No-name GU10 LED lamp teardown - Page 1
Forum section: electronics / general

author: reagle
author_rank: Unknown
timestamp: February 10, 2013, 09:52:03 pm
content: I just posted a bunch of pictures from my teardown of a OneHungLo brand LED lamp.http://kuzyatech.com/no-name-gu10-led-lamp-teardownI just love how they manage to pack everything in, safety be damned

author: david77
author_rank: Frequent Contributor
timestamp: February 10, 2013, 10:18:42 pm
content: Interesting. Somehow I doubt that even name brand LED lamps are much better safety wise.I had one LED lamp here in my lab in the swively work lamp over my desk. After spending two hours hunting down some elusive noise in a circuit I worked on until I finaly realised it was noise the LED lamp sent out I switched back to the good old 60W incandescent at least for this lamp.

author: grumpydoc
author_rank: Super Contributor
timestamp: February 10, 2013, 10:27:29 pm
content: My experience with GU10 LED lamps is that they crap themselves at the drop of a hat - especially the 9W ones.I have several around the house and now a large collection of carbonised PCBs from them. I think the best were the first batch that I bought - horrendously expensive but only one of those has failed so far. The worst was one batch all of which crapped themselves whenever I switched the flourescents off in the garage.

author: reagle
author_rank: Unknown
timestamp: February 10, 2013, 11:08:22 pm
content: This is a 3W version. Oddly enough- electrically it's still alive, but the plastic case fell apart.

author: poorchava
author_rank: Super Contributor
timestamp: February 11, 2013, 07:48:12 am
content: That one in the teardown article actually is not that bad. I've torn apart some of those and they never actually had a transformer inside (I guess it's fine, as they were completly made of glass). They used a capacitor to drop voltage and a diode bridge to power leds.

author: kripton2035
author_rank: Super Contributor
timestamp: February 11, 2013, 07:54:49 am
content: I have lots of 3w leds gu10 at home, will teardown one once it fails...but it's 2 years they shine, and no fail until now...

author: amyk
author_rank: Super Contributor
timestamp: February 11, 2013, 12:40:14 pm
content: The IC is probably something likeFSD200, the 7-pin DIP is quite distinctive and no sanding of part numbers can obscure that.I'm surprised it even has a transformer; isolation is not normally required for these lamps just like incandescent bulbs, so it's only additional cost.

author: SeanB
author_rank: Super Contributor
timestamp: February 11, 2013, 03:33:16 pm
content: I have the 12V versions, and upgraded them to remote ballasted ones, as I am using them as worktop lighting. They work, that is about all, i did add extra capacitors to the input and bypassed the input bridge rectifiers for improved efficiency.

author: c4757p
author_rank: Super Contributor
timestamp: February 11, 2013, 03:36:18 pm
content: I'm usually the first to complain about mains safety issues, but I'd argue it's not necessary here. "Proper" isolation in a lamp-socket LED light is kind of like putting an incandescent bulb on an isolation transformer.

author: T4P
author_rank: Super Contributor
timestamp: February 11, 2013, 06:08:45 pm
content: Carbonized pcbsI have one E17 LED bulb i have been using for a year to sleep nowStill working

author: reagle
author_rank: Unknown
timestamp: February 12, 2013, 03:25:14 am
content: Quote from: c4757p on February 11, 2013, 03:36:18 pmI dunno, these things have metal heatsink that could be easily touched and it's not protected much from shorting to one of the AC lines

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 14, 2013, 05:39:22 am
content: Quote from: david77 on February 10, 2013, 10:18:42 pmFluorescent lights are far worse than LEDs as for as EMI goes. (To the extent that at work, when outside noise is suspected, the first troubleshooting step is to turn off the bench lights.) But going back to incandescent is not at all necessary. You could use a low noise switching supply or even a linear supply for the LEDs and still be way ahead on efficiency.

author: westfw
author_rank: Super Contributor
timestamp: February 14, 2013, 08:32:33 am
content: Of course, safety-wise, it's competing with an electrically-live white-hot flammable-metal filament encased in a fragile glass envelope... :-)

author: johnwa
author_rank: Frequent Contributor
timestamp: February 14, 2013, 09:23:22 am
content: I am a bit worried that LED lighting will end up suffering from the same problems that CFLs experience from having an inbuilt driver circuit. While it is quite possible to produce a high quality circuit, with indefinite lifetime, the race to the bottom for price will ensure that the circuits are only going to be barely adequate. Of course, you could (and probably should) just buy name brand LED lamps, but these are probably not going to be very much better.The disposable nature of the driver circuit obviously adds significantly to the cost pressures. Perhaps a separate driver circuit and lamp is the answer, although this never really caught on with CFLs. I guess people are not prepared to pay for this feature.

author: T4P
author_rank: Super Contributor
timestamp: February 14, 2013, 01:13:11 pm
content: Quote from: johnwa on February 14, 2013, 09:23:22 amWell CFLs were designed in mind of E27 incandescent replacements and to expect separate driver circuits is daft, separate drivers and lamps are in ceiling lamps.And as for LED lighting, there was a phillips LED thread few months ago. Yep and their lifetime is short due to alot of consequences of using separate phosphors

author: Flávio V
author_rank: Regular Contributor
timestamp: February 14, 2013, 06:23:54 pm
content: I think than for LED lighting it can't be really well done using lamps....The best method is to DIY it(it is cheaper to me than buy then(+-20-30€ for a crap brand +-250Lm one))But to others it might be more expensive, but for reliability i think than DIY is the best...(no chinese crap in the design, no overheated LEDs, more efficient, etc)

author: amyk
author_rank: Super Contributor
timestamp: February 14, 2013, 08:23:14 pm
content: Quote from: johnwa on February 14, 2013, 09:23:22 amIn other words theywantthese to fail at some point, so that people will hopefully continue to buy them... the last thing they want to make is a lamp that lastsa century or more.

author: westfw
author_rank: Super Contributor
timestamp: February 15, 2013, 10:09:04 am
content: QuoteIt pisses me off that1) "Energy efficient lighting" building standards end up forcing people away from the E27 base where all the cost reduction effort and new technology is expended. (like GU24)2) lamp and fixture vendors STILL aren't designing lamps to make effective use of CFL-sized/style bulbs.

author: T4P
author_rank: Super Contributor
timestamp: February 15, 2013, 03:36:25 pm
content: And now we're to the point that energy efficient lamps and longer lasting lamps = usually irreplaceableOf course i'm talking about LEDs aren't i

author: ttp
author_rank: Regular Contributor
timestamp: February 18, 2013, 12:19:15 am
content: Quote from: poorchava on February 11, 2013, 07:48:12 amFrom my experience ones that use lot of small power LEDs running at 10-20mA use cap/bridge power supply and they fail quite quick especially if you turn them on/off often - there is no protection againt high inrush current and I've seen LEDs going bad one at a time. The ones with 1W LEDs and above tend to use switchmode power supplies with transformers.

author: ttp
author_rank: Regular Contributor
timestamp: February 18, 2013, 12:26:57 am
content: Quote from: kripton2035 on February 11, 2013, 07:54:49 amI can confirm, replaced about 40 50W halogen downlights with 95-240V 4W GU10 LED lamps. They were all EBay/DX cheapies, close to 2.5 years now and touch wood, one failure so far.

author: peter.mitchell
author_rank: Super Contributor
timestamp: February 22, 2013, 06:16:38 am
content: I thought these two videos i found recently might be relevant;

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 23, 2013, 03:42:55 am
content: For all those who question the quality, maybe we need an open hardware LED bulb? We could even take full advantage of LED technology by providing options for IR or RF remote control and maybe even an integrated PIR motion sensor. It would probably be very difficult to compete on cost, but the extra features could set us apart.

author: westfw
author_rank: Super Contributor
timestamp: February 23, 2013, 04:46:22 am
content: QuoteYou're kidding, right? Do you have any idea how much "churn" there is in this area at the moment?A week or so ago there was the "strategies in light" conference in Santa Clara. There must have been a dozen vendors showing off their latest "LED driver chips", "LED driver modules", "LED lighting ballasts", and etc. All touting different features still, along with efficiency, efficacy, power factor, etc, etc. And that doesn't include the vendors with complete bulb replacements. I rather like Seoul's direct AC driving chips (Acrich2):http://www.seoulled.com/- it looks like it would avoid a lot of the reliability issues of conventional DC supplies.On top of that, the most frequent failure mechanism seems to be the LEDs themselves. :-( (for which there are additional proposed solutions beyond "we make good LEDs": exotic heatsink schemes, "remote phosphors", etc...LED lamps are very much "under development", while "open hardware" pretty much demands a somewhat mature technology...

author: SeanB
author_rank: Super Contributor
timestamp: February 23, 2013, 05:22:26 am
content: The major failure is poor heatsinking and/or overdriving the chips to get a higher per unit light output, along with cost cutting the driver side with inadequate cooling and capacitor choices. Nothing that is unknown, just will cost more and make the units bigger in size for the same lumen output but will give a massive life improvement.I went into the lighting aisle, and there were GU5.3 replacements galore ( I was looking for this in particular so only looked at this size) and I tried them all. Samsung branded ones rated 4W were poorer than the ones I bought, branded Radiant ( I have these already and they are not a bad light inside when fixed up properly) 3W. and were only marginally better than the cheap multi 5mm units. I took the ones I bought and modified them, remote ballast ( runs cooler now as it is not next to the hot lamp heatsink) along with replacing the 220uF capacitor with a 1000uF one ( low ESR one about 10 times bigger, attached with a short lead) and mounted it in the modified lamp holder with some epoxy. 4W lamp is as bright as a 35W halogen lamp, a good saving, and as it is going to be solar powered it will be a big difference.

author: houdini
author_rank: Regular Contributor
timestamp: February 23, 2013, 06:27:43 am
content: I use a atx supply driving a current limited boost converter driving a 100w led at 60w and its brighter than sun light. total cost of the whole thing was like 30$ makes a heck of a bench light.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 23, 2013, 04:01:29 pm
content: Quote from: westfw on February 23, 2013, 04:46:22 amLED power supplies are quite simple and very well suited for open hardware. The real gain is in the additional features like built in remote control and automatic PIR based dimming.

author: reagle
author_rank: Unknown
timestamp: February 23, 2013, 07:43:14 pm
content: It's interesting how the guy in the videos questions why different manufacturer's 60W equivalent bulbs could draw different input power. Different power supply and LED (mainly) efficiencies, different operating points as a trade-off of heats/light output/power etc.