Rotary Alarm System

Oh welcome to the macro tab engineering podcast. Do not adjust your podcast broadcast device. What you are hearing is a rotary alarm system. This siren notes the beginning of the macro fab engineering contest, Episode 200 repeats. This is the beginning of the macro tab engineering podcast episode 200.

And we're your host, Stephen Craig and Parker Dolman. This is episode 200 200.

Cheers, Stephen chairs. And thank you to all our listeners 200 weeks in a row.

Thanks everyone for listening and putting up with us. And being a part of this community which has grown to be pretty sizable now. I think last time I checked, we have what 450 People on the Slack channel and we get 1000s of listens every week. So thanks to everyone who participates and, you know, here's to another 200

Here's her another 200 Cheers. Cheers like 1000 mile Clank Yeah. Josh, like sound effects in there. Also, thanks for putting up with that intro. Yes. So yes,

Parker, what were we hearing in that intro?

So my 3d printed air raid siren works now. As you all heard,

maybe, maybe Josh can can filter my voice to sound more like a 40s broadcast or something that

sounded pretty good to me. Well, I was also having to overhear an 85 decibel air raid siren.

Which How do you know that's actually 85 decibels?

So I use my my phones, computer phone, my computer phones. There's a DB app. sound meter?

So yeah, we actually measured it right before the podcast with with the phone, which, you know, sure. It's probably not super accurate. But 85 decibels is, what 85 decibels is. I looked it up earlier. That's the interior of a car is well, yeah, what it was called out

which doesn't sound too loud? Or is that just because car interiors are loud?

I don't know. Because the next bump up in 90 decibels? It said the interior of a truck. Yeah. But here's here's the thing. Your your actual application of this. I think having an 80 to 85 decibels is good. Because it's it's not particularly annoying, you know?

We'll find out.

I'm sure. I'm sure you'll annoy plenty of people with it at the office. But the

one of the things, it sounds like it's a little bit lower pitch than a lot of erudite words I've heard which is kind of nice.

Yeah, I don't know. Because I didn't do the design on it. I don't know what actually the frequency is. I guess we can just record it and see what the frequency of the

Yeah, just downloaded another app the frequency?

I guess. Yeah. You would just get the FFT of whatever it is and and figure it out that way. But yeah, it is a little bit lower than most air raid sirens least here in the States. But this could be what air raid sirens sound like in whatever country the person who designed it was in?

Yeah, good point. You know, I wonder I bet there's a standard for air raid sirens, you know what frequency pitch they're supposed to be? And like how fast they're supposed to go up and down. Yeah, cuz

also, I had to guess on that because it's a hand crank. So you kind of have to spin it up and then let go spin up. Let go.

You know it that thing must be geared to like a ridiculous ratio, because I watched you spin it up earlier. And your hand is turning pretty damn slow. And that thing,

I mean, so you can see. I can see you can see it. There's like, see how fast the blades are moving. I'm barely moving.

You're moving like three or four degrees of the handle and the blades making multiple rotations. So yeah, there's a hell of a ratio, though.

I mean, I'm not even spinning. It's still going on. There's a lot of is there a word for that? It's it's it's not rotational momentum, but it's like the gearing I guess it is rotation inertia, right. Yeah. Is that the sole same thing? When it's it's kind of like the gearing allows it to have that? I guess because you're spinning that mass that fast already? Yeah. Right. It's acting is acting as a flywheel effectively. Okay. Yeah. out. So it is that I didn't know if there was a different word because of the gearing or whatever, right?

You've used the handle to spin up a mass inside of it. And that mass wants to keep moving. Right? Yeah. And it's. So after you let go the handle the mass is then going backwards and turning the handle itself, right.

Yeah, I guess it is a moment is meant, and I was thinking, maybe the gearing there was a different mechanical term for it. But I guess not. Oh, maybe there is.

I'm an electrical guy. I don't know that stuff.

McMaster doesn't tell me.

So that's all done. I'm gonna bring that into work tomorrow. Let everyone play around with it. Should be a lot of fun. Well, we'll know next week, if I still have a job if episode 201 comes out.

Well, that's that's awesome. How long did it take to print?

Probably about three whole days worth of printing. Wow. spread out over a couple of weeks.

And then did you grease it at all? Or is it just running on bearings?

It's just bearings in there. I didn't grease the gears. I guess I could that kind of because there was a little bit of a clanking noise. When the gears mesh up. Yeah,

the signal to noise ratio is is not too great. Right?

Yeah, well, I mean, yeah, that's the slop in this. That's

the slot. He was he was jiggling the handle?

But yes, the the siren is a lot louder than that. So it's like a what doesn't matter.

So? Yeah, for sure. It serves one purpose. And it does that. Yes. Yeah.

So yeah, that's done. And also was working on a, unless we're gonna keep talking about this, but I think we're done talking about the air raid siren.

I mean, I think yeah, it does one thing and it did it does one thing. It makes loud noises it makes Yeah, right. Well, no,

it makes one loud noise.

Right, right. But But hey, at least the pitch is variable, right? You can you could play a song on it if you wanted to.

But the time in between notes is so slewed that you would have to play something really slow, you play it really slow, record it and then speed it up. Oh, yeah, there you go. Yeah. Or you just had a, you can make a really lightweight rotor out of like titanium. Right. And then a big electric motor that's really torquey that you can like really quickly change the speed.

Yeah, the backlash of the gears would just make it just rip itself apart. Like if it just tried to change speeds instantaneously.

I think we did talk about that, like, you can probably make the outer casing have variable slots, potentially, to change the pitch.

Oh, you know, actually, now check this out. Think of it like a, like a propeller on a or a screw on a ship. If you know how some of them have the ability to change the angle that they chop into the water. Like if you could change it such that they would, they would make the rotor circular. So you could you could make it circular, and then change speed and then open them up and then play whatever pitch that is, then you could make it a little bit faster between pitches. But then we're defeating the whole purpose of this thing being a single use this like spin it up. It's supposed to just let you know that bombs are falling.

Say doomsday arrival sounds excellent. You

know, no, that's not their only use. I guess they they use tornadoes. Tornadoes. Yeah, hear sirens. Yeah. But you know, that's the only time I've lived in Oklahoma and in Texas. Well, and now Denver, but in Oklahoma and Texas. I have heard sirens before. In little in the small towns I've lived in and they are pretty damn loud. That's for sure.

Yeah, when I worked in Oklahoma, there was a air the siren went off and we had to go get in the basement.

I remember very distinctly sitting in a bathtub as a small kid, like with the whole family in a bathtub and I was wearing a football helmet. I mean, there was a giant tornado coming through Oklahoma and they put they put giant they put your bathrooms central in the house for that

yes for that exam and you get in the bathtub. And sometimes if you have time you can grab a mattress throw it on top or blanket. Yeah, but um, football helmets new one? Yeah, tackle that thing.

Both my sister and myself were we had helmets.

Yeah, I guess it would help a little bit.

I mean, I was probably like seven at that time. Yeah.

So I have been doing some electronic work. It's a 3d printing noisemakers. So I've been working on a super secret DEF CON badge, the power subsystem for it. And it is based off the Doom shitty add on I built last year, or I guess it was technically this year. built this year for DEF CON 27. So it uses USB type C for like cable power. Or like auxiliary power, I guess you could say what you can call it, and I'm using the 5.1k pulled both CC pins down, unlike the Raspberry Pi four. So you pull both those pins down. And that gives you 1.5 amps at five volts from a USB type three charger, which is going to be plenty of power for our badge. And then the other power because like the badges have to have their own power source. And we haven't invented like power scavenging for high powered applications yet. So you have to have a battery. So we're using alkaline primary cells like double A batteries. So

the good old Amazon double A's, right?

Yeah. We don't really like lithium batteries that much for badges. Because they're kind of like exposed. And if you get if a double A battery gets shorted out, it takes a while for it to get hot. And it doesn't typically explode catastrophically and burn people or fire Yeah, fire. Whereas lithium, if you short it out, it's going to rupture. It's gonna puke. Its guts pretty fast, pretty fast smoke out. It's gonna let the smoke out pretty quickly. So we typically do like alkaline primary cells. So I'm basing the power system off that. And I'm also using the TPS 2113, which is why use on Doom to do like the power switching. So that's like a power mux that does hot swapping.

So when you if you plug it in, you can see it like right away. Yeah, so it's the power. Yeah, it

will switch power without interruption. That's, that's really nice. It's not the cheapest way you can implement that. But it works really well. And it's a single part. So labor wise, you typically work out. It's cheaper than building it out of discrete parts, like a couple of MOSFETs and some like an op amp. You could do it that way. But yeah, it works really well. I like it a lot. So I'm going to be reusing it this year. For next year's thing.

It's $2 and singles at Mauser right now, in quantity of 1000. It's still about a buck.

Yeah. And the thing is, there's not a lot of competitors to this device. Like if someone else out there knows of a power mics that handles like, around five volts kind of stuff. And about an amp, let me know. Because there's not a lot out there for this kind of stuff. It also has to have current limiting capabilities, which is does have

oh, okay, what do you have it set to?

Ours is set to 500 milliamps.

Okay, so just like regular USB, yeah.

And then also on this, this is kind of like a application note, I guess for badge power is a good way to think about it, because I also have like the shitty add on connector. And we're implementing proper current limonene for it through like a PTC resettable fuse. Last year we just used or this year, I guess, we just use like a resistor. And that doesn't is not the right way to do it.

Did you have any problems like specific problems with the

high powered chigiana ones would get browned out through that?

Oh, yeah.

So this year, we're going to have a PTC fuse they're set to 250 milliamps which is what the shitty add on spec says. And that is why we have the current limonene set to 500 which is basically double that and then I'm going to try a little buck switcher instead of because last year we use an LTO to knock down the battery voltage down to the 3.3 volts we needed. So I'm gonna try switch here this year.

What wasn't what Isn't the battery voltage three volts? on last year's?

Yes, I guess it was a. If it was five volts, it was going through an LTO. And then three bolt volts ran native.

Was it boosting it up to five volts? I thought there was only two batteries. All this stuff could run on three. Got it? Yeah. Okay, cool. Yeah, you could probably get longer life with a with a switcher on there.

Yeah, I think the switch because we're using the TLV 6256. Eight. And I think the I was doing the calculations for efficiency will get about 90% which is pretty good.

Did you use ti web bench? No, actually, no, you

didn't write from the datasheet? Well, I use web bench first. I couldn't find I wanted a lead. I wanted to lead part. Yeah. And they didn't have deleted parts in web bench. It was all like QFN or weird packages. And I wanted to lead it package so it'd be easier to fix in the field. And so this TLV 62568 is it's weird. So it's like a flat SOT 23 Six. So instead of a J lead it's got it's just like flat out. Like, like a no lead. Yeah, except that it has leads that come out. But they're flat. Wait, what? Yeah, go look at the park.

Okay, yeah, I gotta, I gotta see this.

It's really weird.

You know, okay. I had a thought the other day. This is in, in sort of in line with this.

So all the pictures showed as a sought, but it's not that that's not what it looks like,

right? I'm gonna I'm gonna go down to the bottom of the datasheet. As I'm looking at this. When is this this DRL package or whatnot? Yes, we're using the DRL

because that's like the only I couldn't find it in the SOT 23 Five or six?

Oh, yeah, I've seen these before. There's a lot of MOSFETs that come in this style of package where it just has the stubby little like, toes that

hey, yeah, that's a good way to put it. It's like, toes.

Yeah, they're like, it looks more like a bug. But But okay, so I had a thought the other day that would be that that would be really cool. On Mauser a Digi key when you're doing your search, you know how you can arrange or you can filter by package, it'd be really nice if you could just hover over a package, and it would give you an image of it. Because a lot of times like you will have like specific packages that are like T eyes version of an SLI see oh, yeah, it'd be really nice if you could just hover over and be like, Oh, that's what it is. You know, like, you might see something that's like an FR v dash nine c or something like that, like, I have no freaking clue what that means. But if you hover it over it and be like, Oh, that's this guy's version of a really standard package. You know? Yes. Yeah. That would be nice. That could just make things really nice. Honestly, when it comes down to picking components, pictures is a really, really nice thing.

All right, yeah. Yeah, cool. I you know, I used one of these the other day, I can't remember what it what it was. And that's exactly the whole thing. It was not called a DRL package. This was like, this is like a T SOP without J legs. Yeah, I don't, I don't know what I don't, I don't know what it's called.

But it looks like it's easier to service than a, like a DFN or QFN. In the field.

You know, I've, in my experience, these things actually sought a really, really well, that's good, just because like the bulk of the leg is sitting flat in the paste. And with a J leg. If you look at the angle that that the J leg actually touches the pad. Technically, there's only one point that it touches the pad, because it's at an angle that it reaches the PCB. And I know that's like super minor when we're talking about the kind of solder will but the sizes of things we're talking about here. But with this DRL package, the legs have a flat bottom that they just sit down, and just in microscope, inspections. I've always liked these packages. That's good. No, no, there you go.

No. And then so I got that designed over the weekend and got those boards ordered. And I'm also working on a lithium powered version that can recharge overtype see, because I've done like rechargeable lithium battery circuits over like USB micro, but never type C. So I'm gonna give it a shot. See what happens when I blow up.

Hang on, hang on. Did you just spill some secrets that In fact, no,

we're not using them versions.

Now. Okay, I was, I was hoping that he's built some secrets about

this is kind of like I'm building these so that when people ask us like, basic questions like, How do I power my badge? Because we get that a lot? I can be like blop blop? Well, I

mean, I mean, most of the time they have a double A pack on the back, right? Or you just put some batteries in it? Well,

like, how do you handle if you have USB to? Like, if you're going to plug it in? How do you do to power switching properly? Like also those most badges actually use lithium. And it's really scary that a lot of these badges also don't have lithium protection for them.

So right, right, if they got pierced or anything like that, which is a possibility, especially with how much alcohol is involved. Yes, it has happened. I'm sure. Yeah. Badges catching on fire. Last year, there was or we keep saying last year, this was August. It was August.

There were some badges that were pretty large. In physical size. There was the giant, Grumpy Cat one. Yeah, the grumpy cat one. And that one was seriously like, I don't know, like a foot and a half wide PCB. Yeah. And then somebody made a whole badge out of a, like the traditional popcorn tin, you know that you would get popcorn at it. Okay, movie theaters? Yeah. Like, some of them were really quite large. The Grumpy Cat one I believe played music. I can't remember. I think it did. And I may have had a lithium on it. It was certainly big enough that you could conceal the lithium battery?

Somewhere? Yeah. Some of them start to get a little bit obnoxious. Eventually, someone's just gonna, like,

get a slot machine and then put a chain around it. And it's like wet. Or a slot machine.

I mean, what I'm envisioning is like, a furniture mover like with with casters on it. And then there's just a chain that you put.

Exactly. I then there's a little generator underneath it running. Yeah, but running.

You know, the funny thing is like, having been to DEF CON only once? I can, I can already tell you that like, yeah, that would probably go over well, like people would come up and play it. Yeah, if you did that. You can play fine. Actually. Now actually, you would get kicked out really fast. Because I'm sure the casinos would not be cool with that. Yeah. A mobile slot machine. You know, actually. So Parker and I played a little bit of slots while we were there, just because I mean, like you stay here in Vegas. Yeah, you're in Vegas, and you're staying in a hotel. So it's like 10 feet from your hotel room now and like the newer? I'm only saying newer, because that's the first time I've ever played a slot machine. So I don't know what an older slot machine is. Other than what I've seen in like, entertainment and movies. Yeah, but like, they're elaborate now. And like giant curved screens with all kinds of graphics and stuff. There's a guy like you and I who's sitting back there who is like, a professional slot machine designer, you know, or Hello, Buffalo. Yeah, the

Buffalo game that was everywhere.

Oh, yeah. No, I mean, the thing is like Vegas is so weird because it's such like a sensory overload in every possible way where like, everything is screaming at you. And everything is like Oulu like getting like it's, and it's there's cash everywhere. And everyone's trying to give you alcohol, and it's just like, oh my god, what the hell is going on?

It's, it's really weird, because whenever I think about it, the casino floors are small and large at the same time.

Yeah. And there's, and there's, at least in my head, there's, there's nothing that you do that somebody's not watching, like somebody is watching you all the time all the

time. Especially if you're wearing like electronic boards around your neck and are lighting up like crazy.

I will tell this story because, well, because I want to. I asked, I asked for time off. But I just didn't even cross my mind to tell my boss what I was doing. But I asked for time off. And I got it approved. And then the day before I left for DEF CON. My boss came up to me. He goes, Wait, you're going to DEF CON, or you're going to Vegas. And I was like, Yeah, I'm going to Vegas. He's like God, why didn't you tell me you're going to Vegas and he pulls out 100 bucks and he hands it to me. And he goes the first blackjack table that you see. You walk up to it and you put you put this 100 bucks on black if you win 100 bucks. Then you keep the winnings and you give me back 100 And if you lose then we both laugh about it and sure enough I freaking did it I you want I want 100 bucks on black and I know it's not etiquette but like I don't know gambling is not my my my biggest thing so like I'm not really exactly sure I care about etiquette when it comes to it but like I want 100 bucks and I just said okay, and I just left I just took my 100 bucks I know you're supposed to tip the guy and stuff but I was like man I just I just took the 100 bucks Vegas isn't isn't my gym It was fun though.

The whole culture there of tipping like like I tip my waiters and stuff like that but like they're it's a different level of like, what you're expected to tip for.

Right? I'm sure I broke every single rule I sat down I put 100 I put 100 bucks down I want 100 bucks and then just left they probably hate me

but frankly I don't

I don't know if they have your your pictures now inside the door at Paris. And it's big red X over.

And you know what? I if that was true, I wouldn't care. Whatever I got 100 bucks. That was cool.

No. So my next projects Yeah. Oh, we're already talking about the next thing. Next project. I am working on my brewery finally again.

Yeah, cuz you've had you've had the electronic cabinet like

some so I actually looked at February 2018

was the last time you touched it didn't were 18 That's my birthday did

ah, well hopefully it'd be done before your birthday this time. Yeah. And then

you'll have to bring me some let me see here. Fat Elvis. I've got some okay fat Elvis or spotted steer, which are two of Parker's brews.

Yeah. So fat Elvis is a mock Tober fest, which so an Oktoberfest beer. We're going to get into the weeds here. Oktoberfest is supposed to be a lager. But a big fat Elvis is brewed like a lager. But it's with an ale yeast, US cold fermented. And it's pretty fucking good.

We're talking like 64 degrees 65 to 62 degrees in freedom, pretty cold

for nail. And then the other one spotted steer is a clone of the famous beer from Wisconsin spot. It's spot a cow, which is a cold cream male.

Well, that one was good, actually. So when it comes down to if we're talking about February, I think I would go with spotted steer over fat Elvis because? Well, October. Yes. Makes sense. So yeah, I

can I actually what I've done so far, is basically got all my stuff out of the closet and spread it all out of the garage. I'm like, Okay, this is what I have. And what do I need?

I I'm gonna pause you for a quick second. And the reason why, I don't know, I can't remember if we've talked about on the podcast or not. But well, a while ago, we we even pulled up a Hackaday article about like, how many things do you have to do to make something else true? Effectively, like, do you have to make a CNC so you can cut a piece so that you can make a machine such as you can like,

and how far down the rabbit hole right? How

far down the rabbit hole. And the whole thing was like, and I've been talking to Parker about this for a while, like, so. Something that I don't think we've mentioned, you completely stripped your entire garage of everything such that you could epoxy the floors, such that you could put everything in it such that you could get back to doing bronze.

Yes, I basically took six weeks to basically clean out the entire garage, took everything out, clean power, washed everything, painted the floor, repainted the walls, put new more lights in, and then put everything in I insulated the garage door to like all that. And now I'm finally back to doing projects. Now you can get back to making progress, right? Yes, on my brewing rig. So almost a year later. And the problem was I lost all my drawings that did have like, the actual like, through cycle I came up with because it's like, uh, oh, you had some really complex stuff going on with that? Yeah. And I lost it all and I couldn't find it. So I read through it. I had to redraw it again, so I could put it on but it actually I think matches because I came up with the same amount of fittings that I bought. It must mean it's correct. So like all those science stainless pieces I bought, it all matches well, and

you're doing the you're doing the thing that I haven't seen before or let me see if you're still doing it, but you were talking about recirculating the water while boiling right? Yes, I'm doing that still. I've not seen that before at least in the home gamer world. Yeah. So

I was going to do, I'm also recirculating in the heat exchanger for your mash. I'm also cycling that water through, because I can,

right so it's a it's a Herms system.

He is well, terms you go through the coil, right, the heat exchanger, right, right, but I'm also cycling the water in that the, the hot liquor tank, which is

basically a big pot, right? Because you got was it two or was it three pumps?

I have three pumps. Yeah, that's right. Yeah, so I Because Because previously I was using barbs with a whole bunch of silicone hose the pipe it all together. I've decided since I'm actually gonna get stainless, hardline and actually bend it all. And then that way makes cleaning even easier, because I just put like a really caustic material in there. And just like,

I remember the original idea behind this wasn't based off of brewing beer, it was based off of cleaning the system.

Yes, exactly. Right. Because like, I already make really good beer with like, a cooler and a turkey burner. So I'm like, okay, and cleaning sucks. Yes, cleaning is the worst, it takes longer to clean all my equipment than it did to brew beer. So Mike, can I make a system where all I do is put cleaner in the hot liquor tank, which is the first vessel in the Homebrew rig, and then let that run and then turn some vials and that goes into the next chamber, cleans it and then goes into the boil at the end. And that's all you have to do. And then I've rents at the end right? Right. So like, yeah, so I'm gonna run silicone hoses because that because silicone hoses will like sag and so like we're just collecting them. I'm just gonna hard line it. And so I ordered a tube bender and go and start playing around with bending stainless should be interesting.

Are you going to put sand inside of the tubes when you bend it?

No, the bender I got it's got like a mandrel bend. You got a mandrel design manual tune better because doesn't have the particles inside. But it's actually got proper dye forming dye right so it's not gonna just crimp crimp the crap out of it. Yeah, it's not gonna do that.

That's cool. What's What's the so what size tubing Are

you dealing with? I'm gonna do half inch I think mainly because my, my coil is half inch. And so going from a bat, I think like the largest most people using homebrew is like five eighths. So going to five eighths doesn't seem beneficial for me because I'm already restricted on one tubing size.

Oh, geez. We're going back to physics here. Like if you have fluid if you go from one a larger size tube to a smaller size tube doesn't the it speeds and speeds up right? Yeah.

So I think I'm just gonna stick with half inch through the whole system should be fine. Right? It's like I have a half inch is pretty big because most people use three eighths. Yeah. And I have enough pump. Like these are pretty big. The called chunky pumps, right? Like they're pretty, pretty beefy. 230 volt models.

Right, right. Yeah, I have one of those chuggers and if you run it wide open, I mean, it Yeah, it pushes it. I can't remember how many gallons per hour it is. But it's multiple.

You know, my, my ideal situation here is I can run I want to be able to run all the pumps, full blast. I don't want to have the neck come down or anything. So I've been designing everything to be able to handle that. So half inch should be fine. If no like the intake on these are like one inch diameter. They're huge. Yeah, it's silly, how big it is.

Well, and a lot of that's for priming. They have it's so big, it's just so you can collect some liquids and fluid. Yeah. So the biggest thing I found out about the chugger pump that I have is when you're using it to recirculate so there's a step in brewing, where you have your liquid is in contact with your grains. And what you're doing is you're activating enzymes at a particular temperature and making tea. You're making tea Yeah, you're you're literally making a tea. But in in the more advanced versions of it, you're taking some of that tea off the bottom and then off the bottom of a giant pot of this tea and you're recirculating it up to the top. And while you're recirculating it, you're also monitoring and adjusting the temperature such that you can maintain it because certain enzymes work at certain temperatures and others work and others. And depending on what enzyme you're activating, you can actually change the flavor of the beer. Regardless of it.

It's the funny thing is when you say that to it's all it's like four degrees of window, right, right. I know it's super sharp to Yeah, and 156. So you can brew same materials of beer or same ingredients in your beer and 152 You're going to get a drier beer at the end versus 156

exist. actly and that's the hence the whole reason why like Parker and I get kind of like anal about PID controls and electronic stuff with this because like, the biggest thing is it's actually not hard to brew a beer, it's hard to repeat a brew, repeat. That's the biggest, the biggest thing like, I can make you some swill, any day, but like, can I make the same swill is the big thing. But actually, so the whole thing with these trigger pumps I'm getting at is like, when you're actually taking liquid off the bottom of the grains and then replacing it on top, these pumps are, are powerful enough that they will compact the grain and and like basically suck it dry. Like you. So you pretty much have to have flow control on them. Okay, which flow control is a valve, a valve that you do manually, like, there's really, I looked into once doing electronic valves. In fact, I bought a 24 volt electronic valve

that it's a cool valve because it basically just has limit switches at open and closed. So you can calibrate it. But it's a DC motor that opens it. So in order to do like proportional valves, you'd have to base it on time with a microcontroller. And that's kind of crappy, because I don't know, like, it's not a stepper controlled valve, which would be nice. But those are very expensive.

Well, you would I would do with that DC is just have a flow meter in line,

right, and then PID back to the flow meter. Yeah, the thing about it is most of the time, especially with like, going through the grain bed, and like filtering through things, we're not talking about seconds worth of data we're talking about, like, you pretty much have to let it run for four or five minutes, and then take start your PID, because like things are really slow, there's a lot of lag time because you have to learn that that grain bed is a huge sponge. And it takes a ton of time for the for the liquid at top to get to the bottom. Even though like the pots really not that big. You'd be surprised at how long it takes to actually get through there.

So So yeah, I got I looked more into into the process, and I want to talk over with you probably after the podcast over the whole thing. Make sure I'm not going too crazy with it. Now you're

not going crazy enough I can already tell you.

So this will be the challenge. Now is my brewery going to be working before your fermentation controller?

Oh, damn it. Really, you're you're you're gonna do that to me? Yes, well, actually. So I mean, I owe you a fermentation controller. So let's let's just make it a general goal that I give you the fermentation controller when you breweries done. So in Christmas of 20. Now it'll be before then it will certainly be before.

I'm open to burst and beer for Christmas. Well prove by Christmas.

Well, we will wait, wait, wait, wait. You haven't mentioned something though. So we've been talking about your whole brewing system here. But you still haven't mentioned that you're talking about welding up the cart that holds all this stuff together. So remember, before you even touch that you still have to build the

entire cart. Yes, yeah. But I think I need to like model up like what how the pots are going to be set up. It's so funny because like I showed this to my brother, my brother's got a really fancy system that he pairs with. And he's got the normal like Herms style three pot system, right? Yeah, and I've got it's weird because I have two pots that like the normal height and then my brew pot is low. So I'm using it so far. I've got three pumps. I'm using gravity to go from my mash tun to my boil pot. Yeah, because I like for some reason in my brain. I like that. Okay, because that's how I've always so like, I'm having this research of like the mash tun but I'm not, I'm not gonna do spurge batch sparging with the runoff. He's still just gonna like just dump it on that style. Okay. Yeah, so like you do.

I mean, you are insanely Overkill is what you're telling me? Yes. Like mostly, most people alike dream for one pump to do everything you're talking about. And you're doing three pumps and then not utilizing them?

Yes. Well, they're just they just have like specific functions. Like one pump is to pump water in the hot liquor tank, okay, so that's it can pump water from most of the time it's pumping water, the water in the hot liquor tank just to keep it circulated over the the heater element right. But then you can turn a valve and then it can empty A hot liquor tank into your mash tun. So that's your spark water. Yeah, but I'm not using that spark. It just dumps all of it as a second batch. Oh, got

it? Yeah, yeah, I'm

doing it like a batch style like a day with my cooler,

right? Where you literally just lift the cooler and pour it pour

it into your Yeah. So that's that pump. And then there's the other pump, which circulates the mash water into the heat exchanger. And that's all that one does. Doesn't do anything else. Technically, I could use that one change direction and then pump water into the boil. But I'm going to have the boil below because I don't know for some reason I like having to slow runoff instead of pumping the fluid out into the next chamber. I don't know for some reason, in my mind that works better.

You know, the thing is like if you have a choke valve at the end of your pump, it's the same thing.

Yeah. I don't know. No.

All right, gravity feed it is.

Yeah. But then it's like, yeah, then I should just build a tiered system then, which only has like one pump as well.

Whatever. A tiered system technically doesn't even need a pump, because it just relies entirely on gravity. Well,

if you're doing Herms you need Oh, if you don't, yeah, you know.

And then I have another pump that's just circulating for the boil. So, I'm looking forward to that one. Because I want to be able to, because I'm gonna have it, because you know, I have that hot man. This is when when did the macro engineer podcast engineering podcast turned into the Homebrew Channel?

I think both of us want to homebrew and we haven't in a while. I think that's what they're ever Yeah, that's what's

so I have I have that hop, spider, right? That big stainless mesh thing. I want to get another one that my research from my, from the boy in my boil will go into. So it catches all the schmutz. Yeah, I'll be able to catch all the schmucks out of it. Yeah, so it will be able to get all the the hot

with the the protein goop that comes out. If you haven't brewed beer before, as soon as as soon as you get like the sugar water going, and you start boiling it like this magic happens where all this like goop starts to flow. Yeah.

So when you when you bring it to a boil all the all the not all the protein, but all the protein that's on that base denatured I guess is the right word

I did did the hot temperature volatile proteins break

apart breakout part and they clump together. And you you kind of want to collect that. It's not the best thing to put into your when you ferment. It's not the best thing. But on the flip side, the cold break was so when you started to chill it back down your boil, the opposite happens, the opposite happens. So you get a cold break as well. I've actually like the cold break in my, my, my ferments. I get the beasties tend to like that. I think

you know, okay, so there's a, we talked about this a long time ago, man, there was a There's a website called Blue law Sufi, where a guy does semi summit scientific tests on on these things where they will test like, what happens if you put the heartbreak or the cold break in your fermentation? What happens if you do XYZ and then they serve those beers to somebody or to a panel of people. And they see if people can identify the odd one out or something like that, they basically try to control one variable in the test and check for it. And in the test that they did, where they fermented where the yeast had access to the cold break. So basically, all of the excess goop instead of trying to filter it out, they just put it in the fermenter and put the yeast in and said go to town, the yeast actually like having a little bit of crap in there, they do a little bit better, they actually even do a little bit better if there's hot material in there. So, you know, the traditional way of homebrewers doing things is like on a stove where you just put everything in a pot, and then you put everything in the pot in a fermenter and you throw yeast on it and let it go to town. That's actually one of the best ways of doing it according to these guys, at least in their their studies that they did, mainly because if you make this like super scientifically pure chemical environment for yeast, a lot of times it doesn't have all the excess vitamins and nutrients that the yeast needs. Whereas like that extra protein crap. And like the stuff that's on the hot plant actually helps the yeast out with L for the initial growing phase of the yeast so you know, don't don't be afraid to like cough a little bit into your beer I guess. Get some phlegm in there.

So yeah, so I was gonna lead the because I always take the hot breakout or at least as much as I can, and then I leave the cold break in. So I was kind of setting up the system to kinda auto do that. Right. Let's be nice. And I think like, having a circulation in your boil is going to be nice.

Yeah, boiling but also agitating. Even though a boil isn't agitation but like, yeah, you're moving the liquid all the time all the time. Yeah. And then that way well and your your style of boiling which I adopted after boiling with you I used to be really gentle with my Boyles. And then I started brewing with Parker. And he just goes balls to the walls with his boils. I mean, like the most vigorous boil you've ever seen. And I started adopting it. And frankly, I'd noticed the difference, it makes better beer it makes it does make better beer, it's better. The thing about it is you evaporate more

water, yes, you have to start with more water. And I've found is I go a couple shades lighter. If you have like carmelized grain crystal like 60 or crystal 40 style grains, you go a shade lighter, because your boiler is going to is going to criminalize it harder. So it's gonna get darker. If the color the beer matters to

you. Well, and and if you're getting rid of excess water, you what you end up with his higher sugar content, you know, unless unless you're not accounting for that or are accounting for that. So so what I've started doing now that I want to switch over to electric and started brewing with Parker, when it comes time to boil, I just set my PID for 100% where it just 100. But just let's do 20 Go right to the element.

And what is it like 5000 Watts, yeah, 55,500 Watt, 5500

Watts, right into about seven gallons of water, that that's that water starts to dance pretty fast.

That's why I want the circulation is to kind of because with propane, it, it's more of an even distribute distribution, because you're spreading all that energy over the entire bottom. Whereas this is I'm worried about being a single coil. And then like getting crushed, like the coil itself gets crusty Oh, like I have to get. Yeah, and then I have to get in there and scrub it.

Well, that's what that's what Okay, well, here's the thing. I did a bit of research on that. And when you buy those, the heating elements, you get the ultra low watt density style. And that's the one I have those Yeah, the ceramic coating that's internal to it has distributes the heat really even doubles back on itself. So it's longer. Right, right. And in fact, on that brew law Sufi site, they even talk about that a little bit about scorching on your element, or not scorching on your element. So even if you're running full bore on 5500 Watts, you're not there's enough surface area that the temperature isn't so hot in one spot that yield Carmelites, the sugars, or you in other words, you want like stick it to the element.

Yeah, yeah. And then then at the end, what you would do is, since that pump is running, you turn another valve and instead of pumping it back into the pot right away, it will go into my plate chiller. Right. And then what you would do is in the hot liquor tank, which is the first thing you put your all your cold, you put ice in there, fill it with water, and then that pump runs the other side of the plate chiller. And then that cools down, you're done boil back down to 70 degrees or whatever, right? And then you turn the pump valve again, and it drains into your facilitator.

Yep. And then you're good to go, then it's just a month until you have beer.

Yeah. Well, I like to do six weeks. But yeah. Yeah, it's really funny looking at this and be like, the only reason it's designed this way is to make it easy to clean. So you, you seriously put Cleaner in a hot liquor tank and then turn a couple valves and it's all clean.

That's pretty awesome. Because they, I started brewing two batches of beer in one day, just because if I'm going to put the effort in, it just makes sense for me to do a lot in one day. And so I usually start at seven in the morning, and I'm done brewing the second batch about six or seven at night. And then I have to clean and it's three to four hours of cleaning to go Yeah, no, it absolutely sucks if I could just turn a couple of knobs. I mean by that time I've probably had a few beers. And the last thing you want to do is clean after having a few beers being on your feet for 12 hours.

So hopefully by next podcast I have kind of like I want to have like a 3d model of how the flow is going to work not like SolidWorks style but like SketchUp and like these are where the valves would go and this is how my tubing around so

it's just like big rectangles floating and spacing like this is generally where it'll go.

Yeah that way that way like I actually because the next step after that would be cutting the holes into the pots and mounting all the stuff because I'm going to I'm going to solder the with silver solder and solder that The bongs onto the stainless. And then basically, that's the next step is do all the whole cutting and that's part and then I can build the cart. Right? Yeah, hold the cart. And then I can start bending tubes to connect everything.

So you know how you said you were wanting to Brew by Christmas? Yeah, yeah, that's not happening.

That's four weeks.

Okay, prove me wrong. Prove me. Okay.

Oh, last thing on my list man, we

Yeah, we're almost an hour deep on this one. We're halfway through our

notes. Yeah. So this week, macro fab, we turned on guided tours of the platform. So Joey at work been has been working on kind of like these, like guided. Almost like, like, like videos in the platform and, and tooltips that will pop up. Like if you select something that you haven't selected before, stuff like that, to let help people know what's going on in the platform. So let me know, in our Slack channel, how that goes people because it's like live this week. So it's first time Have you ever tried something like this? So it's gonna be exciting. All right. What have you been up to? Steven? You got 15 minutes of content?

No, I do not have as much. I'm sure the listeners like yay. This is not one of us. This is not going to be one of our two hours super special episodes. Well, maybe it knows

that's coming up, though. Oh, 204 to five.

I mean, what time of the air is it? It's gonna be the showers out of the air. Yeah. And we we wink wink, nod nod. We've kind of got a bit of special stuff coming up for that. And by special stuff, we mean, normal. But no, actually, you know, we didn't even mention it. A few weeks ago, we talked about or I mentioned a no do an episode 200 doing like a q&a thing. And people could enter in their their questions and things. We made the mistake of doing that and then putting a string of guests like, back to back to back to back and realize that we only told our listeners to do that once. And so like nobody knew what to do. And so yeah, my bad. Wasn't that that was not planned out very well.

So episode 204 is going to be the Star Wars. Christmas Special. Episode Four.

So right before Christmas.

Yeah, you know, it's right after Christmas,

I think is it really? Is it. Four weeks is right after Chris. Wait. Four weeks from now is Christmas Eve? Are we are we recording a Christmas says podcast?

December 24. So yes, that's Christmas Eve

podcast. Nice. We should get like,

I think my my goal is because we have two guests for that podcast. Yeah, let's get them. I'm going to tell them it's going to Well, now they listen to this podcast. Oh, well. So my idea is I'm gonna tell them to show up an hour early. If you're our guests, don't listen to that. Show up an hour early. And just get them get those two drunk?

No, just them but not

us, does them not?

Oh, that would be great. Actually, you know, we need to hit them up and make sure that they're aware that that's Christmas Eve. We are doing that. I mean, I'm not being any. I'm not going anywhere. I'm going to be here.

So yeah. December 24. I won't be I think recording. That podcast is our two guests to make sure that's okay. And then I probably should ask the other. Ask our audio engineer Josh, if he will get us. Get us to us on Christmas Day. I had to do the editing. Wouldn't that be great? They'd be able to give our listeners the gift of us on Star Wars for Christmas this year. Merry Christmas, everybody. Hey, we have to pull it off first. And I have to be brewing beer by then.

Yeah, this is this is gonna go well. Let's see. So Steven, what do you been up to? Yeah, yeah. Let me talk about some stuff real quick, actually. So I've had a client project that I've been working on that is a multi layer PCB.

Well, that's that's not really descript. It's a six layer PCB, is what I'm getting at. And because the majority the bulk of the stuff I work on is for I've done one or two, two layer boards. In fact, I did a two layer board just the other week. And that was mainly like, really stripped down really small part content. And it was mainly meant for just like, how cheap can I make this board to layer? But the difference between two and four layer nowadays is not that much. Still like it was like, How cheap can we make this, but I'm doing a six layer board for customer mainly because there's a ton of nets, it's a huge amount of components. And now I'm wanting to I did, I did this board before and four layers. And it worked, it actually worked out really, really well. And there was very few, if any issues with the board, but we're doing a reskin and customer added some parts. And so now I'm like, Okay, I think I'd like to move to six layer just to get better signal routing.

One of the things, though, that I've been researching is okay, with four layer, I'm pretty comfortable and confident with my stack up where I do, you know, I have a particular way that I like doing it with like signals on the outside ground and power on the inside. And what's nice about that is your two signal layers are separated by, you know, typically ground planes or power planes. But you also get the inner plane capacitance between your, your ground and your power planes. That's kind of nice. But when it comes down to six layer boards, you get a lot more options. And you know, if you go to eight layers, you get even more options than that. And so, have you ever done a six layer board? Burger?

Yes, I've done. Yeah, the pin heck. System was six

layer. That's right. That's right. But yeah, and you were dedicating one of those layers to like high current grounds, right.

We had a we had signal 3.35 12 signal, ground signal.

Okay, so you were you were doing that, mainly because you had so much power and ground. Now we had,

we had three different power rails and trying to route those to all different parts of the board was maddening. That's actually one of the big benefits of the of the pennant tour is we reduced how many power rails we have. So we get to go to four layers.

Which is cheaper, right? Yes, you know, and in the quantity that this customer is looking at, I looked at the difference in price between four layer and six layer boards, and ended up being $1, aboard extra to go to six layers. So in terms of what I get with signal routing, and everything, this worked out really, really it's worth that. It's worth $1, for sure. But I ended up going with this stack up where I have signal on top first layers ground, then the third layer, inner layer, I'm sorry, signal on top, first and the layer is ground second, and a layer is signal. Third inner layer is power. Fourth inner layer is another power. And then the bottom is signal again, so three signal layers to power layers and one ground layer. And I actually separated the ground and the power layers, as opposed to putting them adjacent to each other, mainly because I wanted to have shielding going on there. So that inner layer that is signal, so my two outer layers are signals and I have one internal layer that signal, I read it all my digital stuff on the internal layer, and then all my analog stuff on the outer layers, mainly because I have tons of, of analog stuff. And I have generally slow signals actually, for the digital stuff. Most of the digital stuff is actually just switching, you know, routing, routing switches, which is digital switches. There's a really, really small amount of digital communication and it only goes a very small distance on the board. This board is about six inches by six inches. So it's not a small board. But the analog is all over the damn place. And the the Digital's you know, the the probably the most traveled the digital has to do is illuminate LEDs on all extents of the board. So that's why I thought like, Okay, I'll put I'll put digital on the internal layer. No, I did. I wasn't necessarily designing this with like the most intense EMC clear requirements. Yeah, requirements. So a bit of my research found that this might not be the most optimal for EMC compliance, which I'm not particularly wired worried about with this customer. It's not a huge requirement. Signal. Signal Integrity is a bit more important to me right now. That's why I wanted to separate any digital crap with my two analogs. And then my two analog planes or signal layers are separated very far apart from each other. And I'm trying to be well not trying to. I'm being pretty really particular about how I ground things. Even though I am doing ground planes. I'm keeping my Digital Ground playing separate. And I've actually got the analog chopped into two different sections, because I've got two VCOs, that kind of work in concert with each other voltage controlled oscillators, and they share a ground and they have their own power supply. And so they have like a contained ground area. And then I have a whole bunch of opposite signal conditioning area that actually has its own grounding. And like I said, this is kind of Rev two of this board. I tried that before. And it was fantastic. Everything was really quiet and worked out well. So I don't know, like, what as soon as you go past four layers, things get a lot more complex, and you get a ton more options. And that's where it starts to get kind of weird. And the whole thing about this board is it has nine separate power supply rails, I've got 12, negative 12, five, negative five, a five volt reference, a negative five volt reference, 3.3 volt digital, five volt, digital, and then I'm lumping ground in there. Also, I wasn't counting, so I'm not sure if that's all the way up to nine. But like all of those like, those are my power supply rails. That's why I was like, I'm going to need two more layers, layers for this. And I'm not running planes for my power supplies. I mean, obviously I will be I only have two layers to do with that. But But so far, like I I'm I have three nets or something like that left to do tonight. And I'm going to order the boards tomorrow morning. Yeah, which is, which is nice. So I like doing more than four layer boards because it always feels. I don't know, there, it feels different. Because like you get to think about things in a different way. And most of the time, I don't get to do six or more than four layer boards. And I've done an eight layer before where I did signal, ground signal, power power signal ground signal, you know, like, in that kind of configuration. And that was that was fun. Yeah, yeah, to have four different power planes, and four different signal planes was super nice. But when you have a big BGA processor, you pretty much have to do that.

When I started making boards, you know, we did two layer boards. That's how you kind of start. And then when I got I found out that four layer boards were a thing, it made routing fun again, you'd like all these in the digital realm, you're like, oh, yeah, I just need ground, grab with a via, oh, I need power grab with a via, like, That's it, you don't have to route ground and power anymore for most circuits.

And we've talked about that a handful of times plane and plunge,

which, for the majority of digital circuits works completely fine.

Yeah, yeah, yeah, yeah. But when you start getting into more intensive stuff, like it's not gonna, it's not gonna cut it, but we don't really do that.

So now, my, my new style is kind of like, how far can I get away with putting all the signals on one layer? Yeah, that's my new thing. And then like, so I can do a two layer. And then so power is on top put signals and then ground is the bottom only thing that can be on the bottom is ground? Like how far can I push that kind of topography. And like that power system I designed that's that way, like everything is on the top layer. And then the only thing on the bottom is ground. Right? Right. So it should be a pretty good, theoretically stable and low noise digital circuit.

You know, one of the things I've been doing more recently is a different method of thinking about how the layout comes together. Because I like to place most of my components before a single trace goes down. I don't like the whole idea of like place a circuit then then route it and then place a circuit and then route it all place the almost the entire board, or, you know, I might route before I'm done placing but it'll be close to done before what's gonna finally be and I will go and readjust my schematic and readjust pin numbers and all kinds of stuff to make sure that I get as many signals as I can as short as possible and on one layer. And then so like, I think if you start thinking of it that way you get, you get your shortest traces, you get the fewest amount of vias, and then any of your extra layers feel like icing on the cake, because like you can just finish off with those layers. For all the stuff that you just can't fit. And especially when you start like with in the analog domain, I really really focus on you know, keeping my feedback pads really short. If I have like mixers or anything like that going on. I'll keep all the resistors that mixed together into the inverting terminal of an op amp. I'll keep all that stuff as cold as I can, to the to my op amps, and then all my signals that derive to that I tried to make them, you know, flow in a in a logical sense. And it's proven to be really, it's proven to be really nice, you spend more time up front, such that like if someone walks by, and they're like, you've only gotten this far on your circuit board, and I was like, come back in an hour. And, you know, all of these traces will be just like black done. Yeah, like, if you lay it out nice, then the actual action of connecting pads to other pads happens in the blink of an eye, because you've already done it in your head, really. So I sort of did that with this six layer board. And in fact, the majority of this board, the whole reason why I even was doing a second revision was because the first one was very difficult to select of solder. So like, above and beyond like electrical like functionality and integrity, which the first board worked fantastic, it was hard to manufacture, because we didn't have enough clearances. So I moved a lot of the components to the top side of the board, giving us a lot more clearance on the bottom side for our machinery. So I don't know, worked out well. I'm happy. This has been a project that's been going on for a while. So I plan on finishing that tonight. And then I can I can be off for Turkey Day. So one of the things I've been working on, I mentioned this last week is that that preamp that I designed with Josh Rosa or Roz, and I've actually been using my high voltage power supply to power it, I have a high voltage regulator power supply that goes up to 400 volts. And that's been great. But eventually, I do want to actually install a power supply in it. And I've got two options now. So earlier 2019, I designed the box in a box, which was just like a high voltage power supply and and a high current low voltage power supply that were both SMPS that ran ran off of 18 volt DC that you could power a handful of tubes off of. And I was thinking I could just put a box in a box inside this preamp and then power the whole preamp and do all of that jazz, which could work out. But I was also thinking a cheaper and easier method would just be to do a multi transformer solution, which I've always liked this, I've done this before. In the past, it's a little goofy, and it's not particularly efficient. But if you just need to get something done, it totally works. If you take 115 to 12.6 volt transformer, so a step down transformer, you can basically plug mains into it and you get 12.6 on the back end. And then you can use that 12.6 For your low voltage, high current electronics, which for this preamp would just be the heaters of my tubes, which is close to 500 milliamps. So about six watts coming off of that kind of thing. But then you can just take another transformer, that's a 12 volt to 220 volt, or take a 220 to 12 volt stepdown flip it around and plug that 12 volts back into it, and then you can get your high voltage. So by using two transformers back to back, you step down and step up, you can get both your low voltage and your high voltage for you know, pretty cheap. So I think I'm actually going to go with a solution like that just because I found some flat pack transformers that will mount to circuit boards and still fit within a one you rack mount device. And it just makes things really quite simple triad electronics have a handful of flat pack transformers that are I think the thickest one I have is like 1.3 inches which still fits within a one you rack. enclosure. Which one you is 1.75 inches.

Is that triad? magnetics

Yeah, that's right. Yeah, I think the the let me see here. I've got the part numbers for these transformers. Let me look them up. I think they're the F P series. Yeah, SP 12 Dash 1900. And then the FP 24 Dash 500. So yeah, the FP 12. Dash Cam TC MT

flatpacks.

Yep, yep. And they're actually kind of cool because it's what it is, is it's just a transformer that has four different coils in it. And so you can wire them in series or parallel. And you can run them as bridge rectifiers or as center tap transformers. So you get a bunch of options with these guys. And in singles, they're not unbelievably expensive. So I've totally used these before for these kinds of applications. And they weren't great.

I didn't know that kind of thing existed. That's cool.

Yep. So really easy to make a little PCB for.

Alright, so onto the RFO. Yep,

we're already like an hour and 10 minutes,

an hour and 10 minutes

Cool. Oh yeah, this first one I put on this list, mainly because I watched a video this the other day, and it's it's pretty cool. So Hackaday has an article titled that cheating at bowling the hacker way, which is just a cool article, go check it out this guy, I'm pologize I don't remember his name at the moment, but he created a bowling ball that has a mechanism inside that's pretty similar to the mechanism that the robot BB eight from Star Wars has where it's basically just a gyroscopic ball that can roll. Okay, so this guy created a bowling ball that had that it's actually a bowling ball, he used that material. But inside he put like a gyro system that is able to adjust its center of mass. And he hooks that up to a system that he puts on his body. Such that when he leans he can adjust the center of mass of the bowling ball. So he can bowl and then lean his body and the ball will go that direction. Or it'll bias towards that direction. Yeah,

it seems like when you ball and you're like,

yeah, no, it totally does actually work. So this like, I you know, I wouldn't be surprised if it was actually powerful enough if he rolled a gutter ball, and then when Yeah, it would pop out. You know, that'd be cool. That'd be super cool. He has a whole like build video of it too. And the design work. It's super impressive. So yeah, go check that out. Cool. It's something I found out this week. Really cool. Um, I don't know exactly what to think of this. Digi key is now actually stalking vacuum tubes. So it's 2019. And they just now started picking up vacuum tubes, which makes me sit back and be like, I guess there must be enough of a market that DigiKey found it worthwhile to stock vacuum tubes. And not only do they stock vacuum tubes, they're actually stocking new old stock vacuum tubes. So vacuum tubes that were manufactured in yesteryear. So the thing about this is, clearly they teamed up with tube depot, which is a provider or a vendor that does vacuum tubes. Because if you look at the Digi key stock, everything is tube depot. So it pretty much just looks like whatever to do depot has in stock Digi key, you can purchase it directly. So I wouldn't be surprised if they dropship now, but it is it is kind of interesting to see like a modern component provider providing vacuum tubes. Like I said, somebody at Digi key must have done their research and said, Hey, this is reasonable enough. I mean, I know Digi key has something in the order of 10 million components available. So it's not surprising that they just add more. But pretty cool. So if you need vacuum tubes, Digi key is now a source. So yeah, if you need vacuum tubes and FPGAs you can buy them in the same place. Now it's a save shipping saves us a fortune. Right? The only thing that's that's interesting about that is most of the time when you're buying especially power tubes, you want to buy them pre matched. So somebody has already measured their values and put them in pairs together or quads. And so far, I haven't seen that from Digi key. But then again,

they have it's like it's like nos 300 B 1961 pair. Oh, okay, so they are actually selling them pairs Go figure. But they don't have any of those in stock and those are $9,995

Are you kidding me? What was the what was the part number?

No es hyphen 300 B hyphen 1961. Hyphen pair?

Oh, yeah, well, the 300 B's like a new manufactured 300 B which is a giant power Triaud is there in the range of like 160 bucks. So like the Vudu ones from yesteryear are expensive. So that's not

even the most expensive one though. There's one here the TK hyphen u 47. Dash and p 25k 25,000. To one in stock. Really? Yes.

I said even a tube.

No, no,

I haven't. Oh, wait. Oh, that's a Telefunken Okay, yeah, that's that's an old school telephone cannon. Man that is dripping with smoke and mirrors and voodoo. But they don't have any in stock. When they do let me know.

Did you send us one?

Yeah. I'll test it for you.

So is that just like old school style tube that like people like it's why it's so I've heard of the 300 B before I haven't heard of that other one.

So you 47 A u 47. is a is a is a vintage microphone. So I'm not sure I haven't heard of a U 47. too.

It's a match pair. hear, Oh, it's a matched pair of microphones, I

think. Yeah, I think that might be possibly a missed label. It is. It is actually a microphone. Okay. So that's a that's an old u 47. Telefunken. Microphone. And those are kind of legendary the Neumann U 40. sevens, legendary. Yeah. So when we wait, let's look at this vintage. I'm looking on reverb.com Right now, which is a audio equipment reselling place, there is a vintage Neumann Telefunken. New 47 microphone for $9,500 right now. So maybe we should just get a pair of those and start recording on those right. Yeah. Jay, yeah, Josh are the our audio editing guy, he's probably like, I'm gonna go buy that right now.

Okay, so our next topic is the Toshiba Tec K e 8x. X, E fuses ICs. So this was I got an email from Mouser about these, like one of their, like, new products, emails. And so this is a e fuse. So it's a, it's a like a reset. It's like a current limiting chip. And it has a overvoltage undervoltage protection built in. So it is a basically a fuse, that's resettable. But instead of it working by basically like a PTC fuse heats up, and then it like, breaks internally. On the basically the resistance goes to infinite basically right. And a PTC fuse. Sure. This actually has like an active component and so works faster.

Right, it has a trip point as a threshold. Yeah,

where's the PTC fuse kind of just like ramps in.

And with PTC fuses, it depends on like how quickly you approach that, like, if you're, if you're right at the edge of the current limit, it can take a long time for them to trip. But if you hit them with a huge surge of current, then it can take a lot less time. So

yeah, so these are more predictable and how they function. And we actually used Ti is version of this part, the TPS 20 592 6x before and I really liked those, but again, it was one of those, it's a TI part that no one really made a competitor for it's like the it's like that power MCSE. It's such a specific kind of part. And it does its job really well and no one really made a competitor to it. But Toshiba has basically almost a replacement part for this. Unfortunately, it's more expensive. And I don't know if it's any better or not than the TI part. But at least say hey, now there's an option if you're looking for an E fuse. Now there's two manufacturers, which is nice. I really like Eve uses a lot. I just wish they were cheaper. Because a PTC fuse is like 20 cents or less. And these are like a buck 20 They're a whole dollar more basically. Yeah. Plus they cost more to install because they usually have like eight leads versus two. So but if yours is nice if you're looking for like hot swapping, stuff like that, if users are usually the way to go,

right.

For pinball, we were looking at basically like how do we protect the board from people poking screwdrivers at it? So we need faster acting than that PTC fuse can handle what's the overvoltage production is really nice because a fuse doesn't really prevent that. So usually you have to add a fuse and then like you know, a TV is not TBSA I guess a TBS diode at the right clamping would work but you had to have a diode, a clamping diode to prevent over over voltage. So no, yeah, we can do it if you're looking for power protection for your devices users. Cool. And that was a long episode 200 Oh, Steven is seen wants me to do this as the outro.

So that was the macro fed engineering podcast. We were your hosts Stephen Craig

and Parker Dolman. Take it easy way everyone thank you. Yes, you are a listener for downloading our 200th episode of our show. Yes, 200 weeks in a row. We have done this recording through hurricanes flooding, people moving across the country, all sorts of things and we still have not missed an episode yet yet. Oh probably happen. If you have a cool idea, project or topic, let Stephen and I know Tweet us at Mac fat at Longhorn engineer with no O's, or at analog E and G or email us at podcasts at Mack fed.com. Also check out our Slack channel, which is where our community that surrounds the podcast lives. We have about 450 people in there now. So come visit, talk about the podcast talk about engineering. Talk about annoying your co workers with an air raid siren, or brewery or whatever you want to talk about we talked about there. And if you're not subscribed to the podcast yet through your podcast app, go ahead and click that subscribe button. That way you get the latest episode right when I press submit on our podcast host and please review us wherever you find listen as it helps the show stay visible and helps new listeners find us. Thank you so much everyone