Good morning, all new printed circuit boards from jlc pcb. So let's take a look in here. My printed circuit boards and they're in fetching purple. Yes, purple is jlc pcb's new printed circuit board color.

I seem to remember they had it once before long time ago, and then it disappeared. Now it's reappeared, and so there they are they're very simple, in fact, they're. So simple that i didn't even draw a schematic for this uh. There are only two nets: uh there's ground on the bottom and there's well.

I called it plus 12 volts on the top, but i've since realized that actually it's 24 volts, because this is going to take power from my lithium ion - phosphate battery and distribute it, and hence the name xt90 distribution to various places. As it stands, the battery will be on the left. The ant miner via relay and buck converter will be on the right and the solar panel will come in on the top. Now i went to a trace width calculator i'll, put a link to that in the description below to work out in one ounce, copper.

You can get two ounce copper from jlc pcb, but it's quite expensive. So i went for one ounce, copper, um, how many amps? I can put through this - i think i specified 12 amps and it came up with a trace width of about an inch, i believe, an inch width. Now, of course, these are just copper areas, so there's one copper area for ground on the bottom, linked to the center holes on all four sides and then there's a copper area on the top, which will be 25 volts linked to the two outer holes on each Of the four sides, so i think this should uh very easily oh and that i specified no more than 10 degrees celsius temperature rise and that's when it came up with an inch width. So this is effectively two inches square and, quite short, runs between the various connectors.

I think this should take the 12 amps i'm expecting at the 25 volt side, it's more current on the when it's bucked down to 12 volts. Of course, i think this should be no problem, so these are three millimeter holes, um they're, quite wide pads, so that i can put nuts. I don't think these are the nuts actually, no, i think, they're four mil i'll get some three millimeter nuts. I can stack nuts on top of this and then put my xt90s on the pitch between the holes is 11 millimeters.

That, apparently, is the spec for the distance between the xt90 connectors. So let's get some xt90s and see how they marry up with this. So the x290s are going to go across there. Now i provided an option to flip it over really just because on some of these positive might be on one side, negative might be on the other.

It might not be convenient to flip it over on my incoming wire, so i provided an option for it to be flipped over at this point um. I measured this slightly different to 11 millimeters, but i looked at lots of google image, searches and they're all saying 11 millimeters. It's not that critical, because if i'm using these rings now i'm probably not going to place these flat on the board, i'm going to stack them up on top of one nut, because i didn't cut away the ground planes. I mean there is a small gap in there, but it's not fully cut away around that pad.

So i'll, probably uh stack nuts and then put these on, and these, of course will be soldered directly into the xt90 solder cups. I did think possibly that's why i had 10 of these made that if there was a problem with current carrying capacity, you could actually stack these with nuts between them for additional current carrying capability right, big box of nuts and bolts, and i'm pretty sure i've got Three mil in there um. I think this came from class olsen a few years ago, but let's get some three mil nuts and bolts out um. I think these are the three mills not sure what length i want.

Yet there are various lengths and there are nuts don't think i've got any washers. I don't actually know why. I'm sure it must have come with washers, because all the other sizes have got washers. Maybe i used them all up on something right.

Let's see how good the fit is: oh, that's, a very good fit um, not tight or anything, but just absolutely the right size. So then the idea is to put a nut on here, screw it down and then put my ring terminal now. I've got a feeling. These are actually four millimeters, but it doesn't really matter.

I mean i can get some three mil yeah, it's a bit of slop in there, but the important thing is to have it stood up off the board and uh going off to my xt90. Now, in my original design, i mean, obviously this wants to be face up. Ground is on the underside and what i call plus 12 volts, which is really should be plus 25 volts, is on the top. So let's get some nuts on there and some of these terminals.

I think i've got two types of these they're the same ring diameter, but i think the entry. Oh yes, let's get a magnifying glass on that um yeah. The entry size is different. I think the one on the left is probably a blue, but i think i bought these as um um.

You know no plastic coating on them come what it's called now um the one on the right is almost certainly a red. Now i've got fairly fat cables. Oh, no, i'm going to straight to xt90, so cables don't come into it. Really it's more about the outside diameter of this.

Let's give that a try, well, the big one. The blue doesn't quite sit in the cup, although it probably would, if i crushed it a little bit um or shall i go for the red, which is actually quite a loose fit in there, but once there's solder in there then yeah. I think i'll probably go for the red ones. I mean that should be more than enough current handling.

Yes, i think i've got the pad size about right. The whole size is perfect. The pad size takes the nut with no spillover. I've got a fairly large.

I think it's half a millimeter um. What's this called the spacing between the copper area and a pad which doesn't connect to that copper area? The other thing is that these pads are not spoked out onto the copper area, they're directly um connected all around. The only reason to use spokes really is, if you're soldering, because then you don't get quite so much heat being sucked away into the copper area here, because i'm using bolts, um heat loss is irrelevant. So, yes, i put a direct connection for the extra current handling.

Tighten these nuts onto the bolts and then put my ring terminals on so i think the way i'm going to solder. These is to just push that on so that it's a slight interference fit so that's holding itself on there and then just apply solder onto there. Solder onto there now it's all going to get sucked back through these bolts, so i really need a very hot soldering iron. Now i don't need to think at this stage whether i want um pause to the left or pause to the right, because these pins rotate in the xt90 housings, so that if i've got this wrong, i can always take it off.

Put it on the other. Two bolt studs or if i need to flip it over, i really do want the ring terminals coming down. I can simply rotate these two so that it's in the right orientation - and the other thing of course, is whether i want male or female on the three sides, i'll probably go out to the shed actually and just do a sketch, so that i kind of know What i'm doing, but i want to try a solder joint first, so i've been out to the shed and just done a sketch of what i need uh. That's male! Isn't it at the top there um, but i've got poison egg the wrong way around.

So i'll flip that over um put the other two on, but now the other thing which i went and got is my old weller soldering iron um, because this one i don't know whether you can see that just there, let me get the magnifying glass. It's 60 watt, um 240 volts. So now i kind of don't like maine's irons anymore, but of course, there's not really a problem, because i can use one of those portable power stations and actually put one of those on, because when i was using this as a field service engineer, there was always A handy iec plugged into the wall, so i i put an iec on the end of my soldering gun, yeah i'll plug it into one of the mains power packs, but this is 60 watts, so it's got lots of um power to replace lost heat. So i haven't used this for years, but let's give it a go right.

Let's turn on the power bank ac on what does it say? Oh yeah, it's drawing 62 watts. So that looks about right. So let's wait for that to get hot, oh yeah! That's getting quite warm quite quickly. Is that going to melt solder well i'll, let that warm up and i'll be back.

This is taking an age to warm up, but i seem to remember these old main science. Did they took forever to warm up? That's now warm, but i think i'll just leave it for a bit longer to get really hot um, still pulling 60 watts from the power bank. So that seems fine, okay, that side's taken; that's fine, i'll flip it over and try the other side. I think this is hot now, i'm not sure i can see very well what's going on, not sure if you'll be able to see very well either, but let's feed some solder into there.

Oh, it feels hot now, oh yeah, that's starting to take quite quickly now, but can i get the connection connector of the xt90? Warm oh yeah there. It goes. It suddenly started to flow, and that's done so lots more of that. You don't need to watch that i'll come back when it's done right, the soldering is done.

Let's have a little look at that. Yes, i think that looks all right, a direct connection between the ring terminal and the xt90. So now it's just a case of putting the bolts through onto my board. So i'm working with my diagram to get males and females in the right sequence and using this little spanner and a screwdriver to tighten these up, keep them nice and tight and then i'll place these on and we can go and test it and there's the finished Thing um male there, because this is the sort of connector the female that you see on a source of power or voltage.

So the solar panel comes in there. The battery, of course, also has that kind of connector, so it fits into this mail and then this is the supply that goes off to my load and hence that's on a female or that star connector. So that should be a drop in connector block. For my uh setup as it currently is in the shed, shall we take it out and shove some current through it now? Could i simply drop another pcb on top of there? My bolts are a little bit short, but yes, i could actually with a nut, tighten up and i'm not sure i need to because i think yes, i've just tightened up on there.

I think it's going to be fine with just the one pcb, but this is um an option. If i find it's getting a bit warm, i don't think it will, but it's an option nonetheless, right i'm out in the shed it's extremely cold uh. Actually, what temperature is it 6.5 degrees? So i've been using this. This is a balancer, but it balances extremely slowly.

It has balanced the cells up a little bit. Of course, it balances by pulling the high voltage cells down using little resistors in there, so it will have lost because i had it running all night, so it would have lost a little bit of uh charge from the batteries. But anyway, i want to remove this, which is my current connection from solar. Now i've got this bulb in series with the solar to limit the current, because i'm not watching it all day.

So if suddenly 8 amps comes from the solar, it's going to take the batteries over the top, but i don't think that's happened yet. So i can take these off. Oh no mustn't sure must not show those should do this in a more logical sequence really, but there we are, i'm all excited about my new xt90 distribution, so i can plug this in because that's just connecting solar to battery. Oh yes, there is, of course, the thought that there might be a short there shouldn't be um, so yeah, that's the right way around.

Let's plug that in yeah, i really should start using silicon wires, rather than these rather stiff wires, that i've been using. Oh that's a bit of a tight fit. Actually, yes, it will that's just the angle. Okay, that all looks good.

That's solar connected to battery, so these voltages should be going up now. Oh yeah. I've got a 3.5 yeah that one's nearly topped out uh cell eight. Oh, can you see that not very well, but you can see the bar on cell eight is way ahead of the others, so there should be en enough energy in here to do a mine right.

Here's my buck converter, to take the 24 volts down to 12. I've got pause on the bottom yeah pause on the bottom, that's good and now i'll bring in there. Oh look what i've done. I've put pause on the bottom of that, but i've got pause on the top of that over that silly, and you haven't seen this yet it looks really good.

Actually, this is my new voltage trigger with a 30 amp relay, so i'm just going to go and have to go and get that spanner. Oh really shouldn't be undoing these nuts um. With this powered up so i'll. Take this out, i could take the fuse out of the battery, but i'll just disconnect that go and get my spanner flip this one over hook up my discharge control relay and i think we're ready for a mine right.

I've got the spanner um now probably shouldn't spanner this with the solar panel connected, but i can quite easily just remove that bulb to break that connection right this. I can now spanner without fear of shorting across the plus and minus flip, this over so pauses at the top. Let's do that um! Yes, i think i'm going to have to rotate the oh, no yeah pause at the top. I want to rotate these.

Don't i so i'll go and get a pair of pliers. These are my shed pliers, so rotate those around so that it fits on that way pause to the top. Oh, i need to move the bolt to the top. Don't i yes, i do right.

I think this is correct. Now so i'll put my um relay unit on there, i could actually plug the solar panel in and see if it powers the relay unit up just as a sort of initial test it may or may not. It does because it's overcast outside uh yeah, that's interesting and the panel's at 33. Oh within a tenth of a volt of my other meter.

Now i've got to attach the battery well, i suppose this is a good way to do it. I was a bit nervous about the buck regulator on the other module of this, because it's now fried so now, if i attach the battery that should drop to the battery voltage now positive most definitely there neg is this center hole and pauses the outer holes? Yes, that looks fine. Let's connect it up. That looks good.

That's dropped to 27 volts uh! Oh, i think that's the point at which the relay comes on. Yes, it is now i've got to try and remember the operating system. Don't want to spoil the video that i'm going to make about this so i'll, just sort that out right 27.2. I've set this for 27.5.

It should creep up with that bulb in the solar panel line. Let's connect the buck converter onto there and that goes off to the ant miner. So when this gets up to 27.5, just see what the voltages look like on there yeah the highest voltage is 3.4. So it's not anything to be concerned about when this gets up to 27.5, which it should do, there's only half an amp flowing through that bulb at the moment uh.

This should turn on and it should start mining. But this i'm very happy with that. It's very neat: it's absolutely rigid because all these wires are stiff wires, that ain't gon na move anywhere yeah. I like that um and then, of course, it's the case of uh, seeing whether it gets warm right waiting for that to get to 27.5 i'll come back when it does yeah this uh highest voltage cell cell eight.

Can you see that it's very difficult to film these things um it's starting to accelerate away now 3.567 27.3 on there, so just waiting for uh well they're all coming up, but this one is going to come up the quickest and uh waiting for that to give A 27.5 on here and then it should all burst into life, i'll, try and capture the moment when the relay comes on, there's a little red led in there, so we should be able to see it i'll. Just leave the camera running yeah it's on battery! That's fine, oh 3.6, on cell 8.. Now, of course, it's dangerous! Well, actually, the bms doesn't turn off until this gets to 3.75. So i don't think we're going to get there before this gets to 27.5.

It's on 27.4 of them, not sure. If you can see that very well, but i don't think we're far away from this relay pulling in our cellate - has suddenly started climbing 3.64 yeah with that having a bit of an acceleration forwards that could push this over it's a bit silly really. I should have set this to slightly lower threshold, but i haven't all 3.66 there. Now, that's really starting to shoot up.

This is so annoying. This thing won't stay on. Oh relay click. Can you see the red light and now i'll move the camera slightly to the right? But anyway the miner has come on now the voltage should uh 27.3.

That's because only the fan and the control board on the miner are on, but when that spins up, which it's going to do any minute now, this voltage should fall, but obviously not to the lower threshold, that's 22 and a half. I think here you can see this. Oh that's starting to fall quickly. Now i think the hashing.

I know they don't start yet. I don't know 26 point naught right. The fan has gone up and come down so now there should be about. I don't know because i haven't measured it, but i think about 12 amps going through this and that's absolutely stone cold.

So i don't think, there's a problem. I don't think there's going to be a problem. I don't think i'm going to need that second board, but it's always an option. No, that's! Absolutely fine.

Let's have a mining session. I won't uh show the whole of that because that's a bit tedious, but what i really wanted was to have the uh load switchable in pulling from the battery, but also have the solar panel connected at the same time, because anything coming in from solar will just Slightly lengthen the time that the miner mines and that's always a good thing, and if the sun came out strongly which is not going to today, i don't think um that could elongate the mining period well almost continuously. I just need to work out how to resolve the problem, and i think it's going to be another one of these voltage relays in here and i can actually connect it into this fuse holder um. What happens if the sun is so strong that it is providing more current than the miner is actually taking, then the battery will continue to rise up, and that's why i think i know i need another relay unit here.

So if the battery gets anywhere close to the bms turning off where a cell gets to 3.75 and of course the problem i've got at the moment is that the cells are so imbalanced. I mean they're all balanced now, because they're being heavily pulled down against their springs, they're, so out of balance that um none of these voltage measurements is is very good because um, the cells are so in balance, i'm waiting for the 8 cell balancer and then yes, If the solar is so strong that it's lifting the batteries up, even while it's mining there'll, be a second relay which will just simply turn off the solar panel, but only briefly, i don't want it turned off for the entire. I can't you know, use the normally open contact on here or whatever to disconnect the solar panel, because i don't want it turned off for the entire duration of the mining. I want it to um.

I want it to supplement the the mining process and, if you're wondering what happened to the ideal diode well it's here, but i don't really need it because the nighttime battery is only 20 milliamps. So it was interesting to test it, but uh yeah, it's out of circuit, oh and if you're wondering what happened to the bolt stack abomination. Well, it's here, but uh yeah. I didn't like it either.

So this is all going perfectly well 24.2 volts here now, um the lowest cell is 3.01, so we might be getting close to the sort of ramp down phase, but i have been thinking about these um. This board, of course, has two potentials on it. It's double sided so ground on the bottom, 25 volts on the top. But what say you if i came up with the crazy idea of not having these big thick copper, um bus bars on my battery pack, but instead i use printed circuit boards.

Yes, i know what you're thinking but you've got to remember that there's only one potential on a bus bar, so you can use both sides of the copper, so you'd actually have twice the current handling capability and the other thing is, you could do really clever things Like i mean you could have little sticky out bits with a a bolt stud for attaching your balance leads this sort of thing, but you could also put little acs-712 current sensors on the board surface mounted and put the balance currents through those current sensors. Now then, have a little three pin connector going off to an arduino so that you could have these not this shape, but probably be one inch by two inches, perhaps sitting on there as a bus bar, but that can also do fancy stuff. Like current measurement. That's an idea that i've been thinking of yeah.

This is all uh working nicely 2.99 on the lowest cell. Now, oh - and i suppose the thing you really wanted to know is: is this warm at all? No, it's absolutely stone cold on both sides. Yeah! That's sucking heat out of my fingers. That's cold! Now i've just gone in to get the other battery checker, because this one, i think, is a bit more visible.

So let's pull this one off and shove this one on. Can you see those numbers? Yes, i think you probably can uh 2.92 is the lowest cell. They are much better balance now, because this thing, which is a balancer, it's a very low current balancer, but it has been on the battery pack. I think for two nights running and a day in between probably so uh.

Yes, they are better balanced, but what this system really needs now urgently is the eight cell balancer for the battery pack just a roving shot, because you don't get to see the whole system with the camera mounted, so battery pack bms fuse there cell monitoring device there. My new xt90 distribution there, solar panel, comes in here with a bulb in line with it just to limit the current. For the moment. That's not gon na, be there permanently uh voltage, switching relay butt converter, some horrible old um connector thing to translate into these pcie cables and ant miner and that battery back.

There is just powering this camera right. We're heading down to the end of the mining session. 2.33 on the lowest cell now there's a race here, because because these cells are so out of balance, it's possible, the bms will actually turn off at 2.18 before this turns off at 23 point at 22.5, so just keep an eye on that 2.26. There 22.9! If this gets down to 2.18, then the bms will cut off and this display will go blank or disappear uh.

Yes, it's definitely a race three tenths of a volt to go on here, but precious little on sale too. And it's because it's out of balance i mean the highest sale is 3.07 2.19. That's about to go so i think the bms is going to cut. Ah, that's interesting did the bms cut out and then immediately cut back in because this is actually powered up yeah.

That's interesting, i don't know why that's flashing that'll be explained in the video about this unit. If i, if i can fathom it out but anyway, i think that's it um. Really. It was about uh, my xt90 distribution board, which has been an absolute success because that stone cold handles the 12 amps.

No problem happy with that cheerio.