Good Morning All! do you remember this where you should do because it was three videos ago I think um, a panel just covered in flashing LEDs which when powered up, looks like this and with the exposure compensation set to minimum. Oh, has that gone back up? I can't see what's happening? Uh, looks like this. All this does different things when the cameras filming. but anyway, that's about um, the best I can get that now. I'm going to build another one of these starting now. so let's get another board and I'm going to put um flashing LEDs on it. Probably just four to start with and that's because I'm also planning to put on one of these things. These are little, uh, 5 volt super capacitors and the way they've been implemented is that you've got two, um, two and a half Volt Or in some cases, actually, this one's a six volt. um, to three volt super capacitors in series. So let's start with this one. This is a 6 volt 1.5 Farad. um I think these two are both five volt, but we'll come back to those in a moment. Let's get this one out of its bag now. These super cats all came from AliExpress I am using AliExpress kind of in preference to eBay uh now unless of course I want something quickly from a UK seller and then I'll go back to eBay Um, so let's have a closer look at this one. Apologies for the terrible lighting today. It's uh, massively overcast and raining heavily. But yes, this one is 6.0 volt 1.5 farad now I'm not entirely sure whether that 1.5 Farads is completely correct because I can see through this plastic film to the capacitors inside. Let's see if I can get a magnifying glass on that. I've put on one of the overhead lights to try and get some more light on this, but just near the sea there of CDA I can see 3.3 farads on the left hand capacitor there. So um, rather than what this says which is 1.5 Farads really, it's 1.65 and over on the right hand side. yes, just down at the bottom here, near the crease. Oh, it's not coming over on camera very well. but I can see that it says 3.0 volts. So the 6.0 volts is correct. Well, now that's correct if this thing charges both capacitors completely evenly, so how well are they matched? And on this one, you can't get to the midpoint between the two capacitors, but on one of these others, you can so we'll have a look at that. And of course, then you could do some tests discharging one of the capacitors while the other one is charged and seeing how well the balancing Works between the two series capacitors. And indeed, I mean it doesn't look to me like any of these capacitors have Active Electronics to balance the two individual capacitors. Um, but do they automatically balance through what I have written the past referred to as springiness? Well, I got a streak of light here from the overhead light. I've got two overhead lights so I can balance it a bit, but I'm going to turn that off and we'll just have to have very grainy imagery because there's very little light today. Um now I'm just going to put some of these LEDs in here, but just pushed in a slightly opened the legs of these LEDs so that they sit in there with a little bit of grip so we'll just put four of those in. You can probably guess I've already done this to test this out and then I'm going to put the super capacitor in. Um. now because this, um, a rare. this board is just two. Nets um I Think the top net is yes, five volts and the bottom net is uh, ground. The bottom copper area is all ground. I can just put this super cap in. It doesn't fit terribly well, but I can put it in across two of the LED empty LED spaces. So I must get my POS and negle right around right? That's negative with the dashed lines. So if I put pause up there and there there. Yes, there is a little bit of charge left in this one. um, but not enough to get those to light up bright. So now what I need to do is charge the super capacitor and what I have been doing? Um, not sure whether it's entirely sensible because I'm not quite sure what the maximum current you can force into these things is if I undo this. I'm just using this set of four batteries. now. the total voltage of this these sit at about 1.25 when they're reasonably well charged. So you've got five volts here. This capacitor is actually a six volt one, so this is entirely okay to do so. Let's undo these two screws. Oops on those shorting together really. And now try and put the wires into here so that is a ground point. I'm going to push that one in and then touch this one onto a positive five volt point. charge the capacitor up. It's not charging very well. Why is that? Probably because of lousy connections, but I think that's brighter now. The charging current from this pack of batteries is going to be I don't know. Two, three, four, five amps. Maybe something like that. Um, so we're charging that capacitor quite quickly. The question is, how long will this capacitor run for? Hmm I should get a little stopwatch shouldn't I Uh, well. my phone has got, um, a little 10 minute countdown timer here so I can use that. Uh, let's just get this charged back up. I'm not sure what. Oh yes, that is going brighter. It might be an issue with these batteries. Again, let's check them. Okay, 12 volt version of the Bl700. let's check these. Oh 1.2 1.2 1.2 and 1.2 Well, they're all okay. So why am I not charging my super cap very effectively? Oh yes, I think I just didn't leave it long enough. Um, to really build the uh charge in these capacitors up to get a nice high voltage? Anyway, that's been sitting there for a few seconds. So let's start the timer. Uh, I can't remember how to change it from 10 minutes, But 10 minutes? maybe enough. We'll come back in 10 minutes and see how much dimmer these have become. Uh, right. The timer is clearly finished. Oh, that's a horrible noise. Uh, yes there. How do you shut this thing up like that? Um, they're quite a bit dimmer, so I'm not sure whether it's going to last another 10 minutes. Let's start the timer again and we'll do another 10 minutes and see what they're like after 20 minutes and so after another 10 minutes, you have to push that up. Yeah, something like that. Uh, 20 minutes in total. This has now dimmed down to the point of being not very interesting. So I want to make a little ornamental thing? Um, with LEDs on the front and a super capacitor on the back such that it sort of sits on the table at a nice jaunty angle? I think I've come to the conclusion to make this interesting: I'm going to put a full row of 12 LEDs across there so we'll get those soldered in. But first, let's take a look at these other two Super caps. So the one I've been using is this CDA 6 Volt 1.5 Farad. although I maintain its 1.65 farads because of what I can see under the wrapping. Um, this one here is a 5.5 Volt 2.5 Farad so it's a higher capacity and this one is a Maxwell 5.0 Volts 2.5 farads. Now these came from an AliExpress Well, they all came from AliExpress but these two were sent by the same seller and I only actually bought one and the seller said we can't give you the exact one you ordered although we got one of an identical value, it's just a different footprint so we'll throw in another one which is another one of these Cdas and they said we hope you enjoy your free capacitor Well, I am. so let's get these out and have a closer look. Uh yeah. so Six Volt 1.5 Farads, 5.5 Volt 2.5 Farads and 5.0 Volt 2.5 Farads. Now, what's interesting about this one is that there's a little PCB on the bottom and you can actually see where you got the positive of one super cap. Its negative is on this Central strip and I think this is actually the PCB So I think I can just, uh, cut a bit of this covering away I don't really want to solder to these solder points. There does seem to be a conformal coating here, but scrape a bit of that away and I can get to this midpoint because what I'm interested in is to see how well balanced these two super caps are. Um, so I'm not going to do that in this video, but on in a later video I Want to put a third wire on here and then measure the two voltages and push current in and pull current out and just see how well these two caps stay balanced because like I say I don't think there's any active circuitry in here I think they just stay balanced by virtue of the way. Oh, that's interesting. Does that say 2.7 volt? Yeah, a 2.7 volt. Which actually makes that, um, 5.4 volts, doesn't it? So these are all mislabeled, Really, aren't they? Wow. It's a lot brighter. The uh, gloomy sky has become much brighter, so it should be a much less grainy image. In fact, let me show you that uh, old style holding the camera in front of my monitor shot like what I used to do in the old days, but this is today's solar graph and you can see that it was 20 watts, dropping down to nothing, going back up to 20 watts which is the minimum that my inverter can produce and then going back to nothing. And it did that for a full I don't know. Three four hours, Uh, in the early part of the day and now it's shot up to what is it? Oh, about 200 and something? Watts So yes, suddenly the sky has cleared. So I think to give this mini project a little bit more run time, especially if it's got 12 LEDs a complete row soldered in I'm going to use this cap 5.5 volt 2.5 farads because it's got more storage than the little 1.5 Farad capacitor. and also I want to keep this Maxwell one back for when I do my voltage measurement of the two series capacitors. So let's get a row of 12 LEDs soldered in there. Put this capacitor on the back. now. Interestingly, will this span neatly across a positive and a negative? Oh, it's not bad. So yeah, that can make a nice little stand coming out of the back and then it'll sit on the desk with 12 LEDs all in a nice row. Let's get soldering foreign ing shot. cool iron. So I'm using a sponge I'm going to get a really hot iron like one of those power tool battery powered irons. Um, you just can't use this band. it's just too hot. So uh, the the um, what are these things called the brush shavings type thing is better for a very hot iron. Oh oh, that's interesting. Yeah, the base fell off my brow shavings thing and it's full of 50ps I'd forgotten I put those in there and they were just to give it some weight on the base. Okay, and I iron up to temperature. So soldering shot. Oh my eyes, that's just shocking these days. Can't see what I'm doing at all even with pound shop close-up glasses. but that'll do soldering the other side the other leg. No, will you stay still stupid Idea Idea Using a pen to support it Blue Tech Far more sensible. that's not going to fly around the desk, is it? Yeah, this is a bit more tricky from the bottom because I'm on the side where the spokes are attached to the Copper area and it's sucking the Heat out of the iron more quickly. right? So there are my 12 LEDs all soldered in a row now. I've just charged this capacitor up so let's poke pause into a pause hole neg into a neg hole and yep, the LEDs light up. Now one thing I thought is that with this capacitor permanently soldered on here, you'll never see that where all the LEDs come on together. I Mean it doesn't last for long. they all randomize fairly quickly. but with, of course, with this soldered on here permanently, I'm gonna be careful not to short out the cat. Um, you'll never actually see that because when you charge this up, the flashing will start to occur even before the lamps reach a visible brightness. We can have a look at that in a moment. I'll get this soldered on and then I can slightly twist it and then it'll work as a little uh, backstop so that this thing sits on my desk like that. So I'm going to solder it with the legs fairly far out of the board so that I can reuse the capacitor for something else If I decide I don't like this idea, but at the moment I kind of do like it. so we'll solder the negative there and the positive there so that's permanently attached. Um, it doesn't look like it lasts very long so you will have to keep charging it up, but that makes it more entertaining. Now, these super capacitor arrays where you've got, Um, this is six Super capacitors in series generally come with a board. This one's in a bit of a mess because I had it outside for some time and not in an enclosure and it didn't survive. Um, with these protection circuits which use a little voltage trigger and when you get to 2.7 volts, these circuits turn on and put resistors across the capacitor and as long as you charge this with no more than whatever current these resistors can dissipate, then you can bring all the capacitors up to the same voltage simply by allowing all of these circuits to come on. and I think I added Le LEDs to this possibly not this one I can't see any LEDs on there so you could see when they all get up to maximum voltage. Now of course, these little two super capacitors in series don't have these protection circuits, but it has just occurred to me. well, a little while ago that um, these LEDs work in a similar way. And of course they don't switch on Suddenly at a predefined voltage. Um, but they will act to. given a constant current into this board, they will act as a voltage limiter because if say, we put 100 milliamps into this board, then at a certain point, these LEDs will be bright enough to be drawing a constant 100 milliamps and there'll be no Surplus current in order to charge the capacitor. So we should be able to regulate the voltage that this capacitor gets up to by limiting the current. So I'm just going to fit the connector and do a few tests along those lines, right? Let's start by voltage limiting this to 5 volts so we don't blow up the super cap and initially a current of 100 milliamps and see what we get. Switch on. So the voltage is coming up now. I'm predicting that at a certain voltage this will stabilize and it won't go any higher simply because as these LEDs get brighter, their current draw will balance the 100 milliamps that this thing is putting in and the supercap voltage simply won't go any higher. Yes, it's jumping around because of course the there aren't enough LEDs for this to present a constant load and we're still going up. Actually, it has now reached just reached three volts. I'll just leave that for a bit and see how much higher that goes right? This has reached 3.75 approximately volts. It is creeping up a little bit. Of course it's in current limit the yellow light there at 100 milliamps. Now when the average current of all these LEDs reaches 100 milliamps. of course, they will draw all the current from this bench power supply. It's a power supply and it's on my bench that is still creeping up. but it must reach an equilibrium point where the voltage on that capacitor simply can't go any higher because the LEDs at this brightness are taking all the current that this thing's able to provide. so it is still creeping up 3.81 I'll come back when it's settled down. I Mean it has virtually reached that point now, but it is still creeping up and it won't creep up indefinitely because these will get to a brightness where they are drawing all this current. I Think we're there actually. but I'll just leave it for a few more minutes, right? I Think that's it. It's topped out at 3.86 volts at 100 milliamps. It's still current limiting at 100 milliamps. So if you have a load which is essentially resistive, it's not quite resistive. But as the current increases, uh, sorry. as the voltage increases on that load, the current draw increases and you have a current limited power supply, then we can hold the voltage on that super cap at a limited maximum. Okay, let's take the current limit up to I Think I have to turn this off to change it. Um, to 120. Uh, milliamps? Yeah, 0.12 amps at 5 volts. Turn this back on and it was 3.86 volts Wasn't it? Let's see what it gets up to with 120 milliamps? Uh, so it's approaching the 3.86 that we had before. You can see the 120 milliamps there. Um, the voltage has now gone above that 3.86 volts. Let's see where it settles down and it looks like that's about it. Uh, so 120 milliamps? This is pushing up to about 4.2 volts. So let's just do one final test at 150 milliamps and see if the power supply, which is also voltage limited so the capacitor is protected. Uh, see if the power supply pushes right up to its full. Uh, 5 volts. So let's switch that off. set the current to 100 and 50 milliamps 5 volt limit. Switch it on. Uh oh, that voltage fell quite quickly didn't it? Um, Okay, let's see where this one tops out. Okay, it looks like it's going to top out at something like about 4.75 volts. Um, by limiting the current to 150 milliamps, we limit the voltage on this capacitor to 4.75 volts approximately as long as this load is in place and working. If this load were to disappear, of course, capacitor would shoot straight up to the voltage limit of this power supply. But if you are only current limiting it and didn't have a suitable voltage limit, then of course the capacitor would go over voltage and that might damage it. But yeah, with this load in place, a current limit also acts as a voltage limit on the capacitor. So there we are. That was interesting. That's a nice little fun thing to have on my desk. If I turn this off by doing that, that will of course gradually dim down over time and then I can turn it back on to make it go bright again. I'm going to have a lot of fun with that over the next few days, but that's it for this video. Cheerio.