How to design your own PCB, or: A quasi-course in KiCad

take 7990 - good afternoon and welcome back to my workbench where today there's no power cut and I'm going to do something without trunks as usual so and this video is going to be to do with this little preamp circuit and which I have had lying around for the last 20 years or so after never really using it for what I originally wanted it for and now I've decided I would like to use it as a way to preamp my cellphone headphone output so I can run it off my standard stereo system without having to turn the volume controls up all the way on both both the phone and the stereo basically if anyone's ever done that they'll know that that's kind of an annoying thing you have to do so I want to have a preamp that I've always that problem and allows me to have the volume levels set normally and then this will do all the work instead of having to turn everything up but before I can use that I need to get a power supply for it so it needs a split 15 volt rail positive and negative 15 volts and I had originally created this little and board on some strip board with a couple of voltage regulators for it using this transformer but that never worked properly these these regulators seven eight one five four seven eight nine seven nine one five and I wasn't getting 15 volts out of them I was getting like 18 or 19 volts or something weird and don't know what was wrong with it but something funny going on it never worked properly so I kind of gave up on it um so yeah I want to redo that and I also want to make this as another sort of part of the homebrew PCB thing and the purposes of one testing out the Chinese yellow transfer paper I bought and we've got that up here along with my other stuff let's have a look so then I've just stuck in here I mean you've got the you've got the blue stuff which I bought pulser Pro stuff that's what I used last time that works pretty well and then there's this yellow Chinese stuff what I got off eBay for about doesn't know a lot cheaper anyway and I want to see if it works someone on one of the comments someone asked if I've tried it out yet in my head and so I thought well I should probably do that because I do want to know if it's any good and B I've been told that it's alright but you know err don't you know how good it is compared to this one so I want to find out anyway and so it's leading up to an excuse we get to test this and I mean I could just print any old design out and test it out but I figured that I was gonna go to all the trouble of actually bothering to do that and making a video about and everything I might as well use a design that I actually want to make anyway so I figured that getting this all working and making a board to do the proper voltage thing and everything for this I'd use that and that that allows me to do that both at the same time and we get a test this out and get this working and I also get to make this video which will be sort of a tutorial on how to create a printed circuit board design from scratch and also drop in a strop schematic from scratch and all that so in comparison to the work I did on this power supply here where I just basically scanned a pre-existing layout like the one in this manual here and you know just the board layout like this I scanned it out of the magazine and printed it out and everything to make the PCB for this supply and instead I'm going to look at sort of like what do you do if you don't have that what happens if all you've got is a schematic and you know whatever which you could have found in a magazine or or online or or you just you know you already had it made up yourself or whatever just working on how to do that and also making a basic sort of design for these voltage regulators and looking at some of that and so kind of I'll be putting together a basic schematic for a split rail power supply and also yeah and then showing how to create this the schematic for the PCB layout from that and I'm gonna be using my card on my computer here which is my preferred EDA tool the electronic design automation sort of Karrde thing for for doing schematic capture and PCB layout a lot of people I know use Eagle well not people I know but I know that a lot of people he was Eagle and which is actually a program I tried myself the first one I tried and after doing boards by hand just on graph paper in that I'm just hi originally started doing it but to do it on the computer there I originally tried Eagle and I really didn't like it I didn't like the way it worked and I didn't like the limitations of the free version but KY cared in comparison I much prefer the way it works a much through the interface and is much preferred the fact that it's completely free and it works on Linux and Mac and Windows and has no artificial limitations that you know you can have up to like I don't know 16 layer board or something I think and size is just infinite basically it's you know whatever but you need it any shape all that kind of stuff so it's much in my opinion it's a much better alternative to the free version of Eagle Eagles probably okay if you pay for it then you don't have the layer limitation and the size limitation but I still don't like the way it works so I'd never want to use it anyway okay cared obviously is really good for hobbyists because it's not super advanced there are you know things like Altium and all cared and software like there is gonna have a lot more more features and things that like it doesn't have but they're all the kind of advanced stuff that most hobbyists in that will never use probably and yeah I mean there are some things lacking in it which I wish it did have that I would like to use and like say free angle routing something like that but most software doesn't have it anyway and yeah relevant to do with what I'm talking about but yeah this is my sort of rationale behind why I use high cards so I'm gonna be using that whenever I show something to do with board design or whatever on on here it'll always be a I care because that's the one I like using okay so over at the computer here now and I'm doing a screen capture for this and I've just gone to the head website and current one is Kadesh PCB dog and you can download the version latest versions here for like I said Windows Mac Linux different versions I'm gonna guess that if you're at a point where you're designing your own electronics you probably already know how to use a computer and how to download stuff so I'm not gonna bother showing any of that but just to show the website and the options you have so yeah everything's there and if you need help there's forums and stuff for all the other stuff and yeah I think that documentation whatever but I'm gonna show basically a basic idea of how to do it so once you have it installed just load it up and your first get a blank screen nothing on it you need to create a project first so you can click this button here we can go file new project whatever so I'm gonna call it Universal PSU I think the older versions akaike had a kind of requirement where you needed to create a folder called whatever you want to call your project and then create a project called the same thing so the project and the folder name were both the same no spaces in the path or the folder or the file name nowadays I don't think that matters so you can pretty much call up what if you want and put it wherever you want but if you're using an older version does worth watching out for that I'm not entirely sure what happens if you don't do that if it'll just crash or something will get corrupted but yeah I just did it out of habit now so anyway something worth noting if you're using an older version for some reason maybe if you have it old the old system you can upgrade and you have to use an old version I don't know anyway and once you've created your project you can create files for it so these are all your different tools for trading in a schematic for editing footprints for editing circuit board layout the first one you always need to do is create a schematic and well we have to know what we're doing first so like I said I'm just gonna sort of basically copy the data sheets for these ones so if we go to this one like the 79 105 data sheet we've got this little basic example circuit of how to create a positive 15 negative 15 volt and I split well power supply and this is basically what I want for my my preamp but we want to make it I'm gonna make it a little bit more interesting than this I want to make it more Universal I want to have it so we can add also a 7 a 3 1 7 or a or 3 3 7 adjustable regulators and have the components basis if we look for example the example circuit for this where is it is there one in here there we go so the three one seven and three three seven they have a couple of resistors for voltage divider some other components for stability and you can have protection dyes and stuff and these resistors used to set the output voltage because it's an adjustable regulator and there's no direct ground pin connection it's through this so yeah I'm basically gonna have it so we have options for these resistors if you want to use the variable regulator and if you don't want to use it if you want to use a fixed voltage one then you omit this resistor admit these diodes etc and then you just replace this resistor with a wire link so that then is connected directly to ground so I'm gonna make sort of a universal one week and you can use either these fixed ones or the adjustable ones and I have all these like this protection diode is only designed for when the output capacitance is larger than the input capacitance when you switch off that might you know back drive this thing and short it out so you want to have this to allow the power to flow through that instead and yeah stuff like that which you may or may not need but I'll put those all in and so it's just optional with it when you want to populate the board when you want to build it you just choose whether you want those parts or not depending on what you're doing but the board will support all those different options that's basically the idea of it so yeah so just having a look at this basic design start with this so go to this schematic editor and you want to put their parts and so quickest way to do that is to click this button here just place component and then you just click somewhere on the on the page and it'll come up with this window here so this is your library browser and the names aren't that great at the moment but you can download other libraries that have a bit of names but I just I stick with this because I don't you know I'm used to it anyway so so say we want like a seven eight oh five we can just search for that and it'll come up and this basic one here is not very good because that doesn't have pin numbering on it but we can choose this one here this has the correct numbering and everything is easier to use otherwise you have to fix that later in the editor and it's just annoying so we'll put that there and and we want the opposite obviously the seven nine oh five and I'm choosing the five volt regulator not because you know that matters but you know all of these are the same pin out there all the same design so you know if it's a five volt or a nine volt or 12 volt 15 whatever it's all is the same but we're not going to add there's no generic thing but this this footprint well not a footprint this symbol here doesn't refer to any particular part really it's just a generic representation you can assign it to whichever part you want later so there's no footprint assigned to this at the moment I mean it says to-220 but you know I could assign this to a teo 92 footprint if I wanted to I could assign it to whatever I want later on so if I want to make a version of this board which used like seven eight a low fives a little to9 to small small current ones I could you I could just associate that with that and and change it and I wouldn't have to change the symbol here I could just keep it the same so I find that quite useful with guy code and something like Eagle doesn't do that and I don't really like it but anyway because these aren't specifically specific to the 5 volt regulators or anything like that I'm going to edit these names you can just hover your mouse cursor over the over the lettering and priests e and this will bring up this edit field and I'm going to change this to say 7 8 X X because that yeah I'm say it could be anything and the same with this 7 9 X 6 like that and we also want a if you hover over press M on your keyboard that gets you to move mode and yeah I'm gonna add also an lm317 as well so that's the adjustable version basically the same thing and I'm adding this separately because the pan out is different for this you can see the pins are all completely the opposite basically and so whereas with the 337 which is the negative adjustable one and I can show you that here 3 through 7 T version assets here to tradition if I put this next to this one we can see that the you know pin 3 is output pin one's ground to just similar very similar the resistor to ground what this is connected really to ground the input is dipinto so these are all exactly the same basically we don't need this we can just put that in the same footprint whether you want to have the fix or the adjustable one but with these ones that pronounced different so I'm gonna have to have both of these in at once I'll create two footprints that are separate but just right next to each other and then it's basically you know when you want to sort of the board together you'll just choose whichever one you want and put that in and the Associated resistors if necessary and yeah so it just makes it easier having one designed board for various options and like I said but but yeah these particular ones are pin outs different so you can't just drop it in this one well yeah I mean this one I can edit this LM 7 x / LM 3 3 7 because it's the same pin out we can just drop those straight in depending what we're doing so I'll move this down a bit another thing worth noting is this cursor I'm using you can turn these lines off if you don't like them and I personally do like them because it helps you line things up like they can get this line here and I can see all these regulators are all in line vertically so yeah it just helps with that kind of stuff I like it but yeah if we go to this basic layout here so we want you know an input capacitor of some kind I'm an output capacitor again like it depends which regulator using if you're using this one you might have these values if you're using the three-one-seven you might have a different value yeah so you know whatever you're using I'm just going to put in a basic pass it up for each one so if I go type in the C and just get a capacitor it could be anything there's no assignment with a value or type or size or anything physical dimensions at this mode at this point we just want a basic thing and you can put another one in on the output I also need some down here now these ones show non polarized in polarize I don't really know why and probably cuz these are higher values make more sense that's worth taking into consideration so I'll put in the type CP for polarised capacitor and again this is kind of a I cared being Kai cared that her default libraries are called this this or they've been called for 4 years so the fastest way to get what you want is just to type that we also need these diodes so again go to Part D the first one has a diode this is fully basic like basic components dieter's capacitors it's easy just to type the first letter of the device and it'll come straight up now you're also been noting if you want to rotate your parts for its R on your keyboard and it'll rotate them you don't take them afterwards obviously but while you're putting them in you can do that too so we want to have this here another one down here and that's pretty much it for the basic basic design so then you have to hook everything up so you go to the wire mode just one here click on that and then you click on the pen you want to connect once go over to what you want to connect it to click once again the older versions arc I cared you had to double click so the new ones it's just one so that might be worth noting if you are using an older version if you wish to connect these two though you were to double click and I believe so let me just test that one one click and that works but in some cases if you say connected this around to here I think it works ok how's interesting umm right so anyway connect these all up and now it's starting to look sensible and this obviously I'll move this down a bit so hover your mouse over the part press M you can move it down and I'm going to click click a trace of power connection here so we can just type the ground and this makes the schematic look Anita so I can put a ground symbol there and I can put one well no make sure that I need to put one here I'll put this as the actual rail going straight through so that'll go straight through as a ground there we go that can go like this and then if we have coming out here we're going to have the grandson born so this is our ground net here and then this pin is gonna be connected to the same connection because it's got the same ground label so this also goes up to ground there now this would connect directly to ground if it was a seven nine series regulator if it's a three three seven it's gonna have a resistor so I'm actually going to get back here Chris our resistor and I'm gonna put this here and I'm gonna put a note next to it just say four three three seven [Music] slash wire link four seven nine eight six I'm gonna create that text a little bit smaller for example you can put that there so that's a good note you know it's telling you that this is gonna be what it is so good schematic will have notes like this especially if there are different options for components so what it's saying is that if this is now on three three seven we have a resistor going from that pin to ground if it's not if it's a 796 version then it's gonna be replaced at the wire link so we just want to know so the anyone reading this will know what that's doing so yeah good idea to put notes like that and your schematic and if we connect this up there and this will connect up there down here and we need to do same basic thing with this now I've run out of room I guess here I can't really put another resistor and if I put this here it's going to be too close to this and I can't sort of well I could but it's not gonna look pretty good so I want to move this down a bit so let's just put this adjuster over here for one second and what I'm gonna do is click and drag and highlight these parts here and then I can right click and go drag block and that means I can drag these down and I can actually extend the wires so bring that to about here and it'll automatically extend the wires if I did that without going drag and it will just move everything like this which is not ideal so remove this over here I think connect that like this and then this can go around here and this particular one out it's gonna go there and if we check the data sheet again the basic idea we have a resistor going from output to adjust and then we have a diet here and a capacitor here for whatever reason that's for the datasheet we'll say another resistor so it'll go there and then again we have the same problem where there not enough room to put the next part so we have to move these over so I grab this again and either right-click into drag or press tab and then that'll extend these out so we've got more room and actually this hasn't I don't know if that's connected so I'm going to delete that wire you just hover over it press Delete and account with this it's asking me do all and delete this part here or don't delete the wire I stuck on the wire so I'm gonna move this down a little but if you don't have one of these junction dots that may not be connected so just to yeah just to be sure of that actually so we've got this here and the same goes for this side we need a resistor so if I want to copy this resistor for example I can just put my mouse over it press the C key I choose I want to use the component and that'll copy it here so for the output we want that and that will go to I other side so again we have the same problem we have to move these around so um yeah good good point to make for that um so I can move this if I press G over drags the whole thing because these two are now connected together so that's not very useful if I move this back and then I can create a thing here actually move this around there's a lot of moving stuff around this kind of thing if this yeah that's starting to look alright this we can line up with this but that's done a silly thing places to leak this wire delete that Junction did it again so there we go things are starting to look sensible and on us we want is a diode in parallel that resistor and a capacitor so diode it's gonna go here and we want to have the same thing over there I'm pretty sure and then a capacitor to the ground so um yeah we can have a look at this I mean what does it say here prediction diode d2 is recommended of C adjust is used and the start provides won't mean disaster and see adjust is recommended to improve her predictions so yeah so I mean if you're using this ready to use that and if you are use a diode so yeah pretty um pretty simple thing so it's good idea to have a wet there I mean you know depends on the design what you're doing but in general you probably want to have those fear for using the adjustable parts so yeah that gives us that and now I've got pretty much everything we basically need I'm gonna add an option for some big filter capacitors over here because you know you may want these on board or you might be driving this directly off a transformer like I will be or you may already have filter capacitors somewhere else and so you won't need them on here you'll just need the decoupling capacitors basically so yes that'll be like optional thing that you may or may not want again it's all basic and the design and what else output decoupling input decoupling main filter capacitors you've got allow adjustment things protection parts for the adjustable reviews if we're using those again if we not just take all those parts out and let's put the reverse protection diode across the back of the regulator again this only is necessary if your output capacitance is higher than your input capacitance ie if the bulk filtering capacitor here is lower than the whatever it's driving but in general you know you don't necessarily need that every time and obviously the one here we want to have it in the other direction yeah so there we go that's a basic sort of regulator thing we could also add maybe a potentiometer trim pot and series of this resistor or in place of it there's another option and I might do that later depending on how it's gonna look on the board but yeah probably not really what Muffy would use but yeah I mean if you want to trim it to be accurate I suppose here we could put that in just thinking how could you do that Oh set wise not connected see that little square there means not connected so it's delete that whoops no let's delete that wire and reattach it and we see it's actually had been connected to that part instead of the junction so good to watch out for things like that sometimes that happens sometimes they don't connect we expect them to so if things don't make sense when you start laying out your board and stuff isn't connected but it should be and check that now that was hanging on that dies completely in parallel here that needs to be connected here to see I'm already making silly mistakes it's kind of late in the day but yeah anyway and girly if I watch for that sort of stuff because if you've if you're beginner if you haven't done this before it's really easy to make silly mistakes like that and miss things up so good idea you know once you've done some of those finish it off come back the next day look over it again and just just make sure that it makes sense now I'm going to move that text over here so it's not going cut off with it wire so yeah that's what else okay so I want to have this for my transformer so we're going to need some sort of rectifying diodes over here so I'm going to go with diode I'm going to go with ya option for discrete diodes now I only need to put a connector I think so here I put connector free pin connector because yeah that's what we'll have if we have a center tapped transformer that would go they'll be a center tap we've got a ground and then you'd have your um diodes going here so one side would go to one of these dials that would be a positive we would have another diode there and that would go down to this side so whichever one of these is positive it's doing full wave rectification and you can see that that hasn't been connected either so I'm going to delete that wire whoops yes this is where you need to double click sometimes you need to double click and sometimes you don't and all depends on what the things doing which can be kind of annoying anyway yeah and then we want our negative rectification diodes for the negative rail so let's put that in so this would be your typical way of doing it you'd have your full wave rectification and this would go over to this pin and as we go to this one now we can see these wires overlap but these ones aren't connected because they've got no junction there and neither of these ones so it's all about whether or not there's a junction or not so yeah if we had a center tapped transformer full wave rectifier for both sides that's how it would look with four diodes I'm going to do discrete diodes here instead of bridge rectifier because there are so many different versions and shapes of bridge rectifier different sizes that Tron accommodate all those would just be really annoying so I'm going to go with discrete diodes and it also gives you the option to change that as well so for example if I wanted to have yeah if this was you know depends on what current level this this thing I'm going to be making is gonna be like exceed ten milliamps or something so we can use whatever diodes if you had a high current thing you'd want to have maybe bigger diodes than the one in 400 for whatever I'll be using but of course these getting you up about 11.5 amps anyway so but yeah that would make sense for that if we want to do half wave rectification like I'm gonna be doing with a non center-tapped transformer the option for doing there will be a bit different move this over here a little bit and then if I was doing that without oh let me think so if I have that half wave rectification means that one of these pins there will be no center tap one one side of the winding will be directly connected to ground so that's okay we can just say we just leave that open I wouldn't connect anything to it and if I was to connect these diodes I'd have to put another set of diodes would we hang on we'd still use one of these that would work actually yeah no what am I talking about basically yeah for for wave rectification it'll be like this for half wave you would omit these ones so I'm just gonna put a little box around these put another note here it's gonna say so yeah actually an well let's say 2 & 3 so yeah so basically if you're going to use a Cena tapped transformer and you want full wave rectification you put all 4 diodes and if you just want halfway if you I met these two and then you just connect your transformative these two pins here which means that the this diode will be doing the negative rectification on this side from this the pin and this one will be doing the positive on this side for the same pin and then this will be your other side which will go to ground so what that means is that these capacitors will only get charged up half as much as they would will not have as much with with power but half often because they're doing it on each half cycle of the sine wave and which also means that your input voltage will need to be a bit higher then it normally would be so that the the ripple if you want to make sure there's not not too much ripple you're going to want to have the have the input voltage a bit higher but you know I'm doing 20 volt 24 volts AC rectified that's gonna be even higher and then you know we're taking down to only 15 so they'll definitely be far more Headroom than the necessary to do all that correctly but yeah I mean that's basically it that's basically done that's the schematic I suppose you could put a fuse in line with well in line with this at some point maybe I'll add that as well add adjustable front part maybe you could also put like a power LED or something across the rails if you wanted to do that but the basic design here is done I mean that's pretty much what we want that's nice pretty much it and then and so I'll stop the video here and I'll make the next segment we'll be assigning all the component values the footprints and all that stuff and then during the board we'll be in like in the third segment so yeah that took a bit longer than I expected but there's the basic basic way to do it so yeah I mean that's how you scared to make a schematic there's also a bunch of other options in that you know you can create a bus and stuff if you're doing like a whole bunch of data lines or something you can connect them all together with a bus and basically as long as everything's labeled with the same name now if you want to label a wire you just place this one so if we had like this we'd have like say inputs rail positive or something you know then then everything here is called that and if I have another wire somewhere it's the same as like these ground flags these labels here you know anything else I call label with this name will be connected logically to each other even if it's not drawn connected with a wire it'll be connected in the netlist and the data behind the scenes so I can you know do whatever like that um anyway that's the basic thing so there we go so this the design I want and I'll get on to doing the board next okay so I'm back for part two of this circle design video and this part will be sort of labeling everything and associating footprints and all that and then in the third part I'll get on to actually laying at the board and doing all that stuff so um this is the basic schematic from what was last time obviously we haven't changed anything yet the basic design is fine but there are a couple of things I want to change just want to tidy up a bit and make some other stuff but obvious so especially with this input here it's a bit confusing I'm going to change it around I'm going to rotate this we can flip this on this axis and I'm going to give it a more obvious name whose going to be transformer and and I'm going to edit this because this is kind of a bit bit ambiguous so I'm just going to change us to say 1 & 2 it doesn't matter it could be could be 2 & 3 or 1 & 2 but yeah I yeah I'm going to change this note it's a bit sort of make that a bit more um readable so I'll put put a little box around that as well so that it's more obvious and I might move this over a bit and then I'm going to put a little line just like that so we get a better idea let me put this here yeah move this reference over here move this up a bit or maybe put this down yeah that's better anyway so that that's a bit more clear I can delete this label because that doesn't really make any sense I also need to put a let's rotate this around but and we want to give it an output connector as well because this is obviously gonna not gonna work so copy that and I'll rotate there's whatever here it at this name so it's out put it over here because without a connector or some sort of component to show for this we don't get any chance of actually putting a putting any pad because this will be associated with footprint so I can have some pads there otherwise be nothing to connect the output wires to on the board we just have the diodes and it will just stop there so you actually do have to have some kind of thing now this ground flag here doesn't look particularly good it's sort of a bit yeah it could be done better I suppose but oh well a little bit functions anyway so I don't mind and yeah so for a start just go around labeling things basically and put your notes in so that if things make sense then for example this one I'm going to change to 1 in 4 X just you know we'll be using and we could have a higher current one like 3 amp but not really any point because these regulators not going to be running you know they're gonna have like an amp it makes women that count they're gonna be really hot so you're probably gonna want to have something else if you're gonna do that this is probably gonna be like four designs that are you know 500 milliamps or less or something isn't gonna be a super high-powered thing if you want a really high power supply then she probably use something else anyway but yeah so yeah I can edit these as well we can sit here and do them all by hand like this or you should be able to go find in a place and if I say you know search for D so all diodes replace with one in for X and if we choose here match case surge rift is no I think that should do everything that whole word otherwise it'll you know change the D in this ground to two that we just want to have it so that only these diodes is labeled as D and this should yeah so it's finding this and I replace all it should do that so that that'll work if I had that sit not to not to match whole word it would have changed the D in this ground label to also say one in four X and that wouldn't be very useful so you have to watch that um the bit where has this question mark that's the reference designators that would be like you know C 1 C 2 C 3 C 4 etc you don't really need to do this manually unless you really want it to be manual but there was an automatic annotation thing feature that'll do that for you so you don't actually bother yeah so mmm suppose I should put a thing around this as well and let's see let's put a little box around all these parts and note that C is optional 103 x7 here and I mean this might seem a waste of time you know to put all this these notes but it is quite sort of important really especially when you go back to the design later on and you wonder why you put such a thing there it's really useful it's like comments when you're writing code and that it's just it just really helps and especially if you put the design out on the internet or something for other people to look at it it just it really does help other people having a look so yeah I mean I think that's pretty much most good enough I'll change let's see so this will be the input filter caps again those are optional unless you you know if you want the filtering on board if not I mean I'm gonna call these let's just say like 2,200 I'm not gonna bother putting a voltage on them because you know who could be whatever voltage you want I mean if you'll you know if you're gonna make a fifteen volt supply like I am then these are fully gonna be you know twenty five thirty five volt parts if you're making a five volt supply then 16 volt parts so we're gonna depend on what anyone's doing I'm just going to you know leave this here larger value so people know as a filter cap this will be again though yeah I don't know any point for this hmm [Music] just label this more I suppose let's go back to the hang on let's go back to this here so typically this resistor is always gonna be to 40 ohms I think you need to have at least a 10 milli ampere load or 20 milliamp load on these these type of regulators otherwise they won't regulate properly so okay 120 this is 240 and it should probably be yeah let's change that to 120 and calls these particular ones it's gonna call our adjust because that's always going to depend on what you actually what voltage you want out of them but these probably be under 20 for most people okay what was that they called it see see you just just call it that because the value again I'm gonna depend on what you're doing so um yeah probably that's about good enough for now I'll change the values later maybe if there's anything specific but um that's pretty much it for what you'd want I put a note you know in here somewhere and later on about what values when I have bit more we'll look at that see if there's it see if any of these have any generic values that would be the code you know the same value of all the time no matter what you're doing I think you know right but really it's going to depend on the circuit itself so so yeah that'll be good enough to start with anyway so once you've done that you need to cut your netlist this actually tells the the rest of the programs what's connected to what you press this button here generate netlist as you default if you're using everything in iCal never actually use any of these other options so yeah just I use that one if you want to use crackheads on PCB editor so generate and it'll want to save this Nicolas just use the default name unless you want to be confused so now of course it'll say well I haven't annotated anything there's no reference designators for any of these parts they're all just question marks so it will tell you that it won't you can do this manually yourself with the annotate button but this will let you enlisted automatically when you want to create a netlist which is quite useful so you just have to do the entire thing is automatically the default thing is that's fine for most people and again if you want to manually pick anything specific you can do that but that's done there that's labeled everything and it'll make sense so now the next part is to go to this program a cvpcb so this will this is the part where you associate each of these symbols schematic symbols with the actual physical part and so let's see so this is you formally green trees okay let's try it and see what it does okay so it's picked up that these are to-220 that's useful um so yeah so this will now have a big list of all your parts and and we do see here that for example you know this one's still called just see and this is just capacitive polarize and it's kind of but you know not that useful so it is better to give things decent names but that's okay okay see it it doesn't matter at this point but there we go I mean for example um take these two capacitors here c1 and c2 we know these are our main filter capacitors so they're gonna be quite large so we want to choose now you have this list here with all the different types of components you can either filter by library you can filter by pin count we can filter by keywords now I personally use like filtering by library cuz it makes more sense so obviously I'll go capacitors through-hole that's what I want for these and we can go to like capacitor radial diameter 16 millimeters that's probably about right um it's probably the biggest I'd expect anyone 20 years or something like that biggest I would probably be using um length 25 link 30 I think we got a diameter 16 link 30 millimeters pin spacing 7.5 IX challenge you here yeah on the bottom although I don't think you can see this down the bottom because it's cut off whether a video but yeah I'm gonna choose this one here and we all want to look what it looks like and click this button at the top a few selected footprint and that will show you the basic thing is it would look in the PCB editor and if you push this button here it'll give you a 3d version not all of them have 3d things but you can have a look you know you can have a basic look it's a capacitor it's that's what you'd expect the basics with a 3d model so I'm gonna start with that and for a start because I'd say that would probably be the right ones you just highlight the thing you want and double click I mean for example all these ones one in Bill the diodes are all exactly the same so we just go like diodes and choose do 41 I think that's a correct one yeah that that makes sense so you know we could have it like that I'm gonna have them sitting vertically that doesn't have a 3d thing but you know if you wanna do that I'll just go with this horizontal one to start with but you know I might change something to a vertical one if I need the space I can always change it later and you know these ones here the transformer input and output I'm just going to go with connector just choose white I store them there we want um I see if you just a basic connector oh yeah you just choose a pin here this is a bit kind of crusty to do it this way but um fin heater let's see straight one by three because of each one's three pins and we can get at that later it just gives us three pads to work with we can move them around and change the size and afterwards doesn't have to be you know it doesn't have to be this small pin header by that or whatever it's the default footprint but we can change that something else we can edit the pads and everything in the PCB editor later on so it's fine these resistors I'm just gonna go with you know standard resistor just as through-hole I'm doing this all through Hall because I know that's the easiest well it's arguably easier to solder anyway and all that and that's what I typically go with but yeah this was just ten millimeter I think let's see he had enough that's giving a pin pitch of 10 millimeters or a body links and well I'll go with 10 at the moment that should be you know I could enough and these capacitors here these are all going to be probably really small little electrolytic or film capacitors or ceramics or whatever so I'll just go let's see so I'll just go back to here actually so we've got c3 okay so c5 and c6 I think see you just as I say so they don't tell you um specifically water does that's going to depend for how do you somewhere else in the datasheet somewhere where it gives you an idea of what that should be but might depend on the rest of the circuit here we go okay so point 1 microfarad input 1 microfarad output pretty small but ID blah so yeah I'll just um let's see I'll put them as um I think these are small just rectangle oh no it's quite large let's try that one instead is your standard sort of sized capacitor [Music] actually you might go with a smaller pin spacing yeah maybe that one this little do a dis yeah small little thing that's a good idea that gives a better idea of the kind of thing we're looking at so I'll make those those and these ones can be great electrolytic or something that's probably what they'll be and the 2.5 normally depends facing will fit pretty much all small capacitors like they're all ten times or whatever so [Music] yeah yeah this is choose that so that should a that'll probably be perfectly fine for everything so you save this yeah save it so this Rhys Aves all these footprint names into the netlist and so the piece of unit who knows what to load when you load up the netlist and that and then you can just close out of this and go back to the schematic now I had noticed with the older versions that I cared that was a lot was sufficient to make the netlist work but for some reason on this version for probably a bug I guess you do have to go back here and just regenerate the netlist and resave it otherwise the PCB editor seems to choke on it and doesn't work for some reason yeah but that should be basic thing pretty much done and like any design I mean you know you start laying at the board you might find that some component to the wrong size or you know you need to change things so you know it's not gonna be all exact and I'll probably end up going back over this and adding some common values and editing some things maybe and changing the dimensions and stuff but for now for now I'm always going to leave it as it is it's all going to be you know good enough to start with so close this down save an exit and so we have to go onto the the next bit which is to load up the PCB editor and actually start making the board layout which is a nice bit of fun on its own right all right so this will be part three of the circuit board design and this is where we actually start laying out the circuit board itself so now we've got the schematic all done or at least mostly done like I said there's a some of these components haven't labeled yet but I'll tell you it at the end and we've created the netlist we've associated all the footprints what we want and now as it's just the sorry what was this thing now it's just the task of opening the PCB editor pcbnew is what they caught and now I can import the netlist with this button here so this is read knit list you had that and you if you chooses there's a read count netlist little read automatically read the netlist with the same name as the project and but of course you can browse for a different one if you want but yeah you just do that recount netlist and everything she can't green so that's all good and no errors typically if everything comes up read and nothing works that's probably because you like I see it you didn't tree save the netlist after after associated the footprint files which seems to be the main problem I've had with there's occasionally it does that in this version for but apart from that anyway so now it'll load everything up and it'll just dump it all on top of each other in a big pile there which is not particularly useful and you can manually move everything mmm key again and get everything out but it's also easier to just automatically get it to just sort of automatically spread them all out for you so what you need to do with that is get your board out front first so I want let's see I want my board this particular one will be 45 by 7 teeth 73 millimeters so I'm just going to add a line here and we choose the layer we want to draw on edge and I'm just going to zoom in to this was the origin of the good origin I believe it's this top left corner yeah which makes it easier to look at now is grid and I said it's a one millimeter I'll just go right up to wherever that SATs 0 0 as it shows down there at the bottom on the toolbar here and I'll just start there so we want 45 down I just find this is that you just way to do it and 45 by 7 III and I turn that because it would have been useful anyway so that's what my board is gonna look like that's the size it's gonna be and then obviously I can just highlight this and move it over to the center of the drawing so now that's good so now press escape to get out of the toy I should have mentioned that earlier on you just press Escape key on your keyboard to get out of any of these tools that you're working with and so I'm gonna go back down to copper I think she will choose the back copper because it's a single sided board click this button here I'll just manual and automatic okay lit it should be the description could be a bit more obvious I suppose but oh well the circular button might click and then go global spread in place and if you go spread out or footprints you have to have board outlined one up first through to do this but it'll just do it automatically and it's put them all over here for some random reason but there we go right so that's automatically done that so now we can start placing them much more easily and so I'm just gonna move this transformer one that can go on the side here somewhere obviously and then you can I have it our filter capacitors those will come in we can have these there's one gonna be quite tight because yeah this board is probably bit smaller than I would have liked but before what I'm doing to fit in I have to make it this this small um yeah so as I start I start explaining things and you have all these little white wires equal the rat's nest they're all the unrounded tracks they show you what connects to what basically you can turn that on and off this option over here and but generally you want that Auntie actually see what's unconnected what's not connected all that kind of thing and so basically you basically sort of start off by putting you know line everything up so that the rats nests makes sense so we should have I wait of course we need the a rectifier diodes first as why doesn't make any sense okay let's bring this over here I need the rectifier diodes so if we follow this trace you know that goes down to here this is our first one and what's the next one maybe one of these I mean d1 d2 it was D 1 2 4 so 3 & 4 so first of all let's put that to rotate some of these I'm going to put that one you know let's see it c1 c2 is go back to the schematic so d1 a3 okay c1 yeah so that actually should be it should go here and that should go there and then d2 that's one of our negative rail rectifiers c1 our first one I could go click on the edge of the board right here actually and d3 there's the same now well look at the stick the straight up here but then these connections have to be routed across to this side and if I put this one here it's much the same thing because remember these these cross over each other so what we do use as we can route the tracks between the pin switch makes things a lot easier so I'll show that in a second and but yeah yeah so design rules track what so one thing I've noticed a lot of people often do is they just click on they just sit yourself up and they start drawing tracks with it with the first thing they get and you get a really thin really thin trace if you do that and they might connect those and then like this and then that's it you know and if we light up the 3d viewer we can see you know these wires of these tracks have connected but they're very very thin they're very you know that that's very bad we want this to be a power supply we need we don't want tiny little wire that this is the kind of thing you want when you're doing digital stuff you know microcontrollers and then just like digital data lines and that kind of stuff it's not really what you want for a power supply so that's terrible so don't use the default trace width which is really tiny is what quarter of a millimeter so delete all those that's let's make that at all what you need is something but thicker than that so for design rules as how I do it you can set different you can choose different nets and stuff and add different custom sizes for that but I personally just go to couple design and I just add a bunch of basic sizes where you go you know point three and point four 0.5 0.8 11.5 - that's usually what I choose is the customs of track widths with widths and you can you can eat it to make sure self you add vias but of course there's a single outboards there are no veers won't matter and there we go then we can go up here to track choose something but I would probably go even 1.5 millimeters for these because you know it's it's big stuff we want something nice and take two would probably be a bit well mean you could use two I guess that doesn't really matter and the other thing also is the clearance so check that as well so where's that clearance default is a change of clearance - I'm gonna say maybe 0.5 millimeters but if you're laying out like you know if you're doing this is like a first board and that you might might even want to choose like a one millimeter clearance it just makes things easier and and if you um you can see these sort of outlines around these pads that will show you the the clearance so this is waiting a one millimeter between here and here so that's two millimeters between those two so you could have this up to that class and you've got a one millimeter clearance between these pads and that's you know really fine if we have a look at a 3d view you know that's that's perfectly acceptable for for standard stuff with you if you're doing this as the first thing I guess I would say to probably keep it at 0.5 at that minimum but you know as you go along and you get better at making these things at least if you're doing this by hand anyway good scene to a board house then you just got go with whatever their minimum is and doesn't really matter but if you're doing the PCP yourself at home then you know start with maybe one or two point five millimeters it makes it easier because you might get errors and the transfer in there and you have to touch it up with a pen and it's easier if you don't have to worry about the on the size of things anyway so if I was to do this I'm gonna go with 1.5 I mean these pins have pads now if they're too close together so actually going to move these so you right-click on a page and go um let's see I'm going to turn that off yeah okay footprints I see here you cursor there pad one drag pad I'm going to drag this out one grid line and that one Wow to actually think of those nice big clearance between these ones we want to have this this is probably gonna be quite thick wires sort of you know don't have space for the insulation to come in and all that and it makes more sense so this will be our ground that'll just go straight through to these for example but the actual outputs from the diodes well and for example you know this this diode here that connects to this pad that's fine that's not the way of anything let's connect straight to this that's fine that's not the way of anything so we could have this diet over here or on the edge of the board there that'll be okay and but this one for example what connects up here this pad also connects down to this other whoops that and in fact if we highlight the thing itself injuries highlight NIT we can click on this here it shows what's all connected so this these three things are there's and of course while this ground traces in the way now so it's much better if we just take this diode and move it down a bit to the point that it's padded on the other side for example and then it's just a simple case of routing that so there okay what's its problem here to Tracking's to close I don't know how because I've got a little bit of track there delete that okay it goes to here and then these ones go straight out to there for example that would probably make more sense to ya anyway let's just say that for example this is not that great but this is to have a look this will go there so the same goes for this one this one needs to connect to that so we could bring this to this side [Music] stick it there possibly throughout that track there underneath this one goes like this can move this diode to the side and that could go like that so it's just a you know a simple thing of routing bits and pieces underneath each other and there's probably a more elegant way to do that but I it works and we can sort of well actually this could probably go up a little bit probably move this up a little fit that in the middle there maybe maybe even bring this one down here that would work now these are kind of centered on this ground trace here and and then we can you know drag these over so fly the 3d viewer now you can see there's a little space there we can move these over we could sort of sneak these capacitors into the side here with his diodes uh and that should work now yeah it's not too bad I can do this anyway and what I do I know importantly though is that if you start dragging stuff around if I you know hover over a component bridgie I can I can drag it about when the tracks will follow it if I press em to move it it'll just move without the tracks and the point is that once you start doing that for a bit you know if I grab this one move this over here and eventually we end up with this thing where the traces are all just sort of flying around odd angles and you know debatable whether or not that looks any good but the point is it's not typically that efficient so I would say you kind of want to avoid that I personally don't like doing that so there's our delete all the traces like that and redo them all just not to move them like that in the first place so they're not to actually drag drag traces better to didn't this way so there's also one other thing to note is when you're moving traces about and when you're wearing traces you can push the forward slash key in your keyboard to adjust the corner angle right handle left-handed sort of thing so depending on how you're wanting to do the auto cornering yeah so anyways we move this down here fit them in about this fit big yes I'm bearing in mind here that this this keep out area of the pad is not where the the actual component will be the component body is over here the the lead is going to come in here this is going to be like a millimeter of clearance between that so we can trim these in like this I'm going to have to because everything's so sort of creamy but yeah I mean ultimately I can do that of course something like this it's not a huge deal how you do it this is a low frequency stuff 50 Hertz transformer it's not gonna be yeah a massive problem if you have a bad routing on this it's you know it's not usually usually important but it is good to show you these things neat and direct as possible so there we go and it starts to shape up a little bit better so now things are nicely sort of compact over here I mean yeah we could probably you know these faces are rather large and we probably need Evan that big if we had smaller ones you could fit them and right in there I guess but to constrain them to the actual board size which is what I have to do and don't really you know want to have components hanging off the side of the board and not know enough room for my thing anyway but you know we could put this out like twelve millimeter one that easily fit in here which probably make more sense I'm just trying you know save as much space as possible and there we go so yeah it's got our filter capacitors got a rectifier diodes that should be perfectly acceptable and let me just take our regulators let's grab this one here is our negative rail regulator and put this I guess on the edge of the board because heats thinking I mean for the thing I want to do specifically I don't actually need really any heat sinking like I said there's only like 10 20 milliamp current so these things won't will barely get warm but yeah it's um it's something you'd want to wear you want to look at defend what you're doing so actually probably would make sense to move this over a bit have this like in the middle between this so there's enough of room to sort of put some kind of heatsink I guess depending on how you want to do that I mean you could have eight think that sort of comes around this way and one that goes around that way if you want to have them facing each other we could have them coming off the back of the board and there but for my purpose that's not going to be enough space to do that do it that way anyway I'm gonna highlight there's a net here and use it to find out which components are still connected how to connect to this so we can have a look at here we can see it connects our output connector at some point but that will be yeah let's stick that and the like here that makes sense for this on the edge there so what's our input to this actually and this is the center pin I guess it makes things a little bit a little bit trickier so that's our output pin and this is well not our ground but our adjustment pin ground if it's a fixed voltage regulator and and Justin adjustment pin efforts the adjustable one so yeah let's have a look at the input pin first which has been that's been here so we could just say let's this is route this just right now let's just wrap this like this of course this doesn't like it because my clearance is too big it overlaps to these pads but of course that's not a big deal so we can turn the DRC off this has on line DRC which means it'll prevent you from connecting something that doesn't make sense and prevent you from making errors it's quite useful and you can see when that's turned off you get this little question mark thing it tells you that you can do stupid stuff like you know I can draw this you know straight over the top of this other track and it'll let me do it even though you know that's that's shorted that track to that one now if I turn the AC back on then you know it won't let me do that it'll just if I double click to place the track down it'll just cancel out of it so sometimes for example like this particular thing here where the currents for these pads violates the global clearance then it doesn't matter I can turn that off and it's fine but for other things and you know you want to make sure you don't you don't leave it leave it off the whole time and do something that doesn't make sense so yeah anyway that's obviously not the best way to route that would make sense to probably move this actually up here bring this along there okay and turn do see check off now you can back up on the previous segment by pressing the backspace key and then yeah I'm just gonna put that there that makes more sense and then we can say you know is our input decoupling capacitor for example which we don't really need you've got the you versus right there but you know say you didn't have those you were running for me already rectified and a filtered thing come let's get our input so that's what's that there's this one here so we want to bring that around maybe - maybe we could stick this there we don't wanna stick it too close to the regulator obviously because we don't want it to overheat and but at the same time we also don't want to be too far away otherwise it defeats the purpose so yeah it's a good point if your regulator is gonna be running pretty hot and stuff like that also you know for example decoupling capacitor we want that sort of inline - so if I put this up here for example and then I ran a trace to that you know the the current flow is just gonna kind of go past that and it's not really gonna into what you want it's it's kind of but pointless so you know basic sort of logical things here we don't want that we want this to be basically you know directly in the path so if we have this here we want to probably delete these segments bring this so it's more like there and then you know it has to you know basically if you can't has to flow it to that pin of the capacitor before it gets to the IC so there's no way for it to sort of bypass that part you can see that's you know staying to make sense it looks like these footprints these 3d files aren't actually correctly synchronized with their pads but anyway and sometimes you get that so that's a bug in the library somewhere maybe or something and but yeah so you know stuff like that sort of habits of good design things like that you can do that kind of stuff how would we got so you know that's our input decoupling then we've got a it's a reverse protection diode isn't it so that goes between input and output the sake of space everybody make more sense to use this as a vertical part in fact if we wanted to use this so I might actually exchange it so that's d6 and let's go back to cvpcb let's go d6 for example and so we go back to diodes so if we choose vertical one let's exchange that for that and we save this and probably have to receive this as well hell and then because we want to exchange that footprint we go back to the netlist we say exchange footprint change so it'll reread everything yeah they should do it we want so yeah that's now changed this this is now a vertical ones we could have this sitting right here for example you know and oh yeah by the way the keyboard shortcut to bring up the 3d view is alt 3 yeah so I could put that on there for example we could have that just sitting right there that would probably be fine and then I have a look at these adjustment parts what's this just resist because this resistor here and this resistor here how does that connect to that connects Silvia that connects ground okay so probably make sense to fit that I'd be there because it's going to ground this is getting the weapon this one and connect possibly like that and then that connects over here so go anywhere else goes to here so we could run this trace like that I also got our anti ledge up diode and again this probably would be better off done as a vertical so might actually do that but we'll see one says D age what's d8 anyway oh I see that's the anti damaged diode because of this capacitor here so that's a parallel with our four so they could basically go right there thanks to that and that's in series basically with this capacitor where does that go that kind of goes and parallel with it diodes if we had this here that should work that's what does our output filter I think yeah that'll be c8 that's probably a bit small we could add another bigger one and at some point but yeah um what else what else is there anything else connected to that no it's pretty much of that ground it'll get here this one goes there is the adjustment it's um where does that go I think you guys between this pen that's the that's the annoying one that looks like it's gonna overlap no matter what I do so output but originally I want to run this output its output trace probably you know through here say we could have that coming down here and then drag this pad down to maybe down here hook where up there have that coming like that which would make most sense and and then say we have this one come up there that all sort of makes makes logical logic and they'll go after ground but be nice if these 3d models actually made sense but yeah this capacitor here whoops make the actual thing it's kind of annoying because it has to go from here to here we could sort of well let's see this is a 2.5 millimeter spacing it's not particularly yeah okay well this capacitor we could change this c6c you just see six that's not Yale has changed that said of a two point five mil spacing let's change it to a five so that gives us some that gives us twice the space to work with put that like that that would probably work that looks a bit better yeah sometimes it's easier to see that that way and that is still fairly that's actually probably more that might actually be more like the size I would want for that part so you know that the 2.5 would probably make sense the electrolytic but for if it was if this was a ceramic or a film then and 5 millimeter width would probably make more sense so yeah we can have that coming out like that that's probably logical that's for that half so yeah let's keep going let's do the other side that's you know I know that that's very fairly decent it's not amazing but it's fairly decent I would say we still have some space here where I can put I mean we can move this left a little bit and this is my space here we can put a nice big output filter capacitor if we need it which I may actually do and I probably put this diode vertical it's a good idea actually D 10 so D 10 and d9 would make more sense to do that like that do you know in D 10 that's got a diode vertical I'll have to change some other ones later as well yeah there and as they look at the other side so I've got these two regulators here but the thing of this looks like I said they pan out so for example if this is a 337 we have all these diodes and resistors and capacitors here and that'll make sense but if this was a seven nine series regulator then this would be the this would be the ground pen and this horse is our ground and actual ground connections over here so basically we don't met this diode we met this resistor admit that capacitor and this resistor here would be just a wire linking from the air to the air just to make that pin ground and then all these other things would just be irrelevant they just do nothing so yeah that's my idea for that anyway whether that's a good idea or not I'm not sure I mean with this when these tracers pick up noise it's possible things you don't think of but yeah it's probably so close that it's not going to be a huge issue but we'll see any way to find out will be to find out so seven eight this one we don't need to have back from the edge of the board but I mean yeah the flow of this for example is pretty obvious you know it's going to come in here let's just go straight down to the ground and this is our output and then you have your capacitors here and if that was just a 7/8 series then that's all you'd need which is really very simple but if we're using the the three one seven then these pairs are opposite it's all kind of swapped around so if I was to that's the best way of doing this if I put this now we don't make sense to put that next to that one because I want to I do wanna be able to have the option of having the heatsink there so maybe if we bring this about there see how would that go until input so we could wrap this behind it that would work I suppose and this would connect our output let's see where's our output die oh that would be den 9 when it yeah okay d 9 that would go about here and then if we drag this pad I guess with all this sort of equidistant from the ground just like that one I think that's about as far as it was was not oh maybe a little but yeah that looks about right we can't check that actually with the measurement tool so if we go to say comments thing we can check the distance between this and this which is 10 millimeters and we can check the distance from this to this which is coming up as 12 so yeah we want to move this down one two I guess delete that there try that again now that says it's 10 so that's gonna look a bit nicer than if we didn't have it like that no that's a big deal but anyway that's just how I want to do it so yeah move me of these two side-by-side and then you just put whichever one you want to use where's the output capacitor for that c7 okay it's a bit small it's okay yeah probably because it'll change these later but probably be the most logical way to do it and [Music] pretty well let's have some wild link or something over here to just get this across from this pared to that pad I think if I flipped one of these around and had it back to back would be alright but then if you want to have a heatsink that was sticking off the side back of the board it would be wouldn't work so it's really best to do it this way so yeah what have we got what's this pin this is our just pin okay so adjustment resistor I can bring suppose like here maybe this one can just sit next to it it's probably right how does that go it just goes to ground so that's really easy could just stick that by the side of that resistor and this goes up to here which I believe is the output pin yes we have to be exact the input but yeah that's what does that go got that died oh dear and actually okay if we brought this now I want to drag this over a bit so we can highlight that and press tab and bring that over a little bit move that there there works we could save more space if we had these vertical but this will do I think now we have so if some sort of input filter capacitor it's going to go yeah again I think if we replace this that would probably make more sense if we stuck that in little there if we bring that like that but I think we want to replace that with a five millimeter one as well so that's c3 wait so c3 this five yeah let's change that because we need to bring this down to ground somewhere for example let's just run a big trace right through the middle there so it'll be our ground going through the middle and this diode is what does this is our reverse reverse output diode could we stick that over there somewhere maybe actually that worked quite well Wow probably makes sense that's hell ground being of this is the yeah if that pretty much pretty much will make sense I guess and took the output for this one so that's yeah this has to connect and we kind of can't get away with this really without having a wire link here so I think we'll just have to have one and I think we can do it easily without one [Music] so what I'll do is I can use you can use a veer for that make a pretend topside trace which will just be a wire link I like to see if I click on here let's go down to I don't know here for example first V you get a video that can go across and then I press it again I get that so you know if this was a double-sided board that would be a topside trace but if this is a single sided board which it would be you just insert a piece of wire in that space and you don't print the top layer obviously and that's alright I don't really like this decoupling capacitor though it's sort of it's not close enough to that to that I see and to be honest it would probably make sense to have maybe actually have two of them yeah possibly one for this regulator then one over this side maybe one down here from this output pin it's ground I'm not sure what is the second yeah whenever the output capacitor C is output and crew stranger chuan is not needed for stability okay so it's not really a huge deal but utilizing that you know having that all the way over there this is a good for stability for this for using a 700 series but and we had this over here with what he want I guess we would want like one maybe going from about here to ground yeah just just four but there could be for the yeah okay well transient response so I know what a big a big electrolytic filter capacitor here and have another one this side as well for people that want that [Music] and in it that solves that problem so then there's a vats output thing and then this already has its decoupling capacitor there is this decoupling capacitor isn't it c8 I think was it nice yes sceeto's that one it's the final output that's it then put decoupling sort of thing that's the output what does the 7 9 series say I don't know two is required for stability so that's the input 1 through transient response ok so the output maybe is not necessarily necessary anyway yeah that looks like it's the critical one which is already in a decent place there well kind of it's close to the input pin but at the same time the return count is gonna have to travel all the way around the ear and back through that link to get to the ground pin and if this was a 7 900 series would make more sense to locate this somewhere else but it might not be a big deal because what I'm going to do thought this basically is a ground plane as well so that's how you have this head filled design this is a good trick not only for signal quality but in some applications but it's also really good trick for when you're making your own circuit boards because to speed up to reaching time you want to etch always least copper as possible so if you carry everything with a large power plane or ground plane and either most of the board then that's all copper that you don't have to etch off I mean if I go with this let me click on it zone fill zone say for example that means this is all going to be just a ground plane if we have a look at this here I mean this bit here obviously doesn't make any sense but always put in the middle and it's quite logical to have all that them done that way so you know and then you don't have to eat all that off you don't have to each of these bits and you know in this corner I might write something put some text let's put do or piers you I know it's quite small then let's see yes sir Figgis you for example we cannot have that there so yeah the South rearrange doesn't look that great does these resistors are all not pretty matching up with their footprints but you know it's ultimately fairly well done filly well makes sense and now we firmest it out and then we can now refill the zone I think if we delete this trace it's going to here because for example these are sort of thermal relief things when you're soldiering and you want to have that otherwise it requires you to heat up all that mess with the soldering iron so to me things make sense it makes more sense to delete these tracks here no I don't know it may be that one could stay and that wanted to be honest the rest was not really necessary so yeah that's pretty much it I guess again like I said this capacitor I think I could probably put this in a bit of location and I might sort of move it I like moving move these parts over a little bit and then fit this in here somewhere but we can change with this resistor guys actually that would be the most logical thing to do I think if we turn this around so it goes in front of this and we move this capacitor over here remove this diode visa there I'm have to delete these tricks redo them here it's much that's a much shorter return path so the input size miss capacity goes to this pin and then return will go through this resistor if it was a just the Y link so yeah that's a bit of solution I think but that's pretty much it I would say there's not really much else to do go see it I might um I might put a couple of bigger put some space for some bigger output capacitors and these in this corner maybe and then move all the rest of this over a little bit but I would say that majority of it is are pretty much done we've got a fairly decently laid out board I think by my own standards anyway which should be perfectly serviceable for what I need it fits within the size that I needed and everything basically just looks fine so yeah that's pretty much it this video will be pretty long now I think so I'm gonna stop it here I guess but aside from that though you can sort of export your own file so for example for me I'm going to want to export this as CSV Giada who used that but you can say plot the thing to PostScript that's what I usually use so we want to plot that the edge and I want to [Music] drill marks you want actual size they give us a sort of pothole and put my road filled scaling that looks good we put that now he used to be an option you could there we go I think we want that so to put this edge on the thing here but if I open this nail fire Inkscape I should yes the video we've got our basic artwork there so I can just print that out you can also print directly from coke ad but you can either you can either go here file prints and all the stuff but obviously you know that's going to print it in the center of the page which is a four I think by default year so that's going to be senior April pages about this big and that's going to be in the middle if you export it first and you can you know edit it and you can you know say I want like three copies of it I can just copy this and put another one in and you know have a bunch of them and then I can print you know here I could print you know I can put nine on a page or something if I wanted to and and more efficiently use the you know and then I've got you know I kind of Lee efficiently use the whole transfer sheet if I wanted to make C nine copies at the same board which is much easier than printing it from here this is good to print for a test for example if you wanted to print a paper paper copy over the board and then you can check the location of things check the sizing all that kind of stuff but yeah it's um it's much easier I think if you do it this way you can then mess around with it add other designs at the same time for it and wants that kind of stuff so yeah that's basically it yeah I just realized I'm gonna have to put some mounting holes actually as well so they can go in these corners and life to move this these diodes a little bit I guess and who might make these ones vertical or something as we can get the the holes and the corners there or possibly put a hole there but yeah yeah that'll just be some minor sort of tweaking that's what probably won't bother showing that like I said this is where you gone long enough and this does show the overall pretty much general thing I suppose the only thing I would change maybe is I'll show you how to edit the pad so for example I want to edit this pad you know this has got a small hole is that this is all three too big so it's got pad here head to hit up pad drill size it doesn't have to be where is this ah draw I've moved that over here okay so one point - it's not gonna need to be that big we can make it say one millimeter and just like the other one that makes more sense for a diode like that it's gonna be about that and we noticed that all these other diodes here have the same problem this hole is bigger than this one so you know I can go here paired to a little pads and if I wanna change this so we choose change pads on identical footprints and that will automatically update these so that all these diodes have the smaller hole there so you know do the same with these as well but that's basically it that's kind of most one of the most common things I find myself having to do is to change the change the drill hole sizes on some parts but yeah that's um that's pretty much it I wish the 3d models were all correct and they looked sensible but you know that's it as it is but that's you know basically that's obviously you know I've probably not used the best design practices here there is the layout sort of things especially with regard do you know this this bit here might be a bit silly but it should work properly for what I want and yeah I don't don't assume that everything I've done is perfect if you do want to layout a board properly you have to look at all the signal integrity requirements and all that kind of stuff and make sure everything makes sense but for the basic thing of just how to basically do something like this you know it's um this is I think the most obvious way of doing it and it's just important I guess is to make sure you know your traces are actually nice and thick for what you're using especially if it's a power supply or something and if you you know not to just run stuff around the board you know have things as direct as possible and if you have decoupling capacitors in there you want to have them so they're actually in line with the with the actual the actual trace and not sort of sticking off on the side so for example like this one here you know that the the input comes in here and it goes straight to this one to another capacitor and then it feeds out to both the regulator's which makes more sense than if we had you know this coming to this regulator and then to this one and then we had a decoupling capacitor somewhere else that sort of you know the the current goes first to this doesn't go to the actual point you want so if you have this directly in line then it kind of has to go through there just that just helps cut down on noise and things like that I think but all that kind of stuff was a big topic into itself and I'm not an expert so I'm not gonna try and try to explain all that here but this is just something I just want to show just a basic sort of thing so anyway I hope you have you enjoyed that and hopefully it's informative in some way and I guess that's pretty much it for this one but wait there's more as if this video wasn't long enough already and hasn't already probably put you to sleep so while I was editing the previous segments that I've already recorded and waiting for the thing to render the screen capture because it doesn't render it in real-time my computer's not fast enough for that I worked on the board some more and I've got what I think is probably the 99% or more complete version final version I had to change a few things like I said I added these large space for larger output capacitors you don't need an output decoupling capacitor on these regulators it just you just need some decent filter capacitors if you want good transient well you know if you load the circuit you're running is going to draw draw some quick spikes of current then it's a good idea to have some decent output capacitors on the power supply so that the regulator can keep the voltage up well enough so that it doesn't you know become I mean the regulator itself 40 won't become unstable and start oscillating or anything but you you may get voltage fluctuations which could affect the load so you want these output capacitors for just general voltage stability basically the regulator itself though really only needs the input decoupling capacitor which I've got you know on both of them and again that's only really necessary this isn't a datasheet if the regulator input pen is is more than like three inches or something away from the main filter capacitor so you probably only actually need to add these capacitors if you weren't using these filter caps and you weren't using the rectifier diodes and you already had a rectified supply you were running wires from and then it was you know a longer distance away and then you may need these but but in general you could probably get away with just having these and just having these and saying that though I probably wouldn't recommend it I think I will be putting these capacitors in anyway just in case I guess but for this sort of thing it may not be necessary the the adjustment to coupling capacitor is probably a good idea especially for thee since the adjustable regulators the three one seven three three seven they'e claimed to be lower noise than the fixed series so specifically for me using this primarily for an audio preamp I would want the lowest noise possible so to add those filter capacitors to the adjustment then apparently provides the best stability and lowest noise for that sort of thing so that's definitely what I'll be doing there I guess if you didn't care about that and didn't mind a higher noise then you could use you know before you even wouldn't need that you just need the resistors to sit the desired voltage but yeah I yes and I decided to replace those fixed resistors with a couple of tintin trim pots because I figured that on having space for those just makes more sense yeah so you could you could mount horizontal ones like so in here or you could have vertical ones in there I made it so the horizontal ones would sort of face opposite sides of the board so you get a screwdriver in there this things like that you got to think about when you're designing it to make sure things actually makes sense and it's worth good idea why you should do a print copy first on just on plain paper and actually physically sort of put the components you know on the paper where they're going to go and just check that and there's also a really good idea especially if you've created a custom footprint for you know maybe a connect that you haven't used before or something that isn't in the library yet to make your own footprint for that and all all just checking the fit clearance and things of stuff so I'll be out doing a test print of this definitely before I actually go to itch it but yeah so this pretty much done to enter in trim port is a good idea for these adjustable regulators if you want good precision I mean you can just you know calculate the basic value and then just put a fixed resistor in but obviously the fixed resistor will have you know a tolerance that maybe I mean yeah depends on how much precision you want in most cases you know 1% 2% resistors should be perfectly fly for most people but if you really want to trim it down to a really fine value you know having a trim pot there as good and obviously you can put a fixed resistor in there anyway if you wanted to doesn't matter so that or if using one of these 7 100 or 700 you just put a wire link there and I'm at this capacitor and I'm at this resistor here and so the trim pot gets replaced by wire link and these capacitor and resistor and capacitor I was just that here they not there and everything else would obviously say the same the reverse this die is not necessary if you're not using this capacitor the adjustment to coupling capacitor if you're not using that you don't need this diode but the reverse protection diode and that's probably a good idea again you necessarily need that depending what you're doing but I don't know it's worth putting up there I guess just in case and it's cheaper than a new regulator um yeah also obviously I made these mounting holes here in the corners so that's where I'll be able to drill a to move these diodes over and sort of cram these ones in here and just sort of push the pads in a little bit closer which will just mean I'll have to bend the leads a bit tighter but that's fine that should fit although of course if you did to get them to close it wouldn't fit so that's another reason why you should print out stuff on paper and just do a check first and to be really sure that things actually you're going to work but yeah this this cutout here is just because I'm using an old scrap sort of piece of blank copper board so it's already had a hole drilled in it in this position so I've just put that there to remind myself that I can't place any tracks in that area because there's a hole there obviously for most people you know you're going to be using unmolested board that doesn't have holes randomly drilled in it already so it won't be a problem but yeah just that's why that's there but I'd say yeah this is pretty much done now I'm just gonna do a test print and check these dials just to make sure they actually fit of course if they didn't fit lengthwise I could always just mount them vertically like these ones already going to be anyway so doesn't matter but you know this kind of thing you want to have a look for I did move this link to the other side of this die because I figured they had a shorter path and be better and then I added some like I filled in this track and my cats are in little well I didn't give it a zone but I just sort of filled it in with overlaid tracks and I'm seeing with this part here to make a little sort of land and for these things so that kind of makes things neater and again says copper and makes the agent go faster um but yeah this looks like they're always good to do rather than you know having just really thin wires running around you keep things thick and nice as you can but yeah that is pretty much it for the design of this I don't think I'm going to change anything unless there's just like a component that doesn't fit and I have to move it around slightly but I'd say the the layout of this is is probably what I'll be using okay so there we go assuming you haven't fallen asleep by now and you can see that I've got the final design or pretty much I'd say final design and and I'm ready to punch it out niche it soon so watch out for the next video we're all on be testing out the the Chinese yellow transfer paper on this piece of board and actually doing this transfer and just seeing how it comes out and but yeah I mean you can make this something in a couple of hours obviously it's a simple board doesn't take a huge amount of time probably could be done faster but hey a few nights where there wasn't a chain store in the background so here we go if the previous two and a half hours of that video put you to sleep the chain saw in the background will now wake you up I was saying that before we can't hear it at all because the background noise canceling but whatever yeah so I mean there we go some water intake so it takes a little bit of time obviously a more detailed one will take longer I didn't show everything in KY care there's a lot more features that I didn't show and if you wanna learn about that then you know don't worry I don't have a play have a look at some other videos in there but this is just the basic thing of how to get a basic thing working it does have a push and shove routing in that nowadays in this new version which I didn't show in that either but I mean you don't really need you for something this simple really and there's no point but it does have it which is quite useful they just recently added that um anyway so all I got to do now is just print this out and do a test fit make sure it actually fits on any piece of board that I'm going to use and it showed because I measured this and did everything properly but you know just to be sure and check that the components fit there's the older Alberta board this is the new board it'll be going on too and yeah I probably won't be using these regulators I don't know if they're something wrong with them or well they shouldn't be but you know I'll probably use the three one seven and a three three seven anyway because like I said they love noise apparently so that would make sense for audio stuff and but yeah there we go so there's it that's how you design a circuit board and a schematic put a schematic together and design on board layout from it and okay and it's not really like very complicated it's just you have to know like I mean using the program I'm not complicated it's it's right really it's just you know you have to know what you want the designers and you have to know how to how to do that basically that's the hard part there's not the not actually using the program my opinion it's just the actually knowing what to put where and with your designs actually gonna work so yeah that's the fun part of electronics is actually getting the design to function so yeah I hold out put the files for this up with a link I once I've actually made it and tested it and make sure it actually works and I'm sure it will but you know just in case so they were feat that to be a couple of days or something and I should do this next video soon will actually do the transfer for this and see how it goes but there we go meant some that one there so hopefully hopefully you enjoyed that one hopefully enjoyed how long it was I was gonna guess about three hours now and what was when I made yet but hey why not I just felt like doing the whole thing so yeah anyway and hopefully it was enjoyable hopefully you got something out of it even if it did was send you to sleep yeah yeah so haha see you next time

Channel: Agent24

Views: 18,717

Keywords: KiCad, ki-cad, pcbnew, eeschema, asmr, cvpcb, relaxation, electronics, ee, electronics engineering, unintentional asmr, electronics hobbyist, electronics workbench, electronics design, EDA, CAD, www.kicad-pcb.org, PCB layout, schematic layout, schematic design, DIY PCB, board layout, board artwork, trackwork, electricity, electrical engineering, power supply, LM7805, LM7809, LM317, LM337, LM7905, LM7909, LM7812, LM7912, LM7815, LM7915, Preamp, PSU, split rail, linear regulators, linear psu

Id: WFgjUnYD-rI

Length: 159min 24sec (9564 seconds)

Published: Tue Apr 24 2018