Ridiculous Relay Ratings

Oh hello and welcome to the macro fat engineering podcast where your hosts Parker, Dolman and Steven Gregg, this is episode 254. So close. So close. So what's next week? Stephen?

It's the eighth bit episode

1. But even more important, it's also the fifth annual Mac fab Star Wars Christmas Special. Hmm.

Not having a official Star Wars movie. We're gonna have to come up with some stuff.

There are or is an official movie. The Lego Christmas special came out.

That's true. What service is that on? I need to go watch it.

It's on Disney plus,

is it okay? Yeah, I gotta watch it.

You gotta get caught up on what we're talking about. Mandalorian tech, and Lego tech, which sounds fun. My

wife went out of town for Thanksgiving. She went back to Texas to see her family. And she's not back yet. And I've been holding off on watching the Mandalorian. She wants to go buy milk and hasn't come back yet. And cigarettes, right? She, yeah. So I, as of this Friday, I will be three episodes behind in the Mandalorian. And I'm jonesing to catch up. And I'm just like, No one talks about it. I know. It's cool. Don't talk about

it. See that? Well, that came up today because I was texting you and Roz about about the Mandalorian. And I the first thing I asked was, is everyone caught up yet? And you said no. So I'm like, yeah.

Sorry. I she said I could watch it without her. But I am not going to I'm going to be a nice husband.

She's going to come back home. And she'd be like, Oh, you have already seen these episodes.

I didn't wait for you. What are you talking about? No, I told her. What's funny is I actually have some some soldering projects coming up here soon. That I know like, I designed some stuff over the Thanksgiving holiday. And just this week, the boards came in and all the parts came in. And I told her, I'm setting up a table in the living room. I'm bringing out the soldering iron, and we're just watching like three or four hours of TV and I'm just gonna solder up all my projects, so it's gonna actually be a pretty great Saturday.

That's pretty good day. Yeah. drink a beer. Watch the Mandalorian Oh, hell, there's some stuff. Yeah, it's perfect. Yeah, speaking of soldering stuff up. My prototype boards for the RGB lighting system for the penetrator pinball system was a mouthful, should be arriving this week. And so over the break, I'm going to be soldering up a bunch of LEDs and a bunch of connectors and stuff. So hopefully that will work out by Oh, on that Penetang car updates revision for in the works. So revision three is up in Wisconsin. We did run into some issues with the relay, not actuating, the relay. But Steve and I were looking at this last week after the podcast we recorded. And we were looking at the automotive relay, because Steven was asking, is it actually rated for 50 volts, which is what we're going to pass through it. And I was like, it should be fine, because I've ran, you know, higher voltage than that through it. So we started looking into it. And automotive relays can be rated up to it, but they're not certified for 50 volts. So like all the UL ratings and all that paperwork stuff.

They don't have ratings that high. Yeah, the I'm not going to burn your building down paperwork stuff. Yes. And so

basically, because that they're not at you can't actually get a automotive style relay that's rated and certified to the voltages, we're running that. So we have to switch that out. Which is unfortunate, which we have to make another revision anyways to change some stuff with some connectors. But it's just like, Oh, I gotta change relays again. So I started looking into like actually doing a deep dive into relays. And I found a couple. When we back up a bit, the big issue we're running into is we're switching quote unquote high voltage DC. Most people consider at least the industry considers anything basically over 36 volts DC As high voltage DC, and we're switching 50 volts, and in some cases depending on like how hot you turn, the power supply can be even like 60 volts. You know,

that's exactly like a handful of weeks ago, I was doing that high voltage, low current sensing circuitry stuff. And I kept running into like, I'm trying to find high common mode voltage, and all these data sheets are like super high voltage 48 volts. I'm like, yeah, come on, please.

I need that. I need a little bit more than that. And so my biggest thing is, Am I missing something when choosing the correct relay? Because I was looking in other pinball machines, like production machines and back in the day, and they're not rated for the voltage or switching. Like you were looking at the side that says 24 volt DC rated for the contacts at like seven amps. The more industrial style like you know, those clear style relays? Yeah, the big bricks? Yeah, most of them use those. I'm not opposed to using those at all or anything, I just want to find what's the correct rating to go for?

Which, okay, so if you look at ratings on relays, the thing that's super annoying is, anytime you not anytime, but most of the time, when you look for voltage on a relay, everyone assumes you're thinking about the coil, not the contacts, correct that too. So you have to sift through a lot of data sheets to find what you're actually looking for.

And what I've been finding out is when you're on Mouser, or DigiKey, they are displaying the max voltage rating for the relays, which is not the rating you want. It's like we were talking about like years ago about MOSFETs. And how like the marketing of MOSFETs is like, they tell you like the maximum amount of current and the maximum voltage and power. If you had like infinite heatsinking on it. Like you could immediately draw all the

power away infinite infinite heatsink for a picosecond. Yes,

yeah. Kind of running into the same issue with these relays is when you look at like Max voltage ratings on those sites and start filtering bomb. That's the max voltage rating of the contacts. But it's not what it's rated for. You go into the datasheet and find what the rated current At what voltage and current is. And so like this one is G two RL dash one a dash E dash CV relay, its max voltage rating is 300 volt DC. Awesome. Going into data sheet rated current at 24 volt DC is 16 amps. It doesn't give you any other rated current above that for DC.

And remind me how much current do you actually need to switch? 10

amps tenant. Okay, so the worst case scenario would be like 60 volt DC at 10 amps we have we had switch that off.

So I don't think I asked the other week. But what is the purpose of this relay? Like what does it do? So the purpose

of the relay is to switch off the high voltage if we detect a problem.

What are the what are the conditions that are constantly going across

a coil burns up or something like that. Okay? Basically, it's a mechanical mechanical fault happens with the machine. And so instead of burning the coil up, we want to safely turn off the high voltage and then let the operator know hey, there's a problem here. Instead of usually what happened older machines what happens is the relay goes and then basically fries the MOSFETs. Yeah, cuz they're what dead shorted? Yeah, cuz they're dead shorted with 60 volts across them, or 50 or 60 volts. So we want to be able to, because we have a current sensor, and so we know, hey, these coils are only supposed to be pulling certain amount of power. And so if we detect an anomaly, we can go Okay, shut it off. And let the operator know that there's an issue. And so we can save the electronics and then the operator can go in and replace the coil or diode or whatever is blown up.

So you send back to the computer some kind of a fault code. Yes. Do current sensing for each individual line or are you just sensing the main power line,

the main main 50 volt line that comes onto the board. We actually are sensing for like all the other voltage lines to that go off to like the servos and that kind of stuff. We're sensing those lines too, but the main one is the 50 volts because that's actually what causes you can cause damage to the board by not switching off fast

enough. Yeah, I guess I guess what I was curious about is you You're basically sensing the oshit current on the main line, you're not sensing each MOSFET. You can't say like, oh, this particular solenoid is bad.

Well, we can do that by if, if it did, it can also detect, like if a solenoid or a MOSFETs gone bad. Buying going, Hey, there's no current supposed to be flowing now. And there's current flowing. Yeah, sure. Yeah. So there's a bunch of back end work that's actually monitoring the current on, okay, it should be pulling as much power it is. So it's good. That kind of stuff. So we're trying to do some smarts just to be more proactive in and saving electronics lives, I guess,

I suppose you could have it do like a diagnostic way where it actually teach thing and then studies its current and then knows what it should be.

Yeah, I don't think we have a learning algorithm like that. It's good idea to put in though, yeah, like

upon startup it could do it could do that. And then say, like, this is what it should be when this

happens. Yeah. That'd be cool. Yeah. Might be a little much for what we're working on. But yeah. Yeah, so relays. Yeah. 301 must be missing something. 10? Eight? Yeah, I must be missing something. Because there's not a lot of for something like even in production machines back in the day. They are not using relays that can technically actuate this, maybe they're only expecting like 10 or 12 actuations. Before the relay goes. I'd rather not do it that way.

Are you using your relay as a normally closed? And you open it if there's a fault? Or do you have to actually energize it to does it have to be energized 100

energize it to enable. Okay,

so So during normal play, it is energized?

Yes. I did find a relay that is actually rated for all this. The G two RG dash two A dash x, it's actually rated at 500 volt DC at 10 amps. And is not the most inexpensive, really, it's it's only 16 bucks, which isn't that bad. But compared to the relays we're currently using, which are $3 to $6. It's a $10 increase on the bomb. Now if that's what gets us into our safety zone, then sure be it. But I would rather there's got to be something I'm missing like this other relay that's rated at or max voltage rating at 300 volt DC, but rated current at 24 volt DC at 16 amps. There's gotta be something I'm missing there. I'm hoping someone in the slack will will teach me on on the ways the relay.

Wow, that's a hell of a relay. Yeah. 10 amps. 500 volts. Talk about welding your contacts together?

Oh, yeah. And it's not the smallest relay either. It's not that big either. But it's a pretty, pretty chunky

little bit over an inch by an inch by an inch. Yeah. Bigger than that.

Little bit, just

a little bit. Yeah, that's cool, though. You see, I when when I was not aware that these existed with this kind of power rating, the first thing that came to mind for me actually is in my in my high voltage amps to have a slow start. Such that you could put this on the transformer, the high voltage tap of the transformer. So it's open when you first turn the amp on, and the low voltage stuff comes up first, and you have a time delay circuit. And then it clicks this on such that all of your low voltage stuff is on before actually clicking this in, or even have this as like speaker protection, or something. That's cool.

Is there a particular reason why you'd want to bring your low low voltage on first?

The it's argued in in tube amps. If you if you apply high voltage to a tube before it's warm, you have an incredible potential in between your cathode and your anode. And people say that you can that's how they that's how you were them. It's called cathode poisoning or cathode stripping where you have this high potential where you're actually putting a force on the cathode and you and people say you can actually break the cathode apart. I don't know how much I believe that. And then these kinds of voltages, it's actually like 500 volts and lower it's not proven to exist now in like really high like radio, transmit tubes that have way higher world Just it is a problem. So it is kind of nice to have like a time delay where you know, the tube is hot, you give it 10 seconds or so and then it clicks the high voltage on. That's a cool little thing. Actually, there's a really great YouTube video, if you don't heat up a tube at all. And you way, way, way, way over voltage, the thing like a tube right into like 500 volts, put 3000 volts or so on it, it actually produces x rays. So there's a great YouTube video of a guy who puts up a Geiger counter right next to one and puts like 3000 volts and that guy, you're kind of goes freakin nuts.

I don't strip it all electrons. Yeah, it's

actually that is cathode stripping happening. And when you strip the electrons off, they release high energy waves. So yeah, I don't know. Honestly, in all the amps I design I don't, I don't put time delays or standby switches or anything. They're just not necessary. But it would be cool in theory,

so it's either relays or start looking at Solid State Relays. Because those can easily handle the voltage and amperage would look I'm looking at. I haven't looked at too much into like board mounted ones those and the pricing. But that's the next step. If I can't find a relay that will handle what I need.

Yeah, don't isn't it Isn't it difficult to find? Maybe I'm mistaken here. I thought it was difficult to find DC Solid State Relays like AC Solid State Relays are super easy to find.

Didn't seem that hard to find. When I was looking on on the Mauser.

Okay, okay. Yeah, I just I just did a random search for one and here's a 60 volt. It's only 3.25 amps, but it's just a few bucks. Yeah, that might be the better way to go. Yeah, you don't have a mechanical thing to wear out. Exactly. And, and you're kind of in the, you're in the iffy situation where you have to have it energized and hold the context closed for normal operation, as opposed to the other way around. So that yeah, I don't know solid state relay sounds a little a better option there.

And then the next big change on red four is the RGB lighting string we're using because we're using serial lights. And the problem we're running into is we want to hold up to like 64 lights in a row. Well, it's like that's like five amps of power if you do like max brightness, all them white lit. So that's like the maximum power draw

At what voltage five volts okay.

So the power off the board isn't that big of a deal. But the problem is like the daisy chaining of all the wires and the make everything compact enough. We are limited on your your connector size. And we're using like two millimeter pitch connectors, jst style connectors. And the I don't have the exact part numbers for those, but I'll find them later. I'll find them one night we actually test these networks. Is there a maximum current on that or something? Yeah, well, you're limited by not connector power because the connectors are rated for like five amps easy. It's the amperage for the gauge of wire you can put into Oh, okay, so the MAX SIZE gauge is like 22 gauge. Right, right. Yeah. And that limits you to like, I don't want to say because I can't remember I'll top my head. I'll pop it's not five amps. It's not five amps. I'm gonna look it up real quick. But basically, we have to go to two chains of lights so that we can handle 64 lights. I just wanted to gauge is what is chassis wiring for that? Is seven amps. Is that really? Really? That is not it?

Yeah. Is that assuming like 100 degree see your eyes or something like that? Yeah, I

don't know. That sounds really scary. That's

yeah, that's a lot of juice going through there. I would not believe that.

Yeah. That's the first link on on on the on the Google's Yeah.

Don't always trust everything you read.

Ah, because that's chassis wiring, which is for small lengths of wires between components. Yeah, really small. We're talking about four foot right right. Yeah, yeah, yeah. What so anyways, yeah, actually,

those are okay, so little side tangent. that's those are confusing ratings because there's chassis rating and then there's power delivery rating? Correct. And I The first time you see that you kind of run into it. And he's like, Wait, there's two different ratings for the same wire. And they're really different most of the time, like, very, very different. And yeah, you're talking about power delivery, not just like talking to a component an inch away. Yeah.

And that's why it's actually I think the max size is 20 gauge. It says that the max power transmission is 1.5 amps, which is Yeah, that's correct. That makes Yeah, that makes a lot more sense. So we had to change the two chains to be able to handle the power. So that just means adding

another connector in parallel,

right? Yeah, it's just, well, another connector parallel, but it's actually two new data and clock pins that come off the microcontroller.

Okay. Oh, so you have to control that whole string separately.

Yeah, it's controlled separately. And we're actually I'm gonna fuse them on different fuses as well, just to be safe.

How are you going to tell the end user about that? Are you just gonna say like, don't put more than two amps on this line? Or

it's gonna have a two amp fuse.

So if they if they overdo it, they'll just know they overdid

it. Yeah. I mean, user beware, right.

I guess you'll have some kind of a notice and a manual somewhere.

Oh, yeah. It says on the board to amp rated. So cool. Yeah. Hopefully next couple weeks I've read for outdoor main thing. Is that really problem?

So? Yeah, cuz rev three is all functional. Right?

Yeah. 100%. Yeah, we actually just put the, the I mean, the relay is working on it, too. It's just not certified for it. So we're like, well, we got changed that we got to make sure it's certified for what we're using it for.

Right? Yeah. You don't want any legal issues down the road? Nope. That would be bad. So this, this will actually a handful of weeks ago. I've been I've been meaning to talk about this, but just put it off for whatever reason. But my buddy sent me a an image of a guitar effects development board that he was like, Hey, man, I found this thing and I kind of want to, I want to buy it. It's pretty cool. And I took a look at it. It's like, that's my FX diff board that I did a while ago. So for those who are maybe newer listeners, I did a crowdsource it was crowdsource? Right. Yeah, I think it was crowdsource

gonna stop you there. You didn't mention this two podcasts ago. 252. Yeah. What did I share? Yeah, the effects that border turns episode 252

I don't remember that. I don't think I actually talked about it today.

Yeah, you talked about them existing. We didn't go into any details other than existed

COVID Land has got my brain all scrambled. I don't even remember that.

So that Turkey you ate before that podcast? Yeah.

Well, okay. So regardless, these

I'm just letting our listeners know because they might be having a ground dog or Groundhog Day situation going on. Right?

Well, I sure as hell am. I don't remember talking about that at all. I thought I knocked that off the list. Or cut. No, that's

well, Groundhog Day would be you remembered it and it's happening again.

Yeah, the same. I can't remember what that song is. But the song happens every single morning and you break the the alarm clock and very important. Yep. It's a great movie. Okay, so regardless. Okay, so these Yeah, these these FX dev boards came back. And and there's actually two different versions of them, which is which is pretty cool. So the there's one called the proto board, which is from pedal pcb.com. And then another one Pro, this one came back, or I shouldn't say came back but it there's a newer version of it. And one of the reasons why I wanted to even talk about this this week was not just because there's FX def ports which thumbs up cool. I'm glad that they're, they're out there. But the fact that I think I think there's there's somewhat of a flaw and I don't want to say that it's a flaw in their design, but not my design, but something that I think is a little bit eyebrow raising. That is worth considering here. Both of these other boards ditched my power supply design that I did on the board, which frankly might I'll admit, I'm raising my hand here. My power supply design was a little bit funky, because I did a capacitive coupled Dual Rectifier design which if you if you type that in Google you're not gonna find anything it's it's weird. And I wasn't like purposefully trying to find a strange topology of power supply here. Just trying to flex on this. No, no, I wasn't. I wasn't. I was literally trying to avoid FCC rules, like getting FCC certification. No Parker's law Big, I actually spent a significant amount of time trying to figure out how am I going to accomplish getting a bipolar power supply using common components and avoid having to get anything FCC certified. And the My solution was to use an AC power brick, not a DC power brick. So a wall wart that's effectively just a transformer. And you you end up with with one tap on the output. That's a it's a 16 volt tap, I believe is what I used. But if you go and if you go look a bipolar power supply on Google and you try to find like concepts of a standard bipolar mains connected power supply, you end up seeing a ton of designs that are like a 7805 and a 7905. Regulators connected to rectifiers that are connected to a center tapped transformer. That's the biggest thing, I didn't have a center tapped transformer, I have a single tap on this on this design. And the whole purpose of going with a with a like a wall wart that's just an AC wall wart was that something that's simple to find, you can you can find that you can buy that you can get on Amazon. And in my original ethics dev board, I wanted that I wanted the parts to be easy to get. Because that was the whole purpose, I was trying to make things easy for people. So I ended up going with a capacitively coupled power supply, which allows you to actually put two full wave rectifiers on a single tap. And then you can invert one of the rectifiers. And you can get a bipolar power supply off of a non center tapped transformer.

So I don't know too much about how that would work. But I'm gonna guess is it shifts, something that is shifted out of phase? Well, it's so how it works.

So here's it's effectively like two independent rectifiers that just don't recognize each other. Because the DC that's on the tap is reference to one of the rectifiers. But if you're capacitively coupling, you're actually sending power through the capacitors into a second rectifier, but they're dc coupled from each other, or sorry, AC coupled with the capacitors from each other. So it's not the most efficient design, because you actually have losses in the capacitor and things and specking the size of the capacitors is actually a fairly, it's not it's not straightforward. Which, which is why I just use monster capacitors on the board just like big enough, right. And I knew that the entire power supply of the FX dev board was going to be fairly limited, I had it limited with poly fuses to plus minus 200 milliamps, so it wasn't a significant amount of power. Regardless, so So the whole purpose of doing that was that you could use an AC wall wart, plug it in to a standard, you know, 2.1 millimeter DC jack on the board and get your bipolar power on the board with just a single tap. Now, here's the thing, these these other and you're

trying to avoid the six kilohertz rating for FCC, right?

It's a nine kilohertz, but yeah, exactly the the the part 15 B or whatever they call it, because you know, because I was designing this under the Mac Feb name, and we were going to be distributing this, you know, and it's something that I didn't want to get in trouble if someone came knocking on the door, figuring things out. Because there's significantly easier ways to accomplish this task. You could put in whatever voltage you want, and then use a switch mode power supply or a charge pump design to get whatever other voltage you want. And what's funny is, I think this is kind of like boils down to one of the issues with googling your, your solution to a problem. So, especially in like the guitar design world, for most people who get the Inkling like, Hey, I'm going to build a pedal or I'm going to learn about this stuff. You're already playing guitar and you know that pedals run on nine volt batteries. And when you first start getting into it, you realize, Hey, okay, I've got a nine volt battery, I can design my circuit around nine volts. And it's actually kind of interesting because most of the simple designs do zero to nine volt, and they do single supply. So you have a half volt reference, a four and a half volt reference and everything is referenced off of that. So you learn how to design a circuit around a single supply, which is actually a pretty cool little skill to have. But as soon as you start getting into more advanced circuitry, you start realizing that zero to nine volts is limited and it doesn't have a lot of capability. So you start looking around and you see hey, these other pedal guys have been using charge pumps to get a pulse nine and a negative nine design so great. It's just this one microchip apart and it comes in a Yep, aid package, which I know how to solder that. And that's great. So I start putting that in my designs. And you start getting into trouble because now you're starting to violate a lot of laws and rules that you're not even aware of. So I think using these kinds of things is fine and whatnot for like your, your own personal projects at home and things like that. But if you're not paying attention to this stuff, it can really bite you in the butt. And these, these two other FX dev boards that are out there. One of them I'm I know I'm aware of the proto board uses the TC 1044 SCPA, which totally cool, great. It's a charge pump. So you put nine volts in or effectively you put whatever voltage in you want, and it just flips it negative, and you get negative out which great you now you have Bipolar rails for whatever circuit you're going to design. And when we're talking about a little deaf board, you know, who cares about the FCC in that situation, it's like your little like thing that you just running at your desk, it's not a big ordeal, right. And the protoboard itself, is, I think you solder it up, they just sell you the PCB. So it's really not that big of a deal for you to have a switch mode power supply, or a charge bump or something like that. Now, this other FX dev board the produce one, which is pretty cool. It's a lot more of a one to one idea of the FX dev board. I don't know exactly what they're using on the board. But it does look like they're using some kind of a charge pump design or something like that. They're actually selling a finalized product, which super awesome. I'm glad that someone's out there getting this to people because I I really wish it would have worked out for us. But it's also like, hey, this does really fall under FCC rules. And if you're using something that oscillates over nine kilohertz, then you got to be really careful about what you're putting out there. So that's one of the reasons why I had originally gone with a kind of a wacko non standard power supply design. That seems weird. From the get go, and it seems like well, why are we using these weird parts? And why do we have this weird configuration so that I can skirt the law? To be honest. So, you know, and it's funny, too, because both of these boards don't use the integrated breadboard that Parker had designed. Yeah, I mean, you designed that like, what, nine years ago or something like that?

No, it's not that long ago, it's

probably not that far away from there.

How much is the well look up the effects dev board suing last commit to that GitHub repo was?

So yeah, Parker had these these bread boards that were that high? Six years ago. Okay. I mean, it was a while ago,

so long ago. But yeah, yeah, um, we custom built, or had custom built some proto boards, like the little plastic breadboard kind of guys that had the rails in them had tabs that would poke down. And so you could solder them into your board. And you could connect stuff up to like, we had the power rails connected up to the power to the fancy voltages that Stephen was making with this crazy power supply design, and then some of the signals as well. So you could jumper stuff a lot easier, and basically do stuff with less wires.

Right? Right. And that was sort of the magic was that, that you had access to the actual tabs of the bread boards themselves, as opposed to having to just jump with wires, because the biggest the biggest problem with with breadboarding, in my opinion, is just having flying wires all over the place. Like that just adds so much confusion and so much parasitics that it ends ends up screwing with your design and hinders you from learning things because it's like, well, my circuit doesn't work, but I haven't connected, right. And it's mainly build quality, or the design quality of what you're actually plugging in and things. So I but uh, but you know, honestly, I don't I don't blame anyone who's, you know, took my repo and went to town with it. It's understandable because Parker had all those bread boards custom made, so they just don't exist. You know,

the best thing too is is they didn't match the design that we gave them. So we had to redesign the board with a different footprint.

Oh, that's right, because they sent me the original data sheet or well, they sent me like, literally like a paint drawing. Yeah. And so I designed based off of that, and their, their dimensions were all wrong. Every

everything was off. But what's one feature that they that these two boards don't have the FX dev board, which is what was my favorite part of the FX dev board was the FX dev board came with an metal enclosure. And so that you could build your circuit, and then put it in a metal enclosure and actually go to a gig and play with it. So you could you could try it in a live setting. Yeah, live setting. And so if you could get all your wires squished into the box, and all that stuff, that it could hold up to some abuse, like we had, there was a stop pedal on it, stop pedal switch, and all that good stuff. And you didn't have to be gingerly with the board once it was in the enclosure,

actually. So one of the this other one that's proto board here, they came up with a pretty cool concept. I love that like both these, these people took the design and they changed it and made some additions to it. This proto board made the the option for you to put some Phoenix connector screw terminals in it, but they put them it's the 45 degree style. So you could take a potentiometer and stick the legs in this connector, and then screw it in such that if you had a particular value of potentiometer. You stick it in there, just screw it and now you have that exact pot. Because there are some circuits that use weird wacko tapers or values or whatever.

That is definitely the biggest improvement to your design.

You okay, so you know what I what I had originally done, I went out, I did a bunch of research and found what are the 50 most built pedals by anyone. And I got all of the schematics. I got all of the values of potentiometers, put them in a spreadsheet, and I did some statistics on it. And I found with six different values, you could make like 45 of them. So I just said okay, I'll put those six values on. And that's going to cover nearly everything. Yeah, but but this other one is cool.

That's a really, it's a really cool idea. I actually, I was just looking at the proto board. And with how it has those at a 45 year angle. It reminds me of a lot of a Atari 2600 style console. And that would be really sick to make a pedal that look like that

would be I'd like to add so actually, it would be cool to just put a pedal inside of a 2600 enclosure. All my guys How cool would it be if the pedal changed based off of what cartridge you put in it? Oh, that'd be so tough.

We can do it. I got like, hundreds of Atari she really old hardware. Yeah.

Hey, actually, I'm gonna I'm gonna put you on the spot here. Did you ever ship that one package that was supposed to ship? Oh, yeah. Okay, you eventually

you're gonna ask me that on the podcast like years ago? Yeah.

I can't remember your hands. Yeah, yes. No, the whole running joke was Parker had this package under his desk that just sat there for a long time. And it was supposed to go off to some customers. And it was there for another customer. Yeah, no, no, it was like a, it was an Atari right? Yeah, it was Atari. See, this is the podcast where I don't remember anything.

Alright, so I got I got one more topic. Yeah. But so on the rep electronics subreddit. There's a picture of a, what do you call these like a bike holder? It's like those things that you can bike rack. That's the word bike rack. It's a bike rack. That is a giant coil. And someone said, this is a giant inductor. Yeah, it's a

public Bike Rack, like the ones you go up to? And then you Yeah.

So it looks like a bass. It's just a big coil stainless steel. And someone said is a 0.1 Micro Henry inductor, and it kicked off my brain of of other things. You could totally use it as an inductor, because it's a coil wire, right? Or it's probably a two but

sure. Yeah. Actually, you know, this is this is the engineering part. Going through my mind. It's not solid. So it's a tube. It's a tube that's wrapped into a coil, right? So I don't I don't know what the effect of a tube being wrapped into a coil would be in

high fruits. If it's a high frequency, it's just the skin effect.

Yeah, but I don't know what what kind of effect that would have for the field that goes inside the coil. Not inside the tube. Oh, no. That's the that's the physics side coming out

high wherever the current is writing though, which would be skin effect. Well, and

it's funny because there's there's an image of it. And if you've ever tried to wrap a coil in tried to hit a target, it's really, really tough to get what you're looking for. And so something something this big, I couldn't even assume that it would be 0.01. Micro, Henry, it's got to be so much less than that.

Oh, and there's a, there's actually calculations in this thread of how to actually calculate this.

That's so great. In my senior design project, we actually had one aspect of it was a we had to have, what was magnetic coupling for communications of this device. So we had coils that were at 90 degrees at a motor would turn them such that they would be in in line with each other, and then they could energize and magnetically communicate. So I had to make two inductors, one that would be on this motor that would turn and it was just, it was incredibly difficult to to hand wine modes in and make it actually work.

So what I wanted to go with this is, what are other normal items that are out and about that you could be seen or used as electrical components. Because the big one that comes to my mind is like using pennies and stuff like that as fuses. Or bullets, bullet casings, like a 22 LR bullet hazing, like fits perfectly in older style automotive fuses. Bock

we're using aluminum foil to upsize the value of a fuse.

Oh, yeah. But what are other other items like this? So like a bike rack?

I mean, other than coming up with the weird device that shocks people, it's kind of hard to cut.

I was about to say, what if we had one of cats, we can actually use the capacitive storage or their static electricity. Actually, I think that might be a YouTube. I wouldn't be surprised.

Yeah. What is what is the whole thing where it's like? A buttered toast, always lands butter side down. And a cat always lands on its feet. So if you like strap them together in a certain configuration, then you have this thing that just floats in space and spins around and creates energy, because both can't be true.

I Oh, yeah, that's also a commercial that's on YouTube as well. Hmm. I'm trying to think of other logical devices or resistors, or something like that. I absolutely love

this. Because this is such a great example of technology and Reddit, where people are not actually talking about technology. They're talking about the inductance of a bike rack.

Yeah. What voltage isn't rated for many

things I think like that. Yeah, quite a bit. Although both ends of the bike rack are grounded, so it's not a good inductor.

Because bolted to the ground. Oh, boy.

I was trying to think of resistive elements and things like that. I'm thinking like a toaster or a hairdryer or something like that. But those are being used for their purpose. So it doesn't Yeah,

there. Yeah, it's being used for its purpose.

I don't know. Yeah. Put it in the Slack channel. If anyone thinks of anything.

Oh, I've done this before using a bucket of water. Well, that's still not same thing using a bucket of water as a heat sink for dissipating energy. And you didn't and you're seeing sea bows like like I dropped like a coil of insulated wire in there.

Well, what was the purpose?

Oh, man, what was like? I think it was calculating battery discharge. And didn't have a way to do it like a big resistor or anything. So I just had a big because I ordered it and water. Yeah, just through the big coil will have an insulated wire into a bucket. Nice. As for testing car batteries a long time ago. Okay, let's move on. Yeah. What's your last topic, Stephen?

I got a gift actually, that I'm making for Roz who's been on the podcast handful of times. So I Roz and I, we build apps together. We build two bands, their high voltage. Everyone knows this. I've talked about every podcast tune in 55 times. But

are you sure? Yeah, pretty much.

So here's the thing that's funny I've wanted and I know it'd be useful for us. I've wanted did resist a decade boxes or resistor substitution boxes that are high voltage and moderate current, so like half watt or something like that, and they just don't exist. Like if you look at resistor decade boxes on Amazon and things like that, they're like half four quarter watt and 50 volts or something like that. They're just garbage resistors. So since they didn't exist, I decided to design them myself. And so I ended up using some bud enclosures that are just diecast enclosures, and instead of using the rear that

spot enclosures spot,

I don't get the joke.

But as a normal name,

I'm moving on. I'm sorry, I'm moving. So I ended up just getting rid of the bottom panel and sizing the PCB such that it screws right into these bud enclosures. So just makes it easy to design. But the whole point of even bringing this up, and I love this, I bought these enclosures, I bought like 30 of them in 2009 I believe I bought them with Roz right after I graduated college, we were going to design something and put them in it. And we designed like three things. And then we had all these leftovers. And I have loved these things all around Texas and now up to Colorado. And I finally came up with a reason to use them and I love the fact that they're going back to Raz So and then the funny thing is I'm only using eight of them so I still have a box full of these things. But it's kind of nice when like yes I'm a packrat but I eventually use the stuff that I do hanging over yeah

oh man that's a go off that story is so last night I built a a Christmas wreath for my wagoneer and I do the same thing is my my mom made me I didn't do the arts and crafts part of it like my mom did that but she built the wreath out of like spare stuff from like around her scrap bins for her arts and crafts Christmas junk so much stuff so much stuff well she looks at my scrap pile part of the same way likely but yeah, I bill Bill all the because I built a rack that would fit on the front of the wagon, the scrap bin just pull the parts out and all I do is just cut some tubing, a little scrap piece of tubing up so nice it's nice when you get to use like recycle and reuse older project stuff and then you just feel somewhat like that warmth inside your stomach

this project would not have happened unless I kept these boxes for 11 years and drag them around this is why I don't get

mine would be I would have been no way for me to finish my project in basically one evening if I didn't have all this stuff because like all the brackets I used were already the right shape and already had holes in the right like almost the right spot so I'm like oh yeah, I just had to weld all this stuff together now and then throw paint

on ice that's the way to do it.

And like I didn't have to wire anything on the wagon I had wiring from the fog lights so I just wired into the fog lights

way so your wreath illuminate Yeah,

that's great. You activate the fog lights and it turns on the roof

all for just an evenings where the work.

Oh yeah. I think the only thing I had to buy was the lights and it was like $15 on Amazon. Yeah, nice that USB powered lights all the only weird thing is the you have there's like a little button on like the USB plug and you had like press it to like actually activate the lights.

So you have to put your fog lights on and then press that button.

Technically yes, but I didn't do that I opened up the thing that the clamshell and I just soldered the wire to the button so it would always be pressed down. So it just cycles through all the different modes as fast as it can. Well, like 30 seconds per mode, but that automatically turns on. Okay, that's cool. Because I thought I wanted all this is it's weird is because it's got two different acts like it has two different streams of LEDs. Because again, like turn on half the LEDs and then fade them out and then turn the other half on and then fade out. But it only does it with two wire leads into the USB box. You know how it works? How It's two LED chains, one going one direction and one going the opposite direction and it drives the two leads with AC voltage so just flips the phase it's flips the phase and then one turns on one turns off well it's cute. And then how it lights over at once is it just runs a sine wave down in

persistence of vision. Yeah.

It's like I was really hoping I could just take the clamshell pot and just put power on you know the leads directly but not only like to pass

everything has smarts nowadays. Yeah.

If I had more time I'll probably do it for next year is I will get rid of because I don't really like the blinky lights on it. I just wanted just to be on a probably just make a little five by five timer that just spits out a square wave. And it just lights the whole thing up. Yeah, now pi work probably probably. So that was probably the Mac fab engineering podcast and let's see even forgot. We were your host Parker Dolman. Probably better one. Thank you. Yes, you our listener for downloading our podcast. If you have a cool idea, project or topic. Let Stephen and I know Tweet us at McWrap at Longhorn engineer or at analog EMG or email us at podcast at macro live.com. Also check out our Slack channel. You can find it at macro voices.com/slack.

We are at 541 members in the Slack channel. Let's get nine more members in this leg channel and let's get it to 550

Yeah, by the end of the year, that'd be awesome.