 So I've got myself a car battery. It's charged by my solar panel. And now I have a wire that connects to my battery, which is just over there in the window. There's two of them, as you can see. Yep, and there is. And so I've got some power here on my bench. This thing is 10 amps. It will display on the current there. And it will go to 100 volt or something. I'm not really that interested in that. I just want it for the battery. I've got the batteries on the window somewhere there. At the back of this, as you can see just down about there, this is a fuse holder. There's an 8.4 amp fuse in there. Well, there's not actually a fuse. There's a piece of 15 gauge wire, which is actually a magnet wire. And I've sanded off and rounded the ends to make it fit as a fuse would. And that's all good, I hope. For the maximum input for the actual display of this to make it light up. It says it's 12 volts. It needs a separate supply because if you go above 12 volts you can burn out the LEDs. Let me shift that out of the way. So what I've done is I've just put a... I think it was a 220 ohm one watt resistor and a 56 ohm in series with a half watt resistor. Because I didn't feel that it actually needed to have a BS resistor so much, but I didn't have anything else to make up just by a couple of resistors or one. It would have been nice to stop those from... But enough so that he's actually connected, you know, just under the same connection as this, just got to resist that. So, adequately safe sort of. I don't have a 20 amp fuse coming out of my charge controller. At the moment I'm going to get one and in line with fuse. But my charge controller has short circuit protection and all sorts. Which just means if I do a short circuit across there it will just switch off the output. And when I remove it it just switches it back on again. I didn't really want to sit here testing it, but I'm sure if you watch enough of these you're going to see me do that at some stage anyway. So, at that point I built in a switch before it then outputs. So this connects a lot. So there's a little indicator on the switch so I know that it's on. And there you can probably see that it actually has a load on the system because the amperage has gone up there. So let me just switch that back off again for a minute. Well, of course the other problem is with 12 volts. So it's 172 volts, isn't it? So if I were to put an SAE and LM317 regulator on there, so I've got some variable output here. I'm only going to begin about 8. Let's say 8.5 to 9 volts with a bit of load on there. Not really good at all. So I need to take that voltage up a little bit. Well, I tried building my own boost inverter. That was my first one, not so very clever. But for £1.69, I think it was £1.69 or £1.67 possibly. I bought this little baby. This is a 100 watt boost converter. So you put... I can't remember. I need to probably play around with... I should have put it probably on my password first and see exactly how low it is. You can go, but basically it serves its purposes for me because I put the 12.7 volts in. I'm not going to run my battery zone 11 and 12.5. I think my charge controller turns off at 12.5. If it doesn't, I want it to. And it does take that up and it takes it quite nicely up to 35 volts. That's all for this one. It's not one of the big 60 volt jobbies. But it does mean that it gives me some flexibility on that battery power. I can take it up. Which is great. But then of course I need to wait to take that back down again. And so for that, I've got this. And this is a 10 amp. Let me try and adjust the light a bit. That's a 10 amp step down converter which is connected into that step up converter. So I can step the power up. And I can do this cleverly as well. So by now, I'm going to be running a few volts. I don't need to be stepping it up to 35 volts, do I? And then I'm trying to step that down. I can pretty much just have 15 volts coming out of that and step it down. Or even a 13 volts, I need to do some low testing to see where it starts stepping out of regulation. But to help me out, I've also attached a display to this. So this display here tells me what's coming out of this. Okay. And then this. Just for the sake of just playing around for a minute, I've got another display sticking out here. And here's a load. So if I want to switch this on now, I'll just flip the power. And there we go. Got the display up the back telling me exactly what I'm taking from the main supply, which is 40 milliamps. This is telling me what this and the rest of the circuit is taking, which includes, of course, the power for the LEDs. And so that includes the power, the one at the back, for this one, for this one, and for this. And for the circuitry here, which isn't really a great deal. And when I consider that my other power supply, which is linear, this one, that takes 25 watts just sitting there with the power button switched on. 25 watts. Now, when you think about it in your battery terms and solar panel terms, that's a lot. When you think about it in your general house terms, that may not seem such a lot, but I like to think of things like, the solar panel point of view and harvesting from what's been going on. What is it? Cosmos. Whatever. So, yeah. So, there's one at the LED. And I'll tell you something funny about this. I'm going to switch off now. Switch off. You count the seconds for the LEDs. Not a lot, but still. Two. Three. Now, I know that the LED is not really doing a lot. Like that. I can turn it up. I've got 20 volts here, so the maximum I can go to coming out of here is going to be a lot just under 20 volts, I suppose. I've got a 200, 220 amp. I think it's a 1 watt or 2 watt resistor there. So, let's turn it up. This is going to get bright. I've got the right end of my finger. Maybe I should put something over that, actually. Let's put this little tiny circuit I've built for my power supply I'm doing. That little circuit is to actually run one of these, directly from the mains, the display for one of these meters that's going to be built into my lamp. I'm sorry, I thought you could see that there. It's going to be 9 volts to 12 volts, which is where it's normal. Working voltage for this LED would be 12 volts maximum. Now, it says I'm only drawing 10 milliamps, but I don't know if you see the one at the back, look, that's going up to 7. One in the middle is on 4. It's going to be 15 volts. I think we might turn the other two a little bit. So, I reckon it's 20 milliamps. It could be anywhere between 20 and 30. I don't know how accurate that is. The middle one says 5, and the one at the back is just flashed on. It's being 9 and 10. Of course, there's going to be conversion power that's being used as well, isn't there, all the time, but it's still going to be more efficient than my linear supply over there. Of course, there's going to be noise coming with this, but I've had a thought about that as well. Because for the smaller circuits, with the noise, and I need to really think about how I'm going to do this, but I know that I'm going to have power come out of here, and it's going to go on to LM338, no? LM338, yeah, I'm sure that's what it is, yeah, 338. And I'm going to have two LM338s. One of them is going to control current. The other one is going to be the output for the voltage. And so I can use that up to around about eight and a half, nine volts. But that'll be nice and clean, direct from the batteries. Do you see, ah, and again, I say that, you know, it's not going to be that clean, is it? I've got a charge controller set in the middle. Oh, why is everything so difficult? I can't anything just be plain sailing. No, I'm going to turn that down, because I just wanted to, I'm showing off. I've just been sat here, going around a little bit. I was building an FM radio earlier, and I've got sound out of it. I've got amplification, but all I've got is hiss, and it's just driving that. So I just, I saw these, and I thought, all right, I need to just throw them together somehow. So let's put them together for a bit of fun. Um, yeah, well. Cheers for watching, guys. Bye.