I Was in a local hardware store and I came across this clip-on light. a little flashlight and I was looking at it and thinking you know the car battery in it The chip on board LED area might be useful as a ring light for a camera. Let's take a closer look at it under a word in advance that this has flashing mode so I'll turn it on Sideways then I'll press it again. It goes down to half brightness and this is where it starts strobing and flashing.

strawberry and flashing and then off. And unfortunately, it's the same thing that when you have these things that, uh, you can't just turn it on and then after a while, just turn it straight back off again. you have to click through the modes if you press and hold the button. as often happens with these, I think it does.

Yes, it does. It's got the the SOS mode. Lovely. It's notable that it's got that little spring-loaded has, but it's quite clever.

By making one leg of the hasp longer than the other, it means it by default wants to actually get a sort of a central position so it Springs back closed. I Wonder who came up with that idea? Very clever. You'd think also that you'd be able to just pop the lid off actually a steel sort of thing here. Think that might be a little battery tab, but to change the battery, you need a screwdriver.

Which means that for many non-technical people, they'll just throw it in the bin, wouldn't they? That's what happens, because they can't be harsh changing the battery because it's complicated and involves screws inside. I'm expecting two, two, three twos could be wrong. Nicer is rechargeable. Uh, there is a little Packer a little housing that we'll pull the whole thing out.

Oh, it comes out as a solid module. I Wonder if this is used in other products? Uh, there is. Yeah, there's the two Cr2032s. Is this thing going to come out further? Uh, there's the two batteries that popped out.

What if I Just push. No, this thing isn't coming out. Is it physically clipped in? It does feel quite tightly clipped in I'm trying to see if there's any obvious thing that's holding that and it doesn't seem to twist out. I Think it must just be clipped in.

Let me grow with a pair of pliers and use Unreasonable Force because that usually works, does appear to be working. Yes. Oh right. This is just a packer.

and there is the circuit board. Oh, that is tight against the end. Is it friction? Yes, it is. So it is a combined uh, cob button.

Oh right. Okay, so that rules that out, doesn't it? It's I Thought this was going to be a separate chord, but it's got the button built into the middle of it and on the back it's got the classic little chip, the little six pin chip, and a resistor. What's the value of the resistor? The resistor is 5.1 Ohm, that's probably going from uh. one connection to the battery.

Is it going to the whole lot? I Think it may be going to the whole lot. It looks as though it's going from the battery connection to the actual chip itself. I'll tell you what. I'll doodle down the schematic of this one moment, please.

There are some puzzling things about this design. One is the chunky, blocky sort of nature of this. um, that hasn't really been used to heatsink. because if anything needed heatsink, it would be the negatives because the transistor knots.

It really is needing heatsinked. Um, but they've got this huge chunk of the positive connection from the battery connection and then the LED connection going through here. And it's worth mentioning: there are six LEDs in the back that will just be one parallel circuit. So there'll be an inner and an outer track.

and they could theoretically have taken this Led switching pin in. and then they could have taken this switch pin much further in because there's a switch behind here. That's common to this pad here and it would just get rid of this track. It's kind of strange I Don't know if they've just butchered it from another design.

Things worthy of note: There is a capacitor between the battery connections. That's the little ceramic capacitor that will run the battery flat when it fails because some of these sort of high-ish capacity ceramic capacitors tend to feel this resistive. State There's a 5.1 Ohm resistor, but instead of being like, say, for instance, here, feeding the LEDs from that pad, it's feeding the whole circuit. Um, which is strange because that means that when the LEDs are lit, particularly when they're flashing, the voltage across the Chip is going to be yoying up and down as the voltage drop across this lifts that negative rail a bit odd.

Um, the blockage design is strange I don't know why they've done that in such a strange stepped way. Um, makes me wonder if it was even a circuit board design package they did it on. But anyway, let's take a look at the schematic for this and I've drawn it as the actual chip. so I'll Zoom down this a little bit a little bit more.

We've got the two CR2032 cells here. A bit of trivia if I bring in these Uh calibers and I put them across the outside the cell. The CR2032 means 20 millimeters diameter by 3.2 millimeters thick. So there's your 19.9 well, 20 millimeters ish diameter and there is your 3.2 millimeter on the button that's how thick it is the capacitors across that battery and then go straight to the chip for the positive and then via the LEDs to the switched LED connector which is a pin four, all three of the bit other pins the other side which I could presume to go into one transistor.

at one two three, they're just connected on the other side of this resistor to the negative Rail and that also that side of the resistor also feeds the switch. which is why when current flows through this, the voltage in this chip is actually going to waver up and down because there'll be a voltage drop across this and the case of fresh batteries and the LEDs being in parallel, giving a typical voltage about three volts. it could go from six volts. It could end up dropping about three volts across that, although there will be a certain impedance thing going on with the these Lithium cells.

can't Supply Huge amounts of current, but it depends the quality of them. But it's an interesting circuit. So what is the mysterious Sot 23-65112 I Type that into Google I Did not find anything, but this is not a surprise. There are lots of mystery chips that just have random numbers under clones of other chips, But there we have it.

It's a useful enough little light, just not what I was hoping in terms of the Uh being able to be used as a ring light because it is all integrated onto one circuit board, which is reason enough. Well, it's also got the little clicky switch tactile switch which is commonly used in car remote controls. so if your camera control switch fails and they do, they just stop responding to presses. You can always if you have one of these knocking about Salvage the switch odor or buy Pax them in eBay they're dirt cheap, but there we have it.

Interesting, worth taking apart and uh, fairly novel design.