#307 – Call In Show #5

Chris Gammell: This is The Amp Hour Podcast. Recorded July 13th, 2016. Episode 307. Call-in show number five.

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: It's a call-in show.

Chris Gammell: A call-in show.

Dave Jones: Song and dance routine.

Chris Gammell: We only have one caller, Dave. I am excited about this one caller, but yeah, I don't... You know, part of this is on me, I think. I did put 8.30am on the look up your time thing, so that may have put people off.

Dave Jones: Did you screw the time up again?

Chris Gammell: Yeah. No, it's always the units. It's always the units.

Dave Jones: Just put an event calendar on timeanddate.com.

Chris Gammell: No, I did. I put the wrong date in there. It was the wrong time in there, rather. Garbage in, garbage out. That's right. Garbage in, garbage out. Pebcac, yep. Well done. So, you know, usual crap. All right. Well, we do have some... A bunch of people wrote in who couldn't make it, so we will have open loop questions.

Dave Jones: Oh, excellent.

Chris Gammell: Yeah, we'll be fine.

Dave Jones: Open loop questions. Yeah. Oh, did you just invent that?

Chris Gammell: No, I mean, that's what it is, right? It's just we don't have any feedback from them, so it's open loop, right?

Dave Jones: Right.

Chris Gammell: Yeah. We're great for us. We're always right.

Dave Jones: Does that mean that we're just going to saturate and overload?

Chris Gammell: The feedback system is email. It's not very responsive, I got to say. Okay, well, let's talk to our real person first, and maybe we'll get a couple stragglers on Twitter. Okay. But if not, I don't really mind. Let's get a real human on. All right. Human. Nerds don't talk to humans. Hey, what's your name? Where are you calling from?

Caller: Hi, my name's Alexander. I'm calling from Toronto, Ontario. Hey, Alexander.

Chris Gammell: From our northern, well, not Dave's northern cousin, my northern cousin. How you doing, man?

Caller: Everything's north from here. Hey, not too bad. Yeah, Cleveland is not far away at all.

Chris Gammell: I grew up in Buffalo, too. I basically grew up half Canadian, you know?

Caller: Yeah, Buffalo's like an hour away.

Chris Gammell: Yeah, exactly. Well, an hour? Maybe by boat.

Caller: Oh, that's true. You have to go around the lake. Yeah.

Dave Jones: And it's super hot there.

Caller: Yeah, we're having an extremely hot week. I'm surprised it's not as hot in Cleveland, because I heard it was coming up from the Gulf of Mexico, but it was like 41, 42 degrees, especially in our third floor apartment.

Chris Gammell: Celsius for those playing along at home. I was going to say, it's like 50 degrees hotter here. Yeah, it was like 93F today. So, yeah, it's pretty spicy. Yeah, it was cooking. Cool. So, what do you have any issues with? What do you want to talk about?

Caller: So, my question was, I'm an electronics engineering student going to college here in Toronto, and my first semester, I took math, and I actually failed it.

Dave Jones: Yeah, well, that's not uncommon.

Caller: I failed a math class. Yeah, but I had a decent teacher, but I just found, especially near the end of the course, really difficult. And then the second semester, I actually dropped the course because our teacher was so awful. He basically signed up for, there's a major textbook manufacturer. They have like an online course. The teacher basically signed up for that, had us all sitting at computers while he sat at the front of the room and said, I'm here if you need to ask any questions.

Dave Jones: Great.

Caller: It was just a nightmare.

Dave Jones: So, you canceled, you quit the whole course or just the math class? Just the math class.

Caller: I dropped it.

Dave Jones: Okay, but I thought they were compulsory.

Caller: They are, so I'm going to have to take it again.

Speaker ?: Right.

Caller: So, that's why I'm calling to wonder how you guys got through math because I know that you guys both have some college education. Dave, you seem to be really, I mean, I know you're not a mathematician by any shot, but whenever you do formulas on the board, you always seem to be quite into it. And that's the thing, when there's an application behind it, like when I'm calculating stuff for, you know, switching power supply, I find it really interesting and easy, but all the theoretical stuff just drives me nuts.

Dave Jones: Yeah, no, look, I've always said that I suck at math. I mean, I absolutely, or mass, as it's called here. Like, I actually, this is one of the rare instances I prefer the, is it the American math?

Chris Gammell: Yeah, I don't say math. I say math. I have no S.

Dave Jones: I actually prefer math because it's hard for me to say maths. Math or maths. You know, it almost turns out like mass here. Anyway. Yeah, no, I suck at it. Those formulas and stuff that I do on the board, I mean, like, like they're kid stuff, right? They're real easy stuff. But when you start getting into the, you know, the integrals and the differentials and the real math, you know, the real engineering math, and I don't enjoy it at all. And I've never really had a practical, much practical application for them in industry.

Caller: Really? You never had to use math when you were working, I guess at Altium, you were doing PCB design, but you never had to use it in jobs at all?

Dave Jones: I, I, I've said this many times that in, I've been in the industry maybe 25 years, I have not solved an integral once. Not once. I, I have used the concept. Yeah. It's not uncommon. I've used the concepts of integrals, right? It's very important to know, right? And I, I, I do like integrals from the concept of like a, you know, an integrator circuit and all that sort of jazz. But as far as actually solving integrals and triple integrals and all that sort of stuff, I, I,

Caller: You're right. Integrals are interesting in the area under the curve. It tells you a lot, but then when you get into more advanced stuff, it just, it just does not interest me at all. It sucks. And as you said, it's compulsory. So it's kind of like, I have to just grudge through it somehow. But what about you, Chris? You went to college. Did you not?

Chris Gammell: I did. Yeah. Yeah. I, it was like I said, I, I, I definitely dropped the course. I was, I was just completely flailing in that course and flailing, not, but not, I guess I was failing and flailing. But yeah. So my, my tip for that is, I think you were spot on with the first semester where you said you had a really good teacher is definitely target the teachers that are willing to get into it with you, but they have good, like have good sessions, have good TAs, stuff like that. That's a huge piece. And then another one would be, you know, Dave's going to get a little sick to his stomach hearing this, but find people, you know, and you know, just get through it together. Or, you know, even if you don't know people, like have study sessions. Like the only way I got through a lot of my courses is having people that I could study with bounce ideas off of because nothing's worse. I just, I still have that, I still remember the feeling of like the, like when midnight hits, not that it was like ever, I was going to bed at that point, but just like, where like midnight hits and you're like one problem deep and you have six more to go and you know that each problem takes like an hour and a half and it's, like there's no worse feeling, like there's no more, there's no worse like, just screw it, I give up kind of feeling, you know? And especially when you, when you have that reference point of I don't even need this.

Caller: When you start to stress about it, you just give up basically. That's how I always was. I'd start to stress about it and just be like, why am I even bothering? As I know, most engineers say they never even use this, right? And that would just get into my head. Exactly. And drive me nuts.

Dave Jones: The motivation, yeah, is not there and I struggled a lot. If I was to do it again, I would get a tutor. I would totally, because I suck at,

Chris Gammell: if you can afford it, sure.

Speaker ?: Yeah,

Chris Gammell: I mean,

Dave Jones: I suck at the, at the discipline required to study. I've never been a good studier, you know? Like, it's like, I've always relied on the fact that I've known engineering ever since I was a kid, you know, six years old. Like, before I got to do formal study, right, I already knew a ton of stuff, you know? So that, I always relied on that to sort of get me through rather than, you know, and that was probably a mistake. Yeah,

Caller: it's funny you say that. All my other courses, we were learning C, which I already knew, I know C really well.

Dave Jones: Right.

Caller: ECP design, how to solder. It's like stuff I've been doing for years. So I got extremely good marks in every other course, except for math, which I bombed.

Dave Jones: So there are some math that I actually like. Complex numbers, for example, I loved complex numbers. Atrices, I love solving matrices and stuff like that, but no, the other, like the real hardcore, that's not hardcore math to the, you know, to the math.

Chris Gammell: Another thing would be like, if you can find an application for the actual topic, so you mentioned integrals, right? That's a great topic, right? So if you start looking at that kind of stuff and you actually find an application for it, you know, look at like, you know, a capacitor, right? So like, how that math ends up affecting it, maybe you can start to create that mental model around it because at least for me personally, when I have that mental model to go back to, at least I have something to grasp onto to kind of visualize. It's just the, some people are really good with just the straight numbers chunking through problems. I'm not like that. It sounds like both of you guys aren't like that either and having some kind of like reference point like that's really important for me. On the rest of it, like, you know, we're going to, we're going to hear from some people. There's some people in the audience right now that are fuming and saying like, oh, well, I went on to get a PhD and I needed all this crap and it's like, yeah, there are and like, that's what a lot of the stuff is built for is built for, you know, taking it further and further especially from a theoretical basis but, you know, like, it sounds like you already kind of know where you want to go towards.

Caller: Yeah, I want to specialize in embedded stuff so it's like, it depends on what you end up working with and what area of embedded you're in. If you're working on cars or something, you might need it but, or if you're building a rocket working at SpaceX, you might need it but, if you're just building a TiVo or something, you know, it might not be as easy.

Dave Jones: Actually, there is, I just remembered, I did a cameo in a video that is up on YouTube. I watched that. I just sent Chris the link and it's about the relevance of math in engineering and how, if you get it wrong, you don't get to Mars. Like, it's... Yeah,

Caller: I watched it. It's hilarious. That was a great video. Yeah, that was great.

Dave Jones: Yeah, so I've done a camera.

Chris Gammell: Where's the time mark on this thing where we can find Dave?

Dave Jones: I'm like, eight minutes, 40.

Chris Gammell: Oh yeah, you're at the end. Yeah, I see you. Eight minutes, 40. 850. Yep. Yep.

Dave Jones: But yeah, so it's a bit long but this was produced by a local uni, Swinborn Uni here in Australia and they approached me and said, hey, we want to do this video to show the relevance of, you know, math in engineering, you know, because everyone goes, oh, you know, you never use it and stuff like that. So they did this whole Mars thing and it's really quite well done.

Caller: It is really well done. That actress was amazing. They did a really good job on it.

Dave Jones: Yep. Yep. It's really produced very well and they actually got her like in space suit, you know, and like pretending to be on Mars and digging up samples and stuff. It's really, yeah, it's really quite involved so we'll definitely link that in. But over on the EEV blog forum, this topic always comes up again and again and just recently, like last month, there was a big to-do and a lot of, you know, there's usually opinions one way, you know, there's two camps. There's those that think, you know, you cannot be a good engineer unless you know the math, you know, unless you're good at it. Yeah. And there are those who go, no, screw it. You know, I'll never, I've never, you can be a fantastic engineer without the math and it doesn't matter and it's like, well, both are true, you know, like.

Chris Gammell: Right. Yeah, it's very important to talk to like what the, what their job actually is, right? Because someone working at like Livermore or, you know, particle accelerator doing like hardware probably still needs to know that stuff, right? But yeah, there's just a...

Dave Jones: And the other argument is that those who are really good at the math will be able to solve problems better because they will be able to understand it at a more fundamental level and analyze it at a more fundamental level. Now, that's also true but, but there is a downside to that as I found a lot of the, not always, but in a lot of cases they're really, the math nerds who really love it, they always try to break everything down to fundamental math when you shouldn't. It just, it just complicates things and you can't get things done because you, you know, somebody who doesn't know the math, right? They might solve the problem 10 times quicker than the math nerd. Because they just don't get bogged down in all that detail. And there's cases where that helps and there's cases where that hinders. So, you know, but overall I agree if you're better at math you're going to be a better engineer. I would err towards that side. Definitely.

Caller: Yeah, and I wish I could enjoy it. I know that if I enjoyed doing it, it would really help. And there are sometimes when I do, as you said, matrices. There is a chip that Intercell makes. It's an RGB color sensor where you actually have to solve a matrix to get the luminosity from the RGB samples. Oh, really? And it's like, I wish I could just do that but it took me ages of reasons trying to figure out how to do it. So, yeah, I wish I could enjoy it and I'm sure a lot of engineering students feel the same way.

Dave Jones: you apply, that would be the majority. I would say the majority of engineering students do not like and engineers in the industry do not like heavy math anyway. I enjoy simple math that I understand because I'm a dummy at it.

Chris Gammell: Same, same. Yeah,

Dave Jones: you know, it's because I'm no good at it. That's why I don't enjoy it. I just never, I don't know, it just never flowed to my boat apart from say, you know, complex numbers, matrices. When I first learned those, I thought, wow, this is, you know, it really opened my eyes and I thought, wow, these are really useful and I understand these but I never really got that same sense of satisfaction from the differentials and the integration and all the other, you know, heavy duty stuff.

Caller: yeah, unfortunately, I bought a really expensive Texas Instruments calculator and so I want to know how to use all the advanced features so that's another motivation.

Dave Jones: No, I survived math barely, like by the skin of my teeth, by simply doing, you know, previous exams and I felt I never really understood it properly but I sort of like, like just did enough to sort of, you know, cobble my way, bluff my way through it kind of thing and, you know, I felt, well, that, I don't like it anyway so that was, you know, it was good enough, right, I was sort of done, you know, and, but yeah, I, I, as I said, if I would go back and do it, I would get a tutor and I'd really try and understand it better than what I did.

Caller: Yeah, we have free tutoring at our school, luckily, although I think you only get an hour or two a week but I should take advantage of it. I was using it for other courses in the first place.

Dave Jones: Yeah.

Chris Gammell: Yeah, that's, that's really nice.

Speaker ?: But you've got to have

Dave Jones: somebody who's passionate about it, you know, like, I don't, I don't deal well with people who don't have the same sort of level of passion as I do.

Chris Gammell: Yeah, for sure, I can definitely relate to that. if they're any more passionate about math than they are more passionate than you. Yeah.

Dave Jones: But no, if they're just going, oh, just do this and do that, you know, like, that's no, you know, I want enthusiasm. Here's where it relates, you know, and all that sort of relevance and excitement. Yeah.

Chris Gammell: Well, hey man, good luck. You get it. Unfortunately, no one can do it for you. You know, that is the test. I know. Yes, that's true.

Caller: There's just one other thing I wanted to say before I go. Dave, a while ago, you got a really strange mailbag item. It was a USB warmer.

Dave Jones: Oh, yes, the whole warmer.

Caller: Yes, that was me and I wish you had found it funnier.

Dave Jones: Thank you very much.

Chris Gammell: What was it again? A whole warmer?

Dave Jones: A whole warmer. Go on eBay and search for whole warmer.

Chris Gammell: No, I don't think I will.

Caller: Big Clive did a video about it and I thought it would be hilarious to send Dave one and he was just very confused although you did start laughing later on but at first you were really confused. It was funny. Anyway, guys, have a good night. Thanks so much for having me on and I'll be sure to listen this week as I do every week. Cool. Thanks, Alexander.

Dave Jones: All the best, mate.

Caller: Have a good night.

Dave Jones: All right. Math.

Chris Gammell: I'm more stuck in a whole warmer.

Dave Jones: You're obsessed with whole warmers now.

Chris Gammell: I just, I'm very confused by that term but I'm sure I can figure it out.

Dave Jones: I don't want to. I don't want to. You're an engineer. You can figure it out. I don't want to. What do you think a whole warmer does?

Chris Gammell: I don't want to. Walls.

Dave Jones: Holes.

Chris Gammell: Yeah. Okay.

Dave Jones: Yeah. All right. So, that's all we got. Hang on. Speaking of math nerds, David too is coming over today. Oh, yeah. So, it's been a long ago. Yeah, it's been many months because he's been doing stuff from home. Anyway, he's coming over to shoot the breeze on some projects we're working on just to, you know, go through stuff and he's a math nerd and he sort of loves it, you know, and I think I've talked about this on here before and everything he tries to bring down to, oh, I can solve this, you know, like, it's like, dude, you don't need to. Right. But, you know, just whack in a 10K, it'll be fine. But I can solve it from first principles, you know. Yeah, I get that one a lot too. It probably helps that his mum's a teacher, his mum's a math teacher, I think, or one of his parents is a math teacher. So, that probably is where he got that from, no doubt. But, yeah, he gets just as excited over that as regular electronics, you know. Good on him. Good on him. That's right. Yeah, I'm jealous of anyone who can, who's really good at math because I always sucked at it and, you know. Yeah. But it hasn't really hindered me. I can't say it's, I can't say it's ever really hindered me. Oh, yeah, I wouldn't say it ever.

Chris Gammell: I'm not worried about it, man. Like, it's, no, no,

Dave Jones: it's nothing that's, you know, it's nothing that, I have never been in the industry and just threw my hands up and going, I can't do this, you know. Like,

Chris Gammell: okay, so I'm going to send you the next question here. Oh, right, yes,

Dave Jones: we have these open loop questions.

Chris Gammell: Yes, open loop. All right, so I'm going to read this out loud. This is an anonymous software geek. Geez,

Dave Jones: that's a long one?

Chris Gammell: Yeah, it's a multi-parter. Oh, God. So I have a power supply with three ports, red, green, and black. Remember, this is a software geek, so this might, this is a little beginner, but it's not, I think it's actually a really good question. Oh,

Dave Jones: we're talking about a physical power supply, we're not talking about a virtual,

Chris Gammell: theoretical,

Dave Jones: black box power supply.

Chris Gammell: Bench, single, single supply, yeah.

Dave Jones: Red, green, and black, yes. Right. Green is earth.

Chris Gammell: Green is earth, black is ground, black is neutral, slash ground, and red is hot. So right there,

Dave Jones: we've established this as a single rail supply.

Chris Gammell: Right. Right. So this person says, I usually connect black and green together. Is there a reason not to do that? Is it good practice or a bad one? I've seen all my EEs do it, so I copy the behavior, but I don't know why they do it. That is the initial question.

Dave Jones: Should we answer them one by one, or should we?

Chris Gammell: Well, I think that's just the first question. Well, yeah, one by one. Is there a reason not to do it? Well, yes, sometimes when you don't want to be earth grounded, that is one reason to do it. No,

Dave Jones: I would, I would always do it. By default, I do not connect, but because, watch my video, how not to blow up your oscilloscope. By default, you want your power supply, whatever that may be, to be isolated. It's just, it's safer and better. But, well, it's not necessarily better, but only if you have an issue with the ground system, then you would look at earth in your power supply. By default, I do not like.

Chris Gammell: Yeah, I don't personally do it. I don't personally do it, but I would say if you do it, then you better be darn sure everything is, right? So if you have a cheater plug on your laptop, or if you have a cheater plug on your scope, or a cheater plug anywhere, at least, you know, in the States.

Chris Gammell: see,

Dave Jones: here's the thing, right? This is an action, right? You're actually deliberately tying the output to mains earth. Why? Is the question. If you don't know why, then why did you do it? Right?

Chris Gammell: Right.

Dave Jones: That's why by default, the supply should be isolated. Okay?

Chris Gammell: You should not do it until you know why. What it is too, right? So, so normally there's actually a separate ground and depending on the type of power supply it is, there may be, it may be actually transformer isolated from earth ground in the first place, what you're doing.

Dave Jones: They're almost always.

Chris Gammell: Yeah. Right. But if it's like, if it's a switching supply, it might not be.

Dave Jones: I don't know a lab supply that's not.

Chris Gammell: Yeah. If it's a switching supply though, and you put, you know,

Dave Jones: even switching supplies, they are, but they're capacitively coupled back. Yeah. Anyway, let's not go there.

Chris Gammell: Yeah. So, but what you're doing then is basically you're doing an end around then basically saying, okay, well, black is isolated normally and there may be some leakage, but you're isolated from earth ground and you're just tying them right back together. And yes.

Dave Jones: So you're bypassing the isolation on the transformer. That's basically what you're doing.

Chris Gammell: Right. And so another reason that this happens in the first place is because you can stack supplies, right? So that's what a lot of people do, at least on mine. I have, you know, like one of the, if you start looking at those triple output supplies and I'm not telling this to Dave, I'm telling this to people listening, that don't know. Dave, Dave knows this, believe me.

Dave Jones: Yeah. I'm pretty sure I do.

Chris Gammell: Well, David, let me tell you something. If you don't know this about power supplies.

Dave Jones: I've been around the blocks a couple, I've been around the block a few times.

Chris Gammell: As you can stack supplies. So like I've got two, two 30 volt outputs. By stack,

Dave Jones: how do you mean?

Chris Gammell: So you can connect the, so if black and the supply one is black, red, you can do 30 volts on that. You can connect the black on supply two to the red on supply one. And then the output is another 30 above that on the red of supply two. So then you can have a total of 60 volts from the black on supply one and the red.

Dave Jones: I did that in a recent, I should explain that in a recent video.

Chris Gammell: Oh, nice. We should link that in. Okay.

Dave Jones: Yep.

Chris Gammell: Yeah. So stacking power supplies is a very common thing. And you can, the only reason you can do that is because you, you are not earth grounded. If both of those supplies were earth grounded, you'd never be able to stack them. What you'd be doing is if one and two were both. Shorting one out. Yeah. Or the earth grounded had been basically one.

Dave Jones: You'd be shorting out the lower one.

Chris Gammell: Right. Exactly. Yeah. Blow it up pretty fast. Blow it up pretty quick. If there wasn't current limiting. So, yeah. So that's the why. And this is a good question. I mean, it really is because if people don't, if I haven't seen it before, you know, I think I,

Dave Jones: in fact, I, I debated whether or not I should do a separate video on that. I sort of like included it in this recent video where I was testing a little switch mode power supply for aircraft, you know, model aircraft. And so I did like a little mini tutorial in there. This is how, cause I needed 60 volts. Right. So I had to put two in series and yeah. So I thought, Oh geez, that should probably be like a separate little five minute video explainer on its own. You can just,

Chris Gammell: you can just reference people to the, uh, the timestamp on the amp hour YouTube. I could,

Dave Jones: but it's not as good. Then I don't get the views in the SEO. I've got mouths to feed. Dave, don't, don't be, don't be like that. Yeah.

Chris Gammell: Uh,

Dave Jones: says he, who is in charge of the media, bloody social media crap.

Chris Gammell: Yeah. Right. Right. Uh, okay. So, uh, there was other questions here. So I guess this is, uh, Oh yeah. So what if my power supply has two or three power sources? So that already was in there, I suppose. I didn't see that second part of the question.

Dave Jones: Well, hang on. We, we didn't explain why you would do it.

Chris Gammell: Why you would do, Oh, why you should connect black to green.

Dave Jones: But I don't think like we, that's hard. That's hard. You really need a, a system example and it can be for many reasons. So why?

Chris Gammell: The cleanest ground that I know of. You're, uh, you're,

Dave Jones: well, it depends whether or not what you're referencing your other signals to in your product and what measurements you're doing and things like that. Common mode noise. I've done a video on that. And even like, I think it's like a 30, 40 minute video on how to explain you what common mode noise is and earth in power supplies and isolating and coupling between primary and secretary and capacitive coupling, all that sort of stuff. And even that wasn't like, I didn't go into enough detail because there's so many variables in the system that you design and measure that, you know.

Chris Gammell: Yeah. Well, so other reasons are safety. I think that, uh, if you, if you do know what your ground system is and you do have the potential to dump a bunch of current, uh, you know, it can go, it can go back through a black. I mean, it can go back through the, the, um, the local ground on your power supply. You know, it wants to return there anyways, but if you need to just dump it all in a safety situation, then yeah, going to ground, the earth ground is another option. Uh,

Dave Jones: sorry, I just had a courier at the door.

Chris Gammell: Oh, that was fast.

Dave Jones: I didn't hear anything you said there. That was bad.

Chris Gammell: Oh, uh, I was just saying that safety, safety was another reason.

Dave Jones: Safety. Yes. Yes. Yes. Yes. Safety can be a reason or it could be noise. It could be common mode noise. It could be whatever. So,

Chris Gammell: yes, there's a lot of reasons. Uh, okay. So are there any other, is this how ground loops start is another question, man. This is a lot of questions here. I'm not in a software geek. This is a lot of questions. Uh, is this how ground loops start? Uh, those mysterious electronic elements that I've heard of, but don't understand, uh, possibly,

Dave Jones: but it can do. Yes.

Chris Gammell: Uh, yeah. Basically in that case, if you're tying some things to earth ground, other things, not, then it would have been like the current would be sourcing through that ground to earth ground, right? Everything wants to get to the earth ground then. And so it might end up going through that supply to get to the earth ground.

Dave Jones: So it is like that can happen when you connect, you know, your power supply is mains earth grounded, and then something you plug on the output of your product is also mains earth grounded. And you can get current flowing through in a loop around through the earth system. So that's, uh, that's also how noise, common mode noise and stuff like that. Anyway, right. we won't go into details, but yeah, yes, that can have something to do with it. Certainly. Um, you may have, uh, experienced this on, um, home audio gear and stuff like that. That's double insulated. And you may, you may hear like a hum, you know, on, on your cable, like you touch the ground of the cable and you start hearing a hum or something like that. Then yeah, that can be caused by this sort of thing. So, right.

Chris Gammell: So we can't necessarily answer any, there's no like specific situations here, but, um, if you're thinking about grounding, then you're probably off on the right foot. Um, it's probably not a good idea to start with everything. No. Tied together. if you,

Dave Jones: if you're thinking about grounding, then as I said, you, you need a reason for it. You have to have something that you go, Oh, is this a ground issue? Yeah. If you're earth ground.

Chris Gammell: Right.

Speaker ?: Right.

Dave Jones: Right. Yeah. I use that, you know, like I just, a lot of people comment on this in my video. I'll just interchangeably use the terms earth and ground and like, you know, like, and they go, Oh, some, you know, there'll be sticklers out there who go, Ooh, that's not the correct term. You didn't, you're ground means, it's mains earth, you know, and you should use that. You should say common or something, you know, like, Oh, yeah. I don't know. I, I granted that could be very confusing for beginners. You know, what is the difference between negative, common, right. Ground and earth, right? Yeah. Well, and neutral in a multiple earth, neutral men system that we have here in Australia, you know, the, the, the neutral is effectively tied to earth, but only back at one point at your fuse box, you know, and like, Oh, like, so there's four different things, four different terms for often the same thing that you're talking about. You know, the common point is circuit. So I guess I should be more rigorous. Yes.

Chris Gammell: Uh, yeah, we all should be. Cause it's so easy to say ground and it's like, what does ground mean?

Dave Jones: Yeah, yeah, exactly. The ground, if you say ground to a, to a, uh, you know, energy transmission, you know, to a power guy, it, it means, I think it means like the physical ground soils.

Chris Gammell: It sure should better. Or else they're going to die.

Dave Jones: Right. Yeah. Yeah. So we're pretty lazy in that respect and guilty as charged.

Chris Gammell: Speaking of, uh, electrical issues. Uh, so I, I had some house work done and I had a inspector come through and stuff like that. And I found out. Did you do it yourself? Did you do it yourself? Uh, no, I, well, I, I had done stuff previously, but they were like basically looking at my old work as well. And, uh, and you know, like, yeah, so I'm allowed to do some stuff by myself here. You're not really supposed to session your stuff. No, it's illegal here. Yeah. It probably should be here to be honest, given, given the quantity, quality of my work. Although the electrician did say I did an okay job on everything.

Dave Jones: So an okay job. Right. Yeah. Well,

Chris Gammell: like it passes, it passes code basically. Okay. Um, but what I did find out is that the violations were actually, um, nothing that I did or nothing that the work that they were doing. It's that, uh, my entire house is knob and tube wiring. And so I have no ground. Sorry.

Dave Jones: What's that?

Chris Gammell: Knob and tube. It's, um,

Dave Jones: knob and tube. I, I've never heard that.

Chris Gammell: So the way they used to do it is basically they would, um, they would take, they would take a, um, a hot and a neutral and they would, you know, a hot and a ground, I guess in that case, because they're, you know, uh, yeah. And, but it was only two wires sent, sent up through the wall. It wasn't Romex. So basically Romex is that, you know, the two conductor stuff that's kind of encapsulated together.

Dave Jones: Is that like a brand?

Chris Gammell: Romex. I don't know what Romex is. Um, it's a brand name, I guess, but I'm not, it's probably like Kleenex kind of, you know, like, uh, it's, everybody calls it Romex, but it probably started as the, as like a trademark thing.

Dave Jones: There you go. It's on wiki, knob and tube wiring. Yeah, exactly.

Chris Gammell: And so the problem with it though, is that there's no, there's no earth grounds. I mean, there's no grounding. Like, so, you know, you had three,

Chris Gammell: three, uh, three prong sockets everywhere. I have some three prong sockets in my house.

Dave Jones: but only two would be wired up. And then,

Speaker ?: yeah.

Chris Gammell: And I was, I always was under the assumption.

Dave Jones: illegal here.

Chris Gammell: Yeah, exactly. Well, it should have been here too. Like, but like basically what happened is, is I didn't check that when I moved into this house. Oh, you didn't.

Dave Jones: And that's the first thing I did when I moved in is go around with my, uh, that you plug in and make sure they're all wired, wired correctly. I went and checked every PowerPoint. Yeah.

Chris Gammell: Yeah. Oh yeah. Yeah. So yeah. So if my,

Dave Jones: so, so you, you had no earth.

Chris Gammell: I had, yeah, exactly. On all of my, like, especially like the big stuff too, like the fridge and the microwave, like anything with like a big compressor or the, what is it called? A psychotron on a microwave. I forget what that thing's called. The, uh, the spinning. Yeah. Yes. Yes. It's got a big transformer. I know that. Um, and, uh, yeah, so nothing. And I've always been like, I selectively like, Oh, I better be safe and plug this one into the three prong outlet. It didn't matter. It hasn't mattered the entire time. So yeah.

Dave Jones: Wow.

Chris Gammell: Yep. Fixing that. America. America. That's right. The home ownership is, is not great. Yeah.

Dave Jones: Oh, love it. Yep. guns and wiring freedom.

Chris Gammell: Yeah. Right. Exactly.

Dave Jones: Oh, wow.

Chris Gammell: Yeah. So did we, did we answer all these? We didn't answer all these questions. No. Hang on. No, hasn't he got more?

Dave Jones: He's got something about JTAG.

Chris Gammell: Yeah. You can read that one. I'm going to pull up the next question.

Dave Jones: If I'm connecting to my computer, such as through JTAG or TT or serial to USB, the ground in that cable connects my computer to the board, but these same grounds are also connected at the wall, right? Correct. Is that good or bad? I've done a whole video on this. He simply needs to watch my video. It explains it in great depth with diagrams and everything.

Chris Gammell: Gotcha.

Dave Jones: Yep. Are there times I should use a laptop to avoid this two ground connection? Yes, there are times that you should, but not all laptops are isolated. Once you're, if you're using the internal battery, obviously if you disconnect the power cord, but if you plug actually go measure it, go physically measure, you put your multimeter on ohms and measure the negative of the power cable, like the negative that plugs into your laptop and mains earth on the other side. And you'll find that they're often either permanently connected or low impedance, like a K or something like that. So yeah, beware. Trap for young players.

Chris Gammell: Yep. Okay. Well, that was a, that was a great question though. Overall, great question. And lots to learn there and be safe, please. And thank you.

Dave Jones: And a very, yeah, a difficult one to grasp sometimes, especially in its entirety. So yeah, but stick with it. He's got another question.

Chris Gammell: No, we're good there. We're good. No, we're good. Yeah. Done. Uh, okay. So next one, this one is from Xander. Uh, so I, uh, looking for career advice. Uh, I'm electronics. Yeah.

Dave Jones: We like career advice.

Chris Gammell: Yeah. Electronics technician with associate's degree working second job at a so-so, second shift at a so-so job. And I would very much like to earn an EE degree and put my practical knowledge to use in design. What are your recommendations for getting the knowledge I need while keeping a roof over my head? Uh,

Dave Jones: well, I, you don't necessarily have to get, well, to which country? Does it say which country is from? I believe this is US. Does that matter? Yeah. US. Okay. Maybe it's different here, but you don't necessarily need to get, to get the degree to do design work. And that is, um,

Chris Gammell: true.

Dave Jones: You know, like, uh, there's, there's a lot of people out there who think that, Oh, I've only got, you know, uh, you know, a technical, you know, like a two year degree or like a two year certificate or a three year degree or whatever associates degree. And therefore I can't work as a design engineer. That's in, in, in some countries, that's true. In others, it's complete, not a bull, you know? And so they limit themselves. They limit themselves in their thinking of what jobs they can go after.

Chris Gammell: Right.

Dave Jones: So I, I would, I would get out of that mindset. First thing, get out of that mindset, at least go for.

Chris Gammell: No, I think, no, I think, I think we should, I mean, I think we've mentioned this before, but we should bring it up again. It's like, it depends on what kind of job you want, right? So if, if,

Dave Jones: if,

Dave Jones: if,

Chris Gammell: if Xander's at a, working at like a defense contractor, it's very unlikely that you're going to be able to get an E design job there without a degree.

Dave Jones: Medical is, no, medical, not in my experience. Medical is a better example. Okay. Okay. Really heavily regulated industry.

Chris Gammell: Okay. Yeah, that's true. I guess I do. Maybe in the U.S. Yeah, I guess military, I think, yeah, I guess I do know some people. No. Anyway. That's true. But yeah, there are certain, certain industries or certain companies, maybe companies is even a better way to say it, but there are certain, certain companies that are going to be, you know, like Google's written about, they don't care anymore. They're, they, they say it's all job experience or it's all experience. It's not even job experience. And, and personally, I agree with that. I think that that's pretty clear. I think Dave does too.

Dave Jones: Yeah. And that's the thing I would do. If you're, if you think you're reasonable at design, if you think you've got some useful skills to offer in the design space because of the hobby projects or whatever you've worked on, then by all means go for jobs where those, where those skills are requirements and show them your stuff.

Speaker ?: Yep.

Dave Jones: And, and you might get lucky and they go, Hey, yeah, we don't care if you've got a degree or an associate's degree. Yeah. You've already got your, what is it? A two or three year associate degree or whatever. They, they might go, hell, that's good enough. Or we don't care at all. We, we love this project that you did. Show us the experience. Yeah. Yeah. We love this project. You did. It's exactly the skill set we want. You're hired. Yep. You know, I mean, I think it's like,

Chris Gammell: you won't be going through monster.com, but if you're going through monster.com already, you know how terrible it is. Anyway. Yeah.

Dave Jones: I do want to do another video on exactly this. Yeah. Well, not, not quite, but close. Anyway. Okay. So that's tip number one, is to get out of that mindset. B is, right. I think what he's getting at is that, is that, I assume it's a he. Yeah.

Chris Gammell: Yeah. That was a bad assumption last time too.

Dave Jones: Yeah. Anyway. Um,

Chris Gammell: I don't think, I don't think the last one was a he either. So anonymous software person.

Speaker ?: Right.

Dave Jones: Anyway, uh, we, what was I saying? Yes. Um, second, I'll get there.

Chris Gammell: I want to make this into a video. I want to make that into a video. I want to make this into a video. Yeah, I know. My mind's continuing. I think that's where you're going basically. Yeah. Yeah. Okay.

Dave Jones: Anyway, um, the second one, I think what they're getting at there is that, um, they want to study how to get the knowledge. Well, I assume the knowledge there by that, they're talking about as in get the degree.

Chris Gammell: I think it's the degree, the paper. Yeah.

Dave Jones: And there are part-time ones. There's part-time ones.

Chris Gammell: And there's online ones too. I mean, like, especially if you already have the experience and you just need the paper, like there are some seemingly like some decent ones where you can actually get the piece of paper at the end of it. Um, if that is the gating factor for you, I mean, like I think, uh, Arizona state has one now and they've got a great,

Dave Jones: uh,

Chris Gammell: engineering program on campus. I know. So,

Dave Jones: but I would recommend a, in the U S I've heard this before. I don't know firsthand, but I've heard that there, I think, uh, do devise devise. What's the name of that? Like, it's like a private university in quote marks. And then they offer, yeah. And they offer degrees in quote marks in engineering, and they're not really accepted in the industry. Right. So just be.

Chris Gammell: A bet accredited is what you're looking for. That's the, uh, right. Is it? Okay. Yeah. That's the, uh, that's what accredits the in-person ones. And if you, that you can get ones that are online. And I think there are some lists online that we'll try. I'll try and find a list. Um, because there are some online programs,

Dave Jones: stick to a, a, an established one. And also we should mention the many excellent MIT ones and other universities have their entire courses online.

Chris Gammell: Right.

Dave Jones: So start watching those now.

Chris Gammell: Right. Well, it seems like though, that this person is not, uh, struggling for the technical content. It's more about the degree. I think there are, if, if someone is like, I want to start from scratch, it's like, okay, well, especially know how you work. Right. So if you work well in groups, if you, you know, if you need, you know, person to person interaction online is not the way to go, you know, like maybe find a, of course. Yeah. Yeah. You know, like, so we were talking to Alexander about, um, about the math stuff. Right. So that's important too. Uh, like if, if you, if you know you need tutoring or whatever, um, find those resources, but you can still try and keep costs low because that is.

Dave Jones: But one of the things, see, he's already got an associate's degree, right? Which is either two or three years, um, depending on which sort of country you're in. And, uh, that's, you know, not far off a full degree, right? So often the decision might come down to, uh, which university offers the most credit for your particular associate degree. Cause you don't want to start from scratch again. Right. That sucks. Um, so yeah, it's might all, it might be about the credit that they're willing to offer you for all your existing knowledge. You know, so you might have to do the math. Um, so you might like, you'll probably get out of math 101 or, or whatever it is, right? You'll get it, but you're, but the higher level math, higher level physics, you might have to take those. And some of the higher level theory classes, um, you'll have to take, but, uh, yeah, it's, it could all come down to that. Yes. What they're willing to, who's willing to recognize your associate's degree and what credit you get.

Chris Gammell: Well, and as luck would have it, we have another question here about that, just that kind of thing. Uh, so Artem wrote in about a lot of this as well. Uh, basically about, um, you know, when, when will the shift happen basically? Um, what shift? So do you expect to see the shift? So the shift away from formalized education, kind of like the thing with Google, right? So do we imagine that happening in electronics industry? Personally, I do, I do not expect that anytime soon.

Dave Jones: But it's no, it, I, I,

Chris Gammell: what are your thoughts on how to go about getting education out there to the kids and adults who hope to, who can't hope to afford the college slash university, right? So that is, that's the real question.

Dave Jones: I think to me, nothing's really changed a huge amount in, I don't know, the last 50 years or whatever. It's like, you know, you've always been able to get a job in the industry without any formal knowledge. It's, it's probably just as hard slash easy as it is now, as it is, as it was 30, 40, 50 years ago, I suspect. Um,

Chris Gammell: well, no, I think what I'm guessing, well, okay, I would guess that there's a little bit of frustration. We have people on the show that are obviously, you know, top performers, right? And that, and a lot of them have non-traditional career paths, right? Right. And so it seems like that's a lot of that stuff out there, but then when you actually go to look for that, you know, like, but the problem is there is no, there is no path there, right? A lot of the, a lot of the people we have on the show have kind of struck their own path, or they've figured out different ways to get around needing a degree, or, you know what I mean? Like there, there is not going, like I said, there's not going to be a monster.com listing for this kind of stuff. And that's the unfortunate piece. That's also the exciting piece. And, um, yeah.

Dave Jones: And once again, it depends on your country thoroughly, like here,

Chris Gammell: you know,

Dave Jones: it's, you guys don't have any jobs anyways. No, right. In my experience, the qualifications are the last things people look at, which is why you put it down at the bottom of your resume. Once you have experience, it's like, nobody cares.

Chris Gammell: Right. Yeah. That's everywhere. But it's a lot of the people I think that asked us. No, no, no. The U S.

Dave Jones: No, I was going to say in the U S has a lot more university snobbery than here. Here. Nobody cares. If you went to the university of New South Wales or the university of Western Sydney or the university of Wollongong, nobody cares. Right. Right. But in the U S. Oh, you went to MIT. Oh, you didn't go to an Ivy league. No, I would,

Chris Gammell: I would maybe agree with that first statement. I usually, it catches my eye when I'm like, Oh, Stanford, MIT, you know, like stuff like that. Sure. Right. But I never have discounted someone for.

Dave Jones: No, no, exactly. But we don't have the same sense of Ivy league snobbery here as in the U S. Like you just said it yourself, right? Your ears might perk up if you see that somebody's. Right. But I don't, I don't discount someone.

Chris Gammell: No, I don't discount someone for going to like Ohio state. No, no, I'm not saying you do,

Dave Jones: but you just said it yourself that you might, your ears might perk. Oh, they're from MIT. So you might get a bit of a warm fuzzy.

Chris Gammell: Yeah. But if someone from MIT applied to a job in Australia, I'm sure their ears would perk up too. You know what I mean? Like, it's not like it's a, that's a regional thing, but it's just also like a, it's a notoriety thing. I, I, so I, I know what you're saying, but I just wholly disagree with it. The amp hour. Chris wholly disagrees with Dave for an hour each week for six years. It's going to be a t-shirt in it. Yeah. All right. Anyway. Don't worry. Dave agrees, disagrees with Chris too. We agree on some things. Yeah. So there is no, yeah, especially I think, I think, I think it, it does, it does warrant calling out that there is no defining, a fine path for like the non-university method. I think that the university methods though, I think those are shrinking as well. Right. So go to good school. Shrinking in what way? Go to career fair. The number of people. The number of availabilities, that number of available jobs that there are in that, in that method as well. Right. I think, so, so here's what I talk to people about. Right. Especially when I see, when I meet someone, I met someone who is a, he's a, so he's like the chief architect or whatever, you know, like basically he's been technical his whole career. He's still working in electronics. He's still doing that kind of thing. And I looked at him like, you know, like I am super impressed that you've been able to work on stuff that you've enjoyed your whole career. But the chance that I will be working for another company doing technical stuff or any of my peers doing that, like I think the only thing, especially in 30 years in the future from now, is if you want to be doing technical stuff, you're going to be working for yourself. Right. That is striking your own path or you're going to be doing like, Oh, a hundred percent. Yeah. In the majority case, I don't, I just don't, I don't see it because just there's, you know, consolidation and there's, um, and because to, to be completely honest, I mean, this is getting off topic, the topic of jobs. The people that I know who have been in jobs in a technical role for a long time, they get crapped on, you know, like they just, because we're, we're going to go. They don't know how to manage people. Right. They don't, they, they are super experts at this one thing. And basically when that one thing is not needed anymore, or when they think they can, you know, uh, get it cheaper somewhere else. Right. They just, they do. I mean, so like, that's what I mean. Like if you're not a consultant at that point and running your own show, then you're, you're screwed. So my advice is to be move, have people move that up in their careers.

Dave Jones: No, no. There's always good jobs at big companies. There always will be.

Chris Gammell: I mean, yes, maybe good jobs, but not like, not what people expect, you know, like, not like pinnacle of the career kind of jobs.

Dave Jones: even when you work for yourself, it's not what you expect. Being a consultant is not the holy grail. No, no, no, no. It can be, it can be worse than working for the man.

Chris Gammell: This is not, this is not a, you know, sunshine and butterflies. This is a, if you want some semblance of control.

Dave Jones: I, no, no, even, even control as a consultant, as a, as a contractor. Yeah, no, you're right.

Chris Gammell: Everybody's got to answer to someone. It's who your boss, your boss is either a person, right? Your manager or your customers, or, you know, if you're running a company, the board, everybody has, everybody has, you know, people who are telling them what to do, but it's pretty much. Yeah. You can choose which one that is. And I, I think that, increasingly, if you look at like corporate structures in the next 30 years, I just don't think that being at the top in a corporate structure is going to be what it was 10 years ago, five years ago. Oh,

Dave Jones: it's not going to be what it was, but it's not going to vanish. Oh, Oh,

Chris Gammell: yeah, yeah, yeah, yeah, yeah, sure. It's not going to vanish, but I just don't think it's, it's not getting better, Dave. That's what I mean. Like, like, I just don't think it's getting better.

Dave Jones: I'd agree. It's not getting better. Yeah, but it's not going to vanish or be completely so crap that you're never going to want to do it.

Chris Gammell: I, I'm not going to want to do it. And I think that, uh, I think that a lot of people, if they look that far into the future, right? Like a lot of people plan that because, okay, here's, here's the problem, right? I'm getting like worked up here. If, if I go to someone right now who is, so if I talk to this guy I was talking to, Lou, who is really nice. And I ask him for advice, Lou, what should I do? What is the advice he's going to give me?

Dave Jones: Whatever he's familiar with.

Chris Gammell: What to do what I did. Right. Right.

Dave Jones: Exactly.

Chris Gammell: And I granted, you know, that's how advice goes a lot of the times, but I just don't think that it's even possible, right? He's been at this place for 30 years. I just don't think that that's realistic. Oh, no,

Dave Jones: no, no. That's, you know, like, I totally agree that that's changing where, you know, you had a job for life. Like,

Chris Gammell: you know. Right. And, and because of that, I mean, it's a feedback system too, where, you know, companies are like, oh, well, we're also not going to treat our people well because they won't stick around. And I'm not going to stick around because my company is not treating me well back and forth. Right. Right. Right. Yeah. But I just don't think, I, I think that if you want to be a technical expert, like a 30 year technical expert somewhere, it's got to be, you got to be a Jack Ansel. You know what I mean? Like,

Dave Jones: right. Hmm. Yeah. Kind of, sort of.

Chris Gammell: Okay. Well, you let me know when you're going back to work for a big corporate, corporate entity. Oh, no,

Dave Jones: I'm, I'm not.

Chris Gammell: Okay. Okay. Sure. Sure. Okay.

Dave Jones: But that doesn't mean other people shouldn't. I mean,

Chris Gammell: right. What we're trying to say is don't listen to anyone's advice, including us. Right. Yes.

Dave Jones: Like, you can't just give general opinion. opinion and advice about this sort of stuff. Everyone is different. Everyone has different needs and wants and, and no, doesn't work. Okay.

Chris Gammell: Well, that's the end of the amp hour. We're going to shut down the whole show because why should you bother listening to us? No,

Dave Jones: we shouldn't bother. No, let's just give up.

Chris Gammell: No one calls in.

Chris Gammell: come on. Next question. Why should you bother?

Dave Jones: They never call, they never write.

Chris Gammell: So I do have one here. I don't actually know anything of what he was talking about. What? So I just sent you.

Dave Jones: Are we talking about Todd, the youper?

Chris Gammell: The youper.

Dave Jones: What's a youper?

Chris Gammell: I believe it's, I think Todd might've called him before, but youper is usually from the upper peninsula of Michigan. Oh, right. Yes.

Dave Jones: You've mentioned that before. Right. Yes. All right. Got it.

Chris Gammell: So I personally have no idea what he's talking about here, but you know,

Dave Jones: are you familiar with magneto restrictive delay line memory? No.

Chris Gammell: Okay. Keep going here. Cause these other things, I don't really understand.

Dave Jones: I have a torsional version from an old freedom one, three, two calculator from the mid sixties. One of the first solid state calcs. Oh, diode transistor logic. Beauty. Featuring four stack RPM and square root all displayed on electronic deflection. CRT. Sweet. At any rate, a plan. I'm getting, it's on its way. I'm getting a CRT calculator. Anyway. You are? Yes. Okay. Yes, I am. Nice. Another retro tear down and play. Nice. Fantastic. Anyway, at any rate, planning to build a test circuit suitable for display. Is successor? Would either of you be interested in playing with it, perhaps showing for a larger audience? Oh, there's a link to it.

Chris Gammell: I have no idea what this is still. Right. So, well, I've seen this before. You're the calculator nerd. Right. So, I'm the calculator nerd. So,

Dave Jones: RPM is reverse Polish notation. Polish notation. Yes.

Chris Gammell: As a Polish person, that's kind of, you know, is that, who am I supposed to be?

Dave Jones: It's basically what the HP, when people think of RPM, they think of HP. Right. Oh, wow. Yeah. HP were RPM calculator.

Chris Gammell: This thing was portable. This is a portable. So, this is the Frieden. Damn right.

Dave Jones: This was portable. Yep. EC 132. It's like a pound in the, in the old money.

Chris Gammell: That's pretty cool looking though. It's got a huge CRT tube.

Dave Jones: Anyway, RPM is based on a stack based system. So, instead of going 10 plus. Yeah. Something. So, instead of having like the operator in the middle, you go 10, enter onto the stack. So, that's why RPM calculators have an enter key. You go 10, enter onto the stack, 20, enter onto the stack, and then you do the operator. So, you put things on the stack first, and then operate on them. Rather than.

Chris Gammell: So, it'd be 10, enter 20, enter plus. Yes, correct. Enter. Is that right? Yes. So, then it would. You wouldn't have to press enter. The plus would. Yeah. Oh, so the, the, the operator is, is the determinant of when it's. It's determined. Yeah.

Dave Jones: If the operator, yeah, it basically has its own enter kind of thing. Or, or you don't even need to do the second enter. You could just enter it in and then plus, and it automatically smart enough to know, oh, I want to put that on the stack, but it's basically a stack based system. And, yeah, it can have advantages in certain, it's quicker and like less, fewer keystrokes in certain circumstances and more in other circumstances. So, you know, like, yeah, you're, you're either an RPN fan boy. Right.

Chris Gammell: Well, I always associate it with like good engineers, but it's only because they're old. And they use HP calculators. Right, exactly. Just because they've been doing it for 20 years, you know? Right. Okay. Yeah.

Dave Jones: RPN equals smart guy with a gray beard, right? Right, exactly. Right, right. Okay. Oh, goodness. Yeah. Anyway, um, my side, my, uh, micro watch, my scientific calculator watch had RPN, had both actually. You could switch. Oh,

Chris Gammell: nice. Yeah. Well, that's, that's the main thing. Like I get one of my hands and I'm just like, I was getting tutored by one of these guys, one of these gray beards. And he's like, yeah, just put it in the calculator. I'm like, I don't know what I'm looking at here, man.

Dave Jones: Yeah. Yeah. It's always a fun trick to give an eye. I used to do, I, you know, I do have a collection of RPN calculators, HP ones. And I like, like, like I used to work and use them at work sometimes. And like, yeah, someone goes, can I borrow your calculator? Sure. And they grin on my face and the, you know, when they walk away, what's he grinning for? And I watched them try and use it. It's hilarious. Oh man. Yeah. Like I've had people, come back and I said, your calculator is broken. Like it doesn't work.

Chris Gammell: Yeah. Usually it dawns on me to, uh, at least switch it around a little bit.

Dave Jones: anyway, um, CRT calculator. Cool.

Chris Gammell: Yeah.

Dave Jones: Anyway. Oh, look at, oh, we'll link in the pics. Oh, look at that. All discreet.

Chris Gammell: Yeah.

Dave Jones: Well, he said it was a diode transistor logic. Yeah. So yeah.

Chris Gammell: With the card edge plugins.

Dave Jones: All the card edge plugins with all the individual transistors on them. Wow.

Chris Gammell: All the, uh, hand drawn traces. Yeah. Oh,

Dave Jones: you can see all four lines on the stack on the CRT.

Chris Gammell: Oh yeah. Nice. Oh,

Dave Jones: it's like a 15 digit display too.

Speaker ?: Wow.

Chris Gammell: Yeah.

Dave Jones: That's sweet as.

Chris Gammell: Dude, that thing must've been so heavy. Um, uh,

Dave Jones: uh, I, normally I'd be interested in these things, but they cost, this would cost a fortune to ship to Australia. It's just, yeah, crazy.

Chris Gammell: So he's got the voltage rating on the, at the bottom. One of 115 volts AC, half an amp.

Dave Jones: Half an amp for your calculator. Yeah.

Chris Gammell: Yeah. Nothing like a 61 calculator guys. Oh,

Dave Jones: that's terrific. Um, so sorry. What was the question? The question was, would we want to play with it? Um, yeah, but it's not economical to do so.

Chris Gammell: Uh, we have a little bit of time left, uh, since we ran out of questions and people, well, I can't believe, well, you know what? This is going to be the last question thing for a while anyway. So no problem.

Dave Jones: This is the last call in show because it's been a miserable failure or was our promotion? Maybe we just need a bigger,

Chris Gammell: a bigger break. I don't know though. The last one was like two 93. This one's three Oh seven. The last one. Yeah.

Dave Jones: Yeah. That's a big break.

Chris Gammell: March. Yeah. So no,

Dave Jones: I've had enough break. I just think nobody cares. People just want to listen to us.

Chris Gammell: Everybody's figured it out. You know? Yeah. After the last one where we had no idea what we were talking about, that's probably why they didn't want to.

Dave Jones: Right. Yeah. We have no idea. We can't answer the bloody questions anyway.

Chris Gammell: Yeah. Uh, I did want to call out the fact that, uh, Electron update took pictures of the die after they blew up your EV blog micro. Yes. I saw that. And I, so cool.

Dave Jones: I corresponded with them. I offered some, uh, boards to them to do the other, uh, chips, but, um, they're sort of, it was a, they've lost interest. One time thing. So yeah. So yeah. Yeah. Yeah. So that was, that was, that wasn't like, they tried to do all the chips, but they lost them or something. It didn't work. So they only got one of the chips on there, which was the voltage supervisor. Yeah. So we just, sadly it wasn't the, uh, the, uh, amp, the, uh, max four, two, three, nine chopper.

Chris Gammell: Oh yeah. Yeah. Yeah. Yeah. Yeah. I was going to say op amps are usually a little bit boring, but yeah, chopper amps. Yeah. Chopper amps would be,

Dave Jones: might be more interesting. I've, I don't think I've ever seen a die shot of a chopper amp. So maybe it's like different in some way. I don't know. I don't know.

Chris Gammell: Well, and that also just to call out, uh, there's a lot of, I mean, I love these kinds of things. So like there's, um, so this, this site does some of that with the, the up close microscopy, microscopy, uh, of the die. What's that other? There's like a Russian site too, isn't there?

Dave Jones: Yeah, there is. Yep. Uh, yeah. I can't remember now.

Chris Gammell: I just Google Russian chip. Yeah. Russian die photos. Russian chip photos. Oh my God. It's pictures of Papa's.

Dave Jones: Don't type in Russian die photos here.

Chris Gammell: Russian. Yeah, no, no, this is, uh, this is like, like potato chips. It's like all the brand bags of, uh, silicon photos is probably a better one. Yeah. Uh, the things we find.

Dave Jones: Lay's chips, Popper's, Popper's brand chips. Yeah.

Chris Gammell: Yeah. Anyways, if I find it all. Yeah. Remember it's a dot, a dot are you? So something.

Dave Jones: What's this photo? Russian geek puts your CPU collection to shame. Oh, sorry. I've got to click on this. Yeah. Got to click on this link. Okay.

Chris Gammell: Uh, yeah. So.

Dave Jones: He's like, this Russian guy proudly taking a selfie with his collection of, uh, CPUs. Oh, I've got to link this in. This is cool. I'll send you the link. Here we go. Yeah. It's good. It's like, uh,

Chris Gammell: things on the list, uh, not too much on this week, but I, I have been posting a bunch of talk. Like, so you know how I always talk about, I do those talks out in San Francisco or I host the talks rather. Uh, Mike Harrison did a really good one. Yeah. I saw that.

Dave Jones: I didn't watch the whole thing, but I skipped, I couldn't spend the whole hour, but I skipped like three. It's 43 minutes. It's good.

Chris Gammell: It's worth, it's worth the whole thing. Uh, there was one from back in February too, where, uh, James Lewis, bald engineer on Twitter. Uh, he did a great one about capacitors. That was on Hackaday too. Um, but yeah.

Dave Jones: That was you sitting down in the bottom left corner, right? Of the video.

Chris Gammell: No. No, it wasn't you? Oh, maybe. Yeah, maybe. I don't know. You were sitting in the front row with in and out. Yeah. So, uh, it doesn't actually affect the, the, the presentation. That's the important thing. Yeah. No, no, but these are just great. Like the, yeah, some of these talks have been so, so fantastic. So I'll keep posting them. Uh, I got, I got a bunch of video to edit, but it's sweet. There's been some great talks.

Dave Jones: So I should do something like that. I should hold a talks thing where people can come give a talk. And I put it up on my channel.

Chris Gammell: Yeah. Well, you've done, I mean, you've done what, like Nate talks before there, or you've done some Sydney thing.

Dave Jones: I've done an ignite talk. Yes. Yeah. Yeah. Yeah. Talk. But that's, yeah, that's different kind of, you know, it's not a, it's a bit of a different ball game.

Chris Gammell: Yeah. Uh, yeah. So, yeah. And, you know, to be honest, you, you, you run out of people. That's the hard part, right? Right. I've just, I've run out of people I know. So you've found that.

Dave Jones: Okay. So you're running out of people to give talks. Oh, yeah. I mean, like. Right. So you've tapped everyone.

Chris Gammell: Not every, I mean, not everyone, but like also availability, stuff like that. So if people are ever in San Francisco and they think they'd love to give a talk, you know, shoot me an email. I'd love to hear from you too. Um, and I'll make sure the video looks nice. Um, cause yeah.

Dave Jones: And the good thing is, is that you're not presenting in front of a thousand people. So there's no. Pressure. Yeah. Yeah.

Chris Gammell: There's no pressure there. It's just, you know, it goes on the internet. So, uh, that's a good thing though. You should get your stuff out there. it's good.

Dave Jones: Whereas the ignite talk thing's different. It's like you've got to get up and give a, give a totally scripted talk. Yeah. Non-stop to, you know, 500 to a thousand people. Oh wow. Really? Oh yeah. Yeah. Yeah. That's, that's nerve wracking. Right.

Chris Gammell: Especially it's not like, so this is another thing too. Like, so the people that, uh, at these, these talks that I do, it's usually nerds talking to nerds kind of thing. And that is another thing that really helps. Like it really helped me where it was like, like everyone in the crowd is like nodding their head when you're talking about like caps and, you know, op amps and stuff like that. Like that is, that is, if you ever want to do, if you think you ever want to do talks, not even at these events, like make a fair, stuff like that. Any, any, if you think you'd like to give a talk at some point, try and get like a friendly audience like that as your first time, because yeah.

Dave Jones: And it helps when there's no time limit. Cause you know, if you,

Chris Gammell: uh,

Dave Jones: you know, or it might be an hour or something like that. And if you've got prepared slides, you know, like you don't have to memorize stuff. You can put the slides up and just talk off the cuff. And like, yeah,

Chris Gammell: some people want to do, I mean, doing scripted is, is, I mean, usually it's a little bit more stifled. Be honest. I think I, I like, I mean, obviously you and I do off the cuff pretty often. Uh, and I think that's the best way to do it, but if you've got some deep technical content, then sometimes you need reference points. Well,

Dave Jones: that's why you have bullet points and slides. That's why it becomes a death by PowerPoint because nobody can remember a one hour talk. You have to be a professional standup comedian and, and rehearse it for, you know, three months before you can do a one hour standup routine. Right. So, yeah.

Chris Gammell: So what we're trying to say is that you should take your electronics presentation and go to a comedy club.

Dave Jones: Because I, I made the mistake.

Chris Gammell: What's the deal with hop amps?

Dave Jones: I made that mistake once. I was invited to give a talk on, uh, YouTube video blogging at a video event here in Sydney. And, um, I, I thought, yeah, I know this time, you know, I don't have to prepare anything. So I turned up with basically nothing prepared, no death by PowerPoint. And three hours later, Holy moly. People were going, sorry, I've got to leave. Like, I'm dead. It's late. I've got to leave. You know, and I'm still talking. So, yeah, you've got to have that PowerPoint. Well, that is,

Chris Gammell: that is a reason to, yeah, gate yourself at least a little bit, or at least set a timer. Right. Right. Yeah. That's, that's rough. It's a good skill to have though. I think, I mean, like in general, like you're probably going to be asked to do that at some point. So it's better, better to do it the first time and be nervous in front of a friendly audience on your own terms, that kind of thing. So wherever you can, if you're, if you're interested in doing that kind of thing, I think it is, it is good for your career. I think, you know, just to have,

Dave Jones: have that. Totally. It's good for job interviews too. That's true. Yeah. It gives you confidence to talk about your stuff in job interviews.

Chris Gammell: Yeah. That'd be interesting to see like someone walk in with like, not a deck of PowerPoints, but like, maybe if you did, you just like pull out your own little micro projector and you're just like, and you'll see here on figure one, here's how I saved my company a hundred thousand dollars last year.

Dave Jones: No, it's all about confidence. Like, you know, if somebody brings out their stuff and talks confidently and can talk confidently about it.

Chris Gammell: That's true.

Dave Jones: You know, like that's gonna, like, that's a huge tick, right? Whereas somebody thumbs around, oh, oh, no, I, I, you know, like.

Chris Gammell: Right. Yeah. Right. Right. Right. And I don't think that's, I don't think that's extrovert versus introvert. It's just, yeah, how well you know this stuff. Like at anyone, you could be the most introverted person in the world. And if you know your stuff, you're probably going to want to talk about it.

Dave Jones: and you can come across very confidently. Yeah, exactly. Because you're talking about your stuff. right. Yeah. So it helps. Practice makes perfect.

Chris Gammell: Yeah. What else we got? Anything else? There's lots of links. You can go on there. There's lots of links. Links, you know.

Dave Jones: Yeah, there's links.

Chris Gammell: Cool. All right. So, you are going on vacation again or something. You're going to be away for something and I'm going to be traveling. So we are going to have some guest shows, but there'll be probably pre-recorded type stuff. So some weirdness coming, but nothing you haven't heard us do before.

Dave Jones: Yep. And what's this holiday business?

Chris Gammell: I said you were going on holiday. No,

Dave Jones: I'm having my knee operation.

Chris Gammell: Oh yeah, that's right. You know, the holiday where they dig around in your knee a bit, right?

Dave Jones: So the opposite of fun, I'll be in pain. That's true. Yeah,

Chris Gammell: that's what it was. Sorry, I forgot. You know, you'll be so hopped up on meds. You'll think you're on a beach, you know, you know, my knee hurts, but I really want to go swimming right now. Well, good luck with that, buddy. You're going to be fine. You'll be fine.

Dave Jones: Thank you very much. My first op.

Chris Gammell: Yeah, you'll be great. All right. Well, last call in show for a little while, but thanks to Alexander for calling in. We appreciate that. Everybody who wrote in too, we appreciate that.

Dave Jones: Oh, good question. So, yeah. So it works, we just don't get much quantity.

Chris Gammell: Yeah. That's because you're in a weird Aussie timeline. That's the problem. All right. Catch you next time. Talk to you soon, buddy.

Chris Gammell: Bye.

Speaker ?: Take care.