#574 – Bubblegum Tap Shoes

Chris Gammell: This is The Amp Hour Podcast. Released January 23rd, 2022. Episode 574. Bubblegum Tap Shoes.

Dave Jones: Welcome to the Amp Hour. I'm Dave Jones from the EEV blog.

Chris Gammell: And I'm Chris Gammell of Contextual Electronics.

Dave Jones: 2022.

Chris Gammell: Well, we said that last time you were here too.

Dave Jones: Oh, did we? Oh, okay. Yeah, that was our New Year's. Remember, we were recording in 2021. I know, it's actually really 2022 and it's really depressing.

Chris Gammell: Yeah, I'm sure the summer is very depressing in Australia.

Dave Jones: Right. I did actually tweet this out once 2022 came around. But 2022 is the year of Soylent Green. That Soylent Green happened. So, yeah, just a warning.

Chris Gammell: You know, if Soylent Green ever does come around, you know that there's going to be a bunch of influencers that are all into it.

Dave Jones: Well, Soylent was a thing like a decade ago.

Chris Gammell: Soylent, the...

Dave Jones: The drink.

Chris Gammell: Supplement, yes. Yeah, yeah, the supplement. Yes. I believe we've mentioned that on the show before. And really, just how terrible a name it is.

Dave Jones: But we are talking about it. Exactly. Exactly. And it's just died away. I haven't heard of it since. I haven't either. Yeah.

Chris Gammell: You know, I actually, I was into it. I think that's probably one of the reasons we were talking about it. Oh, really?

Dave Jones: Yeah, you're right.

Chris Gammell: I was into it. Well, I was into it. They had a flavor. It was like coffee and it was like mocha. And so it was like coffee flavor and chocolate flavor. And then I thought about it. I was like, oh, I can just mix chocolate protein powder into coffee in the morning. And I was like, saved like 80%. So...

Dave Jones: Save having to... Yeah, right. Yeah, yeah. Oh boy.

Chris Gammell: As we do.

Dave Jones: Don't do it. Because then you'll end up with soy face.

Chris Gammell: Soy face. There you go.

Dave Jones: Soy face, as they call it. Yep.

Chris Gammell: All right. What have we got? Well, you just came back from holiday. How was that?

Dave Jones: Not too bad. I was not well over the break. But, you know, I'm better now. Kobe? So... No.

Chris Gammell: Did you catch the Ovid?

Dave Jones: Well, I may have. I don't know.

Chris Gammell: Who knows? It is extremely prominent. Prominent? It's very common around here. Yes, I know what you're trying to use. Everybody's catching it, Dave.

Dave Jones: Everyone's got it. It's really trendy. Yeah. Yeah. Yeah.

Chris Gammell: Right. Luckily, not everyone I know is, you know, vaxxed and boosted and having just like a bad cold version of it. So that's... I'm very grateful for that. But yeah, it is everywhere in the States. So coming soon to a locale near you, I'm sure. Hello, Omicron.

Dave Jones: Don't ever tell you about the story of when I turned, let's just say, 30. Sure. Yeah.

Chris Gammell: You know, folks, he's no spring chicken.

Dave Jones: Yeah, exactly. Exactly. So yeah, I got, you know, I'm doing the thing. Oh yeah, I'm about to turn 30. And you know, oh, I'm gonna, I'm so old. I'm gonna have a heart attack. Sure enough. Like I wake up on my birthday. I am not kidding.

Dave Jones: In a cold, like in a sweat. And I'm hunched over and with chest pains. Oh yeah. Like I'm not kidding. You're psychosomatic-ed yourself into it, huh? I think I might have psychosomatic. But no, I am. So yeah, we raced to the yard. It wasn't like I sort of tried to stretch all myself out and everything. And I thought it might have been like a workout. I just, you know, like did too hard in chest or something, you know.

Chris Gammell: Yeah, maybe, you know, the spicy buffalo wings or something like that, you know, the night before. You know, a little.

Dave Jones: Yeah, but it felt really bad. Right. So anyway, it wasn't bad enough like hospital. So I thought, oh, I've got to go to the doctor. This is like, you know. So I go to the doctor and, you know, I walk in and, you know, tell him the symptoms and everything. And he's going, oh, yeah, yeah. Like he's just, you know, shaking his head. And I'm going to like, I think I've got like might have a heart issue. And I'm going, are you at least going to check my heart? And he goes, no need to. I know exactly what it is. No, it's because he had already seen like five cases in the last couple of days. It was a virus that infects your chest muscles.

Chris Gammell: Oh, interesting.

Dave Jones: That causes them to spasm and stuff. It was a virus going around. He said, yeah, I've seen a whole bunch of them. Yeah, that's what it was. So, you know, it was just a, yeah, it's just a viral infection. But yeah, I thought it was a heart attack.

Chris Gammell: Much like when walking into a troubleshooting session and an engineer like Dave says, I know what the problem is. You do want to still do a test. You know, you want to confirm somehow.

Dave Jones: Assumption is the mother of all you know what's, you know. Yeah. Yeah. Assumption.

Chris Gammell: So, yep.

Dave Jones: Ah, boy.

Chris Gammell: Glad you're okay. But sorry, your holiday wasn't as relaxing as you'd like. No, but- But now back to the world of electronics. What's more relaxing than that?

Dave Jones: Exactly. Well, can we get into some mystery?

Chris Gammell: Mystery.

Dave Jones: Electronic mystery.

Chris Gammell: Intrigue.

Speaker ?: Intrigue.

Chris Gammell: Spicyness.

Dave Jones: Although I think I know the answer, but I think it's more, I think it might have morphed over the years. Okay. You posited on Twitter, I believe. I did posit on Twitter and also in my recent video just released this morning.

Chris Gammell: Okay.

Dave Jones: Which I should have actually Googled it. You know, I should have actually done some research before I actually put it in my video, I guess. Whoa. Anyway, so I think I know the reason, but it doesn't mean it's the reason these days. 1N 4007 diodes, right? Yep. I'll send you a link to a, well, I've got a PDF, right? There's 10 million different manufacturers of 1N 4007s, right? Or the 1N 400-

Chris Gammell: Yeah, I don't know if there's a, this is maybe the definition of a commoditized component, if not-

Dave Jones: Yes, this is a jelly bean power diode. If there, if it's the jelly bean power diode, right? It's been used since time immortal, right?

Chris Gammell: Yeah. Back when Dave was 30.

Dave Jones: Yeah, right. And anyway, it's, it's the 1N 4000 series. So you've got the 1N 4001, the 4002, the 4003, the 4004, 4005, 4006, and 4007. Oh, goodness. And the only difference, have a look at the first page of the data sheet that I just sent you.

Chris Gammell: Okay. Okay. I'm looking. I'm looking.

Dave Jones: What is the difference between them?

Chris Gammell: Well, the first page is maximum ratings. Yeah.

Dave Jones: No, don't worry about maximum ratings. Yep.

Chris Gammell: What else is different?

Dave Jones: Oh, sorry. Yes. Yes. The, the actual, yes. Take a look at the maximum ratings, but also the-

Chris Gammell: I guess the maximum ratings are also the, the VRRM is the, so that's the repetitive, is that the repetitive reverse maximum voltage?

Dave Jones: Peak repetitive maximum. Yeah. So basically, they often don't peak in there.

Chris Gammell: Yeah. Yeah. And like, so if you got it in like a bridge configuration and you've got very, very big sine waves coming in.

Speaker ?: Yep.

Chris Gammell: Okay.

Dave Jones: So the only difference is the voltage, right? Yeah. Nothing else is different. So why? My, my question is, why do they bother even making a one in 4001, which is a 50 volt nominal DC rating. Let's just work with DC. And, and the, and the one in 4007, which is a thousand volts. And then they've got 50, 100, 200, 400, 600, 800, and thousand volt ratings. Why do they even bother manufacturing? Yeah.

Chris Gammell: So why not just default to a thousand you're saying? Yeah. That's what I'm hearing.

Dave Jones: Why don't they just make one in 4007s? And this came about, because in my latest video, I took apart my BM235 multimeter because the customer was having a problem with leakage. Sorry, not with draining of the battery, even when it was in the off position.

Chris Gammell: Right? As we, as we age past 30, there's also leakage problems.

Dave Jones: There's also leakage problems. Not, not at my end. Anyway, I'm not that old yet. So there's, yeah. We're all headed that way, Dave. It'll be, yeah. The puns will start if that ever happens. Yeah. I'll be on Twitter or whatever is being used for Twitter at the time. And I'll be just, yeah. Anyway. Yes. I, my first. BM235. BM235. If it's draining the battery in the off position, it means there's some component across the battery. Right. When, when, like actually before the physical switch, the physical rotary switch. And of course, the classic is the reverse protection diode for the batteries. Right. And sure enough, I open it up and there's a one in 4007 in there. Right. And, and of course it's obvious why they use the one in like the thousand volt rated one across the battery because they use it elsewhere in the circuit, especially across the users on the current ranges. I've got a, I've got a video on that, by the way, we should link it in how multimeter input protection works with fuses and actual diode bridge protection and stuff like that. Anyway. Yeah. So they obviously want to, they want to reuse that part. If you know, you don't want to have, you don't want to have a reel of components on your pick and place machine for the one in 4001s just for the battery. And you've got one of those and you've got 4007s everywhere else. That's just dumb. Right. So they simply reuse the one in 4007. And then, yeah, it just occurred to me, why, why would you even bother buying a one in 4001? 4001. And I asked on Twitter, has anyone ever legitimately used for electrical reasons, not, not, not for cost or some other reason, electrical reasons.

Chris Gammell: Because it's the only thing available in 2022.

Dave Jones: Yeah, exactly. Have they ever used a one, like a lower voltage part for electrical reasons instead of the high voltage part? And then, um, sure enough, somebody on Twitter replied that, oh yeah, it's the, uh, it, it could be the doping. The one in 4007s have different doping to the one in 4001. And then that kind of rung a bell. I kind of have a vague recollection of that being the case. And sure enough, I found, here we go. I will post it to you. Oh, can you post images in the stupid? Yep. Yep. There we go. You've got it. There you go. I found this Motorola, old Motorola data book, which shows two curves for the one in 4001 through to the one in 4005. And then another curve for the one in 4006 and 4007. So it seems at some point in the past that there were two variants, not like seven, as the data sheet shows. Sure. There were only two variants. And maybe then they selected on tested, like, like those ones to get the thousand volt binning or something like that, perhaps. And they had different junction capacitances and they had different reverse recovery times. So it might be a speed thing.

Chris Gammell: Right. So that's your trade off there.

Dave Jones: But on modern data sheets, I can't find this. Granted, I haven't looked at a hundred data sheets, which I'm sure there are. I've looked at like half a dozen and I can't find it. Right. I can't find any mention of this anymore. So.

Chris Gammell: Interesting.

Dave Jones: Does anyone definitively know in modern times, if there's any difference between them? Because the package is the same, right? It comes in a little surface mount SMB package for the thousand volt one, as it does for the 50 volt one. So it's not that.

Chris Gammell: Well, I went to my favorite, just, just now, like not, this is not extensive, but my favorite resource for all things schematics, which is Google image search. And I would just search for, you know, what, what has one, one in 4001 in it instead of 4007. And there's other stuff in here, but it is all just like low voltage. And it's very, you know, at least the schematics here.

Dave Jones: You would put it on a secondary side of a transformer. That's right.

Chris Gammell: Yeah. Like a 12 volt output or something like that.

Dave Jones: A 12 volt output instead of a primary side. AC to DC. Yeah. Right.

Chris Gammell: Converter type of thing. Yeah. But that doesn't really lend itself to. No. Oh, I need speed. That's more, I think probably, well, this was available at the time. This isn't really a precision part ever though, either. Right. It's not like a small single model. It's all, it's all very chunky. Yeah. It's chunky and you get what you get and you don't get upset. You know, it's like. Yeah. Right. Yep.

Dave Jones: Yep.

Chris Gammell: So, yeah. I mean, so I think I agree with the basis of the question, which is why bother having all these other things? I guess maybe not 4001, but maybe the, the four or the six.

Dave Jones: The 4004. Yeah. Like I've always, like, because like way back when I was a boy, like, yes, like 4007s were kind of like special. The, the 4004 was the one you would use all the time because it was, you know, it was the 400 volt rated one. So it can do mains and stuff like that. And it just, you know, it just actually did the business, right. For almost everything you used it for, there was no reason to go to a 4007, you know, unless you were using, like doing three phase mains rectification or something, you know, like some sort of, you know, more obscure thing that the average hobbyist engineer wasn't actually working with unless you're into the power field or something.

Chris Gammell: So now, so now here's a question for you. So back in the day, if you saw this Motorola, you know, thing you sent me and I'll try and post the image in our notes as well. But like back in the day, would there have been more spread, you know, so like everything has gotten so commoditized and so pushed down. Would there have been a much higher spread or especially at the high end for an 07 to like be, you know, so now if you're going to put 10 of these in a product that it, you know, if it goes from one cent each to, so a 4001 is one cent, one cent and a 4007 is seven cents. And so that difference of six cents on a single one times 10 parts in design, that 60 cent difference might actually be worth it. Whereas these days it's all so cheap anyways. Yeah. You know what I mean? Just like the over time, everything kind of gets squished down towards effectively nothing, but in high enough volume stuff, maybe it does matter.

Dave Jones: Yeah.

Chris Gammell: I, you know, maybe you're saving money.

Dave Jones: I don't know, but yeah, like, yeah, there might be a price difference, but I'm asking like, why? Cause surely they aren't doing seven different process differences for seven different diodes in this range. Right. That just seems ridiculous. So I'm kind of, you know, erring towards the old Motorola data sheet where there were only ever two types of diode.

Chris Gammell: Yeah. And that could be, and it could be, they're just binned in between.

Dave Jones: And they're just binned or whatever. But yeah, I like, you would think that these days because the process technologies are so good and so consistent and everything else that you just wouldn't bother. Make it like, it's, it's like they're, maybe they're all one in four double O fours, for example, if they're making like the lower, but, but they just mark them four double O one because some people have them in their bombs. Yeah. Part.

Chris Gammell: Yeah. That's right. Yeah. Yeah. Yeah. And a, uh, military contractor is not changing their part number for anything. Let me tell you. That's it. Yeah. That could be, it could be, I wonder what the fab is like too. You know, you think about like, so there are probably some just size minimums just for voltage spacings and stuff like that. But even still, like it's probably a pretty small piece of silicon in there. It is.

Dave Jones: I mean, it's an, as I said, it's an identical surface mount package for the four double O seven is for the four double O one.

Chris Gammell: Yeah.

Dave Jones: Thousand volts versus 50 volts. That's just nuts.

Chris Gammell: What is, what does these wafers look like?

Dave Jones: They must just be like, I don't, yeah, I, I don't know. I would have to crack one. You know, you'd have to sand one open or something, but yeah, I actually, I, I almost doubt whether you can, the one I found in my BM two, three, five multimeter, it's a four double O seven parts, a thousand volts, but it's an SMB package. Can you even get a thousand volt rated part in a, such a small ish package? I guess technically there's clearance there. I guess it depends how long the leads have folded under, I guess, but oh boy, you know, and how, how close the pads are together. And if you've got an isolation slot, but if you were serious, you'd put an isolation slot under them, which, which you will actually see if you take over like a, like a light switch mode power supply, ceiling light or something like that. One of those, even the cheapies, they will go to this effort. They will actually put isolation slots under the surface mount diodes because you know, like they're, they're directly rectifying mains. Right. So it's pretty high voltage stuff and any leakage on the board is going to be a problem. So.

Chris Gammell: Higher there than here, Dave. Higher there than here.

Dave Jones: Oh yes. Higher here than over there. Although you guys are 240 volts.

Chris Gammell: Yes. We've, we've mentioned that.

Dave Jones: Yes. America is 240 volts, but yep. You guys just do something weird in the box to make it 120. I don't know. Yanks. Yeah. Anyway. So yeah, you'd put isolation slots under them on, especially on the surface mount parts, you know, but anyway, does anyone know definitively, definitively. Yeah. Definitively. Whether or not these days it's the, it's exactly the same die and they just don't bother because the specs are the same. The capacitance is the same. Like there's no junction capacitance difference. There's no leakage current difference. There's no forward voltage difference, which I believe there used to be a forward voltage difference between the 4001 and four and the one in 4007. So yeah, but now, nowadays the data sheets are identical. So I can only assume that the silicon's identical.

Chris Gammell: I mean, looking at the schematics too. So I was just searching on 04, 05, 06, 07. I skipped 07, but just like all the in-betweens, I guess I didn't, I did 03, 05, 06. Right. So like non-common type of stuff. It's all, you know, just really old data sheets, you know, and it's all in the same, it's all bridge configuration coming off a transformer. It's all the exact same thing. So I have to imagine this is a pricing difference from back in the day. So that's gotta be it.

Dave Jones: All right. And they've just stuck around because people need them in their bombs. Yeah. Speaking of which, this would be a good example for multiple bomber items. Because if you're designing a product and you want to make sure you've got availability, then, you know, back when I was working on the military stuff, you know, we would always have to make sure we had three different vendors and three different available parts that were qualified to go into the product so that we can actually swap them out if we needed to. Right? Yeah. Yeah. In this case, let's say, you know, you've got a main switcher or something, you would go, okay, well, I can use the 4004, the 4005, the 4006 and 4007. So you'd have all of those in your bomb. So at any point you could use, you can substitute in any of those and it'll work. So, yeah.

Chris Gammell: Yeah. And that's actually, that is a good example too, because usually it's, you know, you might have like a base number. So like an LM317, and then it's got some other package codes or packaging types around it. And you're like, oh, well, all of these are the same part. But when you actually change the base number, you know, a buyer is going to be like, well, that doesn't look the same. And so you have to specifically call that out and be like, no, no, this is an effective replacement.

Dave Jones: Right. Yes. Yeah. And then you have an internal part number. I can remember getting so many phone calls from the purchasing department going, Dave, can we substitute? We can't get this part. Can we substitute this? It's got one, one difference in the letter. You know, it's like 10 letters long. It's got one.

Chris Gammell: We can't get a resistor. Can we switch in a transistor? Yeah. It ends in ister. Could we call your sister and ask her?

Dave Jones: Oh boy. Yep. Actually, the purchasing people eventually got like really good. They could actually, even though they didn't really know electronics, they actually got to a point where they did know that, oh yeah, this is a ROS compliant letter in the number and stuff, you know, in the part number and stuff like that.

Chris Gammell: I mean, my best friend is a purchasing agent. So I'm not allowed to disparage them. And also I had some very good purchasing agents in the past. Actually, I regularly disparage them, but I shan't here. You know, just the usual. Yeah, of course. Yeah, the usual.

Dave Jones: Yeah, yeah.

Chris Gammell: But yeah, no, I mean, yeah, I think that it's just familiarity over time too. Oh yeah, of course. They're not going to help you debug a circuit, but yeah, they're going to definitely know the node differences over time. It's just, I think the ramp up can be, can be tough, especially like new programs, new. I think like when you go through an NPI process or new product introduction, it's always tough because it's like, this is stuff that you as a design engineer, you've, you've been working on it, you've been trying out all these different things and it looks, you've have all this familiarity, but until it's been in production for a couple months, couple years, whatever.

Dave Jones: Yeah, you don't. Yeah. You can't be a hundred percent sure. Yep.

Chris Gammell: That's right. And then, yeah. And then the purchasing agents kind of get a feel for it too. And then it's, it should hopefully I'm beyond autopilot if all goes well, unless it's the past two years.

Dave Jones: Yep. And I may or may not have skipped qualification because I was absolutely confident in the, that that part would work. I can neither confirm nor deny that I, you know, I use my engineering judgment to go, yeah, that doesn't matter a rat's ass. You know? So, yep. Qualified, you know, tick.

Chris Gammell: I mean, that's, that's great. That works great until it doesn't. Right.

Dave Jones: Right. Yeah, exactly. That never come back to, I can't recall that ever coming back to haunt me. So my engineering judgment must've been good enough.

Chris Gammell: It's still there, Dave. Still lurking. Right. They're going to call you, they're going to call you in about 10 years. Right.

Dave Jones: In about 10 years. Have, have you ever been called up from an old job? Has, has an old job ever called you up and asked you to like, ask you a question or to fix something because you're the only one who knew that thing?

Chris Gammell: No, I was never that important. Oh, okay.

Dave Jones: Right.

Chris Gammell: I assume for you, they, they had them.

Dave Jones: Oh yeah. Yeah. Cause I was the one man band often in companies I've worked at. So it was, yeah. Once I left, like, you know, so I tried to document everything, but yeah, there were tons of stuff. It's like, you know, yeah, you get phone calls. And do you remember how this line of code in this production test, what this was doing? Oh yeah. Yeah. I remember that, you know, so I'd give them a free.

Chris Gammell: Really? Oh, well. Yeah. Yeah. I don't. Yep.

Dave Jones: Yep. But I would, uh, draw the line of like going back in there and actually, uh, troubleshooting. That would cost them. Travel time.

Chris Gammell: Travel time is going to cost you.

Dave Jones: That, that'll cost them. A phone call is free. I'll, I'll do that for nothing. But yeah. Yep. Oh boy. No. So you weren't that important, huh? That's sad.

Chris Gammell: Never have been. Never will be. It's important to stay humble. All right. Okay. And on the electronic side of things, it's very easy. In fact, I was very humble this past week as I was working with a student and he asked me a question about an LM317 and I was like, ah, I know how this works. Let's open your books to page, to section 9.3 of the art of electronics. And I started reading it. I'm like, I have no idea how the LM317 works.

Dave Jones: Well, it's, to be fair, unless you look into the details, it's not something you'd probably learn. You'd, you'd formally learn.

Chris Gammell: Yeah.

Dave Jones: It's not.

Chris Gammell: You know what I think it was? I think it's because, so like I can, I can, with my eyes closed, I could draw an LM317 in terms of like a block. I got the in, I've got the out, I got the feedback resistor, I got the adjust pin. Oh, okay. 1.25 volts is very important here.

Dave Jones: But you wouldn't be able to draw the internals though.

Chris Gammell: Oh, definitely not the internals. Oh, okay. And apparently, definitely not the control equation either, which I thought I had down, but I do not.

Dave Jones: Yeah. But surely you've, you've looked at enough data sheets that have the internal diagram to just get a feel for it over time. Surely you've looked at enough of it.

Chris Gammell: Oh, get a feel for it. Sure. And like, yeah, I mean, like I know how a regulator works in, you know, like in this abstract way. Yeah. But what I'm saying is like, I was like, oh, I know that it's got a 1.25 volt reference. Use a 1.25 volt reference. So I was like, okay, so we want the feedback node to be 1.25 volts. Right. Right. Wrong. That is wrong. I learned that. The, the feedback, because what it really was is I was trying to like explain like, oh, well you can use the 317 as a current source. Yes. That was like the. Yes, you can. That's the basis of all this.

Dave Jones: You tie the adjust pin to the output. Yeah. Yeah. It's nice. Via a series resistor. And then the, and then the voltage drop, then the 1.25 reference voltage drop divided by the series resistor gives you your output current.

Chris Gammell: Right. But it's not because that's, and that's what was in my head is a 1.25 volts. I was like 1.25 volts, 1.25 volts. I know there's a 1.25 volt reference.

Dave Jones: Right.

Chris Gammell: But it's actually, so if you look internally, then there is a reference and then it's the difference. I mean, I'm going to mess this up now too. It's the, you have to add the reference voltage, 1.25 volts to the control voltage at the divider node. Right. So if you've got a, you know, the output is some unknown voltage and then it goes down through a voltage divider. Yes. Two resistors in a series. And then in between there, that's the control node. And I was like, that has to be 1.25 volts, but no, it's not that.

Dave Jones: No, the 1.25 volts is across the upper resistor. It's across the upper divider resistor, not the bottom divider resistor. Yeah. Yeah.

Chris Gammell: That's where my whole mental model is broken, but it has been rectified. So, yeah. Okay. And so then like looking through it and it's really interesting too. Like, so I didn't realize, so like, obviously, like I said, point, uh, section 9.3 of the, of the good book known as the art of electronics has a detailed explanation about this.

Dave Jones: Oh, okay. Excellent.

Chris Gammell: But, uh, seeing it drawn in different ways as well. I felt like the, let's see, what's my favorite one?

Dave Jones: Just drawing something. And this is, this is true in all of electronics. Just drawing something in a different way makes the world a difference. Like drawing your schematic in a certain way. Like, uh, like, uh, like, uh, Bob Pease, by the way, like, like you cannot make heads or tails of Bob Pease. I assure you, he must've done that deliberately. He must've been deliberately. It was Bob Pease deliberately trolling everyone. He must've been, cause nobody draws schematics like him. Right. Go look at any Bob Pease schematic. And it's like a dog's breakfast. Stuff's going in and out and back and forth and up and down and Chris and cross. It's unbelievable. Yeah. Bloody Bob. Like, like absolute genius. Right. You, you, you, you never doubt Bob Pease. Right. But his schematics. Holy crap. I'll see if I got a good example. I'm going to have to call one up. Bob Pease schematic. Anyway, sorry for the non-sequitur.

Chris Gammell: Yeah. I mean, so the real reason is like, I started looking at like a figure 9.13. If people are following along at home is like an actual, like transistor level diagram. And like, you start to see structures. You understand, right. There's like a, there's a differential amplifier in there. There's a current source. There's, you know, it's all these things that are like recognizable, but in terms, but then it's really the simplified view is what I'm used to seeing. And so if you look at like then 9.11, I think. Sorry, I don't have it open. That's okay. 9.9 rather. That's the simplified view where it's like, oh, okay. That makes sense. It looks like a op amp with a feedback element, you know, so you're driving the, you're with the output of the op amp, you're basically driving a transistor. And then there's a feedback control voltage, just like any other current source that's out there. It just looks like a current source with a reference compared there. And so, yeah, that's, that made a lot more sense to me, but at the beginning, it's like, yeah, okay.

Dave Jones: You're right.

Chris Gammell: So it's kind of how you, how you come into it as well. Oh, wow. You were not kidding.

Dave Jones: Yep.

Chris Gammell: Wow. That is some, this is, I'm looking at Bob Pieces as well. This, this is.

Dave Jones: This is some funky. Yeah. Yeah. Yeah. You have to be smoking something.

Chris Gammell: Bob Pieces wasn't a, Bob Pieces wasn't one of the designers. It was Bob Dobkin and, and the middle finger guy.

Dave Jones: Oh, come on. Don't. You know, I have mental blocks. Oh, come on. No, this is embarrassing. Chris, this is just embarrassing.

Chris Gammell: Weidler. Bob Weidler.

Dave Jones: God. Bob Weidler.

Chris Gammell: Yeah. Can we edit that bit out, please? That's embarrassing. Yeah. Yeah. So it was Weidler and Dobkin.

Dave Jones: Yeah.

Chris Gammell: Yeah.

Dave Jones: They, they were what? You, I don't think you finished.

Chris Gammell: They're the, they're the 317.

Dave Jones: They're the, oh, they're the designers of the threat. Right. Yeah. Was it, was it Weidler who did the 317 or was it Dobkin?

Chris Gammell: I don't know. I don't know. Anyway. I don't know. I was reading it in, I'm reading it in the good book. Right. Yep. I'm pretty sure, I thought, I'm pretty sure it said Dobkin and, and, and Weidler, but maybe not.

Dave Jones: Okay. Right.

Chris Gammell: Doesn't matter.

Dave Jones: Anyway. There you go.

Chris Gammell: I think, I think it's very apparent that I should not have been the one designing this stuff. It would not have progressed as a species.

Dave Jones: Right. Oh boy. Yep. Yeah. But anyway, so your challenge, Chris, is to understand Bob Pease's schematic.

Chris Gammell: Oh, yeah. Yeah. Yeah. This, yeah.

Dave Jones: Like, I'm sure you could if you just sat down and, you know, thought of, but it's just like at, like, you can't just glance at any one of his schematics and go, oh yeah, right. You know, that's how it works. It's just nuts. Yeah. Yeah. He had a style, that's for sure. But anyway, I've, I've done a video on that. Wait, what is that the third or fourth time I've now mentioned I've done a video on that in this episode?

Chris Gammell: Third. That was the third time.

Dave Jones: Third. Okay. Yeah. Keeping track, are we?

Chris Gammell: You're talking about the linear versus LDO or linear and LDO and switch mode power supplies.

Dave Jones: Oh, no. I wasn't going to talk about that one, but thanks for bringing it up. Yeah. I thought that was good. How there's, how there's technically in a topology sense, no actual difference. And I'm sure I've mentioned this on the Amper R before. There's no actual difference between a switching regulator and a linear regulator. And if you don't believe me, watch my video and I prove it.

Chris Gammell: Yeah. I mean.

Dave Jones: Well, you could, well, no, you could say that it's entirely different topology, but the actual circuit is near identical, except that you'll have a little oscillator inside and then you have a switch.

Chris Gammell: I think what you're saying is there's a voltage, there's like a feedback element in all of these things. There's a op amp and a feedback element.

Dave Jones: It's the same feedback element. It's the same pass transistor. It's the same reference. It's the same everything, except the output, the essentially the output of the op amp, the internal op amp, which is driving the pass transistor that actually gets switched between a building oscillator and the regulation part of it. So it's, you know, so it's actually, yeah. Anyway, go and watch the video. Go watch the video. Go watch the end.

Chris Gammell: Number 90 back. Back in the garage. Back in the garage. Back before Dave was 30. Yeah. Right.

Dave Jones: Yes. 21. Yeah.

Chris Gammell: I'm, I'm getting ready to, you know, I've been, I've been thinking about your garage lab. I'm, I'm, I'm going to be putting hopefully a, like a woodshop style workshop in the garage.

Dave Jones: Oh, okay. Right.

Chris Gammell: Very lucky to have my, my electronics lab upstairs, but yeah, the, the, the mechanical stuff might be happening in the garage.

Dave Jones: Yeah. I've got to put them down in my dungeon here. My new dungeon. And that's where I'm going to have a drill press and a whatnot. Yep.

Chris Gammell: Yeah. It's nice to, I mean, yeah. When you need to have that, it's.

Dave Jones: Yeah. You can't, yeah. You can't have it in a lab. Like you can't have it in like an office electronics. Well, I could like, you know, but. Well, let's be honest.

Chris Gammell: I mean, the off the office and the electronics lab, that's for having solder splashed all over. Exactly. Yes. It's a different type of mess that we need, you know, and then I don't often do the mechanical

Dave Jones: stuff like, you know, so it, it, it's like actually tight. Yeah. If I had an infinite amount of room in here, of course I'd set up a little mechanical bench that had a vice and a drill press and a grinder and a, you know, the whole works. Right. But no, not in the available space. It's just not worth it.

Speaker ?: So.

Dave Jones: Yep. Yep. Yep. Yep. There you go.

Chris Gammell: What else we got on the list? Not on the list, but I've been learning. Not only am I, uh, trying to improve my, you know, my knowledge of electronics, uh, I'm, I've given up on Autodesk. And I am now completely open source. Dave, it's the year of the Linux desktop or laptop as it was for me. I'm learning free CAD.

Dave Jones: I still don't run Linux. Sorry. I'm still running Windows. So, meh.

Chris Gammell: That's okay. Yeah. Uh, yeah. So I'm, uh, I've switched away from Fusion 360. I've officially made my first thing in, in free CAD. Yep. And let me tell you, if you thought KyCAD's, uh, UI was funky, wait till you see free CAD.

Dave Jones: Right. Well, that's, I think, yeah, I think you posted this on Twitter and a lot of people said like, it's not worth your time. Just pay the, what is it? 50 bucks a month for Fusion 360. How much is it? Monthly thing.

Chris Gammell: Uh, it's, yeah, it's, I think six, five, 600 bucks a year.

Dave Jones: Oh, five, five, 600. Yeah. And there are people who are making the comment that it's just not worth your time. I mean, I'm a person, past guest of the show. Okay. Right.

Chris Gammell: Respect Jay, uh, very, very, uh, strongly. Uh, he, he is someone who said, yeah, you should just pay, pay the tax and it's worth

Dave Jones: it, you know, use the more friendly tool. Right.

Chris Gammell: Yeah. Yeah. I think that's, you know, there is, there's a argument for that. Jay's been very clear about that in Altium as well. And I think it's, you know, from a consulting context, it makes a lot of sense.

Dave Jones: Altium is expensive, right? Really expensive. So the argument could be made that, well, you know, like five or 10 grand a year or something is a lot more than 500. Right.

Chris Gammell: Yeah. I think the prices I've heard from Altium are like 5,000 the first time, 2,000 a year after that, 8, 1500 to 2,000 a year for like maintenance.

Dave Jones: Oh, they want to suck you into the maintenance. Yeah. Yeah, exactly.

Chris Gammell: That's, that's what I've heard. So yeah, not, not a small amount of money by any stretch of the imagination, but even still, right. Like, you know, a couple, like, so.

Dave Jones: It comes down to what boards you're doing. Like if you're just doing Raspberry Pi style, like size and complexity boards, then it's like, meh, like you don't need Altium.

Chris Gammell: I mean, I'd say Raspberry Pi is pretty, pretty advanced.

Dave Jones: Oh yeah, but I'm, you know, I'm just like.

Chris Gammell: But maybe a carrier board for a Raspberry Pi. Yeah. You know, four layer, two layer, six, and anything you might be sending to the JLC.

Dave Jones: No, but even then, just, you know, small stuff, you know, small scale kind of stuff. Even if it's eight layers, you can still do it. It's more, it's more the size and complexity of the thing, really.

Chris Gammell: Maybe. Yeah. I think, I think a lot of that stuff you can do with KiCat is just, it just starts, you start to run into resistance as you start doing more and more. Yeah. Pun intended. You start to, you know, it's just, as, as you're trying to do more and more high complexity stuff, like you're saying, you start to run into problems and there's less tooling for it.

Dave Jones: It's, it's more to do with the efficiency of the tool and the, you know, and the user friendliness of the tool. Once you get into a certain complexity, I guarantee you can do any complexity board possible with KiCat, right? Yeah. Anything. Sure. But it's, you know, but the but is the but part of it. It's like, no, if you're like, unless you've worked a month on a PCB layout, one layout, unless you've worked a month on it, you don't know what a complex board is. Right?

Chris Gammell: Sure. So. I do not know what a complex board is. That's, that's for sure. Right.

Dave Jones: Like, you know.

Chris Gammell: I mean, I have taken a month, but it's just because I'm kind of slow. Yeah. No, you're right. And there's lots of different tools out there that fit a lot of different people. I'm not saying that KiCat or any other open source or even low cost tool is right for everyone. And I think at the end of the day, it doesn't, whatever people choose, it's fine for them.

Dave Jones: Oh yeah. No, it's fine. Yeah.

Chris Gammell: So in this, uh, 3d modeling thing for a long time, I pushed back and said, no, this is not for me. I need to, I'm just going to go. And I always said I was going to learn on something like fusion 360. Right. I'm glad I did. It was, you know, there's a lot of great educational content out there. And my license was up January 1st or something like whenever it was up, right. Logged in January 1st is the, uh, and it was, I learned my license that expired. And I was like, you know what? This is a good opportunity to go and push myself to learn free CAD. And, uh, it's been, it's been rough, but it is capable for what I need to do. You know, most of the time I think about what am I really doing? I'm making enclosures for electronics. I'm printing them on a medium cost, uh, 3d printer, FDM 3d printer at that.

Dave Jones: Yep. What was the driving factor though? Was it because you wanted to save the 500 bucks a year or was it a philosophical thing that you wanted to go all open source tools?

Chris Gammell: Yeah. A little bit of both. I mean, so I will say fusion was fusion 360 was the last thing holding me in the windows ecosystem. So that is why I dual booted my laptop. Oh, okay. Right. Right. And so now I don't have to do that anymore. Again, that's a personal choice for a lot of people, but now I can literally push that aside and just be like, and from what I hear about windows 11, I'm not, I'm not too sad. I'm not on windows 11 right now, but you know, I'll still have a windows machine for when I need it, you know, if I need to get into fusion or whatever. So yeah.

Dave Jones: Yeah. See, I've got the total opposite. I have nothing that I want to do on, on Linux. Like absolutely nothing. There's nothing driving me towards that platform. People ask me all the time. Why don't I use it? It's because there's no simply, absolutely no reason to change.

Chris Gammell: Yeah. I mean, that, that's, uh, I'm not here to debate that stuff. That's for sure. That is, uh, that is some nerdy stuff that we could get into there. And there's lots of other podcasts that do that.

Dave Jones: So anyway, we farm the fusion 360 rental thing. Don't you get other stuff is you get Eagle now. Don't you? Or you get, you know, some.

Chris Gammell: Yeah. I think you do get the, uh, fusion electronics or whatever they're called.

Dave Jones: Oh, is it still called Eagle? I haven't even looked in years.

Chris Gammell: Well, no, they, I think they forked that product too. So for Eagle, still a thing. I think you, I think they're not doing a ton of maintenance on it, but it is still available. I don't think, I don't think you can buy it directly anymore.

Dave Jones: No, I think you have to rent it or something. Don't you? Yeah. Something like that.

Chris Gammell: Oh, I meant like, I don't think you can even rent Eagle specifically.

Dave Jones: Oh, really? Oh, okay. Yeah. You've got to get the package.

Chris Gammell: Everything is migrating towards, uh, you know, and it's inspired by Eagle. It's a very similar look and layout and stuff like that, but it's all built into fusion. Right.

Dave Jones: Yep.

Chris Gammell: Yeah. And you know, from an architecture standpoint, it kind of makes sense to do that. Right. To have.

Dave Jones: Oh yeah. Yeah.

Chris Gammell: You know, to maintain a different code base and to want them to actually like integrate between the two. So I think they, they want to be able to push stuff back and forth between electrical and mechanical. And so they view it all kind of as a, as an electrical thing, uh, in the fusion ecosystem. Got it. So yeah, for some people it's, it's a great option for me. It's, uh, I'm, I'm, I'm out. I'm out. So.

Speaker ?: All right.

Dave Jones: Can we have a follow-up to a, um, we've talked about, I'm sure more than once here on the Amp Hour and that's a reefer, reefer madness. Reefer. Yeah.

Chris Gammell: We talked about it with Jeff. Yes. Oh yes. Yes. Yes.

Dave Jones: Yes. We did. And, um, and then somebody who on Twitter are scribble sun napkins.

Chris Gammell: Scribbles on napkins. Yep. Scribbles on napkins.

Dave Jones: Presumably, uh, these are reefer, like Brent, we were surprised, both of us were surprised to learn that you can still buy reefer capacitors in the polycarbonate case, right? The old style ones. You can still buy them. They still make them. Right. So they've, they've got a bag, which is marked from 2018, February, 2018. Right. So these things are only a few years old and they've got cracks in them. And these things look 30 years old. Yet he took them out of the bag from 2018. Dean, this is incredible. Why would anyone buy these? Why?

Chris Gammell: Well, as we talked about with Jeff too, we're surprised they still sell them at all. Right. Yeah.

Dave Jones: I'm stunned. Like, you know, but, but there are some aficionados out there who want the original replacement. Like they don't want to, I, I, I want to see a reefer capacitor in, you know, it needs to look the same. It needs to look vintage, you know? So I guess.

Chris Gammell: Did we make any jokes about reefer madness? I did right at the start. I feel like there's a joke in there somewhere. Yeah. You did? A reefer madness? Okay. Yeah. Great.

Dave Jones: Called them reefer madness right at the start of this segment. Great.

Chris Gammell: Great. I, I, I did not, I did not catch it. It buried itself deep in my, uh, deep in my subconscious. Sorry.

Dave Jones: Anyway, that's another video I've done. What's that for? At least. Got it. That's five now. You're at five. Yeah. Reefer madness. Excellent. Woo. Yeah. Let's go for half a dozen.

Chris Gammell: Yeah. Oh, I'm sure. Why stop there?

Dave Jones: Yeah. Anyway. Yeah. 2018. And they've already got, they, unbelievable. Unbelievable. So it's. I can't get to the photo here. I'm not sure what's the. Oh, okay. You can't see it.

Chris Gammell: Maybe it's, maybe it is a lost tweet.

Dave Jones: No, I can still see it. So it shows up for me, but yeah. Unbelievable. Unbelievable. Unbelievable. Like I just. Yeah. Done. All right. Don't use them, please. We have a, we have to sing happy birthday. Do we?

Chris Gammell: Oh, we do. Yeah. And you know, not for a 30 year old either. This is for many years past that.

Dave Jones: 50.

Chris Gammell: Yeah. 50 years old to the signetics. Yeah. Five, five, five, triple five to some.

Dave Jones: Happy birthday to you. Oh, and it's, oh, it's by Steve Leibson, former guest.

Chris Gammell: Mm-hmm. Yeah.

Dave Jones: Oh, cool. I, I didn't notice that. Yep. And Hans, I can. Kamenzind as well. Former guest.

Chris Gammell: Not a former guest.

Dave Jones: Oh, wait.

Chris Gammell: Former discussion point.

Dave Jones: Former discussion. Yes. Although no, he sponsored the triple five. He, he was involved in the triple five timer contest. Wasn't he? That's right. That's what I'm thinking of. Yeah.

Chris Gammell: That is what you're thinking. Yep. Yep. Yep.

Dave Jones: Yep. Yep.

Dave Jones: Yep.

Dave Jones: Yep.

Dave Jones: Anyway, 50 years old, is it? I, I would have thought maybe it was already 50 years old. I, I would have guessed. Anyway. Cool. Yeah. Cool bananas. So what was the actual date? So January 10th, 2022. So 72, was it?

Chris Gammell: Yeah. 72 sounds right. Yep.

Dave Jones: Yep. Wow.

Chris Gammell: I think it's more, more frightening than 1972 is 50 years ago. You know?

Dave Jones: Yeah, I know. Cause the seventies, like I can remember the seventies. So. Right.

Chris Gammell: I was not around in the seventies, but, uh, but like someone saying that they were like born in the seventies. I'm like, Oh, that's not.

Dave Jones: Yeah. Ancient. Right.

Chris Gammell: That's not that long ago. Right. No, I'm saying that's not that much older. I mean, like that's not much, that much older. Like, you know, I have friends that are born in the seventies. So. Okay. Like that's not that long ago. Yeah. Right. Exactly. So. Uh. Yeah.

Dave Jones: No, it, it does not say. And the eighties definitely. Like for some, like, you know, new, young. Whippersnappers. The eighties is like something they just see in the movie. You know, the, um, the book, you know, the, what is it? Come on.

Chris Gammell: The book.

Dave Jones: Jeez. We're terrible. Aren't we?

Chris Gammell: Well, I don't know what you're talking about. You said there's something they see in the book.

Dave Jones: Uh, the, you know, the, um, uh, uh, uh, back to the future. No. No. Yes. Well, back to the future. And also the, um, uh, you know, the, uh, the.

Chris Gammell: David Jones folks. No longer just 30.

Dave Jones: The virtual reality. Ready. Ready player. One is what you're talking about. Ready player. One. It was on the tip of my tongue. Oh man.

Chris Gammell: Dave's going to have to, Dave's going to have to, uh, hire, uh, an assistant just to whisper in his ear.

Dave Jones: Just to remember shit.

Chris Gammell: Yeah.

Dave Jones: Right. Yet, yet I can remember.

Chris Gammell: I don't know what this is, but ready player one.

Dave Jones: Yet, yet I can remember vividly a data sheet I read from, you know, 1979, you know, I mean, how is that possible? Like, yeah, I don't know.

Chris Gammell: Well, the human brain is a marvelous thing, you know, maybe I'm just wired for like old

Dave Jones: school memory. I think.

Chris Gammell: Yeah. I think actually it's different. Well, it's not really different regions of the brain, but, uh, you know, between years, but long, long-term and short-term is in different parts of the brain. Right. This is not really short-term, I guess. Yep. All right. I'll. You just haven't really anchored on, you know, books like ready player one or.

Dave Jones: Got it.

Chris Gammell: People. Yeah. Yeah, exactly. Bob Weidler, even though we sell a poster with his image on it. Right.

Dave Jones: Do we still sell that?

Chris Gammell: There's probably a poster somewhere in your lab. That's like literally staring at you right now. And you're like, oh, what's his name?

Dave Jones: Yeah, exactly.

Chris Gammell: Yeah. Unbelievable. It's terrible.

Dave Jones: I don't know whether, what happened to my copy of the poster. Yeah.

Chris Gammell: Mine got torn down after, uh, when I moved to Chicago.

Dave Jones: I've, I've had a couple of moves and it's just, yeah.

Chris Gammell: Posters never make it. You gotta, you gotta put them in the poster.

Dave Jones: Yeah. The poster thing. Yeah. I've got a, quite a few poster things might be down in the bunker somewhere. Sure. It is. Yep.

Chris Gammell: Yep.

Dave Jones: Anyway, 50 years old, triple five timer. Wow. Anyway, we'll link in Steve's thing. He's still writing for the electronic engineering journal. Wow. An actual blog. A real old school blog. That's like, aren't, aren't people on like sub stack and stuff these days or something? What's the latest fad? I don't know.

Chris Gammell: Not me. Not me, man. Something like that.

Dave Jones: Yep. Anyway, I, I put this one on here because it looks like a few, yeah, they actually got the most thumbs up. No. Second most thumbs up. Adam Savage. You know, I'm a big fan of Adam Savage. He's just killing it on the, uh, YouTubes with his, um, Adam Savage's, uh, channel, the tested, um, channel, which he bought. He's just killing it. He's pumping out so much content. It's incredible. It's fantastic. It's got all new Ghostbusters content and all sorts of stuff. Anyway. All right.

Chris Gammell: Let me find out what Dave's really into there.

Chris Gammell: All right.

Dave Jones: But he, he did the science of measurement. He did. He talked about how he had a 45 minute video, by the way, he, he's just sitting in his lab, their lab, his workshop. What does he call it? Does he, I think he calls it the workshop. And he had an epiphany about the science of measurement and he's got these gauge blocks and he's, you know, and, and it's, it's, and it's fascinating. And he uses these gauge blocks to measure this precise height down to microns and stuff like that.

Chris Gammell: Yeah.

Dave Jones: And anyway, I think it's a fascinating video. It's definitely worth a watch. What did I post here? It's got 224 thumbs up. I posted on the video and I put wait until Adam discovers the concepts of measurement traceability and measurement confidence. You know, it's like, he'll be a volt nut before you know it, you know?

Chris Gammell: Yeah. Yeah.

Dave Jones: So yeah, it's, yeah, it's just absolutely fascinating. And this science, science of metrology is fascinating.

Chris Gammell: Are those blocks, are they, are they like mistraceable or anything like that? I actually don't know. Yeah.

Dave Jones: Yeah. They're mistraceable. They come with a traceable calibration certificate. He didn't mention the word traceable in his video. That's why I mentioned it down before. Cause he's never meant he's now, he hasn't discovered traceability yet. You know? So it's like, yeah, but he's getting, he had this epiphany about these gauge blocks. And it's fascinating. It shows you how they work and you have to twist them and you've got to put this silicon oil on them. So when you twist them due to the atomic layers of the, the, the atomic structure of the silicon oil, I think it's silicon oil in there that you, it gives you a guarantee. So you can stack these blocks and it gives you a guaranteed like 10 nanometers or something distance between the blocks or something. And it's like, it's really fascinating stuff. I haven't used our gauge blocks before, so I'm not a mechanical, you know, guy, but yeah, I just found it absolutely fascinating. So.

Chris Gammell: Yep. Yeah. I'm trying to think. I think someone sent me a book about measurement and it was about like how they used to do measurement for in, in the machining industries. Maybe it was recommended on here. I'm pretty sure I read it.

Dave Jones: Right.

Chris Gammell: But it was around, you know, especially like in the old days when, uh, yeah, I guess there's gauge blocks and stuff like that.

Dave Jones: Can we, um, please, are we able to put a date on the old days? Is it like pre-80s? Is it like.

Chris Gammell: In my head, it was like the fifties and sixties. Right. Okay. Yeah. Yeah.

Dave Jones: Right.

Chris Gammell: But that's a good point. You, you are pretty old. Well, to me, yeah.

Dave Jones: The old days would like, if I say the old days, I'm probably referring to at least at, at most the seventies at most, I think maybe it depends on what we're talking about. If we're talking about computers, then I'm talking about eighties, you know, I guess.

Chris Gammell: Yeah.

Dave Jones: But yeah. Anyway, please continue.

Chris Gammell: It's all, it's all relative. It's all relative. Yeah. But no, I can't, I'm, I'm searching through my history and I can't, I can't find it. So either I didn't actually, I just knew of it and didn't read it or it didn't, it didn't take any old brain ticker. So one of the two there. Right.

Dave Jones: God, look at his workshop and just look at the background. I'm just looking in the background and he's got pens. He's got this huge box full of, there must be hundreds of pens in there. This, this guy is incredible.

Chris Gammell: Adam has done a lot of videos about his storage systems and all that stuff. And they're just incredible. I feel like, you know, in this, in the shortages of the past two years, people that have been kind of pack rats have probably been very smug and rightfully so. But honestly, when it's like that much storage, I get a little bit stressed out because it's, it's always a mess. And it's always just like, I'm not good at like cleaning up.

Dave Jones: No, same here. Every time I do a video, every time I do a work on a little project thing or do something here or there, it's the stuff. Oh, well, fix it up later. You know? Yeah, exactly. And it just never gets done.

Chris Gammell: So I was, I was following a thread recently where people were talking about like, oh, I actually like to have a smaller space because then everything's within reach. And like, in theory, I agree with that in terms of like, if you're really moving around a lot,

Dave Jones: you're using a lot of stuff. If you have a lab that has a dedicated function, you're only working on the same type of stuff over and over again, then yes, you want a small lab where you sit there and you rotate on your chair and everything's there.

Chris Gammell: Or like, or like, you know, like Paul Carlson from Mr. Carlson's lab. Like, so like his old lab, I suppose when he had like all of those scopes in like that narrow little alleyway. Yeah, the narrow, the weird looking narrow alleyway. I got claustrophobic looking at it. Just watching these videos. I don't know how you can.

Dave Jones: Yeah, you get claustrophobia.

Chris Gammell: I mean, like, I love Paul's videos. They're really, really good. But like watching him in there, I was just like, it's going to fall on him.

Dave Jones: Exactly. Yep. Yep.

Chris Gammell: Yeah.

Dave Jones: It's nuts.

Chris Gammell: That's not for me, but you know, teach their own. I just, I get very, I'm already a pack rat and it just kind of spreads out. Right. Water on the floor.

Dave Jones: So I, I set up my lab like that once back when I was a repair tech, back when I was a repair tech at my first job, this was in the eighties, but anyway. And yeah. Good old days. Yeah. The good old days. The old days. Yeah. The old days.

Chris Gammell: Not necessarily. It doesn't have to be good, good old days, but yeah. Anyway.

Dave Jones: Sure. Anyone who lived through the seventies isn't saying it's the good old days. So yeah. Right. Right. We might be going back there.

Chris Gammell: Do you remember when a one end four zero zero seven was $10?

Dave Jones: Was $10 compared to the $5?

Chris Gammell: Of course I'm going to design it up one end four zero zero one. It's a quarter of the price.

Dave Jones: Anyway, just saying that we're going back to the seventies with inflation.

Chris Gammell: Yeah. Really? Sure. Sure. Sure. Sure.

Dave Jones: Sure. In fact, we're already there. Anyway, where the hell was I going with my.

Chris Gammell: You're saying you had a. Oh, yes. Yeah.

Dave Jones: Yeah. A lab. I set it up because I was repairing these particular boards. Right. So I would set up, you know, my thing so that my chair would rotate and I had everything there that I needed to, to actually repair, test, troubleshoot a certain type of boards. Yeah. And it was great. Right.

Chris Gammell: Yeah. That's awesome. Yeah. Yeah. I feel like it's really only when you get out of a flow and you like, oh, now I have to go and like refactor this entire bench to do something else. Yeah. Yeah.

Dave Jones: Yeah. Exactly. Yeah. Yeah. Whereas I'm always working on something different because I, I always say I cannot have, I physically cannot have a lab set up. Right. I can't because every video is different. And then I have to move all the equipment to sort of have it in shot. Right. To put in shot because I can't just like, you know, there's no one lab layout that's suitable for every type of video I do. It's just impossible. So I'm always moving stuff constantly. It's bloody annoying.

Chris Gammell: Totally. I just, well, I already, uh, uh, already talked about Jay Carlson once on this, on this podcast, but I follow a lot of Jay's stuff, including his article about lab organization. He has a very good article about that. I think we talked about last time, but I did follow his advice on the, uh, the tray setup, the tray system. Oh yeah. And so that has now arrived. And I have a, I have a baker's cart in my lab.

Dave Jones: Right.

Chris Gammell: I do like that. It's on wheels and I do have trays for everything and everything's labeled, but I'm still learning the ropes in terms of like storage and, and similarly that sort of thing of, you know, you said the idea is you pull the tray out and it's ready to go. Jay also has a USB hubs glued to most of those trays as well. So it's like, pull it out and it's ready to go. So mine's more like, well, I have like long-term storage of parts from, uh, upcoming build and stuff like that. So it's like a, it's like a priority system, that sort of thing.

Dave Jones: Right.

Chris Gammell: But, uh, cool. I'll relink in that. Uh, Jay's, Jay's, uh, post on that is very good. Very good.

Dave Jones: Excellent.

Chris Gammell: So wheels, I like wheels for everything today.

Dave Jones: Do we have to talk about the Raspberry Pi again?

Chris Gammell: We don't have to.

Dave Jones: No, but I, I just thought it's interesting. Blog post from Eben Upton on the 17th of January. Then now you can buy the RP2040, which is their Raspberry Pi micro, you know, it's their custom sort of, you know, even though it's an ARM core.

Chris Gammell: Cortex M0 plus with, uh, 140, 115 megahertz. It's pretty beefy for what it is for the cost. Yeah.

Dave Jones: Anyway, they got so many requests for the actual, just the chip on its own that they now, they now sell them by the reel. So you can buy 500, a reel of 500 of them for at a unit price of 80 cents, or you can buy a reel of 3,400 for 70 cents. Yeah. Yeah. Yeah. Cause they had people actually requesting tens of thousands of chips. Right. Yeah. So I don't like, who's using these? Who's actually, is it, uh, competitors making Raspberry Pi clones? Is it what? I don't know.

Chris Gammell: Well, this is an embedded device. So this is not, uh.

Dave Jones: Right. Okay.

Chris Gammell: Yeah. So this is the, we had the team on the show. Yeah. Yeah.

Dave Jones: But it's used on one of the, um, it's used on one of the new Raspberry Pis, isn't it? Which bloody, I don't keep up. No.

Chris Gammell: Well, I mean, yes, technically, yes, it is a Raspberry Pi board. It's called the Pico, but it really, there's not much on there.

Dave Jones: Oh, it's the Pico. Right. Yes. Right. Yeah.

Chris Gammell: So that's the Pico. And, uh.

Dave Jones: Got it.

Chris Gammell: Yeah. So you're seeing this stuff. So like there's a CircuitPython port for it. There's an Arduino port for it. There's a, I think you just write, you just write C on it.

Dave Jones: Oh, I know who ordered a reel of 10,000 from them. Art of Fruit. Guaranteed. Yeah. Of course. Yeah. Yeah. Yeah. Cause they're making, they're, they're probably chewing out. Yeah.

Chris Gammell: They got a bunch. Uh, I think they got some of the early ones. So like SparkFun, Adafruit, they definitely have some boards based on it.

Dave Jones: Got it.

Chris Gammell: There's two things that's not novel here. One is the PIO system. So that's got like kind of quasi programmable, like kind of side processing, not quite programmable logic, but it can do like a function. It's kind of like a, like a serial engine that you write code for in order to process incoming digital data. So that's very interesting as a, at this price level for sure. Yeah. Yeah.

Dave Jones: Right.

Chris Gammell: But the other novel thing about this part is that you can buy it. Yeah.

Dave Jones: They've actually got stock.

Chris Gammell: Or do they? Oh no.

Dave Jones: They say down the bottom, unobtainium no longer.

Chris Gammell: Yeah. Yeah.

Dave Jones: It's built on a modern semiconductor process for those playing along at home. It's the TSMC 40 LP. But then I'm wondering how do they get fab time at the largest fab maker in the world?

Chris Gammell: I think these have been built a while ago. I think. Oh, right. Okay.

Dave Jones: Right. As a result, it makes extremely efficient use of scarce silicon, silicon wafer supply. Each die occupates just two square millimeters. Very interesting. And each 300 millimeter wafer yields roughly 21,000 dice. Not die because they're called dice at, at that stage.

Chris Gammell: Hmm. Yeah. That's pretty par for the course as far as I can tell. I mean like.

Dave Jones: They actually, yeah, yeah, it is. They actually tell you they, they have sufficient wafer stock on hand to produce 20 million chips. Interesting. There you go. So they must've done a run just before the, you know, the real supply crisis hit. Cause I'm sure that all the bigger manufacturers would have bumped or TSMC would have bumped. Who's this Raspberry Pi business? You know, I'm sure they would have got bumped for Apple or, you know, TI or somebody else, you know.

Chris Gammell: Yeah. I'd love to hear how that works on the chip side because like. So I had a friend who talked to, talked to me a couple of weeks ago. He's like, yeah, they just, all of my parts, they just, they just added 52 weeks to all of my parts. Yeah.

Dave Jones: Somebody posted that. Oh my God.

Chris Gammell: That's terrible.

Dave Jones: I can't remember on Twitter. Somebody posted a genuine date of like 2050 or something. 2050 was the date that popped up on DigiKey or something. I mean, come on. They're taking the piss now.

Chris Gammell: I mean, that's like, they're just like, screw you. We do not want to sell you parts. That's an effective no bid. You're right. Effective no bid. Yeah, exactly.

Dave Jones: Yeah. Unbelievable.

Chris Gammell: I feel for, I just. Oh yeah.

Dave Jones: No, it's terrible right now. Imagine if you basically built your entire business around this one product and you couldn't change a part or whatever. And, and you just got, and due to timing, you just got caught in the middle of all this. And yeah, you just can't buy the part and you built, you know, your whole business, you know, some startup business around it. Put all your money into it or something. And then. Yeah. It all went tits up. Wow. That'd be.

Chris Gammell: Sure has happened to many.

Dave Jones: Yeah.

Chris Gammell: My heart goes out to all of you that are dealing with this right now. We've obviously been talking about a lot on here. It's not going to stop for a little while. I feel real bad about it.

Dave Jones: Oh, we'll still be talking about it in 2023. That's my prediction. I think that's unfortunately true. Yep. We'll still be talking about it.

Chris Gammell: I'm hoping we'll say things like, it's starting to get better.

Dave Jones: It's starting to get better. Right.

Chris Gammell: Maybe we should have a code word for it on here. Every time we're going to like talk about it. Yeah.

Dave Jones: Maybe some sort of a safe word. Yeah. It's a safe word. It might trigger people. So we can have like a safe word before we mentioned the component crisis. Just to prevent people from going. Oh, no.

Chris Gammell: Bubble gum tap shoes.

Speaker ?: Right.

Dave Jones: But considering that we haven't been able to remember three key industry figures in this episode. I don't think.

Chris Gammell: Next time we record, I'm going to be like bubble gum tap shoes. And this is going to be four minutes of silence as we're both like.

Dave Jones: All right. Why did we say that again? You're going to put a sticker on the top of your monitor. Bubble gum tap shoes. Yeah. Right. Right. And the wife's going to come in and go, what?

Chris Gammell: Yeah. What does this mean?

Dave Jones: Yep. Oh, boy. All right. Oh, no. Our hour's up. But I want to give a shout out. I want to give a YouTube shout out, please.

Chris Gammell: Sure. Go for it.

Dave Jones: To... Kathy Loves Physics and History channel. This one blew up. This channel blew up. Anyway, the secret history of electricity. And she's got, I don't know, a couple of dozen videos at least. Many... Yeah. Two or three dozen videos on the secret history of electricity. We're talking like Maxwell. We're talking Wheatstone. We're talking Joule. We're talking Ohm. We're talking, you know, like all of the famous names. Right? There's Kirchhoff. There's Heisenberg in there. There's Plank. There's... Have you said? Coulomb. Sorry?

Chris Gammell: Have you said?

Dave Jones: Oh, don't know. Don't know. Rutherford. Anyway, she's done like great history of electricity videos. And she was like getting only a couple of hundred views per day or something like before a couple of weeks ago. And then all of a sudden, she's bigger than my... She was getting two million views a day. Like it's the... Like I gave her a shout out, but I don't think I was the cause of it. I noticed it very early that the algorithm, suddenly the magic algorithm just started pushing her videos to me. And I started watching and going, holy shit, I've never heard of these. These are great. And yeah, overnight, the algorithm has just pushed her into stardom. So I highly recommend you go subscribe to Kathy and watch her videos because they're just great. You know, the history of the Wheatstone Bridge and, you know, like fantastic stuff. Yeah. Like, you know, Edison versus Tesla, why they invented three-phase electricity, the history of three-phase and stuff. Well, there's the history of two-phase for you polyphase fanboys, by the way.

Chris Gammell: Right.

Dave Jones: You know, and like, just, yeah, I had no idea that this content existed. And the algorithm has bestowed upon her the light, the shining light of an audience. And it's great. Yeah. So hats off to her. They're fantastic content. Yeah.

Chris Gammell: I'll have to dig into those.

Dave Jones: Yep. Yep. They're absolutely terrific. So, and they're all on content. They're all for us. You know, there's a few physics ones in there that are more into, you know, those who are into physics kind of things. But no. Killer. All of, if you've got a favorite one, if you've got a favorite from history, she's probably done a video on it. If not, I'm sure she takes suggestions. So, yep. Kathy loves physics and history. Go check it out. Link below.

Chris Gammell: Right. All right. Is that it? I think that's it, man. I think so. I think so. We'll be back next week talking about bubble gum and tap shoes.

Dave Jones: Yeah. Right. Right. Catch you next time.