A decade after graduating college, Stephen finally did a differential equation for his job! That is some real engineering I tell you what.
Right to Repair is going global and Stephen might have solved his injection molded component's void by tweaking the mold design.
The PinoTaur has reached production status but not without supply chain issues..OF COURSE! Bonus discussion about thermal management for PCBA.
Rapid Fire Opinion
Parker is an Electrical Engineer with backgrounds in Embedded System Design and Digital Signal Processing. He got his start in 2005 by hacking Nintendo consoles into portable gaming units. The following year he designed and produced an Atari 2600 video mod to allow the Atari to display a crisp, RF fuzz free picture on newer TVs. Over a thousand Atari video mods where produced by Parker from 2006 to 2011 and the mod is still made by other enthusiasts in the Atari community.
In 2006, Parker enrolled at The University of Texas at Austin as a Petroleum Engineer. After realizing electronics was his passion he switched majors in 2007 to Electrical and Computer Engineering. Following his previous background in making the Atari 2600 video mod, Parker decided to take more board layout classes and circuit design classes. Other areas of study include robotics, microcontroller theory and design, FPGA development with VHDL and Verilog, and image and signal processing with DSPs. In 2010, Parker won a Ti sponsored Launchpad programming and design contest that was held by the IEEE CS chapter at the University. Parker graduated with a BS in Electrical and Computer Engineering in the Spring of 2012.
In the Summer of 2012, Parker was hired on as an Electrical Engineer at Dynamic Perception to design and prototype new electronic products. Here, Parker learned about full product development cycles and honed his board layout skills. Seeing the difficulties in managing operations and FCC/CE compliance testing, Parker thought there had to be a better way for small electronic companies to get their product out in customer's hands.
Parker also runs the blog, longhornengineer.com, where he posts his personal projects, technical guides, and appnotes about board layout design and components.
Stephen Kraig began his electronics career by building musical oriented circuits in 2003. Stephen is an avid guitar player and, in his down time, manufactures audio electronics including guitar amplifiers, pedals, and pro audio gear. Stephen graduated with a BS in Electrical Engineering from Texas A&M University.
Special thanks to whixr over at Tymkrs for the intro and outro!
Hello and welcome to the macro fab engineering podcast. We are your host, Stephen Craig and Parker Dolman. This is episode 206.
is what the second podcast in the year for no first podcast in New Year?
No, this would be second. Oh, no, you're right. This isn't the first.
This is the first of us recording one and 2020 Yeah. 20
Oh, right, because everyone listened in 2020.
recorded last one on 31st.
So you've finished all your projects, right? All done. Including the brewery, right? Totally.
No, no. So
why don't you give us an update on
all the all the brewery routed out brewing pots are all done. I soldered, silver soldered all the connections on, they seem to be strong and not leaking. And I saw and I polished them all up. So you look all nice and fancy. And I basically like I stack them up, like on the floor and configure how much space you need to put between the pots because I'm doing you know, rigid hard lines between everything. And you know, the thing with rigid hard lines is you have a bend radius, you can't just you know, 90 degree a tube. And so I took some tubing, half inch stainless tubing, and I put it in my Bender bent it. And so I would have like a, like a, like a template, I guess of a bend. And so I can I use that to play around with all my spacing. And I ended up finding that like, I need a cart that's like eight feet wide. Which is ridiculous.
That's huge. Yeah. Eight feet is Monster. And you're and you were planning on wielding up an entire thing, right?
Yeah. Which building the cart that big is not that bad because I built stuff that larger and larger before square tubing. But it's just like, Where the hell do I put this thing? Eight feet is huge. Yeah. It's like, oh, I have to basically remove a work bench in my garage, just the store this thing?
Yeah, my cart is five feet long. And it's already big.
Yeah. So I'm thinking about redoing the setup, not just not the, I don't have to redo the fittings because all the fittings in the right spot, but just were like, instead of doing them all spread out is maybe do a tiered system or figure out a different optimization in terms of how I put the pots together. So I have to work on that.
Are your pots really that big that they demand that much space? Well, it's the fittings. Oh, between them between them that take up
a lot of space.
Right. Right. Because you doing hard, hard tubing? Yeah,
I actually was thinking like, what if I just took the pots and then wrote because they have all the fittings basically go we like 90 degrees to each other. Like, what if I took the pots and then turn them? 45?
Yeah. So it's like triangular tubes between them? Yeah.
That's cool. Like it was closer.
Yeah. Yeah, that would look awesome. And
it'd be weird because all the handles be weird, but you're not using the handles anyways, because you're not lifting these bots up.
Right, they Yeah, they stay still. You know, one of the things I kind of want to do this, but I'm a little bit afraid, because it's a lot of money. And I mean, the money's already spent, it would it would be a lot of money wasted if I screwed it up. But I would love to make my pots permanent on my broom rack such that like you never pick them up even for cleaning. So it would be awesome to drill a one inch hole threaded hole in the bottom of them and put a valve out the bottom of them. And that's just like a dump tube. So you clean everything and you open the dump to about the bottom of them and bam, everything's gone. Yeah, I
was thinking about that for for at least like my my boil pot, because that's the one that always gets nasty. Right, the other ones are pretty easy to clean. Yeah. And I was actually looking at some people setups on kind of doing the same thing I was doing and they actually put a hinge on their mash tun and so you basically take the mash tun and it just, um, hinges from your cart, it stays attached.
It's like an arm neck, you can tilt it with. Yeah, yeah. So the mash tun is the big pot that basically all the grains go in, and then you put like 40 pounds of water on the grains and it's in like at the end of it
You have like 60 pounds worth of stuff in there. Yeah. And it's one of those that's like, I was actually originally planning on just putting like a little. I was like, how the hell do I get the grains out of this pot if it's hard lined in?
Oh, yeah, yeah, you know, okay, one of the way I want to do it eventually, because I do all I have a nice mash tun but I but I put a mesh bag in it, just hold all the grains. I'm gonna hook a winch to my, to the ceiling of my basement, such that I can winch the entire thing up and let it drain and just hold it above the napkin. And just because you don't ever want to squeeze the mash bag, because you release a bunch of tannins, just like squeezing a tea bag. So
some people do that though. I've never have done. I never did that before. Yeah, and yeah, I was I was asking if you were going to do that? I guess not.
No, I want to I want to just like hold it and suspend it above and let as much drain out as possible. And you know, with a bag that big. It takes 20 minutes to get the last drop out of it.
Yeah. So that's what I was going to do on my cart is I was going to weld a basic a little gantry crane. Yeah, that's not a gantry. Crane arm thing. Yeah. Yeah. And I was like, Yeah, but I'm like, this thing is gonna be trying, it's gonna be like a whole operation. Yeah, to do this. And I'm like, so I'm thinking about trying to read stuff up, like maybe try to do a tiered system. If it will work. I'm probably gonna play with it after the podcast, look at what other people have done. Like I actually found someone that pretty much built a similar setup as mine. Yeah, that was a a flat tier one. They called a one tier system with three pumps. And he's using actually like flexible hoses in between, but he just has them with those. They have a special name for him. It's the clamps the hose clamps that are pinch, the pinch, they're pinched, not worn clamps. It says, Oh, I'm not sure what you're talking about, like asked Oska. hose clamps.
What? Why are you looking that up? Something that came to mind, you should totally do this. I love the idea of having a swing arm on the edge of your blue red cart that has the winch on on it such that you can winch up your mash bag, let it sit, and then it rotates out and you can then just dump everything into a trash can. That's also on your cart. So your cart goes from eight feet to 10 feet because it has an extra two foot trash can.
It's like it's it's OETIKERT
ik er, oh took her clamps. Oh, okay. Yeah, those
use that special tool in it. And it kind of puts like a divot in it. And it's a permanent clamp.
Yeah, so I use those on like automotive stuff all the time. So I was gonna use those back when I was going to use silicone hoses for everything. Mainly because like hose clamps always had that like, sharp piece of metal. And that, that six out foam. And I've always cut my fingers on those. Like I'm never using those ever again on anything. I'm like near Yeah, so I'd rather like basic because I have a tool that removes those as well. It basically just cuts the little year off, right. And it's like, I'd rather just have a bunch of these and just go through them that have formed clamps ever again. I've cut my fingers so much on him.
Harbor Freight has a kit of worm clamps that come with a plastic knob on them. It looks like a wing nut. And to a worm. I don't know clamp. And that kit is like $2.50 or something ridiculous for a bunch of them. So I just buy those on occasion and just use them. They're really, really super easy, especially if you need to take it off and clean your hoses that that wins, especially for the cost.
So yeah, I gotta I gotta figure out how I'm going to organize it now. And hopefully I can compact it a bit more. Because that's like a eight feet by two foot by probably about four and a half feet tall. My only problem with Tiered Systems is usually your brewery, you're not brewery, your boil pot is really low to the ground. And so you have to lift it up to drain it into your fermenter
Right, right or pump it because you have three pumps. Yeah, we're pumped. But yeah,
I've never been a big fan of that. But um, well, I'd see I'd start playing around with it and figure out how to because an eight foot cart is not going to do it. It's like, I kind of want to make it like, I think that's the next thing is like, how compact can I make this setup?
Yeah, yeah. The one thing that I don't like about gravity systems is just you have to have a ladder to things. I mean, yeah, you got pumps and things like that. But you still want to be able to see in the pot, and it's kind of annoying because you end up with a nine foot tall, three tier system. And they're Yeah, they're great because their footprint is like two foot by two foot by nine foot.
Like, that's the problem is my garage is only eight feet tall. Right? Right. So I can't do that either. Or that tall of one. And all my pots are like 19 inches tall. Yeah, they're tall pots. So. So yeah, that's that. Hopefully by next week, I have a plan. I kind of want to be welding the cart by this weekend. We'll see what happens. So I had to get to the metal metal fab. Not metal fab, the metal yard. Metal yard. Yeah. There's a place called like Rose metal, Rose metals, overbuy work apart, go over there, they seem to cater more towards like smaller people. I went over there once and they didn't mind me just walking around looking at all the cut offs. So all the rusted cut off. Yeah, all the rest of cut offs.
So there's a couple of places in Denver that that are right around the street from my work that they're, they're like family, metal businesses and things like that. And they're and they're, they're similar to that where it's just like, they have a lot of their metal sitting on like racks in the in the backyard. And you could just go check it out.
I like to go check it out. And then I was over there and they're square tubing was like half the price of like, everywhere else. I was kind of looking. So that's awesome. Mainly because they act they will sell you one piece. At that price, instead of like, will you go to a normal metal yard. They're like, well, we'll give you that price. If you buy like 100 sticks.
Yeah, yeah, they want to do it by weight. Yeah.
Well, they're not set up. Most mail yards aren't set up for the guy come in with his Jeep in a trailer. No.
They're not expecting that. And then if you try to buy steel from like Home Depot, it's like 15 times the cost. Yeah.
It's like, oh, they have one stick. And you need like eight.
Oh, yeah. Yeah, one stick and it's not the right size.
Yes. I hate buying materials that like Home Depot and stuff like that. Because you know, you've been robbed.
Well, in the metal department for sure. Yeah. Yeah, Woods. Not that bad. Not
plywood. There is freaking expensive, too.
Well, yeah. I mean, most like, two by fours and stuff are still what two, two by fours are pretty cheap. Yeah, they're cheap.
By the plywood. It's always like the plywood. It's always crappy, too.
There's so many footballs, yeah.
So yeah, hopefully next week, I have more brewery update. Maybe the cart being done
have a napkin drawing for us?
Yes, I'll at least have a drawing of what says tiered system because my original idea when I drew it up, I didn't even think about the fittings or anything like how long like a because it's got the fitting on the half inch NPT fitting on the pot. And it has to go into a a ball valve. And then it has to go into a fitting and it has to go into a compression fitting. And just like this, it grows like eight inches of fittings. Yeah, fast. Yeah. Really quickly. And you're like, well, that's that's not I need, like 10 inches, and then plus, like the radius bend the hard line. Yeah, it sounds like well, you know, might be also I go look into instead of doing a radius Ben is do a 90 elbow, stainless and then go straight down. Because it'd be a lot more compact too. Huh?
Yeah. You know, I've seen before, let me think about this. You could have two pots stacked on top of each other, and then one kind of like parallel to the side. Yeah, I've seen that those two. Yeah, yeah, that might be it might be worthwhile, or you could potentially have it such that. Well, you know, you don't ever want to take this apart. You want it to be a permanent fixture. I was gonna say maybe a card that like expanded and then you could Get it up on brew day, but that's exactly what you don't want.
Yeah, that's all I don't want. I want to be able to wheel this thing out, hose it down to get all the dust off. Yeah. And then brew, be done with brew and throw in the cleaner, run the cleaner, and then put it away. Right, right. So we'll see, we'll see if that actually happens. My brother who also Homebrews thinks I'm crazy. So the worst case is that doesn't happen. And we just make it a system that breaks down. Yeah, so it's not really any loss besides like, the tubing, I get that stainless tubing. Which wasn't that expensive. Yeah. Because I bought it in a big coil. It's the funniest thing. It's like, you buy like 50 feet of you're trying to buy straight, because we last time we talked about this, I was going to buy a half inch straight tubing, an eight foot sticks. Yeah. And those are expensive. Like, the per foot is like a couple bucks per foot.
And, but if it's coiled up, it's a lot cheaper.
It's curled up, it's like a quarter of the price down. And so I bought a coil and then I bought a, a tube straightener because you got to straighten it so you can actually put bends back into it. Have you already straightened it? Yeah, I took it over this weekend. And I put it in the straightener. And I basically the straightener got you put your eye on a drill. So you can go and suck it in. And so you you do about eight feet as I did at a time. And then I zipped it with the with the angle grinder. Yeah, angle grinder with a cut off. We'll just zip right through it. And then made like six or seven, eight foot sticks, something like that. Which should be plenty. Yeah. Then you just run it through the straightener a couple more times to you know, get all that's cool ends out of
it. I didn't know it was that easy?
Yeah, it was actually pretty, pretty nice. So. And then the other thing I've been working on of course Penetrator, the pinball platform. The PCBA is apparently done. It's sitting on my workbench at work. So it was not done before the podcast. But so hopefully, by next week, I have it tested. Nice. That'd be cool.
You'll have it tomorrow morning. Yes.
And then I got ordered all the through hole parts from Mouser. And they should be here tomorrow as well. So I'll start soldering up all the through hole. Mainly because the the through hole like the lead time was like an extra two weeks to get built. There's a lot of through hole and I'm like, well, I could probably spend like an afternoon on a Saturday just soldering myself.
Honestly, I really you. I love soldering like that. It's just fun. And it's therapeutic. And if I have a project like that, I'll just I'll get my folding table out. I'll put it in my living room in front of the TV, and I'll just solder for a whole evening. And it's just I don't know, it's fun. I like that. I
actually was thinking like maybe coming in to the fab on a Saturday and running this like to solder for four boards.
Just spending all that type programming for that.
Well, it's not that hard to program, that drag drop kind of interface.
Yeah. But I mean, every time I've had those same thoughts where it's just like, I'll just come in on a Saturday morning and do it. And then like five o'clock on the Saturday, I'm still sitting there like messing around with stuff.
Yeah. Yeah. And maybe it's running on Saturday. So like someone's actually already using it. And before their shift is over. Like before they turn the machine off. I'm like, let's run these floorboards real quick.
Slip them some bucks and just throw it in there. Cool.
So Steven, what are you been up to?
So I have I got a funny story to start off with. So this week, we had at work, we had a power supply go out on us. It shorted and made some made some smoke. And one of the operators who was using it at the time, it was in our testing department. They said that the LED for the negative 12 volt rail went off, and then they heard a loud, high pitched squeal from it. I'm like, Okay, well, that means the switch mode supplies to freaking out right. Yeah. And, and then and then that was it, like done. And this was the second power supply that had done this. And we did some investigation as to what was happening and there was just some faults and some errors that were from a bunch of different angles, but we know what caused it now, but we have two bad power supplies. And it was just like, Damn, we don't want to buy new power. or supply so I cracked him open and looked at the boards. And what what kind of sucks is on these boards, there's two regulators and go figure there's a plus 12 volt rail and a minus 12 volt rail. So you know, Lottie da, both of the regulators have their part numbers sanded off. Like, the manufacturer didn't want us to know what regulators they use. But it's the regulators are in like, I don't know how to describe it, I guess. Okay, so you know, Deepak, they have like the big pad and two legs. So think of a Deepak that looks like a Deepak but it has seven legs on it.
I think those are called like Deepak sevens or something like that.
Yeah, there's something similar to 263, dash seven, something like that. Yeah. And there's, and when you see a weird package like that, the first thing that comes to mind is Texas Instruments. Texas Instruments is the only person or the only entity that uses that, to my knowledge for power packages. So I looked at it was like, okay, so TI. So I started like, sniffing around ti for a while, and I find some stuff that kind of matches. And I started like, doing pin outs and stuff. And it matches really well on the positive 12 volt. Like it's one to one, I found the family of regulators and their switchmode regulator. So like everything lines up, and even the values of resistors, and caps that are around these things. were lining up with some of the datasheet, like the reference designs in the in the data sheets. Yeah, yeah, exactly. But then I looked at the negative 12 volt rail, because the negative travel rail is the one that's bad. And I start pinning it out. And it's super weird. Because the way it looks like the ground is the output, like literally, the pin that's in the data sheets of the regulators I found is it says ground in the datasheet. But if you look on the board and the layout that somebody did that's connected directly to the output. And so I'm like, I don't know, this is weird. And I couldn't like rectify that. And I remembered a video that I watched a long time ago from Dave Jones. And with the E V blog, and I tried looking up the episode before this, but I couldn't find what it was. A long time ago, Dave Jones had a video where he was discussing how to you basically deal with chips that somebody has sanded off the top. And there's a trick, I didn't think this would work it straight up Word, you spit on the chip, like full on, like, take a big ol water spit and stick it on the chip. And if they haven't done like a phenomenal job with sanding it off. Like if they haven't taken like a ton of meat off the chip, then the part number will start to like just like glow through the spit. And I probably like it has nothing to do with spit it I mean, it's liquid but but still, I think it's funny that Dave don't just like just bid on it. So I tried that. And I put it under the microscope. And whoa, like all the numbers like just appeared there, like straight up. And I found that it was it had like very clearly the National Semiconductor symbol was on the front of it, which National Semiconductor is is owned by Ti. So it's still like a TI thing. But I went and looked up the part number with the National Semiconductor datasheet like one of the older ones, and they have a special app note on how to use this thing to get negative voltages. And the way you do it is you use the ground as an output. And you rearrange everything so totally found the chip by spitting on it. And at the end it works. So thanks a lot Dave. Like I never thought I would use that and it totally worked. So that was a fun little thing. It kind of sucks though. Because I mean like those regulators like six bucks each, but I think we're gonna I think they're gonna arrive tomorrow the new parts so I can just solder those on. And I mean, how much is a new power supply? Oh, like 100 so it's Yeah, yeah, six bucks. Yeah, it's just like, oh, man, that sucks. I mean, they're gonna be a pain in the butt to D solder because they have a huge thermal pad like measured in inches. So I'm gonna have to get the IR thing out and probably multiple people with multiple irons and stuff, but it also took out a couple of the diodes around it, but they didn't scratch off the diode, part numbers.
Oh, the little identification marks.
Well, I have these these were big diodes, their SMA package. So they actually do have a laser marking. Yeah, they just straight up have their part number right on it. So those are nice and easy. Yeah.
Yeah, that reminds me of back when I worked in Oklahoma on on 900 megahertz radio stuff. So Oklahoma for people who don't know has Lots of lightning storms. Not as much as like Florida, but has quite a bit and tornadoes as well. And our radios were connected, you can't ground the radios. Because the how the code, logical code works for these because they're on pipelines so and the pipelines are, are cathartically coupled. I think that's why how you say it mean that they run a frequency through a voltage frequency through the fence of rusting the pipelines. And, and since they're in the ground, you can't ground. So because if you if you ran a ground rod into the dirt, you'd basically effectively ground the pipeline to that ground line. And so your, your thought, I think it's cathodic is what they call it. Cathodic cathodic? Maybe,
yeah, it's something like cathode is what it's derived from, right? Yeah, yeah, something
like that. Yeah. But so you can't ground it. So basically, when your radio gets struck by lightning, there's nothing you can do, your radio just goes out. Like there, we try to rest like lightning, arresters, all that stuff. Basically, the Lightning has nowhere to go. So it just blows up your radio. And so I started looking into we had like, like, when I got there, we had a whole cabinet, full blown radios. Because basically, after a lightning storm, like one or two will go down, and then mechanic go out there and just swap a radio out. And these are like about grand $1,200 radios, because they're like class one div one radios that go inside these electrical boxes. And so I started, I took one apart and started poking around, because like, you would power it up. And I had in my office, I had a little tiny base station, I made just the test stuff. And the radio would come on, you just couldn't get any data through it. Because like you had a Rs 232 front end that that your meter basically would talk to, and then the radio would broadcast out. So you would actually pick up the radio, the radio section was working with the RS 232 section wasn't working, couldn't communicate through it. And so I started poking around in it, and one of the buses that's like the one that we don't use, communicate just fine. But I think it was like the RS 45 section worked fine. And that was actually we don't hook up to so I'm like, okay, that signal path is working. But for some reason, the 232 sides not working. And I poked around and there was a chip there. I couldn't I didn't know what it was. And because it the whole board was conformally coated. So this is getting kind of your thing. Yeah. And I had to like, chip off the conformal coating, because it was it was a really hard coating, I guess, chipped it off. And then I use the spit method to nice, because, because once you chip it off, like you still couldn't see anything on it. And I kind of just like, welded it, and then looked at it. I didn't have a microscope, I use my phone, the camera and just zoomed in on it. And the part number was an ESD part. So it was designed to hit like 15 kilovolts. And so basically lightning was zapped, and that part is trashing the part. Yeah. And so I went on Mouser bought a spare part, put it in and the radios are working perfectly fine. And basically the company we're sending those off to get repaired for 400 bucks a pop. And this is a 15 cent part. Yeah. And so I really wish we were able to I wasn't there long enough to basic my goal was just repair those there. And then like reconfirm recode them. But we ended up not didn't have time to do that. Before I started, I moved back down in Houston. But I also wanted instead of doing that is like protect the radio in the field is build a little board that just had another one of those chips in between. Because clearly it could have rented anything upstream of it dying, right? Yeah. But I couldn't get any answers because like no one knew like, what the legality of that because this is a class one div one environment, right? It's like okay, do we have to make a class one div one like protector circuit or something? Oh, we had that guy on a couple of months back about that. I should ask them then.
You know, but if you chipped away the conformal coating, then you've you've taken Oh, you've destroyed the class one div one rating. Yeah. So
that's the thing is you'd you'd, you'd have to send it back out to get or you'd have to conform or coat it yourself or get it recoated Yeah. somewhere else. cuz that's clearly what the person who was doing it for 400 bucks was doing regrouping it.
Yeah, it's interesting what what lightning can do the things
in class one div one is, you might be class one div, but you have to do the actual lightning test at the testing centers where they they zap it with 15 gay or what however much it is.
Well, class one, everyone's just like the environment of like it because it was like can be constant, like vapor exposure for like natural gas and stuff.
Right? Right. It can only contain so much energy. Yeah, this circuit at any one point in time. I can't remember which one it was we had to do it for one of our products.
So we never Well, I was thinking our company that I was working for building hardware, anything. And so when I was like, coming up with this idea, everyone was just like, I have no idea. Because we just bought products and then put them into stuff. Right? Technically, it was a pipelining company. So you know, even more interesting, I might have snuck around if our company actually liked design stuff. But that wasn't that kind of company. So you know, the fact that like, battery monitoring stuff out in the field was like foreign to them. And I implemented that with the radios. Because in Oklahoma, everything gets really dusty, because that red dust gets everywhere. Yeah. And it would get on solar panels. Doesn't make solar panels work when they're dusty. And so the batteries would eventually die. And then you get a call four o'clock in the morning that wake up and go replace the battery out in the field and wipe this the solar panel off. And after doing that two times, you're pretty fed up doing it. And it's like, oh, these radios have an analog input. I'm going to put that on the battery. Just pull the analog input. Oh, now I know when the battery's gonna die. So you can replace it during the day. Nice. So Citrix
it's Bitrix, leading to dying batteries in red dust. Yes. So when I got home from work today, I had a nice little package sitting on my front porch. I get I was really super excited about this. It's kind of mundane, but I found a really nice resistor kit on Amazon will, will post the link to this. But I've had, gosh, kits of resistors for years and years. And I've finally gotten to the point now where I've either lost them or dumped out the wrong value or whatever, so much that I'm finally like, you know what, I need to get some new resistors. So the other day, I was searching on Amazon for resistors. And I found a kit. Man, I wish this was available when I was younger, but it's 3350 resistors. All 1% Quarter watt resistors in 134 different values. So it's a it's 25 each have 134 values.
That's 133 more than I need
10k Right? Yeah. I know you digital guys.
A value of zero man.
Well, if you're breadboarding stuff, or if you're like working in the analog domain, it helps to have a bunch of different values. And I say, you I wish I had this when I was a kid just because, man, this is so nice. And the resistors I was buying are the resistor kits i bought when I was a kid, like 10% resistors are what you could find in like, eight different values. Whoo. And it's just like, oh, man, it was it was hard. And
I remember basically like taking resistors and twisting the ends together to make different values.
Oh, yeah, I probably have some sitting on my desk right now that I have done that. And I was I was breadboarding something just the other day and I was I was having to make compromises because I had weird values or off values, and everything was 5% I believe. And I really wish I had 1%. And this this whole kit I found on Amazon is $25. So this 120 $5 kit will set you up with enough to test or build whatever circuit you want. And for most breadboarding applications quarter watt is enough. I mean if you need if you really need more than a quarter of a watt then you're probably not going to be breadboarding. So I just wanted to showcase that because I'm super excited because after this podcast, I'm gonna go and dump all of my old resistors and I'm going to reorganize all of my trays and put all my brand new resistors in place.
And I like how the box has a resistor chart on it.
You know Another thing that I wasn't aware of is there that I'm going to have to deal with now, these are all five band resistors. And I can really quickly read for band resistors. And I know if I bend resistors are easy to, it's just, I don't have any experience with five band or much experience. So I'm going to have to get good at that. So I guess that's a good thing. But one of the reasons why I even did this is because if I breadboard something, I usually don't reuse those resistors. I'm really anal about the way that I do most of my breadboarding stuff. Like if I build a circuit, I'm bending legs of resistors. I'm cutting them to make them as short as possible. Like I do a lot of work to make my breadboard as PCB like as possible. Because I've just found in the past that I've spent, you know, an hour or two making a circuit and it doesn't work the way I want it to. And then I found out that's because I built it the way you see breadboards in pictures all the time with like, you know, wires flying all over the place and resistors three inches above the breadboard and yeah, yeah, exactly. And the thing is, if you take your time and you think out your layout, and you build everything in chunks, like if you have an inverting op amp configuration, spend time making that really nice, like the feedback resistor that goes between two pins on an op amp, bend the legs of a resistor such that it stands vertically and put that as close to the op amp as possible, like the two holes in the breadboard as close like start using those PCB techniques and breadboards. And your breadboard circuits will work really well if you do that. And I always stick by the old rule of like, if you can make something work well on a breadboard, you can make it work really well on a PCB. So I will spend the extra 30 minutes or an hour making a really nice circuit on a breadboard. So all that said, most of the time my resistors are are chopped and cut up by the time they reach my breadboard. So I I've gotten to the point now where it's like okay, it's time to restock.
So totally makes sense. The one I get is the little wires that you're using as jumpers. Yeah, it's I caught those all the time. Yeah, I actually need to get new pack of those.
You know, okay, that's another good one, the those resistor, jumper kits or whatnot, those are actually really nice, because everything's pre bent to hold pin space size. But the thing is, I usually only use two of those colors in there. And so I run out of those really fast. And then I have a ton of these things that are like eight inches long. And I don't need anything. Come on, just give me like a bazillion of the short ones. Because I mean, I'm trying to make my breadboard circuits compact. But I guess most people don't do it that way. So I understand why they would sell it in a bunch of different lengths and stuff. But yeah, there's in the kits i have there's short green ones, and short, yellow ones. And those are the perfect distance to go from your power rails down to whatever icy circuits you have. And so I use those all over the place. And I run out of them very quickly. Yeah,
they need to sell kits. That's just those.
Yeah, that would be great. I mean, yeah, you can always make them out of the bigger ones. But I would rather just have someone else do it. Yeah, just a slap on your board. So yeah, we'll put that up there. If anyone cares about resistor kits, like I do. Yep. So
cute, cute Queen brand. You know that
on Amazon, the people who sell stuff like the the names of people. The sellers are like it's all over the place, especially when it comes to electronics,
or any of these like, Variety Pack kind of things. Yeah, because I buy a lot for automotive like terminal kits, stuff like that. They have weird brand name, quote brand names like this.
Yeah. Sometimes you even see that stuff creep up at like Fry's Electronics and stuff. If you go to their electronics department, you'll see things where it's like that sort of strange name for a company.
If fries still exists. Yeah, or Microcenter. Sounds like.
So something else I've been working on. I've been talking about this last couple of weeks is that my, you know, diving into LT SPICE simulation stuff. And I've been having fun with that. And I decided to change it up a little bit. This week, I actually created a simulation, and I've put it up on my GitHub, and we'll provide a link to it. So if anyone wants to actually check it out, they can go and download it and see some of the simulation stuff that I've been playing with. And as I go further in this, I think I'm going to continue to provide little circuits here and there that that show off some capabilities of some stuff, but With a circuit that was actually breadboarding, the other day was a op amp full wave rectifier, which can be really useful in analog circuits, and there's some nuances to it if you want it to work properly. So I actually threw together some simulation stuff. And instead of doing just one, I actually put three rectifiers kind of in parallel that are all fed by the same signal, the signal I'm feeding these rectifiers as a 10 volt peak to peak triangle wave. And then I'm just trying to rectify it. And I chose 20 kilohertz as the input to it because one of the downfalls of using an op amp and full as a rectifier is that they're getting it to work at moderate speeds is actually a little bit difficult. And in this, in this simulation, I have three different rectifiers one using an LM 741, which is kind of like the beginner's op amp. I remember using that in college as the first circuits we did with op amps. The second one is a tl 072 op amp, which is a jelly bean J fet input op amp that is used all over the place. And then the last one is an Opa 1678. So the main differences between these op amps is that they have different gain, what gain bandwidth product, and they have different slew rates. So the slew rate is basically how fast the output of an op amp can change. And it's measured in volts per microsecond. And then the gain bandwidth product is a measure of what is the maximum frequency that a unity gain will exit the op amp effectively. And so like an LM 741, has a gain bandwidth product of I think it's 250 kilohertz it is really, really slow. And they the OPA 1678 has a gain bandwidth product of 16 megahertz. So it is significantly faster than the LM 741. And then you the 741 also has a slew rate of like, point two volts per microsecond, which in the op amp world is really slow also, in the OPA has, I think it's 10 volts per microsecond. And the whole the whole thing about this this simulation is if you if you look or if you plot the three outputs of each one of these rectifiers, you can see the op amps turning on and off. And the speeds at which the the diodes that are inside the circuits have to recover from things. So if you're talking about rectifying something that's one hurt or 10 hertz or something, then, you know, a handful of nanoseconds or even microseconds is a very small portion of your wave. But if even at 20 kilohertz, a few microseconds starts to be a significant portion of your wav. So you want that op amp to be very fast, and you want it to be able to switch through the rectifiers really quickly. And it's cool because with the simulation, you can see the speeds of those things. And in the OPA 1678 I even swapped out the diodes from one and four on four eighths to some Schottky diodes. So it doesn't even the op amp doesn't have to travel as far it even has like 50% less travel and you can see the speed on it. It's funny because at 20 kilohertz, the LM 741 just doesn't work. Like straight up, like it's not like it's dead, it's completely dead. And then the oh seven, two and 16, seven, eight are actually working pretty well. So yeah, it's it's kind of neat. And with LT spice, it's it's fairly easy to swap in different gain bandwidth products and slew rates to see how it's gonna affect things. And like I said, I actually breadboard this up and confirmed these, the things that I was seeing, I was actually working with a TLO seven, two, and these exact kind of reverse recoveries from the diodes, I'm getting the same thing in my simulations. So it's always nice to get validation like that,
just like the simulations.
So if you want to check it out, we'll put a link up to the GitHub where you can download the simulations and you can check it out. And maybe you know, it'd be fine if somebody wants to try to simulate it and make it better than what I have in here.
If you send that to me, I'll try actually breadboarding it and we'll see if we can do it in real life. So because like the one of the tricks that I've been doing with this is if you take a triangle wave and you put it through a perfect precision rectifier, you get a another triangle wave out of it. But it's half the amplitude, double the frequency. So If you take that through another op amp of two times gain and you offset it, you can produce an octave, you can take a triangle, just through two op amps and get twice the frequency. And you can do that effectively indefinitely, you can, you can keep doubling your frequency in the analog domain. And so, but there's, there's a lot of limitations. And it's a lot of it's based on what rectifiers you use and what op amps you use in that circuit. So it's a, it's fun to be able to simulate it before even doing it because you can't just look at the circuit and be like, oh, man, 741, I'll just throw one of those in there like, Nope, it ain't gonna work. And so kind of jumping off of that I've been, I've actually been working a bit with comparators recently. And I kind of love the, in the analog world, when it comes down to these kinds of ICs, like comparators and op amps. It's not as simple as just like picking one that has the right price and is in the package that you want. Like, there's so many characteristics under the hood that you you can play with to get more to get better performance of what you're looking for. So like with a proficient precision rectifier, you want it to be fast, and you want it to have a high slew rate such that it can bounce back from going into saturation, and not because that's effectively what the rectifiers or the the op amp in the rectifier circuits doing for half of the wave is it's going into saturation. And you want it to be able to snap back very quickly such that it can catch the wave that it's rectifying. But with things like comparators, that you want a completely different characteristics behind them. And comparators come in both analog and, and logics type. But I'm talking more about analog here. With with comparators. If you're looking for precision, you care a little bit more about your input offset and your bias currents on that because if you want it to compare at a very specific voltage, you want to make sure that your input offset is very low and your bias currents are very low. And whatever impedance is driving it is, you know, properly set up such that it doesn't introduce any extra errors on that. On top of that with your comparators. Something I was actually dealing with earlier today, be really mindful about the propagation delay
on those aux through your comparator or through your op amp through the
comparator. So a lot of comparators are just different versions of op amps, like under the hood, they are just an op amp, that's fine to figure it out. Yeah. And so yeah, the thing about it is, if you don't pay attention to it comparators can actually be kind of slow. I was looking at some on mouse earlier today where the propagation delay was in the matter of a few microseconds. And if you're if you're trying to do comparators, with other analog circuits that also deal with logic, a lot of times the logic is a few nanoseconds. And if you're dealing with a with a an analog comparator, that's a few microseconds that's ages longer for the your circuit. So yeah, be really careful about that. One, uh, yeah, one of the, I actually have an analog comparator that interfaces with a digital and, and the the and circuit, or the and chip that I have has a propagation delay of somewhere in the order of, I think it's five nanoseconds, and the comparator is 200 microseconds, or not sorry, not 200 microseconds is a lot faster than that. It's 12 microseconds. And so like, you gotta be mindful of like when things are gonna happen. So yeah, the all of those, all of those weird symbols and stuff on those data sheets actually matter sometimes. One though, that a little bit annoying is overdrive when it comes to comparators. So overdrive is like, if you're comparing signals, it's like how much how much above your compare your signal that you're comparing to it is your input wave. And what sucks is with with comparators, they're not they're not binary, they're, even though their output is the output changes depending on what the differential of your input is. So a lot of these characteristics like the propagation delay gets faster if you drive it harder. So you have to be mindful of those kinds of things. It's not always the same. So I understand really well now why there's logic comparators because they're just like, it always does this. And the only time it doesn't do that is if it's hot or if it's cold
when it's over 100 See or below 40. See, right? Yeah, yeah,
no, but I actually I didn't I'd actually never
thought about an analog comparator. Depending on how you drive it your drive strength?
Yeah, yeah, it's kind of crazy with that I will. And it's, it's not like a current drive, it's a differential and voltage causes the inside to, I guess, speed up and work a little bit faster. So if you're going to design around that, make sure you're designing around the slowest aspect of it. And then if you overdrive it, you're gonna get a little bit better. Because when you have to do that
with MOSFETs, sorry, when your gate drive for MOSFETs, you have to pay attention with how powerful you are driving them. Oh, for sure. So because that how how much you your drive strength on your MOSFET gate, really dictates how fast it actually opens and closes. Right? And, like, if you're a PWM units, how much that MOSFETs actually going to heat up? Like how much does it stay in the non saturated state?
Uh, yeah. How much is it in between, off and on? That's the hot hot state, the analog state. You know, and here's, here's a pitfall to watch out for, if you if you go and look up a comparator datasheet. And, you know, the very front page is going to show you all the magic numbers that the sales guy wants you to hear about, right? Yes, all of these really great numbers. And most of the time those numbers, if you dig deeper down, none of them are accurate. None of them like are its actual operating condition. And if they say like, oh, this is, you know, the input offset is XYZ, you have to look deeper down, because it's not that overtemperature, of course, but it might only be that at a particular overdrive level, you can and if you under drive it then it won't be that it'll be slower, or it'll be worse or whatever. So yeah, keep in mind that that number, specifically for comparators. There's usually strings attached.
Yeah, when we were doing when I was up in Stevens land for July last year. The we were doing calculations with MOSFETs. Yep. On drive strength, making sure hey, if we are using these drivers strength, which is what the what was the it was the shift registers, were driving the MOSFET gates. And we were trying to figure out, okay, we can supply we actually did through a resistor, so we knew what our drive strength would be. And like, okay, are these MOSFETs going to blow up?
We, we were bandwidth limiting them by putting the resistors on there, using that using gate capacitance, and and like basically, what is the maximum drive current that can be supplied through it?
Yep. Yeah. Well, because we didn't want to, it's, it's like you either going to slow down the MOSFET, right, bandwidth limited. Or you're going to thrash the gate on the shift register.
Oh, right. Right. Yeah. No, the output the output pin is just going to puke. It's good. Yeah. Cuz
like, it's like, those are supposed to be limited, like 20 milliamps. So it's like, Hey, you have to make sure to stay under that. So when that that output flips the to output on, right. It's like, okay, that MOSFET gate is going to want to gobble everything as fast as it can.
Yeah, it's an open bucket. That yeah, you're just Yeah, it'll be it'll ask for everything as fast as it can get it?
Yes. Yeah. So it's design considerations like that, that a beginner designers don't really think about? Because they don't really teach that stuff in school.
No, they don't, not at all. And being able to read an op amp datasheet or comparator, datasheet. They don't teach you any of that crap. Like at at college, you learn an inverting configuration. And they're like, good luck. Here you go. Actually, I was talking to my buddy, who was he was really, really big into analog circuits back in college. And, like super good designer. He, he used to actually go to Mouser and purchase his own parts before labs, because he knew what parts came in the kits. And they were to be frank, they were shitty parts. And labs were more difficult because they gave you garbage op amps. So he would buy op amps that were better suited for the circuits that we were trying to do. So he would get into lab and be done in 30 minutes. Because no, because like a three hour lab two and a half hours was debugging why your 741 wouldn't run at 20 kilohertz, even though like all your calculations say that it should
yeah, no No, we've told those stairs before is like if you have electronics lab, buy your own breadboard. Yep. Because it was always wear out and buy own wires.
If you can buy all your own stuff, just do that. Yeah, yeah. Especially, especially the resistance. Hey, buy that resistor kit? I bet you I bet you if you bought that resistor kit, it would you know, before you went to college, you'd still have it at the end. You know?
Oh yeah. Get that resource kit, get a capacitor kit. And then get some jumper wires it gets get a breadboard kit. I bet you have someone on Amazon. Some some elegoo or C? or E boots.
Are you actually reading them right now? Or are you coming up with those? Because those are all really good Amazon electronic?
Those actual real ones? Those are
OSEP Bojack Bucha?
RX Qualis. I trust that guy or gal,
honestly, yeah, that would if I could have done that back in college, that would have helped me out a lot. There's there's back then there were crap. Like we say
back then it's like, that was a decade we still? You know, like 2010. Still, it's like only 10 years ago. Yeah. So it's not like the 60s or so. Yeah, but you had way harder than way harder. But back back when we were in school. Really the only way to get the stuff was maybe eBay. Maybe, or RadioShack. wherever you happen to have a local electronics store in your town.
I guarantee you these resistors that are in my bins right now. Are still RadioShack resistors from a decade ago, or longer.
Oh, Joe knows brand. Joe knows. Joe knows. Joe knows what. Resistors apparently.
Oh, that's great. How about we go on to the RFO. It's going RFO. Yeah, that sounds good. You want to start this first one off?
Yeah. So this is a interesting concepts and piece of software got the try yet because it's in beta. But it's called all spice. And is not for cooking. It is a hardware development ecosystem is how it's marketed as
so we've we've talked about this a bunch on the on the podcast. So someone's actually kind of doing it now.
Yeah, so basically, it's like a word get GitHub style workflow for hardware, that also brings in simulation, and design review into that process, which is kind of interesting.
The design review is is really the big thing. If he asked me, I mean, it'll it'll, it'll show like, you can look at two different revisions. And it'll say, hey, are 10 change from this to that value? But you can also look at two different revisions. And it'll show you know, it'll highlight this has been deleted from that revision, or this has been added, which is super awesome. Parker and I were discussing that a long time ago. Like, there's, it's difficult to do that, like, how do you actually pull that off. And it looks like all splice.io has become compatible with Altium Designer, such that it can actually talk Altium language and get that kind of information.
So if I was running Altium, I would totally be jumping all over this. Oh, my God. Yeah. Mainly just because I like I right now I use eagle and then I use GitHub as my version control. And having a way to easily see this design review stuff would be really nice. Because that's the thing is like, someone will hand me like, this is the worst things, people will hand me a schematic and be like your design review. Um, like, compared to what? Yeah, am I supposed to know how this circuit works? By just looking at it? Maybe, I guess,
I mean, that's the point of a schematic. But but nobody, not, not entirely. There's a lot more to it
than that, which is a lot more to it. Yeah.
Yeah, I would love to get these guys on the podcast to talk about like, what are the challenges they are going through with having to actually do this? And like, are they going to bring the eagle into this ecosystem? And I would assume that if they're, if they're building this whole ecosystem, they've thought about doing a lot of different EDA tools. And it makes sense to do Altium first for a lot of obvious reasons.
Oh, yeah. It's, it's, you know, it's part of the large Just yeah. prosumer it's professional level two.
So does this also handle PCB?
I don't know, I'm seeing
all this stuff looks like it's schematic level.
Yeah. Because it would be cool. If it did PCB, that'd be really awesome. Yeah, this is, this is great. I mean, I even I would use this as just a single user myself just for my own protection, you know, this would be really, really nice, but I could see this working well with teams. And they kind of really focus on design review as a big part of this, where it's like, you commit a new schematic, and then you can like pull people together and say, like, do a do a design review of this? Yeah, so that's super cool. All right. Yeah, I think what we're gonna try to snag those guys and talk to him if possible.
I'm looking forward to it.
So the next RFO is actually a guy I met few months ago at at a convention I went out to, he runs a company called second sound, which he has a patent on a new technology in a chip he creates that's called the AC Oh, 160. So check out Second sounds.com to look at this over that he's created a and I see that does frequency to voltage conversion. He calls it pitch to CV because that's like industry kind of terms and musician terms. But it but in all reality has doesn't have applications that only span audio stuff. It's all over the place. And his his product is absolutely fantastic. So I actually got to play it when I was at nob gone back in August, where the you can actually take the take, like a bass guitar, plug it into this thing and have it control a synthesizer. So you would play a note, it would take that note, take the pitch, make it into a correct voltage and then take that voltage and make it into a correct pitch on a different device. Yeah, so using as a control voltage. So the thing about it is, if you've ever tried to do that, it's incredibly hard to do frequency to voltage. But this guy's got some kind of custom technology going on in under the hood. And it's really, really cool. And the biggest thing is, he solved two really huge issues that exist in it. So the first one is how fast it latches on to the fundamental, which that's, that's always been a problem. Like, it's not particularly difficult to take a fast moving signal and read its frequency because you have a bit more information about the fundamental. But what if you're talking about something that's moving a lot slower, like 10 hertz or one hertz or even slower than that, like you don't, it'll take longer to latch on. Right? It takes longer to latch on and you don't want to wait off. Like, you don't want to wait a full period on a one second signal to be able to figure out that it's one, you know, yes. So this guy's got some some patented technology that actually figures that out. And one of the things he also solved is as for the for the music world, as your note decays, his envelope, like hangs on to it. So a lot of issue with these frequency to voltage converters is like a nice strong signal will latch and you get that but as it decays the pitch start to go a little a little a little a little like all over the place as it's like trying to figure out smaller signals. But his like, hold on until effectively just dies away to nothing. So I'd kind of like to get this guy on eventually to to talk about his the actual technology under the hood. And I think that'd be really fun.
And designing chips and stuff.
Yeah, that's that's another big thing. Because really, gosh, who have we talked about about? I mean, we can chip Gracie from parallax. But that's about it. That's about it. So yeah, it would be really great to talk more about the actual like, what do you have to go through to get chips? So I found the PDF of that chip? Yeah, the ACO 160
Yeah. And it's got to address a Houston Texas address. Really? And that address is seriously like two miles from my house. No lie. That's not the same address that's on the website.
Oh, okay. I mean, you that might literally just be the dude tome. I apologize. I don't remember his name at the moment.
You stalking him.
Yeah, I'm on. I'm on Google Maps, Google Maps. I'm looking at the,
hey, you should just business park, go walk over there and knock on his door. Like you wouldn't be a guest. I didn't know he was from Houston. That's cool. Or
well, maybe he is. I think that might be an old address and he moved to Florida. Okay, he's Florida IC chip man now. Because I'm looking at the Street View. And that whole business park looks empty. Oh, well. Interesting.
Yeah. Well, no, it's cool stuff. So
go check out the website and check out his technology. Now. Great. You have you have anything you'd like to close out with?
I think I think we're done. Cool. Okay.
Well, that was the Maghreb engineering podcast. We were your host, Stephen Craig and Parker Dolman. Thanks a lot. Take it easy later everyone.
Thank you. Yes, you are a listener for downloading our show. If you have a cool idea, project or topic or configuration for the brewery Parker needs to build. That's me. Tweet us at Mac fab at Longhorn engineer or at analog EMG or emails at podcast at macro app.com. Also, check out our Slack channel. If you're not subscribed to the podcast yet, click that subscribe button in your podcast app. That way you get the latest episode right when it releases and please review us wherever you listen. As it helps us show stay visible and helps new listeners find us
A decade after graduating college, Stephen finally did a differential equation for his job! That is some real engineering I tell you what.
Right to Repair is going global and Stephen might have solved his injection molded component's void by tweaking the mold design.
The PinoTaur has reached production status but not without supply chain issues..OF COURSE! Bonus discussion about thermal management for PCBA.