 Where in the world is the Great Search Raju by Digi Keen Adafur, lady editor of power of engineering every single week to find the parts you need and boy Do we got to find some parts? There's a lot of parts fine. All right, so if someone wanted to find this specifically from They read this book and they're like, oh, you know what's going on with yeah So this is I was showing this earlier, but This has a whole section on core memory and how to build it and how it works and so I start to look online You know, I've heard people make core memory Let's go to the computer So You know you make it by getting some magnet wire some thick magnet wire some thin sense of magnet wire That's woven through and then these little magnetic rings and the way that these rings twist will Determine whether the bit stored is zero or one. So, you know, nowadays we read and write memory by putting charge on a capacitive gate for transistor and then we read that charge later and You know, that's basically how SRAM and DRAM work and and it uses a ton less power And it's a lot faster than the magnetic core memory, but I think it's funny that you know It's like now use capacitive storage, but we used to use inductive storage in a sense So while, you know, people don't make core memory and the fabric tech computer probably doesn't have You know these these ferret cores available anymore, although like these are amazingly tiny only 14 mil Which means you could cram, you know so much core memory into like, you know, it's a square inch But you know people, you know people need to store data And you know if you want to store dynamic information, this was how it was done before We came up with a capacitive storage So let's go to digikey because You know, even if you're not making core memory. It is useful to Know that you can get ferret cores at digikey. I used to wind my own inductors For class or because I was making an amplifier, you know, or something or a filter And I'd wind my own inductors So let's Let's search for Ferrite core. So they're actually not called cores anymore. They're called toroids. I mean, they are they are called core. Sorry Sorry, I was searching for magnetic core. They're not called magnetic core. They're called ferret core and ferret cores Actually, you see there's a whole There's a whole section called. Oh, magnetics transformer and inductor components. This is kind of handy. There's three Sections, there's the core. There's the magnet wire that spools around and The bobbins. These are you know holders things that you know, you can store your Beautifully made inductor on so I'm never I'm gonna purchase these but maybe one day we'll we'll cover these on the great search And you guys we're looking for a ferret cores and There's all sorts of kinds like there's pieces and you know ferret cores again They're made they're used for a couple different things one You're making your own inductor. You're making your own transformer While you know in general you tend to purchase these pre-made There are times when you really have to DIY it for some reason or you're prototyping and you want to Try different inductances instead of like soldering in different inductors. You'd actually just change the number of coils in your wire Of course, they're also really handy for reducing EMI You know the having a magnetic core around a wire You've seen them. You've had like it was be cable with a big lump in it That reduces the amount of electromagnetic interference. So Use for a couple things, you know, there's and more, you know, all sorts of shieldings I don't know what this e-shape is for maybe also for maybe ribbon wire. I don't know Actually kind of neat. We have the Apple to disk drive. It has a gigantic chunk of ferrite core material on the on the cable as well Because there's a non-differential so lots of EMI so they're all very neat But what we really want is like this kind, which is called a toroid it's a donut shape but They're they're called a toroid type. So let's Let's look for also. Let's also look for only active ones and then, you know, there are a lot of permeability and Cross-section, we're not gonna care about that. We're just gonna look for the smallest possible one for again DIY Core memory, so let's find where the shape is core type. So we're gonna go for toroid type Boom, okay, so there's a couple hundred of these but yeah, now we're talking these are all the same shape and size and We want the minimum size available Which would be the diameter so they do come quite small, I mean you can get them as small as You know a tenth of an inch Let's look up to about About five millimeters maximum again, we're not gonna make that the tiniest ferrite memory, but if you're just DIYing at home Okay, so let's see what's available So there's a lot of different ones some have photos some don't but you know, we don't really need the photo Let's look at them by Diameter size, so I just sorted Oops, I went down to the the diameter and I sorted up by a diameter So unfortunately, some of the smallest ones are not available So the smallest available one that is in stock, so if we wanted to filter by In stock not a lot in stock, but the ones that are available for Size three millimeters the smallest and it would be this one. So there's no photo But I'm not too scary because we kind of know what these look like there is a Data sheet and it looks like this. So yeah, it's just a little Torrid that we can use And if you want a photo because you want to really I sometimes I'd like to See what I'm buying Hold on My internet is Oh, no, my internet's not interneting. Oh wait, there it goes. Okay The smallest shortage internet supply chain. I know the smallest one that has a photo is this one and there's also a lot in stock We can look at it at 360 But you know, look if you if you need as a small Little toroid, you could you know four millimeters is Let's see. I always like to compare Yeah, so like three millimeters you could you know, you if you wanted to make a small You know a tiny little core memory sheet you could probably use that four millimeters is not That much bigger. So either one would be good and they're both pretty inexpensive Like a zoom in I'm zooming in. Okay. This is now quite big But both are pretty expensive you can get them. They're about 10 15 cents a piece So, you know, I don't know how many people out there are interested in making very memory But you know, if you are making a very small inductor Like a bailon for like ethernet or you know for a small boost converter or Filtering for like classy amplifier. I mean you can still find these quite handy You know, like put a little bit of magnet wire through them and you know, you've got a very small inductance High-current inductor for sure. Definitely more high current than a chip inductor. So I You know, I don't know if I'm going to actually make a Piece of core memory, but this is oh my internet's down again Yeah, I don't know the internet's been Was slow There you go. Um, oh No civilization. Here you go. Okay. So this is the Product I picked for the iron MPI so this this inductor. I like how it has a little three model Available, but they also have tons in stock. So you can make up to, you know, basically 10 kilobytes of core memory Using what's in stock at the Juki right now How many is that and that is a great search?