It's entertaining to watch you dismantle things. I would like to see you take it a step further and tell us if it's a good buy or not, based on construction and parts.
Thanks for the info and advice. I have a small solar array on the house and all the things we have on the lighting branch have to handle being able to run from dual sources. I ran a quick one hour test on our main inverter and was impressed. There was only a slight increase in the heat on the heat sink but not to a dangerous level. I agree with you. These LED bulbs continue to impress me. I hope the longevity is there as well. Also, where are my manners? It's good to meet you.
Very interesting video. I've got five of these bulbs in my dining room and am glad to see they are manufactured with quality parts. Also, here are some side points: -while the color temperature of these bulbs was supposed to be the same as the CFLs which they replaced, these bulbs give off a noticeably better quality of light than the CFLs. -these bulbs are manufactured in the United States, I believe in North Carolina.
Yup! I have a CFL I bought in 1998 or 1999 and paid $45.00 for it. It still works to this day. The new cheap CFLs are lucky to last 6 months. I have gone to LED and the CREE lamps (over 50 of them in house and shop), not one has failed after 2 years so far. The electrolytics in the DC-DC converter will determine true lifespan.
Cree bought out an LED lighting manufacturer called Ruud Lighting in 2011. They are aggressively moving into the lighting product market rather than just manufacturing the LEDs themselves. They do all sorts of industrial and commercial light fittings now which are quite nice (but don't ask about the price!)
Cree LED lamps kick ass. Between my home and 2 shops, I have almost 100 of the cree brand floodlights that fit into the ceiling cans. The ones with the turbine looking external heat sinks. It has been 4 years now and not 1 single lamp has failed. Not even 1 single LED in any of the lamps. They also operate very cool compared to the other brands. Great stuff. The Chinese white LED strips you buy on spools for $9, expect 1 week before phosphors start dimming as they will. Buy the spool of CREE brand which looks exactly the same but costs $150, 5 years on and not one single indication of any LED dim or failure.
+bishplis you are just here to be a jerk. You didn't even read how long I had my CREE lamps did you. I bought the "expensive" genuine CREE lamps in 2010 and they all work to this very day. Five years+ On the first ones and going strong. Even when a five year lamp is compared to a brand new unit, no difference in visible brightness aka no phosphor aging. Seeing as you buy $2.00 knockoffs that don't even use a real ballast inside, your ceilings are probably no higher than 8 feet. So replacing the knock-offs is easy. My ceilings are 20-35 feet tall in most places. I just buy something real and properly engineered, knowing it's not going to be a problem later on. Cheap white Chinese market LEDs use poor quality phosphors that dim significantly over a relatively short span of time. Not all of them, but a significant portion. Lacking a proper potted ballast, they often resort to a simple capacitor/resistor type passive "power supply" that is non regulated.
O+bishplis your the one coming in here acting like a prissy pricktard. I stand by my CREE brand LED products that I buy. Or I should say LED lighting products that use CREE LEDs. For me, not a single problem as long as the lamp uses CREE emitters. You have yours and that's fine and they work for you. No way in hell would I trust a $2.00 18 watt led lamp in one of my ceiling light fixtures. There is a reason why they are $2.00. The $2.00 ones don't have a real ballast in them and subpar LEDs. You get what you pay for. I don't know about this actual lamp in the video as the units I have are their flood lamps and lighting bars which use genuine CREE LED emitters. These run only warm to the touch. The smaller lamps such as in this video run much hotter as they lack the space for heat sinking. I avoid any LED lamp that operates too hot to touch as reliability beces a concern. Even the best quality components run at high temperatures will have a drastically shorter lifespan. I suspect you believe the $1.50 China made iPhone charger clone is just as good as the $40 original iPhone charger don't you? They both plug in to the wall and charge the phone, therefore they are the same..... Right? The $1.50 charger is much lighter. That's because it's more advanced inside right? You keyboard warriors always come here to argue moot facts on RUclips. You troll about looking to argue with somebody for any reason possible. Your kind are always ZERO contributors to any RUclips forum, always hiding behind the blue generic avatar icon. Couldn't help but notice your overwhelming array of educational and helpful videos you produced and put on RUclips..... NONE! Get out of here.
+bishplis no shit Sherlock! Not too much is made in the USA, still engineered here though. CREE LEDs are built in China to CREE engineering standards. White LEDs use phosphors to create white light from the blue emitter die. The LED is only as good as the phosphor and the phosphor is the most expensive material used in white LED construction. So guess where they cut corners on the open market LEDs made to look like CREE but at .03 cents each vs over a dollar each for a genuine CREE? The phosphor! So you a have a nice bright .03 cent white LED the dims and shifts to the blue spectrum after 10,000 hours at best. Some real shitty ones start failing after 100 hours. They look good at first though. CREE was also the first to mass produce and market the blue LED. There was a time when the idea of a white or blue LED was merely a theoretical possibly.
+bishplis the China hate is they don't feel bad turning out crap at the bottom dollar. They don't care... At least in the past. Things are improving and some of the best products come from China when supervised.
Well, after getting my hands on about 50+ customer returned Cree LED bulbs (of which only about 8-10 are actually bad), it seems the biggest single point of failure is actually the AC Neutral wire that simply gets crimped by the screw-in bulb base when it's attached to the plastic housing. They eliminated one too many hand operations. If this wire had been left long enough to protrude from the metal threaded base, enough to bend over the top lip and solder there, over 75% of the failed bulbs I found would have not failed. The symptom is a flickering bulb that will go out randomly, and touching it can bring it back on... depending on which direction you 'lean' the bulb while it's screwed-in tight. I found the simplest way to repair those is to create a small, sharp indentation through the metal base right on top of that wire. The wire position in the base is very repeatable and predictable, so with a small flat-blade screwdriver against the upper lip of the base, and a moderate 'whack' with the handle of a larger screwdriver (it doesn't take much), it dents the metal just enough to make a much better connection than their "slip it over and crimp" friction connection. The small screwdriver blade tip creates a fairly sharp dent that makes for a high point-of-contact pressure on the bare wire below the metal, against the plastic base inside.
You can get to the circuit board from the top without destroying the base. First, slide off the LED PCB. It literally slides right off (reason for my failures as listed other post). Remove all the silicon/epoxy type material where the base of the globe sets. I used a small straight slot screwdriver. You will see plastic tangs that will let you release the cast metal cage and there is your circuit board. BTW. The shock from the two tangs ain't no big deal.
Nice video. Thank you for making & posting it. Kindly, ¿do you know what the drive voltage difference is between the two electrode/contacts that go to the LED themselves, please? Thank you.
excellent analysis.. quick question.. when u tested the bulb u said it heated a little.. What's the cooling mechanism? are those the fins on the side to disspiate heat and how hot was it actually?
The "2d barcode" is a QR code. It has information encoded in it. If you get a picture of it, there are online and android / iphone callers that will decode what's on the QR. I'd be interested in seeing what's on it!
Keeping it cool in a compact package it the tricky part. It would make a great non-lethal weapon to disorient an intruder. It completely wreaks havoc on the retina. I didn't look at the LED directly as it will damage the receptors in the eye, but DAMN..... Amazing how many photons come out of the phosphors in the white LED. I can only imagine how bright the blue LED emitter is underneath. Hat's off to CREE.
Bulbmaster! :) This stuff can be used by said companies since it's of higher production value then their own advertising. I'm still surprised that no one has developed yet an all-in-one module for driver with just a couple big passives nearby.
Yep, DC-DC. The first thing done for input AC is rectification. The actual switch-mode power supply then operates on the rectified AC. Most dimmers use something called a Triac. Google "Triac Dimmer" for more information. If they used a potentiometer, the potentiometer would dissipate an enormous amount of heat. Re: Scoping. In this situation, since it's non-isolated, it's not safe to scope without special techniques.
Is it not safe to scope the output of the power electronics? The contact leads before they go to the LED array. Also, DC-DC? not AC-DC? I had the impression that interior lighting dimmers used a form of potentiometer, so voltage across the bulb terminals drops. This is why some bulbs can't be dimmed because they require a minimum or constant voltage to remain on. Ideally to dim LEDs you'd change duty cycle of the pwm, but you can't do that on an AC converted source without a driver/controller.
A question... Would this driver circuit overheat if driven by a power inverter? I almost get the impression that this type of circuit would do poorly on a modified sine wave power source.
I hope everyone knows that CREE LED "bulbs" are MADE IN THE USA... and done right! By eliminating hand-wiring, they eliminate the most common failure point... AND make it much simpler to assemble. The LED packages are all connected in series. Each of these LED's have 4-die, so you have a total of 80 white LED die in series, for a total of around 240V DC drive voltage. DO NOT play with these while turned ON, with the globe OFF! DANGER WILL ROBINSON!! It's a really great design, through-and-through... SERIOUS reliability! 10 year warranty based on 6hr/day, 7 days/week - or 22,000 hours. Price is real decent.. just wish Home Depot didn't have USA exclusive retail rights. Even my wife doesn't know when I replace old tungsten bulbs with the 2700k versions. Personally I prefer the 5000k version, which I have in my areas of the house... it feels more like natural sunlight lighting. Workign under 5000k seems more productive, I can see my work better (I'm an electronics design engineer). The ONLY "drawback" I can mention is that... being white LED's, they stay the same 'color' as you dim them... there's no "mood light" possible, such as with tungsten lights at very low dimmed levels. I hear some mfr's are considering adding amber LED's when they are dimmed, to emulate tungsten light color at low levels. Don't let the initial purchase price keep you from buying these! It's a paradigm shift in buying bulbs... you need to "think different" now. Remember... you save about 85% in electricity costs with these! And you won't have to buy a replacement for at LEAST 10 years! They pay for themselves in a very few years... then it's pure money savings into your pocket (or groceries)! ...and helping to save the environment!!
The Lightning Stalker LOL!... it's called the Man Cave... our finished basement, which houses our H.T. and my electronics workshop, but to keep it from feeling too much like a cave (not many windows), I use 5000k lighting.
You don't know what you are talking about - these bulbs are garbage. The failure rate is extremely high. They have had a problem with the glass dome falling off on peoples heads since the product was released and they haven't fixed it yet. I had a bunch of these on a dimmer - they buzzed so loud I couldn't stand them. Go to home depot dot com, do a search for Cree LED bulb and read the customer reviews. They aren't good.
Interesting... because I outfitted two houses with them, 50% are on dimmers (several different types), and I have not heard even ONE of them "buzz"! What in the world kind of dimmer did you use?? I have NEVER had a glass "dome" (the globe) fall off... not once... and again, that's with probably 40+ bulbs. My only issue as been the Neutral wire connection... as I already covered in another post here. It only happens on a very small percentage... and usually in a completely enclosed fixture, where the heat buildup is bad. OK, so on your claim about Home Depot reviews, I went on Home Depot website, looked up the original series 40, 60, and 75 Watt versions, and found that the Cree bulbs have a 82%, 85%, 88%, 89%, 90%, and 91% positive "customer recommends" ratings... so what's bad about that??? Considering the fact that historically, far more "unsatisfied" consumers tend to go back to post a "review" of a product, than those who are happy with their purchase... if nothing's wrong, they don't even think about it... this always means you need to know how to properly interpret consumer feedback ratings.
beforebefore You don't have to take my word for it - just g to home depot web site, search for Cree LED bulb and read the customer reviews/comments. The domes will fall off so beware. The buzzing noise they make is dimmer dependent - they are much worse on the cheaper more common triac dimmers. Cree went out and replaced a homeowners bulbs near my hometown because the domes were literally falling on his head. This problem was there when they started producing these and they haven't fixed it yet - been nearly two years. I'll look for the video from the news story about the guy with the domes falling off - i'll post it here if I find it. - Didn't find the video but here is an article : www.designingwithleds.com/tech-blogger-has-trouble-with-led-bulb-cover/
It will probably be fine. The devices that have trouble with modified square-wave inverters are things that are primarily inductive (e.g. some motors, and some transformers). Most switch-mode power supplies (those without active PFC), such as this light bulb, generally don't have issue running off modified-square-wave inverters
What was the DC output from the converter module? I'm just thinking if it would be possible to convert my Ryobi flashlight to an 800 lumen instead buying the small led bulb that fits the fixture for such small lamps. ;)
I purchased these exact Cree bulbs when Home Depot first brought them in. All failed rather quickly. They would start by either not coming on or going dim. Often times, this condition would oscillate. Have APS UPS with frequency and voltage logs that demonstrate not abnormalities in the line condition. Turning off and back on had them working for a few minutes. Reseated (Type A9) to no avail. Dissembled one of them. Nothing appeared out of the ordinary. I cleaned the contacts on the PCB and readjusted the metal tangs. Light began working again. In about a month, light began acting up again. It seams to be some sort of heat stress/fatigue causing possible electrical arching or dissimilar metal corrosion. Contacted Cree and advised them. They very nicely sent me new replacements at no costs. It was only about a month before those replacements did the same exact thing. The problem appear to be centered around the PCB/metal tang connection.
Sam Houston Im thinking about buying some dielectric grease and testing if the dissimilar metals are to blame or bad sealing between the housing and heat sink that is allowing moisture to enter and causing some slight corrosion. Or as you said it could be metal fatigue due to heat. i had a similar bulb failure
Similar experience here. The LEDs in my Cree were in 3 strings. One string went out completely and the other started to blink. LEDs just overheated and died. I strongly suspect thermal contact problems with the LED board wrapped around the cast aluminum(?) heatsink with no thermal compound. 2 cents worth would have saved it.
Re: Voltage - I don't know, but it's probably either for 10 or 20 white LEDs in series. On PWM - It's a DC-DC converter, so it does PWM, depending on how you define PWM. The actual LEDs are likely constant current driven. It also supposedly supports dimming the LEDs. I'm not sure how that works.
I have seen fairly high transient currents when running stuff with any real mains side capacitance as that capacitance acts like a short during the fast rise/fall times when the inverter potential is changing between ground potential and +/-140V.
There are a couple very integrated LED drivers available. I think it's still cheaper to have a separate controller and power device, though. That way, they can use a fancypants process for the controller IC, and a much more coarse process for the switch. That way, you get a lot of controllers per expensive wafer, and the power device is fine with a cheaper process.
The Philips L-Prize is technically more efficient at 94 lumens per watt vs. about 84 for these. Also, Philips has recently come out with a prototype 200 lpw lamp, which is insane. I could easily envision 15-watt bulbs that are 100-watt equivalent hitting stores within the next couple years and 15-watt bulbs that are 150-watt equivalent a few years after that. I will buy a half dozen and have a very bright room. :) Still, these are pretty damn good. I picked up two today and am not disappointed.
Cree redesigned their bubs recently. They now have a smaller globe, different heatsink, and 10 LEDS in 1 row instead of 20 in 2 rows. It looks like the circuit board is a bit different as well from the picture I saw. They have the new ones at my local Home Depot..
I have a question I wanted to see if I could tie a very low current dc voltage. Where would I plug those wires in. I want to see if a small solar panel can lower the wattage usage to even lower possibly 3 watts. How would I go about doing that?
You really can't. Your options are to either completely replace the whole power-supply board, and drive the LEDs directly (and they likely are all in series, so the Vf is likely >50V, or supply the power input with high-voltage DC equivalent to the AC input RMS. If you need low-voltage lighting, that generally requires at minimum, a different DC-DC converter topology, and generally uses different LED array topologies to optimize for the voltage supplied.
I know it's the lens, I just thought it was interesting that they're making the lenses out of compliant material. It makes sense, though. I can see how it would make the wire-bonds last longer, particularly under large temperature swings.
Great vid. Helped me learn alot. I am currently looking for how to mod (and remove) the strobe function from the cree flashlights. I have bought almost a dozen different kind of cree lights, and they all have these annoying multiple modes. At best, i can deal with High and low. Rather than buy more lights, i would just like to mod the ones I have. Any thoughts?
I too am seriously annoyed by having to cycle through every mode to turn it off. Or get to the mode I want. Giver me a switch I can set and forget. (With a cover) My brother gets seizures from strobing lights or even "Picket fencing" while driving. Sunlight through tree branches. Which ain't good. He can kinda predict the picket fence and avoid it.But when I hit my flashlight, I forget...
That soft coating on the led's is a silicone coating. Its often used for outdoor/rugged condition applications. It acts as a protector from grit/grime without scratching, and acts as a cushion support system for the led. It is also often used in achieving a specific color of led, as the silicone can be tinted. It can also be carefully removed if you have led troubles. And simply reapply a good highquality high temp silicone when repaired.
I have in some of the previous videos. I guess I just didn't comment in this one. Yes, It's pretty nicely built. However, I do worry about the potential contact issue with the metal-core PCB and the heatsink. Give them some time to sort out manufacturing issues, and it'll probably be a good deal.
It would have been nice if you would have screwed it into a socket, energized it, and told us what you thought of the brightness and light quality the bulb produces before you showed us it's guts.
It's on your end then. I edit all my stuff with headphones and a nice audio interface, and I can't hear it on my end. There is certainly some fan noise in the background, but that's white noise, with no fundamental.
It is still the early days of LED lighting. Give it a year or two and they will be as shoddily made across the board in the same way compact florescents went.
great video. I just tore into one to try to discern why it failed in maybe 3-4 years of occasional use. First it bears repeating the dc side of the little board is near 300vdc. BE CAREFUL KIDS. I'd have thought the board or the interconnects or the fuse would be the failure points, but in fact ONE of the individual led's evidently failed. With globe off you could see all glowing faintly with one dead, presumably with a big drop across it.
george jefferson i just took apart a bulb that had the same problem that you had and fixed it by scuffing up the contact points. Of course i broke the bulb though lol but it works now. it was a cree daylight led bulb. The bottom pops off at the expence of the 3 plastic tabs breaking. But now i know for next time that i dont have to break the bulb to get to the contact points to repair (it/them) as i have all led lighting at home.
Incorrect. It actually looks to be a data-matrix barcode. QR codes have a very distinct square pattern in three of the corners. This is most definitely not a QR type 2D barcode. There are actually a number of different standards for 2D barcodes. This is a DataMatrix type (google DataMatrix as one word for more info). FYI, the contents are "011304000655-45"
Unfortunately the only problem of the design is the use of a glass bulb. Kind of pointless if your concerned with durability. Other than that top quality components for the LED bulb to last a long time.
I guess I should point out that if you have something you want an in-depth teardown of, and it's too expensive to ship to Australia, I'm in the US, and can get a PO box.
Cree makes awesome LEDs. I just got one to experiment with. Smaller than a dime, but puts out 1700 lumens!!!! I want to make a bike headlight out of it, but will get into trouble.
I have a 'device' circuit board I need a bit of help with.. It's over 15 years old, yes, years not months. The electrical engineer I showed it to said it was 'programmed', but I'm not convinced.. I'm a beginner at best, but can follow most of what you're saying with a bit of quick reference. As far as I know it was never widespread produced, but it should've been. Can I send you a few photos? I won't post them publicly until I know more..
P Huster I'm always interested in electronic oddities... I love the challenge of "repairing the un-repairable"... by tracing out the circuit and discovering why it does what it does... and then why it "doesn't". It's kind of rewarding to sometimes even find a mis-designed circuit, whereby a single resistor value change fixes a problem. (this first happened to me a Sony TV I worked on in a TV & Radio Repair Vo-Tech class in my junior year of high school... circa 1976). Been a EE Design Engineer ever since :-)
squishy lenses .. if removed reveals the true led wavelength which is ultraviolet. the squishy yellow polymer contains phosphorous which when exposed to u.v. light emits the white light actually seen as the bulbs output color spectrum. pretty common technique used in mass produced led bulbs in these early led bulb years... there is a patent on full spectrum LED dye chemistry which would probably be a one step solution instead of this strange u.v. to white light filter trick ... what should be going on instead of the gel filter applied on the exterior of the LED is phosphorous and other appropriate chemical dopants applied directly in the makeup of the LED dye, so the white light is emitted directly from the LED and no exterior filter gel squishy is required.
It's entertaining to watch you dismantle things. I would like to see you take it a step further and tell us if it's a good buy or not, based on construction and parts.
Thanks for the info and advice. I have a small solar array on the house and all the things we have on the lighting branch have to handle being able to run from dual sources. I ran a quick one hour test on our main inverter and was impressed. There was only a slight increase in the heat on the heat sink but not to a dangerous level. I agree with you. These LED bulbs continue to impress me. I hope the longevity is there as well.
Also, where are my manners? It's good to meet you.
The FR capacitor is Panasonic, FR series... quality stuff throughout the board.
Very interesting video. I've got five of these bulbs in my dining room and am glad to see they are manufactured with quality parts. Also, here are some side points:
-while the color temperature of these bulbs was supposed to be the same as the CFLs which they replaced, these bulbs give off a noticeably better quality of light than the CFLs.
-these bulbs are manufactured in the United States, I believe in North Carolina.
Yup! I have a CFL I bought in 1998 or 1999 and paid $45.00 for it. It still works to this day. The new cheap CFLs are lucky to last 6 months.
I have gone to LED and the CREE lamps (over 50 of them in house and shop), not one has failed after 2 years so far.
The electrolytics in the DC-DC converter will determine true lifespan.
Cree bought out an LED lighting manufacturer called Ruud Lighting in 2011. They are aggressively moving into the lighting product market rather than just manufacturing the LEDs themselves. They do all sorts of industrial and commercial light fittings now which are quite nice (but don't ask about the price!)
Cree LED lamps kick ass. Between my home and 2 shops, I have almost 100 of the cree brand floodlights that fit into the ceiling cans. The ones with the turbine looking external heat sinks. It has been 4 years now and not 1 single lamp has failed. Not even 1 single LED in any of the lamps. They also operate very cool compared to the other brands. Great stuff.
The Chinese white LED strips you buy on spools for $9, expect 1 week before phosphors start dimming as they will. Buy the spool of CREE brand which looks exactly the same but costs $150, 5 years on and not one single indication of any LED dim or failure.
Give them a year or two. You get what you pay for.
+bishplis you are just here to be a jerk. You didn't even read how long I had my CREE lamps did you. I bought the "expensive" genuine CREE lamps in 2010 and they all work to this very day. Five years+ On the first ones and going strong. Even when a five year lamp is compared to a brand new unit, no difference in visible brightness aka no phosphor aging. Seeing as you buy $2.00 knockoffs that don't even use a real ballast inside, your ceilings are probably no higher than 8 feet. So replacing the knock-offs is easy. My ceilings are 20-35 feet tall in most places. I just buy something real and properly engineered, knowing it's not going to be a problem later on. Cheap white Chinese market LEDs use poor quality phosphors that dim significantly over a relatively short span of time. Not all of them, but a significant portion. Lacking a proper potted ballast, they often resort to a simple capacitor/resistor type passive "power supply" that is non regulated.
O+bishplis your the one coming in here acting like a prissy pricktard. I stand by my CREE brand LED products that I buy. Or I should say LED lighting products that use CREE LEDs. For me, not a single problem as long as the lamp uses CREE emitters. You have yours and that's fine and they work for you. No way in hell would I trust a $2.00 18 watt led lamp in one of my ceiling light fixtures. There is a reason why they are $2.00. The $2.00 ones don't have a real ballast in them and subpar LEDs. You get what you pay for.
I don't know about this actual lamp in the video as the units I have are their flood lamps and lighting bars which use genuine CREE LED emitters. These run only warm to the touch. The smaller lamps such as in this video run much hotter as they lack the space for heat sinking. I avoid any LED lamp that operates too hot to touch as reliability beces a concern. Even the best quality components run at high temperatures will have a drastically shorter lifespan.
I suspect you believe the $1.50 China made iPhone charger clone is just as good as the $40 original iPhone charger don't you? They both plug in to the wall and charge the phone, therefore they are the same..... Right? The $1.50 charger is much lighter. That's because it's more advanced inside right?
You keyboard warriors always come here to argue moot facts on RUclips. You troll about looking to argue with somebody for any reason possible. Your kind are always ZERO contributors to any RUclips forum, always hiding behind the blue generic avatar icon. Couldn't help but notice your overwhelming array of educational and helpful videos you produced and put on RUclips..... NONE! Get out of here.
+bishplis no shit Sherlock! Not too much is made in the USA, still engineered here though. CREE LEDs are built in China to CREE engineering standards. White LEDs use phosphors to create white light from the blue emitter die. The LED is only as good as the phosphor and the phosphor is the most expensive material used in white LED construction. So guess where they cut corners on the open market LEDs made to look like CREE but at .03 cents each vs over a dollar each for a genuine CREE? The phosphor! So you a have a nice bright .03 cent white LED the dims and shifts to the blue spectrum after 10,000 hours at best. Some real shitty ones start failing after 100 hours. They look good at first though.
CREE was also the first to mass produce and market the blue LED. There was a time when the idea of a white or blue LED was merely a theoretical possibly.
+bishplis the China hate is they don't feel bad turning out crap at the bottom dollar. They don't care... At least in the past. Things are improving and some of the best products come from China when supervised.
Well, after getting my hands on about 50+ customer returned Cree LED bulbs (of which only about 8-10 are actually bad), it seems the biggest single point of failure is actually the AC Neutral wire that simply gets crimped by the screw-in bulb base when it's attached to the plastic housing. They eliminated one too many hand operations. If this wire had been left long enough to protrude from the metal threaded base, enough to bend over the top lip and solder there, over 75% of the failed bulbs I found would have not failed.
The symptom is a flickering bulb that will go out randomly, and touching it can bring it back on... depending on which direction you 'lean' the bulb while it's screwed-in tight.
I found the simplest way to repair those is to create a small, sharp indentation through the metal base right on top of that wire. The wire position in the base is very repeatable and predictable, so with a small flat-blade screwdriver against the upper lip of the base, and a moderate 'whack' with the handle of a larger screwdriver (it doesn't take much), it dents the metal just enough to make a much better connection than their "slip it over and crimp" friction connection. The small screwdriver blade tip creates a fairly sharp dent that makes for a high point-of-contact pressure on the bare wire below the metal, against the plastic base inside.
You can get to the circuit board from the top without destroying the base. First, slide off the LED PCB. It literally slides right off (reason for my failures as listed other post). Remove all the silicon/epoxy type material where the base of the globe sets. I used a small straight slot screwdriver. You will see plastic tangs that will let you release the cast metal cage and there is your circuit board.
BTW. The shock from the two tangs ain't no big deal.
Nice video. Thank you for making & posting it. Kindly, ¿do you know what the drive voltage difference is between the two electrode/contacts that go to the LED themselves, please? Thank you.
excellent analysis.. quick question.. when u tested the bulb u said it heated a little.. What's the cooling mechanism? are those the fins on the side to disspiate heat and how hot was it actually?
The "2d barcode" is a QR code. It has information encoded in it. If you get a picture of it, there are online and android / iphone callers that will decode what's on the QR. I'd be interested in seeing what's on it!
Keeping it cool in a compact package it the tricky part. It would make a great non-lethal weapon to disorient an intruder. It completely wreaks havoc on the retina.
I didn't look at the LED directly as it will damage the receptors in the eye, but DAMN..... Amazing how many photons come out of the phosphors in the white LED. I can only imagine how bright the blue LED emitter is underneath.
Hat's off to CREE.
Will the leds that don't contact the heatsink well cause the bulb to have a shorter life?
Bulbmaster! :)
This stuff can be used by said companies since it's of higher production value then their own advertising.
I'm still surprised that no one has developed yet an all-in-one module for driver with just a couple big passives nearby.
Yep, DC-DC. The first thing done for input AC is rectification. The actual switch-mode power supply then operates on the rectified AC.
Most dimmers use something called a Triac. Google "Triac Dimmer" for more information. If they used a potentiometer, the potentiometer would dissipate an enormous amount of heat.
Re: Scoping. In this situation, since it's non-isolated, it's not safe to scope without special techniques.
I saw you reverse engineer a kill-a-watt and figured you were the right person to ask about this.
Is it not safe to scope the output of the power electronics? The contact leads before they go to the LED array.
Also, DC-DC? not AC-DC?
I had the impression that interior lighting dimmers used a form of potentiometer, so voltage across the bulb terminals drops. This is why some bulbs can't be dimmed because they require a minimum or constant voltage to remain on.
Ideally to dim LEDs you'd change duty cycle of the pwm, but you can't do that on an AC converted source without a driver/controller.
A question...
Would this driver circuit overheat if driven by a power inverter? I almost get the impression that this type of circuit would do poorly on a modified sine wave power source.
this video is so old now. What a blast from the past. Before it was just common knowledge that CREE is best of the best LEDs
I hope everyone knows that CREE LED "bulbs" are MADE IN THE USA... and done right! By eliminating hand-wiring, they eliminate the most common failure point... AND make it much simpler to assemble. The LED packages are all connected in series. Each of these LED's have 4-die, so you have a total of 80 white LED die in series, for a total of around 240V DC drive voltage. DO NOT play with these while turned ON, with the globe OFF! DANGER WILL ROBINSON!!
It's a really great design, through-and-through... SERIOUS reliability! 10 year warranty based on 6hr/day, 7 days/week - or 22,000 hours. Price is real decent.. just wish Home Depot didn't have USA exclusive retail rights.
Even my wife doesn't know when I replace old tungsten bulbs with the 2700k versions. Personally I prefer the 5000k version, which I have in my areas of the house... it feels more like natural sunlight lighting. Workign under 5000k seems more productive, I can see my work better (I'm an electronics design engineer).
The ONLY "drawback" I can mention is that... being white LED's, they stay the same 'color' as you dim them... there's no "mood light" possible, such as with tungsten lights at very low dimmed levels. I hear some mfr's are considering adding amber LED's when they are dimmed, to emulate tungsten light color at low levels.
Don't let the initial purchase price keep you from buying these! It's a paradigm shift in buying bulbs... you need to "think different" now. Remember... you save about 85% in electricity costs with these! And you won't have to buy a replacement for at LEAST 10 years! They pay for themselves in a very few years... then it's pure money savings into your pocket (or groceries)! ...and helping to save the environment!!
I think it is great that you keep your wife sequestered to certain areas of the house.
The Lightning Stalker LOL!... it's called the Man Cave... our finished basement, which houses our H.T. and my electronics workshop, but to keep it from feeling too much like a cave (not many windows), I use 5000k lighting.
You don't know what you are talking about - these bulbs are garbage. The failure rate is extremely high. They have had a problem with the glass dome falling off on peoples heads since the product was released and they haven't fixed it yet. I had a bunch of these on a dimmer - they buzzed so loud I couldn't stand them. Go to home depot dot com, do a search for Cree LED bulb and read the customer reviews. They aren't good.
Interesting... because I outfitted two houses with them, 50% are on dimmers (several different types), and I have not heard even ONE of them "buzz"! What in the world kind of dimmer did you use?? I have NEVER had a glass "dome" (the globe) fall off... not once... and again, that's with probably 40+ bulbs. My only issue as been the Neutral wire connection... as I already covered in another post here. It only happens on a very small percentage... and usually in a completely enclosed fixture, where the heat buildup is bad.
OK, so on your claim about Home Depot reviews, I went on Home Depot website, looked up the original series 40, 60, and 75 Watt versions, and found that the Cree bulbs have a 82%, 85%, 88%, 89%, 90%, and 91% positive "customer recommends" ratings... so what's bad about that???
Considering the fact that historically, far more "unsatisfied" consumers tend to go back to post a "review" of a product, than those who are happy with their purchase... if nothing's wrong, they don't even think about it... this always means you need to know how to properly interpret consumer feedback ratings.
beforebefore You don't have to take my word for it - just g to home depot web site, search for Cree LED bulb and read the customer reviews/comments. The domes will fall off so beware. The buzzing noise they make is dimmer dependent - they are much worse on the cheaper more common triac dimmers. Cree went out and replaced a homeowners bulbs near my hometown because the domes were literally falling on his head. This problem was there when they started producing these and they haven't fixed it yet - been nearly two years. I'll look for the video from the news story about the guy with the domes falling off - i'll post it here if I find it. - Didn't find the video but here is an article : www.designingwithleds.com/tech-blogger-has-trouble-with-led-bulb-cover/
Thanks.
I wasn't sure what base unit is commonly used on inductors. In this case, it looks to be microhenries.
What's the output voltage on the board?
Do these LED bulbs have PWM drivers?
It will probably be fine.
The devices that have trouble with modified square-wave inverters are things that are primarily inductive (e.g. some motors, and some transformers).
Most switch-mode power supplies (those without active PFC), such as this light bulb, generally don't have issue running off modified-square-wave inverters
What was the DC output from the converter module? I'm just thinking if it would be possible to convert my Ryobi flashlight to an 800 lumen instead buying the small led bulb that fits the fixture for such small lamps. ;)
I purchased these exact Cree bulbs when Home Depot first brought them in. All failed rather quickly. They would start by either not coming on or going dim. Often times, this condition would oscillate. Have APS UPS with frequency and voltage logs that demonstrate not abnormalities in the line condition. Turning off and back on had them working for a few minutes. Reseated (Type A9) to no avail. Dissembled one of them. Nothing appeared out of the ordinary. I cleaned the contacts on the PCB and readjusted the metal tangs. Light began working again. In about a month, light began acting up again. It seams to be some sort of heat stress/fatigue causing possible electrical arching or dissimilar metal corrosion. Contacted Cree and advised them. They very nicely sent me new replacements at no costs. It was only about a month before those replacements did the same exact thing. The problem appear to be centered around the PCB/metal tang connection.
Sam Houston
Im thinking about buying some dielectric grease and testing if the dissimilar metals are to blame or bad sealing between the housing and heat sink that is allowing moisture to enter and causing some slight corrosion. Or as you said it could be metal fatigue due to heat.
i had a similar bulb failure
Frank DeLucey thelooneytunesshow
They have replace this whole line but it was one of the first to be able to be used safely in a bathroom without exploding.
Similar experience here. The LEDs in my Cree were in 3 strings. One string went out completely and the other started to blink. LEDs just overheated and died. I strongly suspect thermal contact problems with the LED board wrapped around the cast aluminum(?) heatsink with no thermal compound. 2 cents worth would have saved it.
if it not difficult for you, could you measure it?
are they 3.5x3.5mm side or 2.5x2.5mm?
Re: Voltage - I don't know, but it's probably either for 10 or 20 white LEDs in series.
On PWM - It's a DC-DC converter, so it does PWM, depending on how you define PWM. The actual LEDs are likely constant current driven.
It also supposedly supports dimming the LEDs. I'm not sure how that works.
I have seen fairly high transient currents when running stuff with any real mains side capacitance as that capacitance acts like a short during the fast rise/fall times when the inverter potential is changing between ground potential and +/-140V.
There are a couple very integrated LED drivers available.
I think it's still cheaper to have a separate controller and power device, though. That way, they can use a fancypants process for the controller IC, and a much more coarse process for the switch. That way, you get a lot of controllers per expensive wafer, and the power device is fine with a cheaper process.
The Philips L-Prize is technically more efficient at 94 lumens per watt vs. about 84 for these. Also, Philips has recently come out with a prototype 200 lpw lamp, which is insane. I could easily envision 15-watt bulbs that are 100-watt equivalent hitting stores within the next couple years and 15-watt bulbs that are 150-watt equivalent a few years after that. I will buy a half dozen and have a very bright room. :)
Still, these are pretty damn good. I picked up two today and am not disappointed.
Cree redesigned their bubs recently. They now have a smaller globe, different heatsink, and 10 LEDS in 1 row instead of 20 in 2 rows. It looks like the circuit board is a bit different as well from the picture I saw. They have the new ones at my local Home Depot..
I have a question I wanted to see if I could tie a very low current dc voltage. Where would I plug those wires in. I want to see if a small solar panel can lower the wattage usage to even lower possibly 3 watts. How would I go about doing that?
You really can't.
Your options are to either completely replace the whole power-supply board, and drive the LEDs directly (and they likely are all in series, so the Vf is likely >50V, or supply the power input with high-voltage DC equivalent to the AC input RMS.
If you need low-voltage lighting, that generally requires at minimum, a different DC-DC converter topology, and generally uses different LED array topologies to optimize for the voltage supplied.
Is that a cree's xt-e leds 3,5x3,5mm?
I know it's the lens, I just thought it was interesting that they're making the lenses out of compliant material.
It makes sense, though. I can see how it would make the wire-bonds last longer, particularly under large temperature swings.
it's phosphor pigment that turns the blue LED light into white light.
So it's a hybrid ? A led florescent ?
Great vid. Helped me learn alot. I am currently looking for how to mod (and remove) the strobe function from the cree flashlights. I have bought almost a dozen different kind of cree lights, and they all have these annoying multiple modes. At best, i can deal with High and low. Rather than buy more lights, i would just like to mod the ones I have. Any thoughts?
I too am seriously annoyed by having to cycle through every mode to turn it off. Or get to the mode I want. Giver me a switch I can set and forget. (With a cover) My brother gets seizures from strobing lights or even "Picket fencing" while driving. Sunlight through tree branches. Which ain't good. He can kinda predict the picket fence and avoid it.But when I hit my flashlight, I forget...
That squishy thing is probably silicone lens. I used few osram golden dragon LEDs which used them too.
That soft coating on the led's is a silicone coating. Its often used for outdoor/rugged condition applications. It acts as a protector from grit/grime without scratching, and acts as a cushion support system for the led. It is also often used in achieving a specific color of led, as the silicone can be tinted.
It can also be carefully removed if you have led troubles. And simply reapply a good highquality high temp silicone when repaired.
I have in some of the previous videos. I guess I just didn't comment in this one.
Yes, It's pretty nicely built. However, I do worry about the potential contact issue with the metal-core PCB and the heatsink.
Give them some time to sort out manufacturing issues, and it'll probably be a good deal.
wow, that really is a quality capacitor! o.O
It would have been nice if you would have screwed it into a socket, energized it, and told us what you thought of the brightness and light quality the bulb produces before you showed us it's guts.
Always a join to watch your videos!
Thanks for making and upload the video to RUclips
It's on your end then. I edit all my stuff with headphones and a nice audio interface, and I can't hear it on my end.
There is certainly some fan noise in the background, but that's white noise, with no fundamental.
It is still the early days of LED lighting. Give it a year or two and they will be as shoddily made across the board in the same way compact florescents went.
I liked the joke on improving the gene pool.
The other cap was a Panasonic FR series capacitor
great video. I just tore into one to try to discern why it failed in maybe 3-4 years of occasional use. First it bears repeating the dc side of the little board is near 300vdc. BE CAREFUL KIDS. I'd have thought the board or the interconnects or the fuse would be the failure points, but in fact ONE of the individual led's evidently failed. With globe off you could see all glowing faintly with one dead, presumably with a big drop across it.
btw the led board/ring is easily removed by drilling out two little studs, then it slides right up and out.
george jefferson
i just took apart a bulb that had the same problem that you had and fixed it by scuffing up the contact points. Of course i broke the bulb though lol but it works now.
it was a cree daylight led bulb. The bottom pops off at the expence of the 3 plastic tabs breaking. But now i know for next time that i dont have to break the bulb to get to the contact points to repair (it/them) as i have all led lighting at home.
Frank DeLed
Incorrect. It actually looks to be a data-matrix barcode.
QR codes have a very distinct square pattern in three of the corners. This is most definitely not a QR type 2D barcode. There are actually a number of different standards for 2D barcodes. This is a DataMatrix type (google DataMatrix as one word for more info).
FYI, the contents are "011304000655-45"
Great video about a bad bulb. 6 months.
I don't know exactly what you're referring to, but it's probably my phone getting an e-mail.
Unfortunately the only problem of the design is the use of a glass bulb. Kind of pointless if your concerned with durability. Other than that top quality components for the LED bulb to last a long time.
332=3.3 millihenries
I guess I should point out that if you have something you want an in-depth teardown of, and it's too expensive to ship to Australia, I'm in the US, and can get a PO box.
Generally speaking Phillips only creates Euro-JUNK! However I have Phillips LED's soft white and blue white bulbs which last for years!
Cree makes awesome LEDs. I just got one to experiment with. Smaller than a dime, but puts out 1700 lumens!!!! I want to make a bike headlight out of it, but will get into trouble.
It could be some bug that is only affecting some people.
I hear nothing like that.
But the beard is the source of my powers!
I have a 'device' circuit board I need a bit of help with.. It's over 15 years old, yes, years not months. The electrical engineer I showed it to said it was 'programmed', but I'm not convinced.. I'm a beginner at best, but can follow most of what you're saying with a bit of quick reference. As far as I know it was never widespread produced, but it should've been. Can I send you a few photos? I won't post them publicly until I know more..
P Huster I'm always interested in electronic oddities... I love the challenge of "repairing the un-repairable"... by tracing out the circuit and discovering why it does what it does... and then why it "doesn't". It's kind of rewarding to sometimes even find a mis-designed circuit, whereby a single resistor value change fixes a problem. (this first happened to me a Sony TV I worked on in a TV & Radio Repair Vo-Tech class in my junior year of high school... circa 1976). Been a EE Design Engineer ever since :-)
beforebefore Any idea how to send a private message? I'm not really interested in this being public till I know what it is....
P Huster RUclips's "send message" function is accessed by clicking on a username, then "about".
Possibly. I'm not familiar with CREE's LED offerings.
Don't pull off the silicone domes! They hold the bond wires together!
Probably.
That's why I commented on it.
Damn it, spent the $ on Cree LED light bulb and I had two died under 1 year. What the hell.
Woo, no potting!
Hah, when in doubt, smack it with something. It makes it work better!
2:20 don't turn it on,,,, take it apart!!!!!!!!!!!!1
That's why you have 10. You get extras.
I came here through a shout-out on EEVblog #510 - Mailbag
I didn't pull them off, I just poked one of them.
I have been watching you use the box cutter. One day you may lose a finger.
He will for sure if he keeps the fingers in front of those razor sharp blades.
Hmmm testing to the point of destruction for me lol
ZAMAK=Zinc Aluminium MAgnesium Kupfer
squishy lenses .. if removed reveals the true led wavelength which is ultraviolet. the squishy yellow polymer contains phosphorous which when exposed to u.v. light emits the white light actually seen as the bulbs output color spectrum. pretty common technique used in mass produced led bulbs in these early led bulb years... there is a patent on full spectrum LED dye chemistry which would probably be a one step solution instead of this strange u.v. to white light filter trick ... what should be going on instead of the gel filter applied on the exterior of the LED is phosphorous and other appropriate chemical dopants applied directly in the makeup of the LED dye, so the white light is emitted directly from the LED and no exterior filter gel squishy is required.
ZAMAC=Zink Aluminium Magnesium Cupper
Why do you have to cuss in an otherwise good video?
What the fuck is wrong with swearing?
hahaha you're hilarious mr wolf :) :-P.
you should try shaving once in awhile connor :-P
I prefer "daylight 6500k" CFLs