Flexible led filaments, i thought i'd get some and strip one of them apart and take a look. It turns out they're quite hard to strip apart, i was hoping i was going to be able to peel some of the silicon off to reveal the circuit board, but, as it happens, uh any attempt to actually scrape it very gently. The knife ended up just cutting the circuit board and then, when i cut bits and uh off, i put them in various solvents to hoping that i could dissolve the silicone and reveal the circuit board. No luck, but that's okay, because what i actually did in the end was i illuminated a controlled intensity and i stuck a magnifying glass glass over it and duded it down and then created a graphical representation which i will come to in a moment.

It's a very interesting construction, so the reason i got these is because another youtuber who makes models had made a model of a neon sign and they'd use this. So it's a scale model, but it had this very sharp outline of this stuff and the stuff operates at three volts per section. So basic at four sections here and at the moment it's at 12 volts and it's passing 200 milliamps. The 200 milliamps equates to just one milliamp per led in here, because there are 200 leds in each section of this.

I worked out that in the 285 millimeters that is lit up that's about 11 inch. There are 200 leds, so roughly 7 per 10 millimeter. The circuit board inside appears to be 1.5 millimeter wide and then it's coated in the phosphor. Now it's worth mentioning the seller.

I got these from on. Aliexpress is selling what appear to be slight rejects, and it's not an issue for people like us that are just experimenting with them. But if you look along it and you're not really going to see it because uh, you certainly wouldn't see in the distance, but i can see right now. There are occasionally dark bits along it and it's not because the leds are out.

It looks as though the leds have flipped up sideways and are actually projecting light out the side instead and that's viable for the way they're soldered on. So let me bring in a doodle and show you the construction of this. I shall also zoom down slightly zooming down, so the circuit board is a very thin flexible circuit board, very delicate and it has a pad on each end and then a series of uh pairs of pads with what appear to be flip chips. Flip chips are leds that basically have little solder pads on them the bare chip itself, so it's almost like a surface mount led, but there is no package.

It is just the bare led it's the way a lot of stuff has gone and what it means is that they can apply probably a continuous process. They can apply a solder paste onto these little pads. They can use a machine that, and goodness knows how it does it, because they're tiny that picks and places the leds on and then it will take them into a reflow oven. It will heat the soil drop and it will flow on and soda them.

That's where i think some of these little leds are sitting across like that to think as the sodas they're flipping up in their end, like that, because the light distinctly shines out the side for some of them and the arrangement they've got you've got the positive end And the negative end, they have the large pad thermal isolation going over to the first led and then they've got a bus going up one side that connects to the positive all the leds and then the other side is a bus that goes down all the negatives And that means that, theoretically, this led here has the same sort of circuit resistance as the led in the middle, because the tracks the same length but in reality, and i'm not sure why this is the green - is visibly brighter at one end. Uh at both ends. Actually, but duller in the middle, as is the blue, i'm not sure why the current isn't shearing. Equally, i wonder if that's part of the degradation, the middle with the flowing process, i'm not really sure but uh.

This arrangement means that these leds are these whole filaments. Just operate at three volts because all the leds are effectively in parallel. Let me bring in a notepad and doodle. Oh there's, another pen.

I should use that one. So the construction is this: they have the circuit board with the little tiny chips mounted on it, and then they coat it with a phosphor loaded gel and the other side is coated with slightly less phosphor coated gel it's more translucent the other side and any light That gets bounced off the top also goes through the circuit board and comes through the bottom to terminate onto the strip at the end, has a crimp put on it, a little crimp that just basically goes under it like this and folds around, and bites into that Copper pad at the end and that's the connection. Then they seem to secure and place the little blob of silicone and then put that sort of the phospholoaded silicone on it. It's very neat the crimp itself when it comes off the end, has a little tag.

That comes off like that. The positive one has a hole through it. Just in case you get some of these there's a one of the tags is no hole. It's a negative one of the tags as a whole.

It's positive just for reference, that's how to identify them. The colors uh you've got the sort of warm white. It's goldeny white you've got the green, the blue and the pink. This is red, but red doesn't work that well, it's nowhere near as bright as the other colors, but that's because the red doesn't really want too much blue and blue is the main stimulating led that stimulates the phosphorus.

So they have to use quite a thick layer of phosphor to get the red, but actually hide the blue from say otherwise, you'd end up with a pinky color. So this one is a fairly dark red. I should show you it shouldn't. I i should one moment please and back again: uh here is the red and again it's got a real hot spot at the end, but dim in the middle.

I'm not sure why that is, but you can also see the irregularity of the leds in this stuff. It's really pretty visible. I shall zoom down a bit, so you can marvel at the irregularity hi. It was cheap.

I knew what i was getting, i'm just glad that all the leds are lit, but it's notable that the ones uh that, where there's a gap, it's you twist it slightly and uh. It seems like they're just pointing light out the side very strange. I'm not sure why that is if they've just flipped up or it's something else and the red, though not as bright as others. It's worth mentioning that uh, you run these at three volts and uh, i would say one milliamp per led is ample, i'm not sure what they're rated, but certainly that would equate to three volts 300 milliamp 200 milliamp.

That would be 0.6 watts. I suppose you could run them higher they're, not really going to be too pushed, i'm not sure they're rated, but i think they're more designed as a visual effect. You'll often find these in the lights spiraled round, with big long gangly filaments and little supports, and quite nice, that they're low voltage, though it opens up possibilities of using them in sort of like costume effects and they're very resilient. I did manage to damage one though i put in a connector and then i really absolutely flailed it off the table to see if i could break it, and what i did manage to do is break one of the solar connections and also fracture the circuit board.

With the flexing where it went onto one of the connectors, so if you reckon there's going to be a lot of movement, put a bit of heat shrink sleeving over the end, just to actually reinforce it. I've actually put heat shrink sleeving, where i've soldered these end. To end, and because i've got four of them, the four times three, it runs at 12 volts but uh. I would go by limiting the current i'd, adjust it to whatever it limits the current to a safe level.

For these, so i shall provide a link to where i got these, but be aware that they are kind of reject factory, rejects they're, just for playing with, and also be aware that sometimes, when i provide links to aliexpress sellers, the price goes through the roof. It sometimes happens. It happened with this. I made a video about this little uh portable soldier yarn, one two, three four, five right: that's it and the seller just hiked the price up, uh more than double so i removed the link and i told them why i'd removed the link um.

They just sent a wee question mark back to me. No, i don't know if they understood what i was saying. I was saying, stop being dicks. However, it's also worth mentioning that there are other tempting things available from this seller, like colorful, solid, led filaments.

These are the higher voltage ones, but these ones arrived intact and these ones all arrive, broken and they're. They were shipped in ten little bags just in amongst other stuff and you're thinking. Oh, maybe they've broken the shipping, but i've had experience with buying the filaments from china. I get the feeling that they quite often just throw the broken ones into the packaging as well, so i'm not sure if they were broken in shipping or if they were broken before shipping.

However, they weren't packaged correctly just be aware of that. If you consider buying the the solid filaments, but that is it so what you see is kind of think of for this. Well, it's just a visually nice thing. You could make yourself a necklace out of it, i suppose, with a little uh battery pack, because it doesn't take much current, even at just 10 milliamps, it glows quite brightly, it's pretty good um, but really it's just whatever you want to do that.

Fundamentally, it produces a nice sharp line of light, but that is it that's how they make it uh the construction inside i'll check back later and see if the stuff that i put in the solvent has dissolved in any way, sometimes the silicons kind of puff up. When you put them in acetone and things like that, but so far no luck, but if that i do have luck i'll, maybe make a note down below in the description or whatever. But anyway, that's it. The gangly very flexible, led filaments.