Finding this "garbage" is quite easy, you need to go to any company that refills cartridges and ask for a pair of such drums. But it is not for us to give advice to the managers of the firm. I think it’s a pretty good indicator. The LEDs start to glow (visible dots appear) at 9.5V, and the current is very difficult to measure.
The next problem is how to connect the leg to the lampshade.
The voltage mismatch immediately catches your eye, the title says 12-14V, in the description Input Voltage: DC12-24V. If I could find longer ones, the lamp would look more elegant.
It seems to me that the COB matrix fully justifies its characteristics both in terms of brightness and temperature. It is better to write about engineering miscalculations or offer your ideas on how to do it better. I think it’s just a "cheat". It turned out not so exquisite, but as I wrote above, everything is made from improvised materials. They will need more than a dozen. What am I all for? If the same Xiaomi made its lamp a little dumber, threw out the batteries, but added a couple of watts and lowered the price tag to $10, then such lamps would fly like hot cakes.
Let’s not argue about the accuracy of this device, especially since we are not measuring the child’s temperature and a spread of 2-3 degrees is not important here. Whether the acid I have is “of the wrong system” ©, or the plexiglass is of very good quality, but I could not dissolve it.Superglue and solvent also did not help (acetone is not available now). We set the white balance as "Daylight", fix the exposure and start shooting. – hot glue;
If the guys there are not greedy, they will not only give you a couple of drums, but also allow you to choose. – cutters for dremel (review) So the 24V input voltage is not even worth mentioning.
My device sometimes tried to show 0.001 A. If they offer me “much better fur” © for less power, I will only be happy. There is a cat. – dimmer. (review) Yes, and batteries, if they come in handy, then a couple of times a year. There are a lot of life hacks on the Internet where to use plastic bottles, but where to put such necessary and useful burnt hard drives, photoconductors for laser printers, etc., one, two, and counted.
For convenience, I glued a piece from each photo into one: Lamp
incandescent 60W (I couldn’t find a 100W lamp, and I didn’t want to run to the store and it’s not a fact that they were there), color temperature 2700 K. 1.JPG” /”> Fluorescent lamp (housekeeper) 13W, unfortunately I can’t tell you what temperature (0). Although, such a block could well be found from an old modem or router.
As a result, I sawed out three radiators and glued them to the matrix using hot glue (I don’t know if there was a review on it. If there are advertising agencies in your city that make all sorts of light boxes, etc., then it is quite possible to get hold of the necessary piece of plexiglass from them.
I ordered a 200mm by 10mm, 10W (I like bright light), 12V voltage. As expected, it did not live up to expectations. And this is the finished driver and LEDs. I placed the thermometer probe between the radiator fins, applied 12 V and began to observe.
3. We connect devices to the matrix and begin to observe. At 14V
the current rose to 1A, and on this I finished testing the fate of the matrix. Now you can buy a regular 10 W LED lamp offline from $1. – cutting discs for Dremel two; But it turned out that such substrates are sold in batches of 5 pieces or more, and the price is not much lower than the finished COB matrix. I do not have a light meter and I can only evaluate the brightness of the matrix "by eye". Radiators are needed for additional cooling. We are used to the fact that the Chinese are always trying to overestimate the performance of their products, but everything seems to be true here. A few words about the power supply. However, already at 13V, the current is 0.83A, which is the same 10W (or close to them). I am amazed by their power (usually 3-4 W) and price (from $ 30 and above for the same Xiaomi). Then later, when I thought that the lamp from Ebay would not come (it was a month and a half), I ordered a similar one on Ali on 11.11, but only 120 mm long. So, let’s start making a lamp. The idea of lamp design was borrowed from the same company Xiaomi. You can also
use a piece of metal-plastic or polypropylene pipe, try to borrow a piece of copper pipe from air conditioner installers or builders.
Of course, the ideal option would be to find a heatsink from a burned-out video card, but I don’t have such, and in my small town there are practically no computer repair companies . There are a huge number of sizes, shapes, power, voltage, and other parameters of these matrices. On the page of one of the sellers it was written: Direct Current (IF): 830mA. 
I wanted to make the plexiglass frosted, but all the tips from the network did not lead to the desired result: quite deep scratches remain from the sandpaper.If you take the “zero”, the glass becomes almost transparent. acid, they say it sticks together well, etc.
4. If the plexiglass is thin, and you have a desire, then it can be bent to the diameter of the drum The following will participate in the review: For this, the following device was used: I dug through my stock and pulled out a bunch of
heatsinks from various devices: power supplies, motherboards, etc. I found from 20 mm outside diameter to 65 mm where I managed to fit a halogen with a reflector to make it look like a light pen for photography. LED lamp 10W, purchased offline, temperature 4100 Kb 850 lum (- 0.2) Now the only tool left is a drill ala Dremel and a few screwdrivers. Some manufacturers began to come across such ones). It may very well be that the gear and plugs are glued, then you will have to tinker a bit removing them.
Instead of the promised 2A, he was able to squeeze out only 0.3A. I liked the glue, but I didn’t test it). At the first
I left the stub, it will still be useful. Three years ago I lived in a big city and worked as a "computer", i.e. engaged in assembly, repair. As you know, the drums are covered with a photosensitive layer.It is quite easy to remove, even with a fingernail.But it is better to use a piece of plastic or even metal for this (I used scissors). ) . Unfortunately, the length of almost all drums is about the width of an A4 sheet. But photoconductors can be completely replaced with a mop pipe or finally bought. How to make a table lamp with your own hands from improvised materials … An incandescent lamp of 60 W was taken as a standard, in parentheses for each lamp is the shift of the exposure meter of the camera. In order to connect with the leg, I inserted a wine cork into the last cork (the cork is not made of cork, but of something resembling rubber or soft plastic. Below I will tell you what I got from
LED COB strip and various spare parts, which can be quite simply and free of charge, i.e. free © to get. They come in different lengths and diameters, are made of aluminum and have a "presentable look". Here comes another problem. LED lamp purchased offline 12W, temperature 4100 K, brightness not specified ( 0.2) One of the main problems with COB LEDs is that they get very hot (but which ones don’t?). Why does a table lamp cost $30? marketing? In the future, the current begins to increase almost in proportion to the voltage. I had a small workshop at home with a bunch of tools and almost unlimited access to various computer parts that failed. From the second, he pulled out the gear and the plug on the other side. The only thing that I have seen useful from using faulty HDDs is neodymium magnets and a “grindstone”, with which you can only fix a drill up to 2 mm no more (there is not enough engine power). The fact is that there is nowhere to put them except in a landfill or with metal. But with the cost of aluminum scrap a little more than $ 1 per kilogram, there is not much point in dragging drums. This review, "This is not a vocal, this is a sketch for a vocal" © We take a thicker drum and cut out a sector in it with a length equal to the length of the lamp. I found such a matrix for the cheapest price on Ebay. The idea was taken from the same Xiaomi lamp. Actually, I was motivated to make a lamp with my own hands not only by an inner toad, but also by the desire to do something (I haven’t picked up checkers for a long time ©). I used 25mm for the lampshade and 20mm for the leg. I used to think that I would have to tighten the screw every time. I made a "plafond" from it that would cover the matrix. The next important parameter is the temperature to which the matrix is heated.
Reviews on LED table lamps often slip through. This lamp was assembled literally on my knees. True, at the very beginning I applied 19V (the maximum that the power supply from the laptop can), saw a terrifying figure of 4A and immediately turned off the power. So: The temperature did not rise very quickly and after about an hour, maybe earlier, it stabilized at 60 degrees. In addition, I had a lot of acquaintances and friends from whom I could get plastic scraps, plexiglass, and other very necessary things. Many letters and photos. And taking into account the fact that in two or three years their capacity will fall … But, to tell the truth, this power supply is quite enough for the lamp. In one of the reviews, a friend complained that he put it in a chandelier, and after a while the wires soldered off. In my opinion, it turned out well. Initially, I wanted to buy an ordinary LED lamp, disassemble it, solder the diodes, solder them on another rectangular-shaped substrate. I "little" a piece of plexiglass 7 mm thick, taken from an old 15 "TFT monitor. I chose a few pieces, mostly 20 and 25 mm. In my case, Canon 1300D will act as an "eye".
2. — Power supply;
COB LED matrix or junkyard table lamp
For the lampshade, you need to use a metal with high thermal conductivity: aluminum or copper, in order to effectively remove heat from the LEDs. Of course, it does not shine at full power, but quite brightly. — power connectors (overview);
Now the actual tests of the LED matrix. At 12V, the product consumes only 0.51A, i.e. almost two times lower than the declared 10 watts. The temperature can reach up to 80 degrees. Maybe I’ll use it somewhere too. This cork helped not only to fix the upper part well, but also to keep it in any position due to friction. I ordered a 2A power supply from the same seller. – cutting discs for dremel times (review); But for me it is even so important what power the lamp has, and how much light it gives. On the other hand, why does a table lamp need batteries and the “mind” that many manufacturers are trying to cram into it? No, of course, there will be a consumer for such products, but, for example, it is much easier for me to reach out and press the switch on the lamp than to look for a mobile phone, open an application and do something there.
5. .
If you do not press hard enough, there will not even be scratches on the aluminum surface. 1. The hero of our story, the input voltage is 12 V, 10W is promised, the temperature is 6000-6500 K, the brightness is > 100 lumens per 1 W, i.e. 1000 lum ( 0.2). And if there is, then people are often greedy and ask for money for such radiators. I cut out an element from plexiglass and fixed it on the lampshade. On the contrary, they smoothed out the scratches left after the sandpaper, making the plastic almost transparent. So But enough of the lyrics, let’s get started. Therefore, you should not write that somewhere unevenly cut or poorly processed. To begin with, we go to the seller’s page and see what they promised us for our money (I ordered Pure White (6000-6500K)). According to the norms, as well as approximate calculations, an LED lamp of 5 W is needed to illuminate the student’s desktop, and then, for smaller jobs and older people, a brighter light is needed.
or so — COB LED 10W; While searching for a matrix on the pages of Ali and Ebay, I have not seen such an input voltage anywhere else.
The price of an aluminum profile is from $1 per meter, the only problem is that you cut off a piece of the desired length. – and a bunch of spare parts in the photo below. Let’s start with the main element of the lamp: COB matrix. The photos below are provided without any processing, except that the size has been resized. As a "leg" and "head" of the lamp, I decided to use photoconductors from laser printer cartridges. I cleaned both drums and sanded them. After a dispute was raised, the seller returned the full amount for it.