A classic retrofit LED panel. But if I zoom in, you can effectively see that the original circuitry was the little Buck regulator, the commonly used the little inductor and the switching circuit. But something has changed, but the packaging hasn't. If I open this up, you can instantly see that all that stuff shown in the front of the packaging is missing. So I'm going to plug this into the hoppy and we'll analyze its power output. Well, it's electrical characteristics as opposed to its power output because it doesn't really output power outputs photons right? I'm going to plug this in there and it's going to be right. Is it going to be flickery? Yes, it's going to be flickery. Uh, my apologies for the flicker. That is because there's no smoothing and they could have added smoothing. The power is 17. Watts The perfect factor is 0.9 which is very good. Current: 77 milliamps Okay, let's open it up and take a look inside that is annoyingly flickering. So the concept behind this type of weight is it's designed for those bulkhead ceiling fixtures that are made. They've expressed your back and they've got the plastic front that just being at caps on and there are magnets in this and it's designed that you basically just hook it up to the wiring and then stick it to the metal somewhere in that. Not good, but uh, it's a common thing. It appears to be very common in China for there are classic little bulkheads everybody seems to have in their homes. so there are, uh, the magnets are the bit holds this together in the sense that they have this little push in plastic rivet. There are also screw holes, but they've not used them. So if I push all the magnets out, then the thing will separate into the circuit board and the plastic housing. That's a new thing, the plastic housing because it used to be. you just did a beer panel like this with live connections all over it. That shows that the circuitry has evolved. Well tell you what, I'll give you a close-up of this. The circuitry has evolved to the two linear current regulators and then we'll try and hack it and see what we can do with this one moment. please. The reverse engineering didn't take too long, so let's explore live on neutral. Coming in, we've got a bridge rectifier. there is a facility to have a resistor across there, presumably for providing a slight load to avoid ghost glow when the switches are off through capacitive coupling between the switch wires. and then we've got these. MLS 3535a I Did not find any information in those at all. I Could see pictures of them but not actually a data sheet and these are simple linear current regulators and they're quite hard because the the way it's wired, the positive from the bidirect fire goes out to LEDs and then the current flow through all the LEDs and then comes back via these Regulators but there's two in parallel to the negative. Why didn't they? Why did they? run the positive track beneath the rectfar when they could have improved clearance by actually running it that way and run the LEDs in the opposite direction I Do not know why they did that. Uh, here is the chromatic. It's not that exciting. Uh, but we'll hack it. Uh, if I zoom down this. we have the incoming Supply the bridge rectifier. We get a very humpy 340 volts with no smoothing, which is why there was flicker. We've got a 12 LEDs in the series times four and each of those LEDs appears to have nine chips giving about 300 volts and then it's current limited. So really, these LEDs are light and fairly close to the top of the same wave, which is why they're very flickery. Uh, the current central resistor. The easiest hack in. this is just probably to chop one of these resistors off and that would have the power because it would just be one current regulator and that would just be the easiest thing, but it wouldn't stop it flickering. What I'm thinking of doing is as an alternative to that. Uh, if I just remove a bit of track here and here with a tip X corrector which is just not working at all. Excellent. It normally works quite well. it's just made a huge mess. Excellent. What to think of doing is adding a capacitor in line with a resistor Crosser to for discharge. I'm not actually going to probably put that in just how it releasing this and then a 10 Ohm resistor to limit inrush current and I'm robbing that out of a existing kit. then I'm going to put a capacitor across here. four point seven microfarad, 400 volts to be honest. Yeah, that's about the right value and I've got a choice here. I could put in a real good pastor from, well, a capacitor from a local supplier or I could use one that came a little. Chinese kit for a lamp which is a much smaller capacitor and kind of disposable. It's not something I'd use in a critical application. so I'm going to go with this. So initially, I'm going to try it without the capacitor just to see what happens with uh, the capacitor, this limiting capacitor and I'm going to use 470 Nano initially just because that's what I have in that LED lighting kit. So I'm going to get this out of the way I'm going to bring it in and I have already added the capacitron series and the resistor here, but I have not tried it yet I thought I'd save that for when you were here Select: grab the hobby Duff the capacitor in. Say we'll put this one in here noting that this will all be live when I do this. So uh, quite spicy. I'm not going to touch it though and we'll see what the power changes to so it's still going to flicker. So flicker alert. You know it's a lot dimmer. It's an awful lot dimmer. It's actually it's gone down to three. Watts which isn't bad, actually. that's a fairly typical I mean it's a lot less, but it is flickering. Let's see how that changes so that's almost. see what's on the bottom? Uh, perfect. just 0.5 latch. we'd expect 22 milliamps. So I'm going to add the capacitor now. so I'm going to unplug this I'm going to disconnect these I'm going to uh, bridge this capacitor before I get a zap off it. Going to my laziness, there was a little pop. that's why you put a discharge resistor across it. Then I'm going to brighten things up here because it does make sense to brighten things up. Oh, that's swamped that out. but that doesn't really matter. and because this is an aluminum substrate. PCB I'm going to bring an absolute Beast of a southerner and it's the little one that has that fetching 500 uh degrees Celsius output which makes it kind of suited to this type of applications. So I'm going to solder onto these pads I have kind of pre-tinned I'm going to crop this down and it's interesting that they didn't add a capacitor. It would have been so easy for them to add it. and if you think they did it because of thermal reasons, then I don't really see a reason for that because the original unit used to have a capacitor. I'm looking for the solder I have misplaced the solder. Just give me a sec. I'm going to grab some more I will find the other soda later. So I'm going to Tin these pads try and solder on the correct way around. That A bit dramatic. Yes I know you want me to Soldier on the wrong way around. It's always more popular, but this is a scientific experiment so it's being done correctly. So I'm going to solder that one on there if I can solder on there. It is such a high mass solder joint and this one on here. the aluminum substrate wants to take the heat away from that instantly. So this capacitor is now sorted on and I'm just going to gently fold it back this way so it just floats in the thin air. Double check the polarity right. Tell you what. I'll bring back the hoppy back in again now and we'll see if that's changed. It shouldn't flicker now. Has the power changed? So I'm putting that one in there putting that one in there. Flicker alert just in case. But to be honest, I don't think it's going to flicker. Not unless it makes one big bang and flickers. Uh, nothing whatsoever. That's kind of worrying. That kind of suggests that I'm probably not got the wire trapped in the connector. probably. hopefully. or that or the capacitor is, uh, shunting. Oh, there we go. Uh, no flicker. and now 2.5 Watts Okay, so can I go better? Can I put a bigger capacitor in like one microfard one moment? please? The one microphone capacitor is now on. Let's try this out. I Have not tried this yet? Uh, are you ready? So this is with one microfard? Uh, the power of it has now gone up to 5.5 Watts which is actually pretty useful. It's putting a lot of light out and with no flicker, that's good. Now there is one other thing I can do here and that is to remove the capacitor from the series circuit. Let's short that out just in case it's holding enough to current to hurt me. Oh, there was a little pop. It depends where it is in the same way of whether it actually stings or not. So I'm going to Reflow that solder I'm going to leave the 10 Ohm resistor in. but what? I'm actually going to do I'm going to snip off one of these resistors on the circuit board I'm just going to get a pair of side Cutters and I'm going to brutally just chop one off which is the most accessible. That is the most accessible. That's it off. So that's now one of these current Regulators is now out of action theoretically and I have rectified it and smoothed it so it'll be interesting. What happens I mean this is where there could be a bit of a angry confrontation. We'll find out when I Plug it in. So the power is now 14 watts. What was it before? Was it 17? But that is all being regulated via one chip on that board and that chip may get kind of hot and it may self-regulate down I See it already self-regulating down I think I can see the power rating. It's now down to 12. Watts So it's not that happy because it's now putting so much. it's now dealing with so much power dissipation that, uh, the chip is getting hot enough to actually self-regulate down to protect itself. It actually limits the current itself right? Tell you what? I'm going to pause for a moment. We'll see how far it goes down or if it just blows up one moment, please. So the trip is throttling back. It's showing a temperature of about well, 77 degrees, the current stabilize about 10.5 Watts Well, the power stabilized at 10.5 watts and the temperature is kind of dropping this, but it's hovering I Suppose 75 77 degrees roughly. It's kind of that. maybe is itself regulating position? its temperature? Well, that's kind of interesting. Um, so I Suppose that is a fix The other fix we can do here. I'm going to unplug this. It's garishly bright. The other fix we can do here, that capacitor will actually hold a charge as well. Let's see if we can ensure to the electrolytic out well, it'll pop off that as well. The other thing we could do here to regulate this further is the resistors on the circuit board could be changed to higher values and if they were changed to higher values so this was by default uh, regulating Then you could add the capacitor. So say, for instance, doubling the value of these resistors to 22 ohms would have an effect on the actual power dissipation of these as well. It would reduce the intense LEDs and compensate for the addition of the capacitor. Uh, So many things you could do whether you should do them is debatable because let's face it, it's just a generic, cheapy, crappy LED panel. Uh, but interesting. They've really basically skimped on everything with this pal. They've taken the original driver circuitry and just said how cheap can we make it and it would have been nice if they basically just uh, if they'd said we'll just be sense about this, they could have maybe configured the LEDs in a different way. They could have added a smoothing capacitor and change the value of those resistors, but maybe they just want them to burn out. You know what the lamp manufacturers are like? But there we go. It's an interesting product. It is hackable. Uh, but to be honest, it's not that great, but still worth playing about with and experimenting with. Bonus extra footage just experimentally. I've got two 22 Ohm resistors and I have soldered them because these uh pins here are common and they're this a sense pin. I've actually put the solder directly on here and soldered resistors and then tapped onto the negative pin of the capacitor just to actually make it easier to put them on. They've done that with both of them. So that's two resistors like that going on to the capacitor. and then I've removed other resistors. So that's two twenty two Ohm resistors. I've not tried this. This could all end dramatically, but let's stick into the hop in and see what happens. See what power we get us. Hopefully it won't be Mega Power the loud bang which sometimes happens. Uh, so I'm plugging it in now. Oh, that's not bad. That's not bad. What we're getting what we're getting, we're getting 17. Watts Isn't that what we had before? But this time there's no flicker. Okay, maybe you could go higher with the resistors, then maybe go to 33 ohms with those to actually tame it down. But uh, that is a huge improvement over what it was before. So there are many ways you could hack these and I'm just going to double check that capacitor is discharged. Yeah, it'll pop off that. Yes, I'd rather it was a pop off that, not a pop when my fingers touched it. But yeah, it's an interesting little panel where we can finish the job for them by basically doing what they should have done in the first place. And that kind of makes it better.