This seems to be a very common little light. It clips onto your phone to provide illumination from all directions and avoid shadows. This one came from a UK Pound shop called One Below, and cost around £2. Not bad for the functionality and components.
I've tried this style of light for macro shots, but it tends to give a lot of reflections in shiny objects. For my PCB photos I use a much wider ring of LEDs.
It's interesting that the PCB clearly has the functionality of being USB rechargeable for use with a lithium cell. Although those component positions were unpopulated I still reverse engineered that area and added it to the schematic.
Both parts of the assembly are well worth the small cost of the unit. The LED ring can be powered directly from a USB supply with suitable resistors to limit the current to around 360mA (36 LEDs at around 10mA) I'd guesstimate around 5.6ohms at 2W.
There's one component position I didn't mention. The resistor between the gate/base of the transistor and 0v rail. It's for a pull down resistor to allow the use of a MOSFET.
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I've tried this style of light for macro shots, but it tends to give a lot of reflections in shiny objects. For my PCB photos I use a much wider ring of LEDs.
It's interesting that the PCB clearly has the functionality of being USB rechargeable for use with a lithium cell. Although those component positions were unpopulated I still reverse engineered that area and added it to the schematic.
Both parts of the assembly are well worth the small cost of the unit. The LED ring can be powered directly from a USB supply with suitable resistors to limit the current to around 360mA (36 LEDs at around 10mA) I'd guesstimate around 5.6ohms at 2W.
There's one component position I didn't mention. The resistor between the gate/base of the transistor and 0v rail. It's for a pull down resistor to allow the use of a MOSFET.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators
A clip-on ring light. This is designed to clip onto your phone. Let me get out and show you it's not actually for taking pictures of people's rings. It's purely for circular elimination to provide even illumination around objects from all directions.
So here is my little micro camera. It's a little moto g6. The thing clips open like this, you clip it on and ideally with the ring light, the camera would be right in the middle, but with these it just tends to be where it lands. So it depends on where your camera actually has that.
Well, the front's already tried popping off that's excellent um, but then you try and get around your your camera there and when you actually point at a surface it provides even illumination. I have tried it for macro. Photography, it wasn't very good uh. This small ring just created dots of light in the image, so these dated rechargeable cells are now in.
Let's try it out where's the button one comes on at low intensity. Is there a flicker? No, it's not. Okay, that's good! That means the pulse of modulation is fairly good, high setting and then off so uh low, medium and high. That's what you're getting arms.
If i hold the button in oh, it actually goes into a strobe mode. That is just absolutely i'm sorry. I did not know it was going to do that. It makes a change in the sos right.
Tell you what now done that now, we've seen it, let's get my little other camera out of the way and we'll take this to bed. So this is already trying to pop off. That makes a refreshing change, the other one i use uh that was glued on and broke off quite dramatically. This one appears to just unclip, revealing that the leds actually almost look like they're in parallel hold on where's the meter.
Let's uh use it in diode to make the leds light. I don't think they're going to be in the series. It'd be very odd if they were hold on. Are they not really getting anything conclusive here, not getting anything lighting at all? Maybe it's because my probes are blunt and not quite reaching to the solder joints.
Uh i'll train these connections again, no, nothing! Okay! Oh! I saw a little glitch there nope nothing uh, that's a waste of time then, but i shall be able to deduce it from the circuitry. So are there any hidden screws? Let's get the batteries out, shall zoom in just a little tiny bit, not too much, because otherwise it gets a bit cramped uh. I think i could need my spudger for this spudger, my isis ammo spudger. This is still the original one.
I do have a spare on standby. All the other clones of these just broke. The isis samo just seems to be the magic, correct mix of metal that it just works really well, so this pops off is there anything holding this in? Oh, that's, quite easy! Right. Okay, circuitry looks very straightforward: let's take a closer look one moment please and resume: there is an unpopulated section.
This circuit board, which it turns out, is a charger with potential for a usb port and a charge control chip for a lithium cell. But it's not used they've got the batteries coming on to this end of the circuitry here and it's just three uh two triple a's. Let me show you that end of the circuit board i'm gon na zoom out a bit now, i'm not just a little tad. Okay, so there we've got a generic flasher chip. It's the sort of thing you'd find in bike lights. I guess it might be a microcontroller or a dedicated function. Chip, particularly given it's got the strobing mode and that uh has a power supply going to positive negative. It's got a switch input pulling to ground, and then it's got the output going straight to a j3y transistor, which is an npn transistor and then the leds things worthy of node.
There is the option here to put a resistor across here and then connect the leds negative down to here, but the positive goes straight to leds, but it just gives you the option in this case they're not using a resistor which is kind of naughty they're. Just relying on well the low voltage of the three volt batteries and perhaps the wire resistance and track resistance. It's a bit shady um, the circuitry. At the other side, though, it's kind of interesting because it is based on a classic lth7 chip, there's the position for the programming resistor.
This looks like capacitor position, then there's another there's a resistor here for the leds and then it's using a little trick with the leds that it's only got one control line, but it can actually toggle between the two of them um. I shall show you the schematic and it will all make sense here. Is the schematic here's a bit? That's completely missing, so the usb could potentially come on and there's a decoupling capacitor. Then there's one resistor feeding the two leds.
If the unit is charging, it pulls the negative of this led low and because this led will be chosen to have a lower voltage, maybe it's a red led to show its charging, then it will actually pull the voltage on this resistor down to the point that This led won't light, so while this led is lit that one can't, because it's not exceeding its forward, reverse forward bias voltage when this chip has finished charging, it turns this led off and then the current just flows straight through resistance through that led and shows green. For charged, there is a resistor for programming the current, and then it would normally go over to the rechargeable cells, but in this case they've got two aaa's. Instead of the lithium, i think it'd be better to have a protected lithium. But having said that, uh, if that would just protect, if the voltage went down so low that uh, it went below obviously about three volts, but at that point in time with the resistor the intensity.
These are going to get quite low and usually the cutoff point of the protection chip is 2.5 volts and at 2.5 volts these leds won't be passing much current at all. There might be a little bit of a gate base current in this transistor, though, but it would be dim or out, but you could use a protected cell. There is a decoupling capacitor for the flasher chip. I should have shown that over this side it would be more accurate, but it's actually right across the flasher chip. It has the button pulling that input, pin down to the zero volt rail to actually toggle through the modes and then it's straight out to an npn transistor j3y rated 500 milliamp that then lights, the leds. That is it it's pretty straightforward and it is designed to be multiple use type scenarios. So what else can we do with this? If you bought one of these, it might be worth actually just taking the leds out of it. The led ring, because that's a fairly useful low voltage led ring it's just three volts it requires you could actually make a little usb cable for it.
Oh tell you what where's the structure? That's the correct tool to get this off spudge, let's whip that out! This is basically adjustable conduit going down into the bottom there just to protect the wires and a stiff spring in the middle. Let's power up, i don't think, there's a resistor in these there isn't it's just a marker for negative and positive: let's get the bench power supply on and see how evenly the light at very low current, because i got the feeling that there was a bit of An led mismatch in the pcb, but then it is a cheap thing. It's not really expensive. Technically, you should have actually put those wires through the other side, but i didn't uh.
Technically speaking, i should get crocodile clips that grip super thin wires power on uh. Let's turn the overhead light off, let's zoom down in this, i could take the exposure off, but let's get a more accurate indication. So if i turn the voltage down, i'm trying to turn the voltage way down. Not super duper led matching.
Here i see a dim one here, but they're not too bad and a dim one under there, but as i turn it up, then you end up with a really bright uh led light. What's uh around about three volts, it's 250 milliamps, i'm just shorting things together. Right here, uh, it's not bad right. The light is coming back.
Watch your eyes. The light is back uh, so it has its uses as a little led pcb, that's flickering because i'm getting a bad connection. The connections i think here i heard that or it's flickering because it's got a dodgy led, but i don't think so. So that's interesting enough.
I should turn that off. I shall zoom back out. So that's what you get. I think this was about two pounds in it from one below in the uk: it's a sort of pound shop, but this was one other slightly more in a pound range.
It's okay! Actually, it's a very basic setup. It's the most rudimentary control possible and it just has a fairly useful little led ring just that you could use for other applications. If you connected a resistor and a usb supply to it, you could actually mount it actually around the lens or camera. But having said that, if you're wanting super duper brightness, this would be quite a close range thing. If you want super duper brightness, you might better going for a dedicated light, but there we go interesting stuff, it's still quite a lot for your money. It's really not too bad at all.
I have the rechargeable version of this, it came with the cutest little 50mah li ion pouch cell (about the size of a finger nail), upgraded that to a more reasonable 400mah cell salvaged from disposable vape device. Work great as a light in a tent too.
Who needs a mode switch on a camera lamp? Cameras need as much light as possible, so the low setting is pretty useless. Just put there an on/off switch and you don't need any electronics.
Big Clive beat me to it! I bought one of these and promptly disassembled it just for the LED ring and diffuser. These work great as lighting around a 3d printer hotend so a webcam can pick up exactly what is happening. 😃
FYI Clive, Poundland have started selling a rechargeable version of this, and a few other interesting bits and pieces under the Viido brand name
I generally assume these days that those 6 pin chips are probably PIC clones (paduk) which have been factory programmed. I would think that at the silly price they cost, custom ASICs would be an expensive option even in massive volumes
I downloaded a circuit program I just wanted to test some capacitor times, but at first when I drew it out like your schematic it just said capacitor shorted, which made me wonder, how ttl are your drawings 👀
I'm amazed they're still selling these, they're so loosely made and it would be better if it plugged in to the phone
Its for the inward for selfies and applying makeup etc
And possibly for my laptop webcam and my weekly zoom meetings if I get my hands on one.
A few years ago I designed a custom ring light PCB that was simply a friction fit in the 58mm filter ring thread of my Canon PowerShot SX40 – it works pretty well, though could do with some more diffusion 🙂
The ring is just a couple of dozen 0805 white LEDs in parallel on a 0.8mm PCB, with wires leading to a micro-USB-powered, variable, constant current driver based on a traditional linear regulator (whose number escapes me right now) and a fat potentiometer. Not very efficient, but it works nicely and there's no flicker as far as I'm aware!
Plus, the driver PCB fits within the inner diameter of the ring light, so OSHPark didn't charge any extra for the driver board 🙂
(I didn't even have to panelise the two designs, IIRC. I just needed both designs in the same gerber files, with the driver inside the ring, and at least 1mm clearance between them for the router bit, then OSHPark's panelising software did the rest!)
(To be clear, the PCB permanently lives in a spare UV filter – that's used more as physical protection for the lens than for blocking UV. I just screw it on as needed.)
I'm still trying to figure out why anyone who would use this for making selfies would want a strobe function in the first place 🙂
I'm pretty sure that light is mainly intended to go over your front camera, for selfies and video calls. In that case the camera lens should be fairly centered in the ring. It would cover a bit of your screen though.
And thanks for the comment about the iSesamo – my generic clone gets bent quite easily, will check out the original.
Kmart here in Aus sells a USB rechargable version that I quite like. I have used it on my laptop webcam, and I also used the pcb&battery out of a few to make some other led lights
That's not a great design on their part; direct connection of batteries to LEDs means it won't work well on partially discharged alkaline batteries and probably would barely work at all with rechargeable batteries.
Great video Clive – Would be good to know the CRI value of the leds? I'm guessing low given the price, but for photography it does matter.
I bought my Isesamo spudger after the first or second video I ever watched of yours and it has been a great tool! Still on my bench to this day!