Test and analysis of unusual (dead) LED lamp.
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- Опубликовано: 20 окт 2024
- The thing that makes this LED lamp odd is that the current regulation is physically built into one of the LEDs. Given that the lamp was running at around 9W of power it's almost inevitable that one of the LEDs or its bond failed on each circuit.
And you even printed out scaled up picture of that LED, thats really awesome.
"I don't know if that's a real 9 watts or a Chinese 9 watts..."
+pillsnotbills i wonder if there is a conversion guide
+Mr Jay White It's easy. A Chinese watt is approximately half of a normal watt, or a third if the light involves "three watt" LEDs.,
bigclivedotcom From my own experiences, I would say that sounds about right. :)
bigclivedotcom this is the sort of information sorely lacking in textbooks :-j
+NaxNir
Seems lejit.
The bigger LED named 5730 and the one in this board embedded with current limiter which builded in "FET" field effect transistor. As you guessed, it control the total current running through the whole circuit.
Those kind of current limiter can be used safely if using plastic case as your video but not in metal case.
Love these tear downs Clive!
Even the great Big Clive have one cheap M-830B multimeter :-). I have one but in black and still use it although i have others... Great channel you have!
Could this be an LED with an embedded CCR (Constant Current Regulator)? I experimented with a few of these a while back to drive an LED flashlight. On Semi made them in versions from 20mA to 350mA. They are used in circuit just like a current limiting resistor but they fix the current instead. Only problem I had was heat. If the voltage was much above the minimum needed to regulate, they get quite hot. One CCR fell off my test board when the solder melted.
"Chinese 9 Watt" ! I wonder if it's going to be Clive or Julian to come up with the exact ratio of CW:W, or even Champ:Amp.
+Jon Simmons (Neffers)
formula on converting Chinese watts (cW) to proper watts.
its very simple,
example
9 cW/2 = 4.5w
very simple.
+Jon Simmons (Neffers) Actually the conversion is rather simple:
Chinese Watt = Real Watt / 1.414
+RandomPsychic
That's just Watts ÷ √2
Thank you. I've found the same when I tried to test a bulb that stopped working. This is a mean challenge to my shallow knowledge in electronics - trouble shooting 😡
Real watts vs Chinese watts... is that like imperial vs metric tons? :)
Clive, would you happen have a recommendation as to which of your consumer LED lighting fixture videos have the most representative examples of what is out there on the market? I'm trying to get a deeper understanding of the operating principles of some of these circuits, and they seem to vary quite a bit. I'm not sure if you check the comments on these older videos but here's hoping! Cheers from the US :)
Could you possibly do a teardown of a generic eBay RGB GU-10 lamp?
Clive, can you do a video on your bench power supply?
Constant current driver embedded inside the led package? Nice!
A little more maths:
-The peak voltage from that rectifier is 240*√2 =339v.
-The forward voltage of the LEDs is 219v, as you say.
-The regulator chip in that larger LED package therefore has to drop 339-219=120v.
-The power dissipated by that chip is 120 * 0.02 = 2.4W just in that tiny chip. No wonder they fail, though I'm surprised it still worked well enough for you to test it like that...
Not quite, you recognized that you were dealing with RMS voltage when you calculated the peak voltage, but by the finish you seem to have forgotten that you were dealing with a *peak* impulse power, not a steady state dissipation. The peak dissipation may well be 2.4W, as calculated, but that peak is for a very short duration each cycle, leading to a much lower *average* power dissipation and it is that average power dissipation that matters most in most instances. Although it had a heavy chassis for heatsinking, I did not notice an especially good interface between the metal core PCB and that heatsink chassis, nor any obvious signs of thermal compound to assist in heat transfer, which was most likely the greater contributing factor (but that is my $0.02). Power surges are also a very possible culprit if they ever exceed the breakdown or dielectric voltage limits for the semiconductors and their junctions.
This guy is knowledgable and cool
Hi Clive, Just wondered, do you know what the difference between 12V non dimmable and dimmable down lighter LED bulbs is?
What eventually failed? Possibly one of the LED elements was being thermally over-stressed, causing the entire series ring to fail?
Couldn't you put the board in a freezer and then put a oscilloscope over a shunt resistor to see how it reacts on the cold start to see if you get a current spike or not when it's at -20 or so centigrades?
Thanks for the info, what is the Vf of that LED ?
Dear doctor Clive am correct in saying that you film using a iPad? If so what video editing app do u use? Cheers Charlie
+Moonkiny dmf None at all.
I was thinking they put a JFET in there hooked up as a constant current diode, but the biggest one I could find could handle 5ma at 20 volts. It has to be some sort of dual transistor current regulator.
I've become interested in these LED lamps but i haven't pulled the trigger on one yet.
What I really want is one of those LED filament lamps, man those are retro-tastic.
Just order some on eBay or aliexpress. They are less than $2 including shipping, there really isn't any reason not to try them.
+Paul Klinger too many other projects
Could it be a JFET? It doesn't look like there is much more on the chip but also it doen't really look like a resistor.
so we are heading towards a single component led array that is mains voltage input? means no circuit board at all...
+jusb1066 That is possible with COB style LED with all the parts integrated into one yellow blob.
+ELECTRONTHORP Smoothing capacitors would certainly be a problem, but there is an alternate solution and that is to use higher persistence phosphors in the LED to carry over the light which could greatly reduce flicker without needing large smoothing capacitors.
+jusb1066 Just had a look at AliExpress and spotted quite a few LED COB modules designed for direct mains power.
A search for LED COB module 220V (or 110V) and you should find them
Maybe it's just a constant-current diode, and you're seeing the die of the current-regulating JFET under the phosphor. So still passive, but with more intelligence than a simple PTC resistor.
love your vids, but once again i suggest getting a better camera or upscaling your 720p videos to 1080p so you can use the higher bandwidth that 1080p provides. Perhaps then we can see the faint images with some more detail.
Wonder if there is a number somewhere on that odd LED?
There is a stream right now, must watch later ;_;
I still wonder, how did I find your channel, Clive? I can't remeber at all....it was not even long ago, but it was absolutely before the 100k hype^^
One thing for sure: i am super glad to have found you :DD I was interested in electronics since I was about 8 years old....still up to today my mother doesn't want me to do stuff with electricity, even USB power is "too dangerous" for her D:
I'm 23 damn ;___;
Put her in a special home
+8bpspfreak2 You may have been recommended the channel by RUclips, perhaps coming from EEVBlog viewership or maybe AvE or GreatScott?
By all means do electronics; just learn what's safe and what's dangerous first and i think Clive will prepare you quite a bit.
the end for BigClive's drinking game - every time bigclive says "I'm not 100% sure" you take a shot - sober now for 2 videos
It must have been flickering like mad with without any capacitors. yuck. I have a bunch of G4 LEDs where I have replaced the 12v PSU in the attic with a DC PSU, even though the LEDs had a capacitor.
To be fair, the people who sold me the LEDs, did recommend it too.
The hard part was to find G4s with a CRI above 90, but the ones I got should be that.
+ELECTRONTHORP Don't think the voltage has anything to do with it.
+Someone Somewhere
Well... it kinda has everything to do with it... if incoming AC is 240v and you need 200v to light the leds there will only be a small part of the incoming waveform that can produce the required forward voltage. If the forward voltage was 100v the led's would be passing current for a much higher percentage of time.
As far as flickering goes though... we have to take into account parasitic capacitance/ inductance (maybe the led with reg chip is helping here too).. IE: If voltage is applied to an LED there will be a measurable time before it starts to light and also a measurable time for it to turn off... If the off time takes longer than on time and A/C frequency is high enough a capacitor would not be required to reduce/eliminate any noticeable flicker.
+Ben Lucas LEDs have turn-on/turn-off times that are extremely short - in the microseconds, I think. Remember the same tech is used for fibre transmitters with bandwidth in the GHz.
Flicker is more about frequency than duty cycle, unless the off period is very very very short.
bigclive, our new chandelier is killing Florescent and LED lamps. how do I go about finding the cause and fixing it? all three LEDs were running at about 50 degrees Celsius and rated at about 12w. voltage was also stable at 230v. halp !!!!!
+darthmaul Are the lights enclosed in shades? Is there a dimmer or electronic switch in use? It might also be down to the fact that many of the higher wattage lamps are not really fit for purpose and fail very quickly. It might be worth trying some more down to earth 3W ones.
+bigclivedotcom , yes actually. lamps are shrouded with a double layer of plastic and glass that seems to have the top sealed. trying a 3 Chinese watt lamp ATM that have lasted the night so far.
+bigclivedotcom , no dimmer but there are a few small LEDs decorating to mounting plate.
Mr clive,can you make a video.about this led module?about reverse engineering makeing the cercuit daiagram??
Is this satire?
I watch so many of these videos, that occasionally I forget exactly who did what to which device and when. That said, was it you who used leds to make a small rectifier?
The control panel indicators had the LEDs working as rectifiers.
Anyone found these 'integrated regulator' led chips yet? Tried a few things on aliexpress but no luck yet. Seems like a very neat way of doing current regulation for small projects.
First!haha
I love your channel clive. You gave me the confidence to make a telephone external ringer
I've just got one of those cheapo yellow meters and there's no fuse in it, despite what it says on that back. Has yours?
I can't say I'm very bothered and could always fit one.
+ThePillenwerfer It does. Right down at the bottom next to the battery. I've got some others on the way though for analysis.
Mine's got pads on the PCB where clips could go but they aren't fitted. It looks like they are shorted by a very fine track between two of the concentric rings under the knob.
+ThePillenwerfer "It looks like they are shorted by a very fine track between two of the concentric rings under the knob." sounds like a fuse to me :p
+ThePillenwerfer Sounds like a countefreit.
+BloodySword Not counterfeit but a permanent fuse etched directly onto the circuit board. Burn that fuse and the meter is gone, suited only for the circular archive.
+bigclivedotcom Clive, I know you run a tank system for your printer, but do you have any recommendations for who/what to look for in ebay ink suppliers? (sorry, I know you've probably answered this. but I haven't seen it...sorry, mate). My ink experience is generally, "bend over, and HP will now do terrible things". :/
+TheJohn8765 It's an old printer so I just used a generic cheap CISS ink system for it, and fill it with equally generic cheap ink. HP aren't the easiest cartridges to refill.
What is mostly the volt rating of each led that size?..thanks
Most white LEDs have a forward voltage of around 3V, but some have multiple chips inside and can have much higher combined voltages.
currently have most of my house using 12W COB GU10 LEDs, which inside the heatsink has all sorts of wizardry on a board.
I then bought 9W COB GU10 (Sealed units) AS in instead of a ring, bulb, and wire, its all one unit, and it came with a Driver.
Turns out this Sealed unit with a driver, is just an exploded version of my 12W Cob Gu10 bulbs, Very bright, very good spread, and possibly the best Bulbs I have used.
however one of these 9w (sealed) Bulb units, does not work, I can not see any sign of burns, and have opened it, could I just be a duff lamp.
Was thinking of sending in for a video investigation?!
+Burgattti Have you narrowed it down to a driver or lamp? (If they have an inline connector between them.)
+bigclivedotcom it is just the lamp as I have swapped the drivers around. (same pics as the email) cheers!
+Burgattti The COB arrays have a multiple series/parallel arrangement of LEDs in them, so I'd expect some to light even if one had failed. Check the polarity of the connections to the COB in the lamp in case they have swapped it accidentally.
+bigclivedotcom Brilliant sounds like a plan! And now that you say it i feel rather silly as yes usually you get some glow but this is totally zero will definitely try swapping!
just tried, didnt work either way, tested other lamps driver is fine, just checked the face of the unit again, and it seems there it two tiny black spots now, must of burnt out instantly when i reversed
you mean to test every single led you need a voltage of 15V DC,Am I correct?
You could put 30v across two LEDs. Etc
Thanks for this video.
What is the number of ic.
We have 3&5(ish)W Philips Gu10 LED spotlights. They die as their capacitors get baked.
I have several dead GU10 claimed to deliver 340 to 370 lumens. Warm or cold white, they don't last very long, but neither do the tungsten type.
I had a look in one today and the 5 LEDs look as though they, in series, take 97volts. Can't remember what all is in the circuit, although it does seem to have a tranformer.
The LEDs are probably close to each other to make it easy for the plastic focusing lens to make it look better.
What the black chip was?
Led panel board 4 lead chip.... What?
PABITRA PATRA Bridge rectifier...eg MB2S
interesting
sir please teardown A Intigral led bulb.. its have photo sensor..its a request
Awesome.
There is an ic in that led...
Why do the Chinese lie about EASILY provable numbers? if I say I'm 3M tall we can debunk that pretty fast, same with watts etc
It gets even more interesting with batteries where they play the "dropped decimal" game, calling a 500.0mAh battery a 5000mAh battery, making the 10x over spec'ing all the more absurd. But I suspect it stems from the same sociopathic tendency that enables certain Chinese businessmen to use Melamine as a protein substitute in infant formula and pet foods without such wrecking their conscience when infants and pets predictably die so that they can pocket the savings. It is the dark side to capitalism in an environment where their are few to no regulations enforcing serious consequences and accountability for such behavior. The West went through some similar dark periods as well in the absence of early regulations (and still does from time to time, but there tend to be greater consequences on the average).
Really?
hey @bigclivedotcom you shoud check out Q Leap he have a lot of technical lighting repair (stage lights)just a littel tip. (note: he have a W as profile picture)
If you ever want to toss something like this in a SEM to find out for sure let me know!
"chinese nine watts", sounds about right... :P
Dead - with a capital 'f' :)
I would say that was clever, but it died, so i wont lol :-D
if i show u a chip can u tell me what it is 3 past black chip looks like mossfad chip its in my led light it a diver thats gone bad win i band chip it make led go on win power on or led get more power win chip bant or moved its has het sink on it it looks like a current regulator diode black chip i need to put in a new one if u cant tell me wher i get 120 to 140volt dc. 400 mah. diver pleezz help find one cheep ebay
Nice sir
Rofl, "dont know if thats real nine watts, or chinese nine watts", teehee.
Interesting
shit my cat got electrocuted today. and he died he tryed to jump from my table to the box that I keep all the power poins at bammm the house trips I run to my room and see Mr Turner dead on the floor. yeah having a crappy day.
If that's true I'm sorry to hear it :(
Real 9 watt= 9 watt
Chinese 9 watt= 0.00000000000000000 watt
farata fan banane ki vidhi
You might want to run your photos through some sort of filter sometimes... Look for GIMP.
bit.ly/1SZYBBr
+Fabio Iotti I use Irfanview to try and enhance the contrast and colour in some of the images. The contrast in the LED pictures was too low to pull out a usable difference.
+bigclivedotcom Oh, I see. :) Anyway, thanks for making these videos!
farata fan banane ki vidhi