Inside a Samsung LED retrofit tube. (Older style?)
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- เผยแพร่เมื่อ 26 ก.ย. 2019
- I was expecting the circuitry in this tube to be simple, but I was very wrong.
This is an older style Samsung retrofit LED tube that can be put into existing fluorescent fixtures without bypassing the original inductive ballast.
Some notes that will make more sense after viewing the video.
The big MOSFET might be purely a safety feature that only enables the switching of the inductor once the chips circuitry is stable. It might be to avoid stability glitching at power-up that could damage the chips own FET. I don't think it will be used for the high frequency switching of the inductor given the surrounding circuitry. It will also probably shut the drive off quickly when the tube is powered down. Those are guesses though. It's quite odd circuitry.
The use of two large electrolytics across the LEDs are to reduce flicker. The positioning of one at the incoming supply end is partly to use the available space for more capacitance, but also has the advantage of being in the vicinity of cooler circuitry and therefore not likely to degrade too fast and cause visible flicker over time.
The 420 reference apparently relates to a holiday date (20th April) when certain plants are celebrated.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.com/coffee.htm
This also keeps the channel independent of TH-cam's advertising algorithms allowing it to be a bit more dangerous and naughty. - วิทยาศาสตร์และเทคโนโลยี
After manually reviewing it, I hereby confirm this is original BigClive content.
Big Clive should voice for audio books. Audible hook this dude up.
Look for Hellfreezer, he does various narrations with a similar voice and accent.
I think if I changed the round fluorescent tube in my closet to something modern my routine would get scrambled.
Standing there while it pings and backfires until it brightens up is somehow harmonious with my morning routine.
Great talk on how complicated a bit of new technology is in the beginning.
That tube must have cost a bomb to make, much like cfl's were in the new.
They were like 20 times the cost of an incandescent bulb in the beginning.
I watched this on a big screen tested, and I still value the zoom-in.
I sometimes watch on a 55" TV, still find the zoom-in useful.
It wouldn't be right if nobody disagreed with you so I will. I only watch on a 24" monitor but I still find myself leaning back quickly in my chair when Clive zooms in. I mean, I could see everything before that just fine ans there's no issues with stuff going on later out-of-frame.
@@alexatkin me too but 44 inch
I dont like the zoom in at all, its pretty unpleasant when sitting at my pc.
We all do. If course, there always some poor dear who has to complain.
Oh, 555k subscribers, would it be a time for a 555 special?
Yes! Clive should do stuff with 555 timers that they're not supposed to do... maybe make a few go bang... A recomposition of his resistor sonata
557k you mean... ;-)
Lilly like da flower - hey, what about a 556 special?
Looking forward to the Op Amp Special when BC gets to 741K (shortly after the foray into TTL "logic Lego" when he reaches 740!) :-D
@@phils4634 Would I be showing my age if I said we could also have an 807 special (CV807).
main reason for the fuse in the starter is in case someone puts an old-style tube back into the fixture.
That would apply to where the ballasts are bypassed. In this case I don't think the cathodes would pass enough current to blow the fuse. They'd just glow in the same way as when the starter contacts weld closed.
....i dont know if i'd rather see mike or clive try doing things you arnt supposed to like this, actually, both of you can just leave it to photonicinduction :D @bigclivedotcom i think i agree with mike on the reason, when starting a FL tube can take upwards of 100+ watts per tube on a magnetic ballast due to the thermionic coils glowing, i haven't tested it directly but if you leave them glowing, the total current probably would pop a slow blow fuse after a while
Frogz photonicinduction channel is since long gone and the internet has become a better place.
Some say he is in India saving the planet while slurping curry.
Some say you can still hear his voice every time the UK power grid dims
Or if someone takes it to be a normal starter and puts it into a standard fitting.
yeah youtube is being silly, thank you for being you and providing good content for us!
Sadly YT is going off the monetisation rails. I suspect that the multiple levels of management within the Empire have to justify their enormous salaries by experiments. The bad news for them is that while content creators migrate down the road in Silicon Valley to Apple (!) et al the shine (and $ returns) is reminiscent of FW Woolworth
They have gone back on the de-verification, though. Anyone already verified will stay verified, the change will only be for future new verifications.
@@rolfs2165 why did Clive get that message then ?
TH-cam are a law unto themselves, they let someone else take my /licensetodrive URL which I'd been using for many years, so now I have to tell everyone it's /user/licensetodrive
I signed up to Twitter to contact them and try to sort the issue out - fat lot of bloody good that did, they stopped responding after a couple of days. They don't care. F* them.
@@maicod Because TH-cam is run by a bunch of people who can not think clearly. They were caught with their collective pants down when they initially announced this decision only to be astounded by the content creators complaining about this decision. I never thought the checkmark meant the channel was being promoted by TH-cam. I took it to mean that the creator behind the channel had been verified. Even moving one's mouse cursor over the checkmark indicates that. I guess TH-cam feels that the majority of their viewers have low IQ .
Between BigC and Electroboom I am in my happy place. Thank you Clive for the hard work to putting great content into TH-cam. This is very hard to do week in and out and your passion makes a difference. I appreciate your work and willingness to go places where others do not and pour your time into it
Do watch diodegonewild he also makes awesome content about pulling things apart
@@chilly1661 He is great, he sings when he talks, always funny to listen to.
i was like 343 and clive is still teaching everyday , love the guy for the captivating way he teach things and how fun he is
I love the fact there are still companies out there that care about good engineering.
Yeah this is pretty much power factor correction, no flicker, no emi interference (extra copper plate pcb)
Very good product from samsung😮
I will buy these as replacement led thingies from Samsung now
BigClive: I don't know what 420 is.
Also BigClive: Look at all these LED grow lamps.
I posted a video a few months ago of a very similar type A LED retrofit tube and I was amazed you drew it out almost identical to how the Feit bulbs were. Then very surprised how different the internal circuitry ended up! Your video of course 100% better than mine! Great video!👍
Lots of suppression because tos long power busses will make great antennas.
I have no idea what this big guy is talking about, but i could listen to you all night, thanks Clive :)
As always, Very Cool. Thanks Big Clive. That really is a bunch of circuitry which I was initially thinking necessary because of the random orientation the tube might take in a fixture. Nope. Like you said, just spread to both ends of the tube to make use of the space in between. Pretty neat.
For the LED-Starter i often see a fuse inside. But some manufacturers has nothing but a jumper-wire inside. The one with the fuse are better, because for some reason when you want to replace the tube with a old Vacuum Tube the Fuse blows by the time. With a jumper wire the preheat-coils in the Tube are always on and the CCG heats up and can cause fire.
That Oh Henry bar looks to be identical to what we know as a "Payday" bar in the US.
A lot of fixtures with soldi-state ballasts use the so-called "shunt" sockets, where the two pins on each end are connected together (the tube heater isn't used). I retrofitted a number of 4-foot F40 fixtures in my home with line feed at either end, so that shunt sockets don't have to be replaced. The replacement tube instructions state that you can leave the iron ballast installed or remove it (better efficiency). The lamps are quite bright and have no flicker, so I suspect a high-frequency inverter is part of each tube.
“Vintage led”
That made me feel old
Not as old as I feel when I think back to when LEDs were first sold in electronic component shops and cost quite a lot for a very dull red or green one. (I chose the green one.)
bigclivedotcom hell not many component shops anymore.
@@cdawson198600 Do CEF not sell red leds for 3p ?
It's been downhill since we switched from good ol' torches to that fancy modern gas lighting.
@@bigclivedotcom remember when laser pointers were $100 for red? the first pointer i got was $30 usd, came in a folding padded box with 2 AAA batteries now you can get a red blue and green 3 pack for $15 including a pair of 18650s and charger
I haven’t been able to find these locally in the states. The guys at Home Depot and Lowe’s told me they were discontinued and there isn’t a drop in retrofit available any longer… Without completely overhauling or replacing the fixture.
I bought these several years ago and they’ve worked for me great probably going on eight years now maybe six I don’t remember…
However I sent my dad to buy some for his shop.... (because florescence give him headaches)… And he was told they don’t make anything like this anymore … And that was just last week.
Maybe I’ll try to order some of these on eBay for my father and for my remaining fixtures.
I always greatly enjoy your videos!
It’s not hard to rewire old fixtures. You can leave the ballasts, just disconnect them. I used double ended bulbs, so I just connected one end to live, and the other to neutral.
In fact the lower part of the schematic is a typical buck (step down converter) but is floating connected in the high side for driving the lamps.So the free-wheeling diode is connected between +310v and mosfet's drain and passes through the buck coil that is connected to drain and the output load.The led voltage is measured against the +vcc of the rectified input voltage.The buck mode coil has a secondary isolated output since as said it is floating against the ground and is used for the ic power supply and output voltage feedback monitoring.
At my previous job we had a lot of LED lamps made by just having a frame, with plastic conduit clips, which the led tubes fit into, and then it was connected by 2 connection blocks to the cable, with a piece of plastic conduit slipped onto the end (perfect fit) to cover the connection
Well just when you think hey this will be a nice little video with a simple yet functional thing.. ow hell no.. it turns out to be way over the top complex and just blows up lol love it Clive, keep it up dude.
Fascinated by this. The small condominium I live in has 9 fixtures each with its own magnetic ballast driving one old-style T12 4-foot fluorescent tube. I replaced all tubes last year with identical Philips LED tube-replacements designed for that. Purely plug-and-play. No problems so far. I wonder how similar the circuitry is. 2100 lumens but the LEDs point downwards, supposedly 20 watts power use each.
I just got an ad for grow lights, TH-cam must be thinking Clive is all about 420.
Pretty clever splitting up the circuitry to just the two ends.
I have a 1960's 4ft fluorescent fitting in the kitchen that is on its 3rd rebuild. It originally had a combination starter and 40W? bulb as ballast in a light fitting at one end. Sometime in the 1980's my mother forgot she had spare stock of the combination starter bulbs and as they were now unobtainable I rewired the light with an inductive ballast and ordinary starter in the light fitting. The lamp hangs from a single thin plastic conduit tube pendant so given the increased weight of the inductive ballast I had to move the pendant to rebalance the fitting. Then in the 1990's I assume an electrician replaced the ballast and starter with a starter-less ballast.
Last year I found the stock of combination bulb starters so I flogged them on eBay to someone with the same light fitting. Around Christmas I again rewired the lamp for an LED tube, junked the ballast altogether, and relocated the pendant to its original position to rebalance it. All was well until the onset of spring and sunny weather when the lamp began to flicker. Eventually I tracked this down to the proportional immersion heater controller which uses the surplus energy from my solar panels. I assume the noise ripple from this is enough to cause the light to flicker, albeit I have conventual LED bulbs on the same circuit that do not flicker. Therefore I'm guessing the 4ft LED lamp is of the simpler design that Clive was expecting here, so I am now looking for a 4ft LED tube with the control circuitry.
PS Ordered and fitted a Crompton LED T8 Glass tube; flickering gone.
Have a great night Clive 👍
Well Clive my dear mentor, that all blew my newbie mind!!! But as it surprised even you sir then maybe I shouldn’t be so surprised?!.
Cheers Clive
Bob
There's something about the word tube, spoken in a soft Scottish accent!
I watch Clive before I got to bed his voice is super relaxing plus the videos are pretty awesome
Tshubz
another good video Clive
would be nice to have some oscilloscope readings of the working circuit. just to confirm power factor and working frequency
C8-R16 is a snubber to damp down the snap-off noise from the flywheel diode (D5). The switch in the chip appears to be only rated at 18V so the external MOSFET is a common gate stage to boost the voltage rating up to 400V or so.
"I am not a number"
@@twotone3070 You are number six.
@@petehiggins33 I am a mere fraction of that Leo.
These videos are excellent
Great video clive
With LEDs I mostly care about flickering. So much difference between different lights. This is why I use normal Tubes in my room with a 40 kHz driver. This, along with the fluorescent screen of the tube prevents flickering 100%.
You're a legend!
Love the humour.
This made me finally get unlazy enough to look up options for replacing the tubes in my kitchen that stopped working about 2 weeks ago. Lead me to find the Philips t8/t12 universal LED tubes that are supposed to work with either magnetic or electronic ballasts. I guess I'll give them a try. No idea what type my light has, it's an apartment so I'm not going to replace and rewire their stuff.
Big Clive is a good TH-camr that doesn’t make content that TH-cam can demonetize him.
The circuitry seems so much more complicated than it needed to be, based on what you said in the first half of the video... But, like you said, maybe it's so complex because they're trying to make it more efficient? Make it so its power-factor is closer to 1.0 than it would otherwise be? And to add some stability to the output current? Either way, I definitely did not expect such complexity... Excellent analysis, as usual. I always learn so much on this channel -- thank you so much!
Yellow transformers can also be a VW Beetle.
Or a yellow Camaro.
Clive, I bought 10 of these for my workshop, they’ve been running for 2.5 years now without ballast (straight mains connection) I was concerned at first but I got them from CPC for £1 each on their clearance, so was well worth the random purchase
I think that's where I got this one, and also on clearance.
Interesting! I was wondering about that. I would kind-of expect it with such a sophisticated driver.
I think it's a normal single ended LED tube, one end is the input and the other end is just short circuit. The LED starter is also short circuit (in this case a fuse), it can work with the ballast because the LED tube consumes less current than the fluorescent, so the ballast is just there (in practical use can be considered short).
Some people strip out the ballast and the old wiring, but in my opinion it can be benficial as it protects the LED against spikes and also compensates the capacitive nature of LED supplies.
I picked up a few 5ft ones from Aldi for 99p each earlier in the year. A bit of chocbloc on the feed end and looped power between four of them and I’ve got an illuminated garage for a few quid.
I wonder if we'll be stuck with the fluro tube fittings long after the traditional tubes are out of production? A bit like horse and cart -> road width -> car width.
That's a bit like we still talk about dialling a phone number, even though telephones haven't had dials for decades!
@@NOWThatsRichy my phone definatly has a dial that's how I called my school when I needed to schedule something with someone without having to make a contact labeled school and input the phone number there
@@bland9876 The genuine old dial telephones would still work on a pulse dial exchange but i think you may need some sort of adapter to use them on a modern tone dial system.
@@NOWThatsRichy can't use an old phone unless there's some way to connect it to a cell phone tower luckily I have a smartphone and it has a button on it which says dial and when you click it a bunch of numbers pop up and you can click them and if you inputted the right numbers you can click another button and it will call that particular number without having to make a contact or anything in your phone it's really cool and has come in handy a few times
I got the electronic guts from a simpler build quite recent LED tube, just electronics on one end. Not sure if I may send it over or first try to fix it. Also not sure what actually failed.
The originally 120 cm tube got at least a more shipping friendly format now, as I absolutely shattered the glass tube when I tried to disasemble the thing. Pretty resilient stuff this white goop they used to glue absolutely everything in place. had to peel of the plastic sockets in strips to release the board.
Nice analysis. I would be interested to check using an oscillator the effect of that additional circuit at the end.
Hi Clyde. It is quite a coincidence that a day after I bought 2 18 inch Great Value 15 watt Non Dim T8 or T12 LED lamps, similar, I suppose, to the one you just discected. One is 2700k the other is 5000k; the label states T8 25.4mm T12 38.1mm. "Replaces T8 or T12 in you fluorescent Fixtures... Both the old style fluorescent tubes went belly up so I bought these to replace them (one is Soft White the other is Daylight. Well short story of it all is aaater I installed them I plugged the lamp in and they immediately came on. Unplugged, plugged, same thin frever, I suppose. Before, with the old style Ihad to hold the "ON" button down for a second or two before they would energize and start giving off photons. These LEDs lamps come on as soon as I plug i in. The OFF switch does nothing as in when I push it the lights stay lit, no flicker, no nothing, just bright Daylight and soft white. They aren''' running hot, smoking or giving of fumes of any kind but I still decided to unplug them; 10 minutes later your video popped on my youtube screen. In all of your eletrical wisdom would you be able to just give me a guess as to why this is happening? Unknonw damage? Balast gone bad? Oh, btw the lamp is a 2 tube portable lamp. The sticker on the bottom: E69325 120v 60hz 1115Wx2 0.48A AC ONLY Made in Taiwan Another sticker: Inspected 0922004. And a small oval, blue colored UL sticker.... 2 buttons = ON and OFF and no visible ballast(s). It does have some handy phillips screws on the bottom, holding the case together. Thank You O Wise One.
The 2 foot length specification is for the fixture. The lamps are shorter to accommodate the socket at each end. Same for the 3 and 4 foot models.
So, if this is an early application of LED lighting, then it might be fair to say that we are seeing a circuit before it goes through what AvE would call "Value Engineering". Do you think all the additional coils and caps and FETs are there to make this circuit more reliable and robust? I ask because I've had a couple "high end" LED lamps fail on me. Thanks to your channel I'm pretty confident that it's the power supplies that have failed, due to there being lots of noise on the AC side from a dehumidifier sharing the same circuit. (Not ideal, but nothing I can fix without getting a new power distribution panel in the house.) It annoys me the theoretical reliability of LED lighting won't be realized because of cheap power supplies that work for weeks or months an end up failing as commonly as the incandescents that they replaced.
No no
I have a LED light that has run over 75 thousand hours, and it's still going strong. That said, there are some simple cheap LED lights that use a series capacitor to limit current. They are supposed to use an X rated capacitor that will fail open, not shorted. But instead they use those red gumdrop caps rated for only 400 volts, sometimes less. Well, 120VAC is 370V peak to peak, so the cap is running at its max, sometimes over maximum. So failure happens, and it takes the rest of the circuit when the current becomes excessive. Just pray the light doesn't catch fire! 😱😱😱
@@acmefixer1 I have seen some LED tubes fail, not just the cheap ones. Dissecting them showed either signs of crappy build quality, crappy cheaped out capacitors, or 80 % of them temperature issues. They put the led strip into a plastic difuser/reflector, shrouded that one with another difuser lining the actual glas tube... By the way a pain in the ass to disassemble the way they glued everything in place with the usual white goop.
C1 in the schematic is needed to provide a path for the high frequency current flowing in the buck converter loop. It does distort the zero crossing of a power factor circuit though. So its value is a compromise. It's normally in the 1uF range.
420? Roll a fat one bro.. yeh, that's what that means Big man.
Thanks for the vid as always, was wondering how these worked
These are awesome
The tubelight of the future
I'm glad to see they let you the best mortal youtuber to keep the verified thing :p
It's like you are inside my head - I recently replaced three tubes in the garage with Sylvania LED tubes (from Wickes) which also came with 'dummy' starters (or so I assumed - I haven't opened mine!). a) that made me tear apart an old neon starter to see how it worked and b) it made me wonder what was in these new tubes and I thought "I wish Clive had done a tear-down of one of these". I wonder if it's the same circuitry as these Samsung tubes..
I would not say it is an older style, it is just as you said for retrofitting older style fixtures.
Those blind starter dummies will not work with an electronic ballast, for those you have to take out the electronic ballast and reqire the fixture.
those blind starters usually contain either just a wire or at most a fuse.
The fuse is to pretect everything else in case someone erroneously uses this blind starter with a regular non LED tube.
The shorted out end is helpful if you eliminated the ballast and wired the sockets over cross, this way it does not matter which end goes in where.
I for myself eliminated some electronic ballasts and simply put the warning sticker that was included with the led tubes I used to the wired end. My tubes have all been marked something like "power from this side"
I (and Project Farm if you want to see a video) retrofitted my shed with Hyperikon LED retrofits, which intend for you to completely remove the ballast and have live at one end and neutral at the other. You can get these on Amazon. Very good lights though. A bit harsh for the inside of the house, so got some Philips retrofits for that, and they needed a switchmode ballast (there is a list of "compatible" units) which luckily it was easy to find a $12 unit that was on the list
I've done a lot of mine with toggled dimmable ones from home depot. The 5k color was quite an improvement in my shop. I was even more impressed when they turned on properly on a subzero winter night.
The instructions didn't appear to say plug power back in after replacing the tube and shunt starter!
The on off cycles due to inverter ballast charges, it actually is less damaging for the 2 second cycle vs 30 seconds on off since 30 seconds it discharges further and cools further and of course heats further when on for 30 second test. Thus 2 second tests temperatures stay less varied and damage is reduced vs 30 second test.
But in the real world, you tend to turn the light on and leave it on for a long time. In workplaces for 10 hours plus. At home for less time. So what would be more useful from the manufacturer is the impact for those situations.
556K subscribers NE556 timer builds seems logical
If you have a Walmart near you you should get some of the universal replacement leds that are rated for use with electronic and magnetic ballast as well as direct wire. They’re made by intertek iirc.
woah this was much more hard work for you than anticipated eh
Yeah. I thought this was going to be an easy video. I was almost disappointed when I popped the lids.
@@bigclivedotcom I did feel that a bit :)
@@bigclivedotcom I was kind of shocked when I saw it was going to be 30 minutes but then I watched it because I figured it had more of a story to it. I wasn't disappointed.
TH-cam have announced that they are not removing the verified tick now if you already have it, not that it does anything anyway but you should be keeping it now, make the most of it mate 😋
In hindsight would have been good to stick this through the Hopi to check the power factor but an excellent teardown if a little (lot) complex, especially for us mere apprentice level mortals. I only did electrical stuff as part of my mechanical apprenticeship.
I think you may be misreading things. The box has CCG (conventional) and VVG (low-loss) ballast markings just to indicate it can be used with in these fittings without bypassing. (Electronic ballasts are -EEV- ECG.) But you can use the tube direct to the mains - every LED substitute tube I've bought in the last few years can be used like this and Philips ones even have L & N markings on one end.
Circuits like that constantly blow my mind because it looks like so many things are cross connected that I have no idea how to follow what is going on from startup.
Thank you for the share
Ur vids are informative and inspire us technicians. What is wrong with TH-cam?
These retrofit LED lamps work absolutely fine with completely removed ballast, both tube and compact style. A good way to salvage light fixtures with defective ballast, just rip it out and connect the LED lamp directly. But you have to provide a fuse inside the fixture in case someone tries to put in a old stile fluorescent lamp. And this is the only way to retrofit double Lamps with serial circuit and only one ballast.
Its especially useful in cases where you have dozens or hundreds of downligts, one fails and there is no equal looking replacement anymore.
Not all of them will work without a ballast. I have some that would immediately release the magic smoke if run without a ballast to limit the current.
@@rocketman221projects never seen one like this yet.
The external MOSFET is used with the internal MOSFET in a cascode. Essentially the external one limits the voltage across the internal one. This means the external one is doing all the work while the internal one has a the control. While looking odd this allows the external MOSFET to be added and not need to worry about gate drive for proper rise/fall times.
Yes, according to the data sheet, the internal MOSFET has an absolute maximum voltage rating of just 18V, hence the need for a higher voltage external MOSFET.
Maybe T1 circuit looks for AC imposed on DC supply ...? AC present at that point could indicate several failure modes and trigger a protection feature that shuts the thing off ....
It’s more fun if you skip the formalities and just shove the end of the tube into the wall outlet. Of course, you’ll want to make sure you don’t use the shunted end, or you might set your beard alight! 😬 I’ve found this to be the best way to make an EOL video; though, I’d take it outside with a long extension cord, pack the tube with sparklers, thermite, and cut-off match heads, and re-glue the end on. Oh, and finding an area free of anything flammable is helpful! 🤣 Sounds like something on the TKOR channel, or maybe shango066. 🤠
There's a complicated circuit in the Phillips LED T12 replacement tube equivalent to this one. the ones that are directly connected to A/C are much simpler. I know because I bought a bunch of different kinds and the Phillips was the most complicated one.
oh yeah! one more thing, those Phillips replacement tubes indicate that they are designed to work with magnetic ballasts and shouldn't be used with electronic ballasts. I tested that and if used with incompatible ballast, they stop working.
Sometimes those confidential marks are just overlays (if the text is searchable). They can be removed for example in Inkscape.
There are(were?) retrofits which don't even need the starter replaced; they are much simpler, consisting of a pair of bridge rectifiers on each end, a smoothing capacitor, and as many LEDs as needed to make up a similar voltage to the original tube.
U R Awesome. thanks for this.
For a second there I thought you were going to run a continuity test on the Reese's peanut butter cup.
557k, now we need a special about pnp transistors...
Seems we have some specials waiting....
555k timer special, 556k dual timer special, 557 PNP transistor special, and soon it will be time for the 558k quad timer special.
The 555 video is coming up, but it's NOTHING like you'd expect. Clue. It's E555 and involves ethanol.
@@bigclivedotcom haha you little BIG :D rascal
MOSFET Q1 in common-gate configuration. Probably to allow the chip to handle higher voltages.
That was my thought too.
Also my first thought. I skimmed a not zoomable version of the datasheet and I think it said the internal FET can only do 22V or so.
That secondary circuit with the transformer looks like it acts like an OPAMP with degenerative feedback in order to provide additional protections and regulation that would otherwise not be available to just the power supply itself.
I'd keep an eye on TH-cam and their verification. Others have mentioned it happening to them, also with no explanation, but apparently it can have consequences.
Keep up the great videos. I'm actually learning something! Who says you can't teach an old dog new tricks?
They rescinded that decision the day after they announced it. Guess the heat on the back of their collective necks was too much.
Oh hell, thanks for the vid big man, I'm going to replace the entire fitting now. This seems like too much of a kludge.
I wonder how many of these so called home professionals forget to replace the old starter with the new 'starter' cause people don't read instructions
none because the led will keep flashing!
Or the other way around. Thats why there is a 2A fuse and not just bridged connections.
Normal tube would just warm and warm up and never "start" until a failure or a fire.
Unless somebody put a 13amp fuse in the holder
@8:00... yep, agreed, here in the states as well
These line-connected LED regulators are hard to understand, but in this case it's an "upside down buck regulator" where the entire topology is flipped around the horizontal axis and "normal polarities" are all reversed. C7 is the output filter cap, D5 is the catch diode, T1 is the inductor that is has a small secondary tap to power up the controller chip. Ignore the common mode choke LP1, then draw a few LEDs for the load. Once you do that, you can see the rudiments of a buck regulator, whose purpose is to keep pumping the LEDs with a triangular current at all times as opposed to just hitting them with 100/120 Hz hits, which cause flicker. Unlike a conventional buck where the flyback action happens when the inductor swings below ground, in this one the flyback action occurs when the inductor swings high through D5. The external PFET is a bit of a puzzler, but draw in its body diode and you'll see that when the controller chip switches low, it drags the drain low with it. I'm still unclear what happens to the PFET during flyback. The Samsung boys are using a buck switcher to feed their LEDs, which is highly efficient at the expense of complexity!
420 was the police code in California for weed smoking in progress, also happens to be the date when the temperature is warm enough in most areas to plant your seeds outside. So potheads made that their favorite time to smoke and April 20th is like national pot smoking day to them. So if you smoke weed on 4/20 at 4:20 you appease all the pot gods and they will bless you with a bountiful harvest. Ok I made up that last part! Lol
We definitely can't risk having a lame harvest though.
9:28 Five minutes to half passed four is one of my favourite candy bars to enjoy five minutes after four twenty.
Sylvania Erlangen has just launched their new development next generation LED fluorescent tubes by the name "Helios". They do not use the simple strip of cheap led inside a plastic pipe, but an actual glass tube with glass welded mounts like a traditional fluorescent tubes, coated with phosphor to diffuse the light, and the inside there are two rigid wires going from one end to the other and many, like 100 pieces of sequential parallel connected individual very high quality led filaments. Those are the real deal. If I would ever give in into this LED forced nonsense (says the guy who has 8 boxes of T12 fluorescent tubes stashed away for future use, some in halo 530 color even) I would definitely use the Helios ones. They are weather, moisture and chemical resistant, and with a proper ballast they could be used in factory settings where traditional fluorescent tubes are still king, mainly because of oil, dust, thinner fumes, etc. that would basically ruin and dissolve the cheap LEDs.
I think that this tube is not actually "using" the inductive ballast. The fact that it is intended for conventional control gear means that it will not work with HF-ballast. I recently placed a LED-tube made by Philips. They come with instructions on how to modify a fixture with an HF-ballast (which means taking the ballast out and doing some rewiring). So, the modified fixture does neither have a ballast nor a starter.
There are also led-tubes available which work in HF-fixtures without modification, but they are more expensive.
At the beginning of the video I was unaware that the tube had significant active electronics in it. The way it was shown with the original ballast suggested it might use it as a current limiting component. By the end of the video I realised that the ballast is just a coincidental component in the circuit after the tube has been installed.
Thanks Clive. I always wanted to know this. Is it worth to buy a lamp and this kind of t8 led tube for growing plants?
03:14 - Striking won't happen until the starter - as the bimetalic strip cools down in it - opens up again, applying full voltage across the tube again, plus a little EM kickback from the ballast, which results in a high voltage spike. An aged, faulty tube with worn off thermionic emitter, often in one end, starts to rectify the AC current, which results in too high voltage drop accross the starter during every second halfwave, which results in a neon glow discharge, even that the tube is essentially stricken. This makes the starter close and go back to preheat mode until the bimetal cools off again. And the cycle goes on. Removing the starter at the right time stops the cycling, and the tube stays lit, but it'll be awfully flickery. The ballast may also overheat. Fun experiment, even I tried: replacing the ballast with a 100W incandescent bulb.
That's quite a complicated thing there. Flywheel diode?? I know it as a freewheeling diode, but flywheel diode sounds almost like blinker fluid. xD Compared to this, classic fluoros are a piece of cake!
Hi Clive, very interesting video allways. I don't think the external mosfet is a startup device. It's the main switch. It is used in "source switched mode" as it says somewhere in the datasheet. That probably means "common gate circuit", like " common base circuit" with bipolars: You put the gate on an intermediate voltage, say 12V, and then switch the source pin to ground. Now the switch in the chip does need to switch the full current, but only 12V and not the ~300V max mains voltage.
when you explaned the starter you forgot to mention one of its most important function:
It will open the circut right at the phasechange, the only moment when its possible to start the tube.
You can start a tube without a starter, but then you have to be lucky to hit the switch right at the phasechange.
We fit loads of these in the factory i work, annoyingly the majority of fittings are digital fittings and need rewiring. The older generation of tubes with the L and N input at one end the opposite end pins are common'd out and causes a big bang if you accidently insert the tube the wrong way round!!
The modern tubes have the feed from one end and the other end shorted. The ideal wiring arrangement is to have live to one end and neutral to the other. with the starter wire linked out. That way the tube will work either way round.
"One moment please"... 6 hours later... "One fairly large..."
Great teardown and reverse engineering, as usual. However, I was hoping Clive would look at the date codes on components for a further hint at the vintage of this unit. _What is the earliest date?_
i tried one of those in my kitchen light that still had the old ballast in it but it didn't work for me. after a couple hours of use they just went dim and flickered. so i had to go back to the original fluorescent bulbs. not sure why they didn't work in mine
Wow this thing is a complex mystery.. It looks to me like they're trying to balance out the mains ripple without using a huge capacitor. Its complex because of the low frequency and its a phase circuit. The telling thing would be that there should be less or no flicker when the tube is running.
Reese's are some of our best offerings here in the USA but one tires of them after a while.
Thank you.