The quest for the right connector for a project! The right of passage for any hardware electrical engineer starts with a connector catalog.
This is the last installment of Stephen's 'Adventures in Injection Molding'. We are going to recap the entire two year sage and close the book on it.
The Jeep Prop Fan project rides again! Well some iteration of it at least. Lets design an open source PCM (Power Control Module) for automotive apps!
Visit our Slack Channel and join the conversation in between episodes and please review us, wherever you listen (PodcastAddict, iTunes). It helps this show stay visible and helps new listeners find us.
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!
Welcome to the macro fab engineering podcast. We are your host, Stephen Craig and Parker, Dolman. And this is episode 126. What's up? Alright, so two weeks ago, I was talking about the Mac 6682, which is that thermistor temperature sensor chip, the weird thing that you didn't know the resistance or whatnot? Yeah. So I finished the layouts, and ordered the boards. So that should be in like a week and a half now, or a week. So that'd be pretty cool. Hopefully next week, I have them. But I'm going to bet you in two weeks, I'll have something more to share about that. Yeah.
So those Yeah, these are for those weird thermistors that I found. And I found a chart for the resistance. Now, I don't know if I mentioned in the podcast, but yeah, basically, when the thermistor showed up, they actually had a part number on the bag. And so I was able to Google that and find a chart. And so I was able to calculate the right resistor to use for the the voltage sensing on that on that Max 6682 chip. So I'll put a link in the podcast description where you can go check out the layout, and it's actually really cool. I did it all on one side. So it's, you know, my favorites. plunged the plane. Yeah. Out style.
Yeah. Uninterrupted ground plane. Yes. The only thing that can be in the ground plane or vias? Yes. Yeah, that's fun. Should be pretty good. Low Noise circuit. I kind of made it so that like, when I'm ready to implement this into the Jeep, I can just like copy the layout directly. So that should be nice. So yeah, there's that and then I got a Jeep plus one this past weekend. Oh, no. Yeah. So every Jeep project times to now? Exactly. I picked up a 9090 grand wagoneer. And so we're gonna call it so there's a distinction. Now, while I'm talking about the Jeep is my red Jeep because it's a Wrangler. It's Jeep classic, Jeep. Jeep classic. Exactly. The
thing is, it's newer than the wagon year, but the wagoneer is going to call the wagon.
Oh, okay. Okay. Yeah, so if there's a Jeep project, we know it's Jeep classic, and then wagon is new. Yeah. Oh, wagon is new. And I'm thinking about getting because I can get like custom emblems made for like the side. Yeah, I don't think I'm gonna make it get the same font cuz it's like cursive font, but make it grande raggin here? Because why not like Dan? Yeah. Because yes, because again, yeah. So the yes, there's a 9090. So it's what almost 30 years old now. Yeah. And so it actually is in pretty good shape for its age. It's been like in a garage for like the past 10 years. And so and then and then you picked it up and drove 400 Miles 300 Miles Yeah, get up and go from Dallas to Houston. And like, one shot I just stopped halfway for gas. And everything works on like the electric windows works electric doors work, the AC kind of functions. Which is actually the first thing to fix because I we live in Houston, and it was 102 degrees on i 10. Today. Yeah, you don't you don't even drive and if that doesn't work. Exactly. Yeah. So call in sick they would understand Yeah, they would. Yeah, absolutely. In fact, we're not even going to duck PTO we understand.
The so the AC is the first thing to fix. And the thing about the AC is that all works mostly, so it doesn't blow cold air that well. So that's the first thing to fix. And I think that's just it just needs I put my pressure gauges on it and it just read low so I'm like okay, just needs gas because the compressor works the vents work all that stuff works. But the previous owner Bubba the hell as a compressor turn on switch, because it sorts be controlled by the the climate control module, if you want to call that it's not really it's like a couple relays and some switches.
I hang on, I think I think for those who don't live in the south, I think you should you should explain what Baba ng means. Um, it's like, the northern version would be like farmer good. Yeah, like it's Like, it's like fixing something to make it work without realizing the consequences of your actions. Yeah, it's sort of like one step above using duct tape and staples. Like you actually did. You did somewhere on this thing. Oh, duct tape. Not even electrical tape. No. Okay. Okay. I've given them way too much credit then. I think another term would be called like redneck EAN it possibly. But when usually when I use that it's kind of like, it's actually been put together. Well, it's just it's it's really hard to explain. It's like putting something together really well, but there's no engineering behind it. That's like rednecky Yeah, redneck engineering. Yeah, sure. Yeah. Yeah. It's usually it's not gonna fall apart. It's not gonna catch on fire. It's just like, oh, yeah, it's just not pretty or whatever. You know, how you want to describe it, go to Urban Dictionary and start looking at these terms, people? Well, I mean, yeah, and a lot of stuff that we do in professional engineering is just redneck engineering. But there's a nice drawing of it or something like that. You know, we wrote numbers down. Yeah, yeah, we have we have records. So yeah, the wiring is pretty bad. Basically, you turn on the AC switch. And then there's a button on the dash that you press that is hard wired to the compressor relay. So it's just hammers it on. Yeah, hammers it on with no consequences at all. Nice. So the first thing to do is going to be putting more gas into the system and then making sure it blows cold air and when that's working, is basically revert the electronics back to normal. Just on Baba it, yeah, on Baba. And so what to do that I found the factory service manual for the for the wagoneer. And then I found and that FSM I found the schematic. So I post screenshots of the schematic, but basically there's a couple things that need to happen for the car. This is before I even start tearing apart the vehicle like I'm like looking at schematic but but but the automotive schematic not like the electrical schematic it is electron what is the automotive electrical schematic?
Yeah. So there's a couple things that needed to like work correctly. For the compressor turn on first, the AC control module has to be working.
I'm assuming that's working because like if you switch between, like defrost and cold and hot and stuff, like the vents move and stuff, the fan changes speeds, it does what you expect it to do. Yeah, it's doing what is expected to so that's probably working correctly. The other thing is for the compressor turn on is the AC temperature sensor needs to be functioning, which is a basically it's in the vents, and it says how cold or how hot the air is coming out of it. Okay, like coming out of the vents. So that needs to be functioning. So that could be not working. And the other part is the thermistor. And the thermistor is in the evaporator coil. And so that's making sure that the evaporator coil doesn't freeze up. So if it's freezes up, it turns off the compressor and lets it you know, thaw out. And then the last part that needs to be working is the compressor, low pressure switch, and that's on the low side of the compressor. And it makes sure that there's enough gas for the compressor, not the ruin itself turns on. That part I know for sure is bypassed. Hard bypass, it's a hard bar, it's connected, it basically went past the bypass and put that switch in. So I think, well, I'm looking at what the person did. I think it's just the compressor, low bypass switch, okay, that that pressure switch is just bad. And for some reason, instead of paying $8 for that part. He put in like a $10 switch and mess up the wiring forever. Well, you never know, maybe what he was doing was just like, jumping, shorting switches and things like that. And he found that if you shorted that one, it just worked. So yeah, might have just run with that. You never know, maybe. But I'm like, Okay, what if it's not that? So how do I test these other things? And because that the pressure switch, you can just buy it? It's like it was it was used on like, bazillions of vehicles in like the 80s and 90s. So it's like, I can get that part. But the thermistor you can't buy anymore, and the AC temperature sensor you can't buy anymore. So I'm like okay, what what is it? What's thermistor? Is it right? Let's say if mine's broken, how do I figure out what to replace it with? That's good. glean and look at all the all the forums for these things. And no one knows what this thing is everyone, everyone basically says if yours is broken, find another one and rip it out of the junkyard. That's everyone's solution. Really? Yeah. And so I'm like, okay, that can't there has to be a way to test it. Yeah, just characterize it, right. Yeah. So so there has to be weight testing. So I open up the F, the factory service manual and flip to the air conditioning for the SJ, which is what this chassis model is. And they have a procedure to test it, and a temperature profile for it. Wow, they basically copied and pasted the temperature profile from the datasheet datasheet for the thermistor and put it in there. And guess what, at 25 Celsius, it's 5000. ohms. So it's a 500k NTC. bone stock, but you mean a 5k? Right. 5k? Yeah, yeah. 500k? Yeah, yeah. Five, five, okay. Yeah, yeah, yeah, 5k, NTC, thermistor. And that's just something you can give, you know, off the shelf, I basically pulled an Omega part. And I'm like, the Lincoln, this is a really good Omega datasheet that has, like, the standard and TC values for like, like six or eight of the industry standard ones. And so I have that, like, when I come across a thermistor. I will measure it and see which one it is. Yeah, for replacement. So yeah, it's a it's a 5k. So I'm like, okay, that part solved. The only other part is the AC temperature sensor. And there's a way to test it. So I know how to test it. But it looks like it's just a potentiometer that you like, go back and forth. And so I just have to find basically a big column, AC compressor, turn off switches or something like that. I can't remember the exact name. And but no one sells one that fits this one. But I can find one of those that has basically the same characteristics. It's like zero to 100k. When it's like Max cold, it's some it's like 2k or 3k. If it's on like, medium, and then it's infinite when it's heated all the way up.
Okay. Which could be I just like, shorted out when it's when it's when the I want AC, so we have to figure out that part's working or not. I
mean, you can bump it with a switch. A smart switch, I quit smarts in it. Okay, the worst case scenario is I put a microcontroller with a board mounted sensor, and it just feeds the right voltage to the AC control module. Yeah, yeah. So that way, it's smart. It's a smart Baba cool, it sounds like it sounds like you have you've got plenty to work on with the the new wagoneer Yeah, the Grande wagon. That's awesome. So yeah, the first goal is to get the AC working there's a lot of other little tiny things I want to get working before I actually start like like well I want to do is get it in a really good state where like it's not falling apart anymore. And you can daily drive it without it like exploding or without worrying about it. Yeah, worrying about it and not melting in the driver's seat is important. And once that's good, I'm gonna park drive it for a couple months on like, you know, either ultimate days or on the on Fridays just depends based on well probably days it's not raining yet and it's a good one Yeah, seals are kind of worn out and I don't want it to rust anymore. I kind of want to dry it for a couple couple months and then figure out what exactly I want to do with it. I don't want to do a full on like restoration because one cost too much money and to the moment you finished restoration. You don't want to do anything with it. Because it just sits in your garage. Yeah, perfect. And so I'm like okay, I want to you know, I want new paint but I don't it doesn't need to be perfect. You know and I don't want to be exactly how it came off the factory floor or I don't care about that at all. I just wanted to be a really good daily driver and reliable and stuff like that so sure. Well and and on the way from Dallas to Houston you had kind of a mishap with the radiator right?
this wasn't on our show notes on surprising Parker with this one. The the, so we well actually let's let's start from the beginning.
Oh, three things. Okay. Three things. I think I only told you about one of them. You told me. Yeah, that one for sure. So I signed the paperwork at the dealer. And it's as is No warranty, no, nothing like that, right? Yeah. I back it out of the parking space. Go around the corner, and there's a speed bump in the parking lot. Go the speed bump, the speed bump engine dies.
Seriously driving it after the test drive. Seriously driving for 30 minutes, 30 seconds since I've owned it dies and the owner comes out and he's like, Excuse me, sir, you have to get your vehicle off the premises. Sit there, and it's cranking, cranking, cranking, cranking and then finally fires up. Yeah, I like. Okay. So some some I'm like, something's loose under the hood. Probably logical. And I'm like, Yeah, whatever we'll worry about later.
We're driving out Dallas, because it's in Northwest Dallas. So we got to go run the loop. I can't remember what they call it up there.
And then get on 45. And we're going on the changer from like, 20 to 45. I think sweats called. And the engine starts chugging hard, like, bam, bam, bam, bam, like that. And then I get in, it gets over the crest. And then it starts running fine again, and then go up the next hill, bam, bam, bam, bam, coasting. It's like okay, get over, I pull into the gas station, stop pulling the gas station. And I'm like, that's weird. It really felt like it was running out of gas. Kind of. Okay, but I've never, I've never driven a carbureted vehicle that was running out of gas. Fuel Injection feels a lot different when it runs out of gas. But it felt like that. So I'm like, Okay, I'm gonna put gas in this thing. put gas in it. And that was the problem. Basically, the gas tank when the gas runs all the way to the back of the tank it It can't pick up anymore, right? It's just breathing is just sucking air sucking air. Yeah, so filling up the gas tank. fix that problem. So I started driving that back, going back down and then we got about halfway.
Actually, no, not halfway. It was the first water burger out of Dallas.
That's how we measure distance in Texas. The distance between water burgers are down the road. So I pull over the water burger, get a burger. And you know, I haven't eaten since eight o'clock. And it's like, you know, three o'clock in the afternoon now. So I'm like scarfing that thing down. And this is the thing it doesn't have cupholders so I had to like I bought the basin Extra Large iced tea and just downed it. Somebody I need the hydration condition is not working. So I had the windows down. Yeah, yeah, yeah. And I come outside and the radiator had puked its guts out of the parking lot like Ford. It wasn't like down it was Ford over the parking lot.
Yeah. And open up the hood. And it has bubbles around the filler neck
and like ah like ending right there. Yeah, yeah, sure. Am I okay, I wonder if there's any pressure in it. So I like I take a like a rag and like wiggle it just a little bit and goes all over the place. I scraped back tight and I'm like okay, it's got pressure. It just didn't like the extra pressure of it just heat soaking as long as it's moving it should be fine. And yeah made it all when he was in stop go traffic on like beltway eight. Yeah, home and, and it made it all the way. Okay. All the way. That was that radiator fluids nasty. Well, but you've already flushed it. Okay, that was that was sort of a part of your weekend project. Yeah, I've watched the bases a lot of the fluids over the weekend. But on that radiator, I'm going to actually try braising slash soldering. It's Yeah, cuz it's, it's all copper. So it's like it should work. I'm actually never, I've sweated pipes before. So I have all the guts to do that. So I'm gonna try that same tactic with the filler neck and it should be clean it really good. Put acid flux on it. He ended up with a propane torch and then feed it
the ledcor lead acid core stuff, right. So yeah, and the good thing is that solder that I have is the vintage of the vehicle
to it's from the same year. I think it's older I think that's that's in the 70s
Yeah. That's cool. So yeah, so I've been up to sweat as
weddings, weddings pretty fun and like what you explain there where it's like keep your joint clean, use as flux and use the rest of it. The funny thing is like there's three things there you know, acid core, paste flux and keep your joint clean. If you if you compromise any Any one of those three, that joint is just screwed? Like, yeah, that's one of those processes. That's not like super skilled based it is very much you have to have the right thing. Yeah. And it's, yeah, it has to be super clean. Yeah. And you have to have, it doesn't have to be the right flux. But you have to have an aggressive flux. Yeah, if you try to do it without flux, it's just game over. Oh, yeah, it
won't work at all. Yeah, you need like an aggressive like a rosin core will work. But What's better is the acid core stuff.
And then just lead. Technically, you can do it with silver, and it's stronger, but like, this thing was put together with lead lead solder. So I'm like, I'm just gonna use lead. The silver solder also melted a lower temperature, and it solidifies at a lower temperature. So it can make it a little bit easier. And for the silver solder, if you're if you're bracing for what I know, if you're doing something that's more cosmetic, silver solder actually does better. So you don't discolor the metal as much. So you don't have to buff it as much later on. But if you're just doing copper to copper, who cares? Just use the use the heavy lead stuff.
I'm just gonna spray paint it black afterwards. Yeah, so it doesn't it doesn't matter too much. So cool. That's the thing is on our brewery rigs, we're going to be silver soldering them. So silver yessing with silver solder
silver solder, because it's a little bit more, it's a little stronger, because these joints get continuous stress. They also get a lot of temperature stress, because they're going from room temperature to boiling and back. Yep, like, practically every time but they at the same time. You kind of want your pots to look nice. So the the silver solder doesn't require as much heat. I think it's also because you don't want lead in your pot. That helps too. I think that's like the number one. Although, if you look at a lot of these, hey, Baba rigs that are out there, they're just like copper with like, dripping led, you know, solder all over it. And it's funny because copper in in beer is actually it's actually a nutrient for yeast. And so they actually, it's okay to brew with copper. That's why a lot of like, cooling coils in beer, or people just drop it right in boiling water, because you got a little bit of copper in there. And that works out well. But luckily, boiling water is not not enough to rip lead off of solder. So I'm not going to say it safe, but a lot of people do it.
And lead pipes exists. So yeah, right, right. And people can get lead poisoning from it. So. Right. Cool. Steven, what do you been up to? So I'm gonna buy a jeep?
Um, I don't think that's really ever going to happen. I'm sorry, Parker. Just because I see how much work you have to put it. I ain't gonna touch that. No, my truck has 176,000 miles on it. And and so whenever it dies, I'm just gonna buy the exact same truck. So no Tacoma. That's good choice. Yeah, yeah, can't go wrong with it. So for the past couple of weeks, I had been talking about my micro tracer, the you tracer project that I've kind of been dealing with. And I've been working on mute tracer mutates, I think that's technically the correct one. Because it's good, the Greek letter mew is in front of it. So it was sort of just like something fun to do. And because I was doing it, I decided to talk about on the map. But now that I've gotten a little bit more into it, what I thought would be fun is to actually instead of just talk about it, I'll show you guys my progress. And whenever I have the layout, like fully done, I'll show the whole layout and then whenever I build it, I'll show that kind of thing. So I actually did one of the most difficult things to do this last week, and it has nothing to do really electrically is I finally picked what enclosure I actually want this to be in and and for those out there who have designed you know, anything you know that sometimes the enclosure is the most difficult part because it's just like what do you use and how do you do it? And like yeah, the,
the number one most difficult thing about electrical project is picking an enclosure and number two finding knobs.
Yes, yes, that is 100% true. So I got a little bit I got a little bit wonky on this project. And so this is this is very much a one off thing there's no chance in the future that I will build more than one of these and so because of that like money is not necessarily like an issue. It's not that I'm wanting to spend a bunch of money it's just that's not a critical point. So the cases gold encrusted almost practically gold plated so the case that I went with is it. The port number is 1441 dash one six BK three C WW, which is a Hammond box which if you've ever dealt with, you know projects and Like Hammond is, like, everyone knows Hammond. But if you look that part up it's a black like a steel box. Everyone knows Hammond that's like a sitcom from the 90s. Yeah, but but only for nerdy electrical guys, everyone knows him. So yeah, this is the black steel box, but it has walnut sides, like the wood wall. Because it because it looks kind of cool. And the thing is like, so that's what it does that that macro amp project that I was have been working on for like a year and a half. I also got a Hammond project box that is a walnut on all four sides with a black steel top. So this tube tester will kind of look like the, you know, the little kid of that version. And I think this will look like really snazzy, it'll look kind of like slightly vintage test equipment. Because it's like, who makes like, who makes test equipment with wood ends on it nowadays? Like nobody was cool, but it'd be really cool. Oh, yeah. So I picked this box, and I decided to go with it. For a handful of reasons. The you know, the aesthetics are probably the main reasons, but it is just about like the right size to encompass everything that I want in it. So I have a drawing that I've passed over to Parker, but for anyone who's listening, if you want to check out the drawing, it's, you can go to macro fab.com/podcast, and then navigate to Episode 126. And we'll have a copy of this drawing up there. So you can follow along too, if you want to. But I'll try to explain it. So you don't have to if you don't want to. But basically what I've done and with this kind of drawing, I do this a lot with the projects that I work on where I do like these big, bright, bold colors and like big squares and things to just kind of represent like where things are going to be. And it makes a whole lot sooner. Yeah, go ahead. So I'm looking at this and like you're saying, like, there's a lot of boxes, your encoder drawing is perfect. Yeah. Yeah. You know, we'll go into that in a sec. Okay, so let's, so this box is a is a rectangular box, and it does not have a bottom on it, you have you actually have to buy that bottom as a separate plate. So the enclosure itself is two pieces, yet you Yeah, you know, and it's goofy. Like, why would it not come with the bottom? Why do you have to buy that separately, I don't know, whatever, it's just part of this crap. But regardless, so this box is a is just a rectangular box. But on the bottom side, it has the flanges bent inward. So if you're looking at the box, like the the internal area is a little bit smaller than the the total size of the box, because it has flanges bent in at the edges. So I drew that as this gray kind of square over here. And what I've got is the big blue rectangle represents the board that I'm designing right now. And the green rectangle represents the board that I already have as the tube tester, which I've had for years. So what I'm actually designing so
you're making you're making, I thought you were redesigning the whole thing. No, no, you just you're you're making out on board
I'm making Yeah, basically, I'm actually treating the original board as a daughter board, where I'm going to be controlling all the signals from it. And I'm going to be sending it signals. And it runs on like, you know, it's it's USB and is Rs 232. And I've got like a USB Rs 232 cable and stuff like that, I'm I would rather have that be on board as an FTDI. So I can just plug USB right into my board, and then jumping over. I'm also going to have power conditioning on the board that I'm going at. So basically I'm building a larger board or a board that's bigger than the original tube tester. And the tube tester board that I currently have is going to mount directly to my board. And I'm going to plunge all the signals from that bored down onto mine and send them wherever they need to. So I have like a whole relay matrix that has like 45 relays on it, that are all going to switch and do whatever they need to. And I've got three different tube sockets, I have a nine pin an eight pin and a seven pin tube socket, then I have nine encoders and nine seven segment displays such that I can you know basically you press a button you press one of the displays, sorry the include encoders these are encoders with a switch on it. So you press that encoder and then you rotate that to be you know, I want to send you know pin one I want that to be connected to the anode. So you read the first encoder, you rotate it until it read letter A and then you press it again. And what that will do is it'll rearrange all the relays such that the anode gets sent to whatever pin on the nine eight or seven pin tube suck. This thing is gonna have like $300 of relays in it. I actually I so I did a bit of research on getting the right relays for this that can handle 400 volts, you know And I actually got released that are not significantly expensive. It's probably going to be more like $15 for the release. So really, yeah, it's an issue of that part number eventually, uh, yeah, I can, in fact, well, next week, I hope to have the main board layout done. So I'll share, I'll share the replays when I'm when I'm ready for that. So we'll do that. So just to kind of as an example of like, my mindset, I mean, everyone does this kind of thing differently. Everyone, like does their this is this technically what I'm doing right here with this image? Is? What like system level engineering or industrial design or whatever they call it? Product Design? Yeah, yeah. Yeah. So I'm thinking, I'm thinking a little bit less about like the individual traces on a board. And I'm thinking more about, like, how does everything connect together as a whole, you know, yeah. And so, on the right, I have my underneath or bottom view of the box, where I'm showing, you know, all the PCBs and how they kind of like stack on each other. But on the left, I've actually been I do this, on a lot of the products I design, I do like a, an across section view, where I show the stack up of everything, because I want to see, you know, like I have encoders that stick through the chassis, I have tube sockets that sticks to the chassis, I also have seven segment displays that may or may not stick through the chassis, but I also have the original micro tracer board, that has to be a daughterboard on mine. And all of that combined have to both stick through the chassis, but fit within the confines of how thick the enclosure Yes. So I've on the left, I sort of drew that out. And this is where Parker was remarking that the the encoder is like this really nicely drawn thing, whereas everything else is just like big rectangular colors, chunks. You know, a trick that I did I started doing a while ago is I just go to the datasheet. I, I load it into whatever program I'm going with, and then I just copy whatever that is, whatever like image I want out of it, and then make sure it's scaled properly. And then I have that I do that all the time with potentiometers, with switches, and with encoders. Because most of the time, they're actually drawn correctly on the datasheet. So if you just extract it into whatever, you know, drawing or drafting program you have, and then scale it properly, it will all show up, right. So I can actually see how far out of the chassis my encoder is going to stick. So I could make sure that it looks kind of nice. So that's what I was doing with this. You know, the big red rectangle represents the micro tracer board plus all the capacitors and all the other stuff that sticks up. Hi,
I think you need to I think you need to build a custom knob for that encoder. Yeah. A brass brass, solid brass.
Oh, like a real nice heavy one. Like, two and a half inches in diameter. Just a monster anggota. Yeah. That'd be great. You know, that would that would, actually. So the enclosure, if you look at it from the top, it's gonna be black. And it has walnut side. So having a golden knob on it will actually look at it cool. And it needs not actually the bigger diameter, the better. Because then you can hold it like, like, Y'all can't see I'm holding looks like a claw hand over the knob. That's how you adjust it. What we'll see. So the thing is what kind of sucks. I wish I could have found better stuff. But I like these encoders a lot. They're their prices, right? They they do exactly what I need. They have like the encoding pulse properly done. But the lowest detent I could purchase from Mouser at least was 12 detents per rotation. So that too bad? No, it's not too bad. But I don't even have 12 options, you know? So oh, the amount of four you can get all around. It's already reset the OG Yeah, it's probably it's almost reset twice. I think I have seven options. So like, that's, that's not as great. I wish I could get something where it had like, four or six, six would be nice. Six would be awesome. 60 dents, but of course I could buy those. But the difference half the time is like three times the price, you know? Yeah. And you can do it in software. But it won't make for a really good user experience. Right? You want you want to connect the detent to undo an item. Yeah. And so it's not the end of the world. I really don't care but it's just one of those things where it's like, Man, I wish all the stars aligned and I got exactly what I wanted. Sometimes you do sometimes you don't with a one off product like this. But let's put it this way. If I if I was designing this to be a product that would sell multiple, I would get an encoder from the manufacturer with the amount of detail that I want. Yep. And you'd probably put the my mute tracer board on You're bored. And yeah. Oh, for sure, yeah, this would be a one board solution. And and so actually something that I've been wrestling with this, this last week with doing this kind of industrial design here was, Do I purchase tube sockets that mount directly to the PCB, or do I purchase tube sockets that mount to the chassis, and then I send little wires off to the PCB. And I actually went with the ladder, I decided to do tube sockets that mount to the chassis. And the reason I did that is because the whole purpose of this device is to put tubes in and pull them out yet like, yeah, it's not a set it and forget it kind of thing, like the whole point is like you're putting them in and out. So that will put a lot of stress on the PCB. So I'd have to have like standoffs and stuff around having some isolation, there will be good, right. And so there's two things that go along with that. First of all, the three different types of tube sockets I have there, don't have the same height. So no matter what if I did them all PCB mount, they'd be three different heights, some would stick out of the chassis, and some would be inside the chassis, I don't like that, aesthetically, it doesn't look good. Here's another thing that's really nice about doing the little flying wire thing, I'm going to put a small ferrite bead core on each wire that goes to each tube socket. And what that what that will do is I'll put, I'll put a little loop of wire around it, and it will make sure that no radio frequency or it ends up being a large impedance to radio frequencies. So so I can give me the walnuts not gonna impede the radio frequency. If anything, the woman amplifies radio frequencies. So so the whole thought of this is, if you're looking at the image here is that each week, I kind of want to show up with a little bit of a show and tell kind of thing. So this week was product design. And the next week is going to be a hopefully a layout of the mainboard. If not a layout, it all have a board with component positions. So Parker is trying to signal me with a Hackaday. Dot, what dotnet or.com project? So you're suggesting making this a Hackaday? Project?
Yeah, make it on hackaday.io project. That way, you can document everything, like what you just did, and just copy it over after each podcast?
Well, I was thinking about, I was thinking about just getting back into my Get Game, and putting this up on GitHub. So actually, let's, let's ask the listeners, would you rather, would you rather, if you were even interested in looking at the crap I make? Would you rather that be on GitHub? Or Hackaday? And whoever whoever answers, you know, in the next week, we'll we'll make a decision on person that way, even if it's one, I'll just do whatever that one person says. So not gonna say something completely different. What No, no. Okay, so it has to be one of those two choices. You have the document via MySpace, but space. Yeah. Only ASCII characters in text. The whole thing? Yeah. Yeah. So yeah, hopefully next week, I'll show up with a PCB layout that you guys can take a look at. And I mean, to be honest, after I get the layout done, then then it's just a matter of building it and writing all the firmware, which I have. I don't want to call it feature creep on the firmware, I want to call it feature enrichment. On that, feature fortification. I like enrichment. It's very portable. Well, it's portable, but it's also like, it's also like sugary cereals. You know, like when when you go and like get like Froot Loops or something like that. It'll say, like, enriched with minerals or something like that, you know, something. So so that's kind of heart healthy. Yeah, that's right. Yeah, the heart healthy yet, and frosted. So, yeah, hit us up, actually, you know. So here's a good, here's a good bit, I'm going to do a little bit of advertisement for us here. We have a Slack channel. And it's actually pretty, it's pretty thriving. Now. There's a lot of people on that. And we have like, 130 people on that thing. And that thing is very lively all day long. And Parker and I are on it all day long. So if you want to talk to us live, or if you want to do things like hey, you know, use GitHub or use Hackaday. Like you could do that right on Slack. I actually I use it a lot for getting ideas for our foes and stuff. In fact, I think one of our flows is actually going to come from the Slack channel today. So what's what's the best? That's a good segue? Yeah, what's excellent, real quick. What's the best way to get on the sighs Mac fab that slack.com Yeah. or go into podcasts description and there's a link that will because you have to get like an invite
for the Slack channel. Ooh, it's elite. Well, that's just how Slack channels work. But there's a public accessible link that you just click and you can just get in. There's no like request access or anything. Sure.
So yeah, cool. Yeah. Join us on Slack and have fun. So speaking of RFO, this one is all yours. Yeah. So I found this one. actually found this one earlier today. And this is a little bit of a two parter. It's called Spider silk microphone. Also Sencha senses slightest waft of air? That's actually hard to say. Yes. So this is a really cool article that I found on electronics weekly.com, that electronics weekly is weird. They have a lot of like advertisements, and then the like, switch and they'll just have like this really cool article. And it's just, I don't know, it feels it feels awkward. Their content. But but some of its really cool. And and I'm working on my favorite quote from this article. Oh, yeah. What's it? Oh, keep going. Keep going. Suspense. Let me explain this real quick, because I got a little bit of a twist on it. So there is, excuse me, I don't remember the guy's name. I apologize. I should have researched it a little bit further. But this gentleman had created a microphone that was intended to be one of the most sensitive microphones. And it's actually Ron miles. There we go. That's his name. So this microphone was actually made. The sensing element was made from a single strand of spider silk. That was gold player aluminum film one to shame. Oh, yeah, it makes a ribbon mic look yet look stupid. But the thing is, so he gold plates this silver, or that? I'm sorry, this gold? Spider silk? Yeah, he's gold plated. I don't know how he did that. Yeah, I know. Seriously, it's like, yeah, look like silk. I don't water it on, or, yeah, you know, I probably not butter because butter is pretty hot. I would think that the I don't know, like this, actually. Okay, so this is gonna segue. But But let's continue on this real quick that. So in order to send something that's small, you actually have to have a pretty hefty field around it. So it only works. or I shouldn't say only works but but the way he designed it, it works in a 400 volt field that he's putting around this spider silk. Well, in 400 volts, you can actually you can induce enough of a force that you're actually counteracting what you're what you're trying to send so that you're trying to send vibration, but you also have this pretty strong EM field that's flowing, but so he gets around it with this like nifty contraption with multiple magnets and blah, blah, blah, does all this stuff and eventually creates this microphone that actually has a sensitivity of half a volt per Pascal, which Pascal is a unit of pressure, pressure and sound can be measured by SPL or sound pressure levels. And half a volt Pascal is pretty damn good. You know, that's something that is able to measure a very low a very low signal. Like I if I remember, right, I was looking at like a Wikipedia page earlier today. It's like a leaf blowing on the ground is like 10 to the negative fifth or six Pascal's which would end up being you know, micro volts, in this case, which, you know, that's small, you'd have to put a ton of gain on that to hear it. But that's still pretty good in comparison to like, the microphone in front of my face is certainly not doing half a vote for Pascal, you know, and putting a bunch of juicy gain on the end of it. So
So So regardless, microphone doesn't do that. I'm sorry. Well, I thought oh, I hope my microphone is not that sensitive.
Yeah, yeah, exactly. I mean, that's, that's the kind of stuff where you can hear someone breathing, you know, when they're like, very lightly breathing. So that's, that's really cool that he makes heavy breathing. Yeah. So check this out. That is the extent to which I know about this. Because this article, basically just mentions everything that I told you, and nothing else. It's like three paragraphs. And then at the end, it's like you can read more about it at in his paper. And if you click on the link to go to his paper, it takes you to one of those like I triple E sites that's like, if you want to read this paper, give us 50 bucks. And I'm like, really? And that's actually kind of the whole point of putting this RFO on there because I was so excited about this and I wanted to read more about it. It ends up just being like this pay to play paywall for an academic paper somewhere. And I'm curious, have you ever run into that before where like, you're looking at this really cool thing and then it's like you have to pay for this? Actually, yeah, I have and this scary thing about this is I don't know how much you know about this this, because you you were asking about, like, you know who pays for it? And stuff like that. And it's like, well, it could be, you know, publicly funded research which you should have access to right. Well, if it's publicly funded, then I funded it. Yeah. Which I don't know how much you know about Aaron Schwartz from back in 2013, which is like, ages, it feels like a lifetime ago that this was happening. No, no, I'm, I probably do know, but I don't know right now. So yeah. And like 2011. Schwartz was, basically he was arrested, because he uploaded a whole bunch of academic documents from MIT, I think, okay, that were all publicly funded. And they were basically
arrested him for like, Computer Fraud and abuses and wire fraud and shit like that. And eventually, right before his big, like, big.
Course, Kate, he actually committed suicide. Oh, geez. Yeah. And yeah, it's, he's like, I'll know it's one of those. Like, when you mentioned that, I'm like, oh, man, that can be a sticky topic. Well, like I brought it up, because like, I've run into this multiple times. Yeah, I have to, and I do agree is like, if it's publicly funded, we should have access to it. And, you know, I think that was one thing that Aaron was a proponent of Sure. Yeah. Well, and you know, what it actually reminds me or what this kind of like, brings to mind a handful of podcasts ago, there was somebody who asked us like, they asked us a question something about like, hey, how do I learn? And one of our, one of our thoughts, or the one of the things we told them was just like, go read everything and go research everything and like, just go down the rabbit hole. And I got this article, and I was like, This is freaking cool. And I started reading it. And then it was like, Ah, you can't go any further unless you give us money. And I was like, ah, that they like, I hate that.
Yeah, it's it's one of those. I'm not you. It's like, knowledge should be free,
but you have to pay for it. I mean, I kind of think I was like, going to college. I suppose it's so like, I guess, people, you know, somebody doesn't take it and immediately make money off of it. Is that what I know? I don't know. It's like, it's because they want to make money off of it. That's solely it. Yeah, it's kind of it's kind of upsetting because I wanted to read more. And then it was just sorry. Yeah. And it's a really cool project. Yeah. And this is the thing is, you know, this is like, the one time we will get political on this podcast is, oh, if you're in the States, call your senators and representatives at this at the federal level and tell them to make publicly funded research papers available to the public. I mean, technically, you paid for it, I guess. Yes, exactly. That's how it works. We paid for it. We shouldn't be able to read it. Yeah. So that was that was my RFO. It was kind of weird. Yeah, that's fine. But But okay, so here's the thing, I'll admit, I'll admit a hefty amount of laziness here. And the reason why is because as soon as I hit that paywall, like my mind was just like, I hate paywalls and and then like, that immediately goes away. So I didn't Google anything else about this project. There could be like a whole nother page where they discussed like a lot more there could even be images about it, but I didn't even go any further because I was kind of upset about the paywall. Oh, I would be too. Yeah, that's really annoying. Yeah. So So because we are a proponent of free information. We're gonna be talking about voltage regulator heat sinks and when they are required, what do they say you attempting a segue, right? Yeah, exactly. Well, well done. Yeah. Okay, so. So basically heat sinks on voltage regulators.
Yeah. When do you need one? I found this on this was on Ask electronics on on Reddit. I actually really liked that subreddit because it gives us really good topics for the RFO. Well, thank you. Spoiler alert, and it's not behind a paywall. Yeah, that's right. So yeah, it's like, when does your regulator need a heatsink?
And it's basically like your maximum power distribution is like, that goes too far. So you have to calculate your maximum power that you're going to basically bleed into heat with your LDL, right? Yep. Yeah. And
so do that. It's like voltage, voltage. In minus voltage out, top times crimes currents will give you how much power you're just wasting. Right and, and actually, so really important for new gamers. That's, that's one thing that a lot of people mess up, its voltage regulators don't, they don't transform one voltage into another voltage, they just burn off all the extra heat. It's not like 12 volts magically become five volts, in the same way that a switcher does. A switcher will actually like transform it, as opposed to burning that heat. So that's, that's important to note, because you're guaranteed to have heat with a regulator. Correct? Yeah. And so once you have that, so you know how much wattage right. And so then you need to look in your datasheet. And you need to find, like the, it's called, like the temperature, oh, there's a temperature to ambient light thermal resistance of your, of your part. And then basically, you can do up post the equation up, it's gonna be really boring if I start listing out what the equations are, but go look at our at the podcast notes. And you basically need to figure out like how much water you're burning and how much your part package can radiate into the environments. And so if your wattage that you need to dissipate is less than how much your package can radiate to the environment, you don't need a heat sink, right? So like, the bigger your package, like a to two to zero is going to how do you print you like you like smiling and like nodding your head? How do you pronounce that? I was actually laughing at the bigger your package thing as opposed to the T? Yeah, no, but I call it a to 220 is what I call it, not a two to zero. Okay, so yeah, so the larger your part, the better it is at dissipating heat. And you can find that in the datasheet. And usually it's, it's called junction, ambient thermal resistance. And it's measured in like Celsius to watts. Right? And that basically, is how much how much temperature increase per watt of dissipation. Yeah, and so like, let's say your part dissipates three watts. And your part has a tendency to watt ratio, which is actually really low, it would be 30. C. And so basically, you go, Okay, from Amiens plus this temperature differential, is that at the max temp that my part can hit handle? Which is usually like 150. C for lto? Yeah, it's usually 150. But but any good design would never let it get close to that. You will. Yeah, cuz every I think the rule of thumb is every 10 C increase half slide for your part. That's, that's absolutely true on electrolytic capacitors. I'm not entirely sure it's I don't know about LBOs. But regardless, yeah, so like, you, you basically calculate k if I'm having three watts, and is that going to exceed my maximum temperature? For my part? That's thing that's an ambient. And so like, Okay, what's the environment this
thing is going to run in, it could be, you know, if it's in a car, it could see 140 Fahrenheit, which I don't remember what that's an SI. But
that plus it's the MOT it needs radiate is above it. And so then you need to put a heatsink on it. I haven't actually SPECT heat sinks a lot. Usually, I just like look at other examples of boards that work.
Yeah. And, and we're like, okay, I need a heat sink about that big. Maybe.
Do you have any experience specking heat sinks? I've yeah, I've certainly done a handful in, in some of the guitar amps that I've done, because I've designed some circuits that with a potential ometer you can either trade the dissipation of the power amp from the you know, whatever silicone device you're using, and as you turn that, that knob, you can you can share, trade that off to something else like like a MOSFET. That would just burn it. In other words, you have the capability to adjust the output power of your amp by just burning excess. And And what's kind of nice about thermal calculations is for electrical engineers, they've sort of set it up in a way that's just simple enough for us to understand where it's like, okay, so here's your junction, the, the amount of thermal dissipation, effectively you have or the thermal resistance, in reality, you usually have a value from the junction to ambient. Sometimes you have multiple values, you'll have like, junction to case or, you know, case to blah, blah, blah, you'll have a handful of others. But what it really is adds up to in a lot of ways, is, it's like a it's like a circuit. That's a bunch of series resistances, we just add them up. And the thing about thermal resistance is it is practically always against you. So, you know, you don't want high values. Yeah, I mean, unless you're trying to heat something up. And, I mean, sometimes that's the case, but But you know, I think it's always practically you're right, it's practically always against you. So the thing is, low values are good, and high values are bad, basically, and, and what lower high is kind of relative to whatever project you're working on. But what you what's cool about this kind of thing, this kind of calculation, is you start at the junction of whatever chip that you want, and you work all the way out to your case, and then you find out, am I good? Or am I not at my maximum dissipation, if I'm not, then you can add a heatsink. That gets you down to a safe level. And if you can't find a heatsink that does that, then you can do a heat sink with forced air cooling like a fan. And usually heat sinks will have values for what this fan would be like with however, you know, cubic feet per minute of air crossed it, they'll get values for that. So what's cool about these these equations is there's they're mostly just like additions and multiplications. There's not a lot of like exponentials or logarithms or like these goofiness in there, you just kind of like add all the values up. Is it good? No. Okay, well throw something in there that cools it down is it's good. Yes. And then I'm done. And I And that's grossly simplifying it. Of course, it's not always that way. And you have to look across the entire, you know, like, what is my product going to do? across the entire temperature range? What's my power dissipation going to do across? Blah, blah, blah, blah, blah. You know, I, I hope that there's, this is what I really want to know about is like, how you design something that needs to go into space, then how do you radiate? I guess it's black box radiation. Yeah. Like, how can you create two nothing vacuum? Which would be your radiating infrared, then?
Yeah, you just you just basically radiating? Yeah, yeah, at that point. That's the that's the only way you can do it.
Well, but yeah, and your your temperature swings would be based on what energy is being put into the system based off of like, radiation and light, versus what energy is not being put into the system. So it's either it's either easy to radiate or it's hard. And space. That's a good way to put Yeah. If you're a space, if you're smart, something if you're smarter than Yes, right. It's not very hard. Actually, that'd be really cool.
If we can find someone that has done that kind of design for the podcast, that'd be great. I want to write down space engineer for the podcasts.
I'll put, if I worked on space stuff, that's what my official title will
be a space engineer. space. And hey, you can always join the Space Force. We're going to have a space force here soon. Yeah, you could be as basic Johnson did the question. The question I had about that. The no space engineers.
They drive locomotives in space.
With the little cap and everything. For the low cap. You're hanging out? That's right. So shoveling coal. And what I'm curious about is if you join the Space Force, and then you do fact, are you a space pirate? Like can you can you become a space pirate that way? Because if so Sign me up. I'm gonna be the first space or space treason? Space. They hang you in space. That That just means they throw you out in the space.
Oh, and bounce look, they just call them they call it bow Star Galactica when they did that.
But thrown yet in the space over the amount the air lock? How's my impression of a Cylon? No, no, no, that's captain. What's his name? Adama a Adama Adama. Yeah. Yeah, this show got really weird. Like, it started off really cool. And then it went like, whoa, kind of weird. Basically, it because it's a sci fi series, and they basically ran out of money for one season. And so there's just like, a shot in like, two rooms. It's all political. And then it goes back to being great again, because they got out of the political stuff. Yeah, it was weird. So if you have it, that's the new new Gattaca. Right not the go watch it not be watched yet. If you like sci fi, it's a really good series. Watch the first two or three seasons and then stop. Oh, watch all the way through. It's really good. Yeah. Okay. Yeah. So, regulator heatsinks voltage Yeah, that was a tangent. Yeah, so go check out I got a couple like, like AP note, app notes. So check out the a n 1028. From Fairchild. There'll be a link in the description below. And then I actually just noticed this is that the TI app notes are called slump. Real why slept? 230 up to three? S L up to three zero. Yeah, I don't know what slump is. But that's most of the TI stuff is named. Go fake. Yeah, so go check out that one. And so and then we have one more RFO. And this is from Jerry. This one actually came from the Slack channel. Yeah. So Jared, from the Slack channel asked us today. What do you do with 2 million free LEDs? I apparently Jarrett somehow inherited 2 million. And then and and we'll put a little stipulation on this. These are 2 million surface mount LEDs. Yeah. And they're all one color. So there are I believe that's what I believe. That's what he said, I may be wrong, but let's just put that stipulation on it. Okay, that's 2,000,003 surface mount LEDs. Can you imagine soldering all those? I don't want to that'd be brutal. Anything, anything that needs that many also cost a lot of money do I would donate them to my neighbor. Because he needs 2 million 2,000,003 LEDs. So okay, so I actually, I posed this question at work. And I got I got four responses from a couple different people. So the first one was, and I thought this was great. First one was, if they're all red, replace all parking meters with these LEDs. So it looks like it's free parking all the time. So I like it. That's that's really great. That one's that one's fantastic. This next one is a little bit like, just like straight engineering nerdiness. But like, put a whole shitload of them in series, enough until the the resistance, the inherent resistance in the LED is enough to not turn them on and see how many that is. That's kind of nerdy, but cool. Now, I liked
it. But hooked up to what voltage mains? Oh, okay. Okay. Yeah,
I actually did suggest putting, putting all of them in series, and then putting like a two and a half million volt power supply, and try trying to light them in series. I wonder if you would have any issues with that the the use? For sure. Would, ya know, the first of all, the capacitance of each one would be crazy. If you put them all in series like that. But at the same time, the resistance diode has an inherent resistance in there would just be you know, of 2 million
crates, thinking of how. So I think I'd come back next week with this, see how long 2 million resistors would be? And like, how long would it take an electron if it's DC to travel all the way across? Right? Because if you just turn it on, there might be a point where like,
I have no idea how that would work. Like, because the electrons isn't going to flow continuously and instantaneously, it's going to take a finite amount of time. Well, I mean, and maybe it will blow an LED fast enough, because it has to travel so far. Well, technically, it's not like one electron traveling across the entire thing. You know, like, yeah, you obviously have a whole bunch of electrons in its, it's also electrons don't travel at the speed of light, electrons are actually pretty damn slow, if you because there's so many of them. But but, you know, the speed of light is, is effectively when you apply voltage to a conductor, you know, it technically travels at the speed of light minus some bit because it's not in a vacuum. Right? So well, so you know, however long this would be it would it would have some propagation. Yeah, well, that's what I'm getting. That is like when you turn on an induction device like a motor, there's a bunch of lag on the power, there's a big sag on the power supply
as it spins up. Right, but I think that has to do with magnetic interactions. Right? So I don't know if that's the same with Well, technically you have a however long wire this is and that hasn't duction to
Oh for sure. Yeah. And the thing is with each one of these diodes you do have to develop a junction drop across each one of them and To be honest, I don't know how long that takes. I mean, if you're talking about one diode, it's like nothing. Time and she was very short. But if you have 2
million series have like, but if you have 2 million of them stacked up and you have four, let's say it's two volt drops, so
you have to Yeah, 4 million volts. Yeah. Is that gonna fry the first LED as it's treating that junction? Oh, I see what you're getting at. Well, okay, technically it
has 4 million volts across it for how little time it takes for that junction form.
Yeah, but but but I bet you if you have that much voltage across it, it basically just avalanches so fast that you never know you never know it. May I? You know, I don't know the answer to that the someone who is much smarter than us will probably weigh in on this.
Yeah, that that, and Jared should just do it, you should just make a 4 million volt power supply get back to us. We'll put our SSPs to shame. I've got two other suggestions. Real quick. In the end, these are these are fast, I think they're fun. One guy said, cover every square inch of your car with LEDs and have it on a switch. So like your cars just go down the freeway and you hit it you hit the switch and just turns white of whatever color whatever color it is and your you know your battery is draining like 50 100 And so all of a sudden, but yeah, but that would be hilarious. And then another one I great, great idea. You know those like videos you see pop up every year around Christmas time when somebody has like a house that does like you know the lights respond to music and stuff like that do an entire roof. Like just just like solar panels. It's it's the exact opposite in the exact opposite of a solar panel. I thought that was a great idea. Like I can't even look at the person's house. No airplanes are crashing everywhere
so yeah, those are those are some great ideas. If you have any ideas go to our Slack channel
let Jarrett know what to do. Yeah, he might actually do it if you have a good idea and that's, that's not a small amount of LEDs for I mean, in terms of cash. So but the funny thing is, it's not like he's gonna be able to sell those like, how do you sell 2 million LEDs? You know if you're not Digi key or mouser Yeah, eBay and somebody offers you five bucks for
for real? Yeah. All right. That's actually a pretty good deal. Anyways, yeah, let's wrap this thing. Yeah. Well, that was the macro fab engineering podcast we were your host Stephen Craig and Parker don't take it easy. Later Thank you. Yes, you are listener for downloading our show. If you have a cool idea, project or topic that you want Steven Knight to discuss, tweet us at my crab or email us at podcast at Mac prep comm. Also check out our Slack channel where we talk about lots and lots of LEDs. If you're not subscribed to that podcast yet, click that subscribe button. That way you get the latest episode right when it releases and please review us wherever you listen, as it helps the show stay visible and helps new listeners find us
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