I'm trying to remember if this came from little or aldi, but it's a dynamo running light that, as you run and jog along it generates power itself and flashes lights. Let me just open this and show you. Let me completely make a mess of opening it to show you so here's a device - and i have to say i was a bit cynical until i started shaking and realized that's pretty bright. Let me turn the light off here and, as i shake it, you'll see it lights up now, it's worth mentioning that it is actually super bright.

It's actually quite surprising how bright it is and if you uh notice, there's four leds, but they alternate backwards and forwards. I'm guessing ultimately the the circuitry is going to be fairly straightforward in these and that uh it's really just a magnet shooting backwards and forwards in a coil, but there's only one way to find out and that's to open it. So i see this end. It's kind of glued on so let's start squeezing things and see.

If we can get it off, it will be sealed against water and grass oop yeah. This is well sealed right. Tell you what one memory please! I have my investigatory device. Let's just squeeze this! Oh, this is tough.

This is very tough. I am impressed so far in its ruggedness. Oh, that is very tough. I may have to oh.

No, maybe it's not that tough. It is not tough enough to withstand those grips. Let's give it a bit of leverage. It is completely burst now, but that's okay! That's why? Oh, i hope that wasn't electrical.

You know it's just a piece of plastic right. Is this going to come out? Oh it is it's going to come out uh revealing uh. It's almost going to come out! Oh there's a magnet there's a little pad at the end. I thought it was magnets, it was repelling it, but it appears to be just little pads alrighty how this is.

Oh there it goes. Here's the coil, the coil is connected to these leds. I think they're. Just inverse parallel leds right, taiyo art and it's just a little foam pad at each end and that neodymium boron magnet, which is a hole down the middle of it.

Why is that uh? So when you sugar powers and forwards? Oh, that is that's even more bright. Without the dark cover, uh, that's quite good! Oh actually, you know what am i right, i'm saying that those little neodymium magnets they are. It has pads, plus it is the new doom and magnets that they end to actually repel it when it gets to the other end. It's just like the original shake light right.

Tell you what i'll take a picture of this i mean there's not much to see but i'll take a picture of it i'll look for any other circuitry, and then we can see what it is. One moment please continuing on very simple: it's got the coil that the magnets flying backwards and forwards through it's got two identical circuit boards. One well they've both got pads in the front, but they've also got pads in the back for these wire links, and the leds are in reverse parallel in each one, so that as it shakes backwards and forwards, initially say, for instance, these two will light and then Those two will light so very, very simple. I think there is something special about the magnets, so let me show you the schematic and the internal layout.

This schematic is super simple. It's that coil a resistance of 255 ohms, and it's got the inverse parallel leds on this circuit board and a link across, and then the verse parallel leds in that board. The magnet that is flying up and down the middle has a hole through it. Now is this to concentrate the magnetic flux in the outside? I don't know that's quite unusual, but there's also two little neodymium magnets at the end as well.

They're all neodymium, because that's the only one that really makes sense for the amount of magnetic field required at the end of the tube we've got foam inserts these little black foam pads, presumably to protect other magnets from if it's shaking really hard and it smashes against The end, but i don't think this magnet really gets too far to those because by the time it's getting near the end, these little tiny magnets in the end are actually the opposing magnetic field. So if this is a south end to the big magnet, this one has a south pointing in the way and vice versa, north at the other end, and that means that even without these foam pads, there is a strong decelerating effect when the magnets come up because They are the wrong polarity, the closer it gets, the stronger it repels it. So it's almost like a little sort of magnetic spring, but the pads will also help dampen that it's an unusual approach. Well, it's not that unusual, because the first shake flashlights did have repelling magnets at the end as that uh buffer, that potentially the close, the magnet got or the harder it was going to actually have a stronger push back against.

It very interesting, very neat, very simple and, as i say, from testing this just even taking out the packet and tipping it up down it lit brightly. I could, technically speaking, just demonstrate that right now i put these magnets down somewhere they're not going to suddenly and violently attach to something. So if i stick that little foam pad back in here and shake this, it should be nice and bright. It is nice and bright, very bright.

Maybe it's down to the efficiency of leds, maybe it's down to the power of the magnet, but that even just jogging with very small movement, you actually get a distinct illumination, just tilting backwards and forwards. As that effect, it's very good very interesting. It works a lot better than i was expecting, but there we go. That is it, that is the uh dynamo running light super simple inside the instructions that come with.

It must be in every single language, because most of the space in there seems to be taken by the usual big instruction book that covers every single language - oh pdf online, but there we go interesting. That was really interesting to take apart. It's a neat little gadget, uh, very, very simple, so it's going to be super reliable. A very much doubt significant current is going through these leds, even when it's shaking forcibly, because there will be a limit to how much it can generate, and even if it's putting quite a high current through them, it will be limited in duration.

So uh these fairly standard, but high efficiency, leds uh, will last a long time. I should think it was also very well sealed, as you saw from when i tried opening it was glued shut, so it should theoretically be fairly waterproof as well. I think this is a product that would last for decades very interesting, very clever design, very neat.