The next generation COB LED? (Radical new style of bare LED chip.)

a very interesting twist on the chip on board arrangement the cob LEDs this one came from eBay rather predictably and it's described as one piece 50 watt hydroponics dob does that mean the driver onboard and guessing it does AC LED cob chip F grow plant light fill spectrum loads of key words things I ordered a blue one the reason I ordered the blue one was because I wanted to take a closer look at the LEDs themselves it comes this little frame designed to actually a large clamp it down without shorting stuff out on the circuit board or damaging and it's interesting because it's completely different to the traditional LEDs before this of driverless ones that use the separate power supply and it's a step in the right direction and that idea of buying this led test this was inspired by the teardown of a low voltage lamp that had a really unusual filament and had never seen the LEDs you sneeze before when I look to them so before we go any further I think we should test this it's a blue one the reason it's blue is so it's clear gel so we can see the chips I have got a couple of leads made up here which I shall now attempt pretend you have not tried this yet so I'm not sure how easy this is going to be I'm guessing this the pushdown system it beats soldiering the wires on and guessing that's a common complaint with the hydroponic Posse because this makes it much easier to terminate the virus when you've got this connector pre-sorted on ozone oh that I don't think that's supposed to crush down like that and not return I've already broken it okay right that's a good start note to others there this is quite used to break let's say I get out the way and we'll see if I can recover from this I'm not sure if I can recover from this push this to houn yeah this is where a little interlude have been quite handy that wire is just not going to stay in there right one moment please okay yeah I've completely broken that so I have mushed the wires and in a non compliant manner the hopefully will stay put on a plus note you could heat this on a panel yeah these things if you want to solder on to them because they've got the humanum core at the back it makes them absorb heat away from the sort of joints but it does of the live and neutral pads here so if you do I've just done and just press that little thing down then it makes low crunching noise and never works again then there is another option so let's test this I I've not got this in a heat sink yet so I'm not going to run it for too long so let's get the hobby inland and are you always a flickery display and let's get the quick test I want to do two things here I want to just make it light up just to see it is working it may not be working who knows let me go bang that would be very exciting and worthy of videoing so I've got the clip quick test here I'm just gonna pop the wires in and then you want to actually try it with the resistor in series so this is gonna get very bright eyes over here plug this into the hopper and then close this lid down so it's very bright yeah that is and flickery and that is an important thing here it's very flickering let's say let that cool for a second then let's look at the readings here which I should have done the first place 33 watts point nine perfect which is pretty difficult yep that and as it heats up the the chips the whole metal plate will get warm and the power will go donor want to stick a resistor in series of this purely because that will let me see how well match the LEDs are or if there's any that are shorted out so let's s stick a 1 mega ohm resistor in series the current won't even register on this now it may show visibly it's not even gluing that I'm gonna require a bit more there's obviously of course there's enough of a load in that secretary one moment please okay with a 220 key resistor in series they all like very evenly at low intensity the current the power is 0.5 of a watt at the moment so you can tame these down by fit resistors or I suppose a capacitor in series the secretary let's take a look a closer look at the secretary though that's what we're really interested in here I'll get these bars out if I can get this wire out now because I the blue one who should hopefully just pull open your ass does the brain one cool it you know it does actually acquire that to be pressed down in a more delicate manner than I did it there we go it appears that just using the subtlety works and not super full on beer strength excellent I'll just tuck these bits out that way and then bring in some more exhibits in terms of pictures that have already taken this already so for reference here is a blue chip which is this a low-voltage one this one has LEDs in it and if we take a look at this one here's a bit redder color you can see the busbar down the side and then you can see the gold bond wires jumping onto each chip it jumps onto pad at one end to chip and offer the other now if I bring in the listing here and pull this over just because it's the closest bit of paper to hand to doodle on and I grab a pen to do the lawn then looking at what I'm seeing here the chips look like this the LEDs are a rectangle that has been bonded onto the back plate and they have a pad for the goldwater bond onto one each end and the one at that end has a little electrode going out like that and the other ones have a little electrode going out like that and I'm guessing these electrodes may not be in the same level because they're these ten these tend to be done as lehrer as these chips but the idea is that you can see the wire comes on the bond wire comes on here and it bounces off and then it's bridged right over to the next LED and it just continues all the way across and on to the end now the end we'll keep in mind that these have to be almost that a micro spot welded on and it's quite a laborious job it's a semi-automated but a lot of it is manual and when it gets there in the same spot welder is used to try and tag the leads on well I can tell you when I pair this up and just squeeze the ends it makes a bad connection and quite often one of the failure modes of these LEDs is losing all lanes of LEDs and if while it's powered with a suitable safe low voltage or if you're using an insulated thing if you poke the wire when it was on to the bus bar quite often that strip of LEDs will a again not their lovely image of the of the ring later is using to get these nice clear pictures also notice all the lint this LED was very dusty and I washed it with soap and water as one does with LEDs and then I foolishly after that because this silicon e-type stuff is sticky I wiped it with tissue and unfortunately all the lint that's all the little strands but you you've got the gist there it all that bond wires are going across and it is quite laborious and complicated Fitness bond wires on here is the chip word account at the moment and it has zero bond wires and if you take a closer look at LEDs you see that there there's not even board wires locally in them they appear to be almost soldered in like almost like tiny surface mount chips and if you take an even closer look and this the magnify magnification here is ridiculous er to get there so I had to but put up basically I had to light this well and hold the magnifying glass in the microscope in front of the camera to try and then line them up and focus and get a picture at that kind of got a picture but what we can see here is that the outline the chip here goes on to the pads which are these things here and there's a very obvious layer of solder going here so these LED chips these bare emitters have just been soldered onto these pads which is incredible I've you know I would say never come across this before I have I came across in this thing but I didn't realize how widespread it wasn't suddenly the reason the market is flooded with these cob LEDs makes sense and there is an obvious a pattern there's a properly one here and a properly one here and a properly one here in a properly one here and then a purple line here and I'm guessing these the color is affected by the layer on and I'm guessing that these might be coupling down to this sold earlier not sure but then there's another electorate little head round pad here and then the other lecture comes along here so we've got our three electrodes again much like we had with the gold bonded one but this time there should actually traumas waiter they're actually a lot wider than that they're actually quite modest strips but this time instead of actually having a gold wire bonded onto them they are a gas these might be some kind of the equivalent the of our plated through hole through the semi conductor led to some some metallization the bottom and it really does look like soda so it looks as though they've perhaps pick and place these at some micro level because they are absolutely tiny and then just floor sort of them with the rest of the chip that's incredible it makes it's so much less complicated to actually make these other things one they've note here here's the mins coming in on this connector that is apparently easily broken if I if I try to operate it the next thing in line is quite commonly used in these it's always a good idea to have these these are metal oxide varistors and the idea is if the voltage exceeds a certain threshold if there's a spike instead of affecting the circuitry and potentially causing quite a high current pulse or damage causing an avalanche effect that could actually because the transistor to basically turn on continuously and blue LEDs this thing is here to protect against that it clips any voltage spikes by going low resistance when a certain voltage threshold is exceeded in this case it says 471 that means for seven and at one zero then so 400-some d volts it'll actually turn on to protect itself kind of have a sort of curve in that here then we get a bridge rectifier so we're good AC going and I'm guessing without actually scraping that off and guessing that that's easy at that site could be wrong and then the DC community this side the connections then go there is one pad that I can see a ghost of actually coming it comes out as a we track from there and then it fans out and I think the reason it fans out is because these LEDs are wired as parallel pairs across the circuit board and that track then seems to continue underneath the edge there a gas that kept it well in a way from the edge because there's going to be hardware mounted here and then it goes to the circuit rip there's another track coming up and going to this empty resistor position and that empty resistor Bishop position happens to go into the middle of the LEDs you can probably work out what's happening here particularly when there's one zero ohm link green here and it's connected there and there and I can see a track come up there and this one is probably connected to there and the output from the LEDs is a fairly flat track here and it's coming across over to the transistor here plus again there's a connection coming up and it's basically skimming along the edge there curving around that hole and then going to the circuitry so my guess is that since there are 144 LEDs it's 12 LEDs by 12 that is a lot of LEDs if they were all wired and serious then the voltage required to light them would be a 144 LEDs times 3 volts each if the so 432 volts that's not even gonna light and peak UK voltage so if it's 144 LEDs and the wireless parallel pairs divided by 2 equals 72 LEDs times 3 suddenly and that comes 260 folks comes well within the range of the 220 240 volts the flicker is caused because there's no smoothing which is unfortunate here that it is down to the fact that you know it's a simplest circuitry it's using that current regulation based on a chip here and a transistor to limit the current resistive layer fective li and through the LEDs now the reason for these links is that if you put one here it's almost like a transformer with the secondary windings it connects two sections of LEDs in series and that means that all the LEDs those are what was 144 divided by 2 equals so the 72 pairs of LEDs are all in series but if you actually remove that link I'm guessing and put a link here and here then it connects them in parallel so this is one feed from their going up to the middle and one feed from here being branched down to the other end so effectively it creates two parallel clusters and know where that would be the equivalent of 144 LEDs divided by 436 peers in that section 36 peers in this section all connect in parallel and they are going to require about Saeb 108 volts so there that's 110 120 volt option so if you've been supplied one of these and it's got the wrong voltage option if it's just got that one link it's probably been set for 240 and if you want to crack that you can remove that link and just link over these total ones and that should theoretically send it to 110 volt the circuitry here I looped for the chip numbers this transistor is called a Sh one 808 - 406 which manages to only pull up one link to some Facebook page it's debts nothing it's just it pulled up a random coincidence number of thing the chip here says 108 9b and underneath it says 1831 given her and you this says the date is 24th the 7th month 2018 I'm guessing that's a date chord 31st week of 2018 so 108 9b I drew a blank on that but let's deduce what's probably going on here this will be monitoring the current through I guess these resistors there's three identical resistors - four are all 24 ohms and I'm guessing I've not measured this that they are probably in parallel giving a total of 8 ohms or that could be wrong let's say bring a meter and and measure that let's just poke it right through the gel this is all covered and gel to read these numbers I had to scrub the gel off so let's probe through to their probe through to there what am I going to get 8 ohms they are all in parallel so they are the current sense resistor that'll pervading oops let's put the metro that we are not the led they will be providing the feedback - I'm guessing this chip the Zener diode is possibly a power supply reference for that chip and they'll just be to give it it's a little current supply they'll be e one of these resistors this is 560 ki this is a 180 km guessing and one of these is probably being used as a power supply for that chip just to limit the current to it and then it's probably cap but there's inner to stop the voltage grew up too high and then the others will be just a perhaps I have guessed the capacitors are bits for stability there these resistors here not quite short surely before maybe oh they'll be for air they'll be for fault detection functionality but the gist is that when the current exceeds a certain level through the LEDs the voltage across these resistors will be high enough to actually start turning this transistor off and all then limit the current this may it may all just be based on a discrete transistor arrangement this may purely be a management chip but the reason that they've not get any numbers that are obvious I don't know if there's data sheets out there for them that's all or is it just one of these things that either you know it's abbreviated number I didn't find the fool number or is it because it's such a specialized and recent chip just dedicated to these high output but compact driver on board type LEDs that they're just a em strictly at the manufacturers at the moment they're not there may not even be data sheets and free availability for them yet but that's their very interesting that is a very interesting LED who else is there to say about this it's worth mentioning it says T 4050 I'm guessing that just does 40 or 50 what the LEDs obtaining but having said that there's a lot of them spread their loot over and I do prefer if they under run LEDs I suppose that really if you wanted to do that if you wanted to make them last longer you could ultimately change the value of these resistors to a higher value effectively so that the voltage threshold was reached sooner at a lower current other things worthy of note yes the hydroponic pasear have been getting very adventurous of these driverless chips because they're so cheap and easy to get I've seen some exciting videos there on YouTube of people who have made large panels of them to get a metal panel on their lap and they've kind of propping up in their lap and there's no obvious our connection and they've got two meter leads and one is neutral minus 240 volts straight off the mains and they're probably around testing their LEDs on the panel like this and it's like a shirt for for cleric don't do that and it's not the safest thing to do particularly when you get the metal in your lap and you're sitting down and there's a yeah anyway it's worth mentioning that some people seem to think these don't need earth the if you've got this metal plate and a heatsink although there's a shim of fiberglass circuit board it really is just absolutely miniscule a thin and to the point let's see if I can even feel this there's a little air hole through that there it just feels almost like a piece of sellotape stuck that is probably just that pad there isn't it is there can I see how thick this is is there any easy way to test that what if I use a little magnifying glass in the edge it's just wafer thin it's tiny I can't even tell how thick tires but it is very thin and there have already been reports of metal reflectors coming live because an LED fills and burns and when it burns it actually burns through the fiberglass and creates a conductive path to the aluminium so if you are making large panels of these I strongly recommend that panel is earth just for safety so that can air basically avoid giving you electric shock this doesn't make you think of someone who recently contact me and said they'd had two hydroponic lights sitting next to each other and they touched and there was a loud bang and one of them died and there was a big skid mark where a touch the other one one reserved the other wasn't earth that case had been live at mains voltage exciting so there you go interesting I wonder how these are going to evolve they are so tiny the failure mode if the other ones tend to be the bond wire is this going to solve that problem is this gonna make them more reliable they're so cheap it does make you suspicious but then again theoretically everything can be done with the silk-screened a solder paste and then basically pick in place for all the little led the beer LED chips as well it's a it's very interesting I wonder how they arrange the orientation of that or even how they pick them up they've been pressed and seeing the machine that's doing this but it's so new that I guess they're probably not gonna be much video footage of that about because they'll be protecting their technology but there we go that's a very interesting twist for LEDs that they've got rid of those gold bond wires and they are basically just relying on them being simple soldier on components no it will be very interesting Sierra long they last

Channel: bigclivedotcom

Views: 430,763

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Id: hpF5O0W8Bdg

Length: 20min 55sec (1255 seconds)

Published: Sat Feb 09 2019