs.

You could just slide the program packs in, they just go on. These are point one inch headers and they had pre-programmed you know, expanded memory and pre-programmed apps and things like that. and these were very popular, not some not you, more probably more so in the industrial market for like you know, inventory control and things like that. There are really huge and you know I don't know which would it be bigger, the consumer or that industrial market but I guess might be the industrial market in the end because these things were built like a brick dolly.
I Know all my Austrian viewers in particular a Reinard Grail from Ostrich in Austria not Australia Let's crack it open once again, we've had these on way that sweet. That is a a fun Radio Sun We have had one of these before, but this hour the summer we've had the Vasila radiosonde before, but this looks like a complete intact one. The one we had before was like like a real old or much older one. It was like 20 years old or something in like a it was a cardboard and styrofoam box or something.

This one's in a proper plastic Jesus Weighs a bit because normally like if you don't know what a radiosonde is, these things are atmospheric sensors. hence all the fancy whiz-bang stuff up the top. and they since you know temperature, pressure or altitude, all that sort of jazz and they transmit it back to the ground. They send them up there basically weather balloons and that's how they do it.

They whack them on the helium balloons and up they go and they drift around and they get the ice in. They get the location as well and transmit it all back anyway. very cool. Wow This Is this worthy of like a separate ariane video? perhaps? cuz they're fascinating stuff.

They really are. Yeah, oh jesus even got a little poor word on it. Wow yeah if you don't see this in the mailbag, it's probably because I thought it was to interest you know I decided to a separate teardown video on it I got the note with it. This one actually fell into Reinhard's backyard with a note attached to it saying it belonged to a weather balloon and he should be so kind as to dispose of it.

so instead of disposing of it, decided to send it straight to us fully intact. Awesome. Yet these things litter the planet. they just you know, they send up thousands of these radio songs probably every day.

Um, and to get you know, weather data and stuff like that. So okay. Fantastic. I Love it fella knew his backyard.

What are the odds have fallen into a well? I've got like almost four million subscribers I may be alright. Can anyone calculate the odds? How many go up per day versus the square area versus like number of viewers? thank you very much Reinhold Who is lucky enough to have one of these land in his backyard directly knew his garden hanging from a parachute and I've done that one before but it was an older model. this is a newer model um which has the GPS antenna, the transmitter, all the sensors and things like that. but I'm going to save that for not only secretary on video but I'm thinking it might be an Eevee Discover video if I can get the right contacts.
I might be able to do some interesting stuff at this. but yeah, as somebody on Twitter said, they actually work for a Vey Vassallo face solar I don't know I'm and how he pronounced it and they manufacture like that without. they said thousands of these are released per day and they are a one-shot deal so I'm gonna leave that as a tease. sorry next.

and also somebody in Twitter actually converted their car into a tracking vehicle I believe he's from uh South Australia and actually our tracks down. These you can actually get modeled in software to predict where these things are going to land and then you can go and hunt them down. It's a bit of a game and some people out there go and hunt these things down and have a big trophy wall of all their radio. Sun's brilliant and you may know what this is are from Zintan E rah Thank you very much I've done a video with a video.

you know it's a video review of the Zinta near our backpack light and they they actually saw that ICO Gala is the company and they said that sin. They said they liked the video and they appreciated the feedback and all that sort of stuff and they said that they would send me some accessories for it. so thank you very much. Umm Egyptian stuff Cool.

I'm really into Egyptian stuff and yeah, these are like little attachment things which you can put on it so you can put it on your backpack and and whatnot. and they've sent me another battery pack. Tiny little battery pack. Oh isn't it cute? Anyway, yeah, can't do a teardown.

It's all altra, sonically welded or whatnot but assembled in China US Patents pending. How can you Pack. like what a design pattern for? you know, like how how can you patent a just a battery pack? It has to be a design pattern in terms of the look and feel kind of thing. So yeah, I think we might have a couple of more PCBs this one's from person unknown so let's just oh I probably shouldn't have done that because it has like a no, don't we have a piece of EE it is a Smart supply.

Oh wow, okay cool, it's a there you go. It's probably a variation of the micro supply somehow. Um - 18 650 s Neat. zero to 20 volts 0 to 1 M I'm sorry for ripping those.

oh that's a real pain in the didn't it? Jeez. Electronics Engineering student from: Belgium thank you very much Thomas Even though it wasn't on me yeah, he stumbled across my micro supply project and you he wanted to make one I Only find out after 14 episodes that you didn't finish it. Yes, sorry. various reasons for it, we are working on it again.

I'm actually from completely from scratch. Ah, it's not based on this LT 3080 design anymore. Um, and so it's the Spot Supply. That's neat.

Glad it worked out for you. I Got quite a lot of people actually built their own variants based on the well my last micro Supplies schematic based on the LT 3080 Cool Ice. What? Hi I'm Thomas An electronics engineering student from Belgium Hi I'm Dave and I'm A for tearing your note with my big-ass knife. Anyway, um, he stumbled across a Mercury Supply project first time I saw I knew he wanted to make it.
After 14 episodes we'd never finished. Yes, we didn't finish. but having said that, David do and I are now working on the micro supply again. it's going to.

It's not carrying on from where we had before, but trust us, we are working on it big time. so hopefully um, we will come out with that and videos will be post. There's a talk I've done. There's a section on the EEV blog forum where I've shown like a custom LCD which we're going to do for it and stuff like that and everyone's discussing it and things like that.

but apart from that no other details. sorry. Anyway, Specifications: Similar: 0 to 20 volt, 0 to 1 air power from 2 protected 18 650 lithium cells and it looks something like that? Isn't that neat? I Can't remember what my interface look like. it was very similar.

that wasn't it. Setting out and put it into a funky little case and isn't that cozy? There you go. So I'll link it in down below. where is it? We have a website somewhere? Get up there we go.

Github Thomas Vdd Smart supplied, fully fledged open-source hardware logo. Excellent. Hasn't got my letters on there though, so that looks pretty jazzy, doesn't it? I like it. Cool bananas.

There you go. A lot of people have done micro supply type variants of the project and I totally encourage it. It's great to see and yes, lots of people on the forum. who've you know done that sort of stuff.

I Like how it's almost all through-hole except for that puppy up there. but anyway, those looks like a nice layout. Jezzie Wow, there's inside the finished product and yeah, we've got. They're using the back panel as the heat sink in time-honored tradition and it looks like it uses the LT 30 80 still.

So there you go. So world on. Thomas That's an excellent implementation. LinkedIn Down below, it's all open source.

e Hi to all my Finnish viewers, this one's from Julius Will will you go from Espoo Espoo In Finland there you go at seven squares I Believe this one is a PCB feels like a PCB it's always it did give away hi Dave this is mystery PCB Can you guess what it does and what its electrical function is? Thank Julius Will hoe from Finland The answer is this in this second envelope. Ah, there's a second author life. No no Can I guess the circuit function. Ah jeez, it's got to.

It's like it. There's no. the only traces on there are till the hand did you focus the only traces on there are those two big fat ones that you can hear. You can see that there.

there's two big fat ones so it's some some sort of well it's high current so I like and everything else is like mechanical type interfaces. So it's like I would say it's from some like maybe a little robot car or something like that. It's probably got like some high current motor drive or something. It's kind of like a base or it could be like for a quadcopter or some other like you know, some other base that mounts motor.
II type things onto it would be would be my guess. Gotta go to that web address to see if I'm right. Ah, hang on. I Just went to check and it's for a slot car.

It's actually the bottom chassis of a slot car with the motor connection and stuff like that like a homemade slot car. So yeah, I was bang on it. hooks up to the motors and and it's the mounting. Like I said, it was a basis kind of thing and motors hooked up and that's exactly what it was I made Sloka cool See wasn't that hard mystery PCB Nailed it.

Hang on. That was easy.

Avatar photo

By YTB

19 thoughts on “Eevblog #1034 – mailbag”
  1. Avataaar/Circle Created with python_avatars Richard Crowley says:

    Thermal relief on the regulator tab are antithetical to the concept of using that large area as a "heat sink". Doh! ๐Ÿ˜’

  2. Avataaar/Circle Created with python_avatars John Walsom says:

    I was using Psion 11 back in early 90s with world class air and water flow balancing programs. All written by my favourite stepson while still at school……in use commercially for about 20yrs. I have only just recently replaced with superamoled galaxy tab s4 running wps spreadsheets, its better but not quite as foolproof or as easy to use.

  3. Avataaar/Circle Created with python_avatars Gregg Jaskiewicz says:

    where's the new microsupply?

  4. Avataaar/Circle Created with python_avatars Raketenclub says:

    wtf? you got an hell yeah its rocketscience shirt? ….just had the idea to send you one… sh…..

  5. Avataaar/Circle Created with python_avatars David says:

    I used to like the Dick smith projects back in the day when Dick Smith used to be a electronic parts store. I don't know if anyone does them anymore.

  6. Avataaar/Circle Created with python_avatars runforitman says:

    I know that I personally use very small package parts because it means I only need to have one size of that part, and it'll work for practically all things I make
    and they end up useful on perf boards when I realise I didn't leave room for a pull up/down resistor and need to fit one in

  7. Avataaar/Circle Created with python_avatars Frode Lรธtvedt says:

    So, what is a good book to learn electronics?

  8. Avataaar/Circle Created with python_avatars Steve Tobias says:

    Love the mailbag episodes, pity you destroy some letters with your big ass Dundee knife. Need to get slow down a bit or just cut the top 5mm off the envelopes instead of the top third. Good on ya Dave still love your down under thunder videos. Should be more Aussie electrical engineers like you entertaining YouTube electronic enthusiasts.

  9. Avataaar/Circle Created with python_avatars Gazza Boo says:

    My old Psion gave me endless hours of fun. Can't recall for the life of me why I bought it or even what I used it for, (it was over 30 years ago) but I do recall spending lots of time playing with it ๐Ÿ˜„ Mine had the four line display and I even had a couple of expansion packs. Good times!

  10. Avataaar/Circle Created with python_avatars Aaron Brandenburg says:

    This is not a letter.

    This is a letter after I used the big knife.

    Lol.

  11. Avataaar/Circle Created with python_avatars Mr8ohms says:

    Is a ducks guts good or bad?

  12. Avataaar/Circle Created with python_avatars ayitsyaboi says:

    Pretty late but I live near Leo!

  13. Avataaar/Circle Created with python_avatars tikabass says:

    Sampling the inputs switches every 30ms or so provides good debouncing. No extra parts needed.

  14. Avataaar/Circle Created with python_avatars herauthon four says:

    Dave, about the protective res. – what if somebody removes the badcap – and inserts a jack for a power supply solution ( like 5v) ?

  15. Avataaar/Circle Created with python_avatars Tripcore says:

    Maybe the penship is peter popof

  16. Avataaar/Circle Created with python_avatars edgeeffect says:

    I like the new "grid and oscilloscope trace" animation… that's cool.
    I want your "bodge" T-shirt! Where did you get it?

  17. Avataaar/Circle Created with python_avatars dotdissonance says:

    Nice new logo/outro! BTW I agree with the others about a PCB review series, but people have to send them in. I think the issues to find would get thin if you go after just production boards. Super helpful and will cause me to look at my boards a lot closer.

  18. Avataaar/Circle Created with python_avatars Zodliness says:

    I'd have to agree that publishing a project orientated book, will inherently limit their sales. Although some of the projects look interesting to students looking for a good start in the subject.

  19. Avataaar/Circle Created with python_avatars Manchee says:

    dave? I was wondering is a vacuum tube basically an old type of transistor?

    Faz is a "youth"?

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