Let's take a look at a one word for student lamp. Now this is our two watt one that I looked at previously. this is the new one watt one. I Have to say that compared to the two one, it doesn't look half the intensity.

it looks about quarter intensity of that. It's much dimmer. but it does have a notable Advantage There's no flicker off this one and this one does have a slight flicker to it has a slight Shimmer So let's unscrew them and plug them in individually. Well, let's just plug the the one of interest in which is the one Watt So I'm going to plug it in and so on.

It's relatively nice, but it is a very dim you can look at it comfortably, type of filament and the power it's drawing is 0.9 Watts with a perfector 0.5 um and a current of seven milliamps and to try and work out once, well I'll show you what I did to try and work out what suckridge is inside one moment, please. So the first test, well all the tests are a don't try this at home type of thing I've got two high power resistors here, each rated 100K and if I put the lamp across and it doesn't strobe, then it suggests it's just glowing there very dimly. It suggests that it's not got a switching Paris Planet because they tend to strobe and Flash the next test I shall unplug it before doing this and once again, I'll say don't try this yourself at home with exposed connections. It's been done like this here because it's just more suitable for the video.

So I've got a diode in line now and if this is a capacitive dropper, then it will not like having a diode in series. It will glow very dimly just with slight leakage across the discharge resistor. So if I put it in series, it's lighting fairly brightly. Uh, on us, a half wave.

So I don't think it's capacitive dropper and that kind of suggests then that it contains a linear dropper. I'm just I've unplugged that. So I will now disconnect these weapons of mass destruction. So let's open it.

It could be uh, linear current regulator or it might be uh, just a resistor. Kind of hope it's just a resistor because that's kind of interesting when the the corner cut to that. Oh, incidentally, this one got came from a UK seller Longlifelamps.co.uk I'm not necessarily going to endorse it because I do note that it is massively less efficient for a one. Watt Air filament.

it's not bright at home. oh I Also took a close-up picture of it with uh at low intensity and then uh, zoomed in the image and saw there are 24 LEDs and given well, we'll see what the circuitry is. This is me just nibbling away at the metal trying to get this open. I Do notice from looking into it that it's not super skimped.

well. this is a plastic shell inside which is interesting. The lamp Globe is one of these type that flanges out quite quite. It's very shallow, it flanges out in there so there's plenty of room for soccer trained.

I Will say this does definitely have smoothing because there's no flicker, which is nice. The other ones do have a bit of flicker. This might not be the most efficient way of opening these, but I find it's a relatively useful way of opening them. I See that this one has a plastic liner inside.

This is interesting. It kind of hints. It's quite good quality. actually.

it's like being made to sensible standard. some that we stuff that comes from eBay is sometimes just not 100 what you'd want. until I Zoom down too. No.

I don't think I've seen down too far right? Is this even gonna come off easily? This plastic dish me make things a bit more complicated. there is the uh, the base is coming off. It's not going to reveal much inside. it's going to reveal the that there's a connection in there.

That's all right, We'll just keep mincing away and chopping away the metal exploring lamps in taking main apart so you don't have to. These are quite good for the first student because they are very low energy. They give a nice visual effect, but in this case I think this one should be too dim? I might actually say that of the two, maybe the two watt one was actually the better here for actually casting with some useful light. All right.

So the tin opening is going okay. The bases come off. Oh, there's a linear regulator. I shall show you the picture of the circuit board.

Exotic picture of it. It's the easiest way of doing it. This foamy cement here is the stuff that is always really hard to get off. Now you have a pure priority as I do.

Let's try and get this off. So there's an electric capacitor. There's a bridge right far so there's a linear regulator, right? Tell you what I shall clean this off and we'll take a look at it one moment, please. Before I go any further with this, let's check the voltage across the filament inside the lamp.

So if I plug this in and we monitor it with the fluke, Ah, the fluke, It says 129 volts across that filament, which is much harder than I was expecting for 24 trips. let's do the calculations on the Kink calculator. So that's 129 volts divided by what appears to be 24 chips is about 5.3 volts per chip divided by 2 gives what I'd expect 2.7 for one chip. So each of those little chips I saw inside is actually two, possibly two LEDs on the one substrate and that's interesting, right? Okay, next, I'm going to actually disconnect one of the connections here and we'll measure the current that's uh, flowing through the filament one moment, please and resume.

So plug the power in again. 2.4 milliamps. That's a lot less than I was expecting. So that means the filament is dissipating at point zero.

That is ridiculous. To four four. Uh, so 2.4 milliamps times 129 volts equals it's 0.3 Watts That explains why it looks so dim. That is strange.

This is possible because they're trying to take the load off that regulator. The linear regulator. How unusual. Um, so let's go further.

let's take a look at that circuit board. Reverse engineering is complete. Let's explore. So I shall Zoom down onto the circuit board so we can get closer.

and then I'll show you the schematic. But let's take a look at the circuit board first. The main Supply comes in and goes straight to the redirect fire, with the neutral going straight onto the Bridge Farm But the live coming via this 33 Ohm resistor. It's a fusible resistor, which means that it's not just limiting the inrush current to the circuit, but it's also going to act as a safety device as well.

And the color code on it is orange, orange, black, 330 33 and a 0 as a decimal multiplier. so it's just 33 ohms once it's been rectified to DC it charges this little 3.3 megafar 400 volt death beam capacitor and there's also a one Meg Ohm resistor across the output. the bridge right far and that serves three purposes. In my case, it discharged the capacitor and starts me getting a tingle off it it.

also applies a slight load so you don't get that ghosting effect that you get with LEDs because this lamp would be very sensitive to the leakage you get through the capacitive coupling between switch wires and that can make the lamp continue to Glow even when it's off. The other thing it does is it will discharge this capacitor fairly rapidly so the filament doesn't just glue or we just fade away very slowly. it will go out quite decisively. Then there are two components in the board are the linear regulator and its programming resistor.

This is our regulator device that will limit the current and you set the current and it measures the voltage across this resistor and then when it reaches a certain level, it knows that the program current is reached and it'll just it will act like a variable resistor. And one of the most interest things about the circuit board is that on the back of it there's these three plated through holes and that's all I Thought they might have put some more down here, but they've got three plated through holes. and uh, as well as having a fairly large area of copper on this side of the board, this regulator also couples through and the dotted outline. here is our copper plane on the other side that is also designed to help dissipate the heat from this.

and it turns out that the LEDs dissipating 0.3 watts and this. is dissipating 0.5 which is a bit disappointing. But let's bring in the schematic: I think that's everything covering that it is. Oh, these are square posts.

The LED lamp. The wires come up from the base, the lamp through these little notches at the side, and then they just wire wrap around these posts. It's a fairly common way of manufacturing, it just means no extra soldings required at that point. Here there's the schematic: Let's Get Closer incoming Supply in this case, 220 to 240 volts, 33 Ohm resistor the bridge rectifier, the dash beam capacitor 3.3 microfarad, 400 volts, and the one Mega Ohm resistor.

Now earlier I mentioned that we have roughly 340 volt DC on that capacitor. That's because the mains voltage in our case is say 240 volts. That's the RMS value root mean Square that's the average value of the sine wave. the peak.

multiply that by 1.41 and that will give you about 338 volts. It'll actually Reaver up and down. It can be quite high in the UK I should put the Kink calculator out the way. There's about megum load and discharge resistor.

and then we've got the LED chips and it's quite interesting. It is like each chip is two chips, so it's effectively 48 LEDs and the current being passed is 2.44 milliamp. As we saw earlier, the chip has the number eight two GA on it. The closest I could find to that.

It's kind of like it's also got uh, it's also got lettering on it. it says IBM iraj and that doesn't really call up anything. It might be a manufacturing could, but the closer I could find as an example as an Sm-208 to B which is very similar. and as I say that's dissipating 0.5 watt which is a shame because if you put two of those LEDs in series, The Voltages ample because there was about 120 volts across.

so I think it was 120 volts and with the rest being dropped across here say about 220 volts. so they could easily have run to those filaments in series and with this just with the same values and it would have doubled the light output for the same amount of power. anyway. I Decided that since it's dropping such a high voltage and normally if you drop a very low voltage a super friendship resistorian and the voltage cross is quite low, any Mains fluctuation would result in intensity variation.

The current would modulate through the LEDs and when people turn things on the lights with different things like that. so this uh helps prevent that by providing the linear regulated current. But I Thought it'd be interesting putting a resistor cross there because with such a high voltage over 200 volts across it, it will effectively not really matter too much. It won't affect the current too much with the voltage variation.

So what I've done? there's this. Let me just show you the doodle first. Then I'll show you then things. So I've got the atenum resistor just because it's what I had.

Oh, look at me just drawing this so hastily bridge for very hastily. this is high speed drawing. The other terminal comes in here. AC plus minus I've got the two connections coming out I've got the capacitor in this case a 4.7 megafar just because it's what I had 4.7 and it is of death beam capacitor 400 volts as used in 5G lamp push to blow people's brains out remotely apparently according to weapons experts.

not uh. I'm not even going to point to that guy's website, it's a conspiracist, but this time I've got the LED and I'm just going to put a chain of resistors in series. In reality, I could use a single resistor route. It's a it's going to dissipate half a watt.

It could be one watt, roughly about 80k. What? I've actually used is a four resistors. uh, four times. 18 k? Uh, quarter one.

So let's bring in the soccer train. I'll show you it working. This is going to actually result in slightly higher current through the LEDs but not that too dramatically dangerous cobbled setup. Here is the lamp which I've put some Mars into and put some resin in to protect it from my twisting of the wires.

The power supply is just made from discrete components soldered together I've just all beer and lived yet not not great, but uh, it's fine. Uh, this is prototyping. 10 Ohm resistor the bridge rectifier just cobbled out 1n407 diodes. The Uh discharges this to the One Magnum discharge resistor and load resistor, the capacitor here, and then the four resistors in series with the lamp.

And if I plug it in, let me just zoom out a bit here. If I plug it in, there is a lamp lit nice golden color. It is A it is a warm color temperature. that lamp.

it's now just fractionally over a watt. It's gone to eight milliamps. Per factor is still 0.5 That's because of the capacitor because the currents are only really being drawn at the sort of peak of the sine wave. Um, and it would be interesting measuring the voltage across those.

But let's measure the voltage across the lamp, which is probably still going to be in the region of 120 volts. Let's just zoom out here because we're yeah, I'm working a smaller area. There we go. Let's keep my fingers away from that juicy bit.

So I don't get zapped. Uh, the votes across the lamp is 128 volts say 130 volts. The voltage across each pair of resistors get a connection. It's about 102 volts so I can work out the dissipation.

Um, let me grab the Kink calculator and move this to the side. I'll show you leave it lit so that's 102 volts. So it's 204 volts being dropped across the resistor. The current is going to be 204 volts divided by the combined value of those resistors.

I Should have calculated that first. 18K times 4 equals so 72k. So two hundred was that. 204 volts divided by 72 k equals the current is now 2.8 milliamps times the 202.

I think it was I think it was 204. It doesn't matter, it's very close equals the distribution is about 0.6 Watts divided by the four resistors. it's 0.143 watts each. so a less than almost half the rating I should tilt this up so you can actually see it.

So you could just use the same surface mount circuit board, but you could actually in place of the this. you could actually just put a little cluster of resistors there and it would achieve the same thing likewise. Uh, you could have used the two filaments still, but at that point, the voltage being dropped across the resistors would be more critical. You're more likely to get a slight fluctuation, but that is it.

It's a nice enough lamp. It is that warm golden color temperature which also impacts the intensity. kind of like it. This is notably just a bit brighter actually because of my circuitry here, but only because it's driving out higher current and still maintaining roughly a watt.

Uh, but that is it. Uh, it's a nice lamp, Very simple circuitry, and uh, it does the job nicely. Also quite pleasing hacking up with a bit of a my own DIY circuitry too see if it could be done with resistors I Know there are some lamps but like this one that do actually use resistors. uh if I did more resistors and outside to test this.

but um, they actually just use a resistor in the base and crudely, they use their LEDs for bridge ratification which is a bit naughty. Those lamps tend to feel a lot, that's probably why, but that's it. This is a nice lamp.