Inside a very clever LED headlight lamp.
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- Опубликовано: 24 авг 2024
- This started off as a simple autopsy of a faulty lamp and turned into something so much more. It's a very clever design that makes the circuit very universal.
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"mechanic proof". 😆 As a mechanic I appreciate the efforts of designers to make my life easier. Simple screw ups can get costly so items that can only fit one way or wiring that's not polarity dependant get a thumbs up from me.
As a machinist through to CNC over 45 years that machining reaches another level ......
Agreed, and as a former mechanical quality inspector, that piece looks like a nightmare to verify dimensions lol.
@@Hakuna_My_Tatas probably not very critical
3D printed ? ;)
If yer talkin about the purple bit, then it's an aluminium extrusion which is subsequently machined. First off inspection of extrusion by comparator. Inspection post (CNC) machining is fairly straightforward, particularly on diameters, linear dimensions are less critical. QC in production most likely by dedicated gauging.
@@johnharvey4496 as a fellow machinist and now process engineer… You hit the nail on the head.
God damn it... Every time you say "Bridge rectifier" I just have echoing in my head "FULL BRIDGE RECTIFIER" in a middle eastern accent. xD
Quontex I think a lot of us do... it's just a part of being involved in electronics these days... if your into electronics as a hobby, job, or whatever, you can't ignor the wealth of free knowledge that is the internet, that includes sources like EEs who post to RUclips... there are certain really popular such channels each that tend to teach different things in different ways... if you want to learn practice you watch Great Scott & learn electronics, if you want to learn electrical theory you watch Dave on EEVBlog, if you like seeing the guts of interesting electronics, you watch BigClive & Diode GoneWild, if you want to learn why you don't do the things that are generally considered bad practice you watch electroBOOM, and if you find slapstick funny when done well, than you'll probably be entertained. These are just the sources of this info... so yeah, many many of us here have T's from these RUclipsr's merch' stores, and we have phrases stuck in our heads like: "it's a FULL BRIDGE RECTIFIER!!!, not a puny single diode rectifier" , "Bob's your Uncle", "We're in like flin" "That would be awesome, and I will see you next time!" and "It's kind of a dogdy-podgy botch" and well you get the idea... I guess what I'm getting at is your not alone in this.
What's the difference between a "full bridge rectifier" and a "bridge rectifier"? I've always thought of "bridge rectifier" as the standard 4 diodes one?
Oh, now I think I get it. Is there another yt channel where they shout "FULL BRIDGE RECTIFIER"?
electroboom - definite must watch
> "We're in like flin"
s/flin/Flynn/ as in Erroll Flynn the actor and ladies man... en.wikipedia.org/wiki/In_like_Flynn
The thermal failure of LED headlights often occurs when the headlights are off! Basically, at random, you pick a parking space or location that accidentally faces your headlights directly into the sun. The result is the headlamp reflectors act as a solar furnace and cook the LED emitters. Was never a problem with filament lamps as the filament didn't care about heat. Ran into this with a friend who would drive into work, comer out at the end of the day and the headlights would not operate.
I had a pre sunset display of my 1200 W bicycle headlights (12 100W LEDs with 4 inch lenses and separate fan for each). While setting up I could see and smell smoke from the array. I isolated everything as fast as I could but it still kept smoking. It was only later that I saw the scorch marks on the plastic surrounds of the LEDs from magnified sunlight. Fortunately no LED damage because it was not accurately aligned, but it was close. Details on my tesladownunder site.
Wouldnt the sun have to shine in from a "parallel to ground" angle? Because thats where the light is going out. The only way back in is the very same its coming out... but the sun has next to no power during sunset.
Can you explain how this is supposed to happen?
Solar furnace fries LED ... thats an interesting remark and may something to it. Thanks.
But how is it supposed to work? How does the light get to the LED? The lens refracts any light, doesnt matter where it comes from.
Leo Curious
No, it could also be heat bouncing off the pavement.
You can't see Infra Red light but it focuses just like visible light...with a softer focus than blue light.
That means if you park facing West you have heat and light hitting the parabolic reflector from both above and below.
Any photon hitting a parabolic surface will refract toward the Focal point.
These Cob panels have a huge surface area compared to a metal filament.
That means they will soak up a lot of heat while the fan is shut off.
A safety feature could be activating the fan when the temperature rises.
My first thought was "the fan is mounted too far from the LED".
It would be better if the fan was mounted to the parabolic reflector to blow cool, dry air in and VENT across the heat sink.
The cost of most good led headlights are really well made and thought out. The problem is planned obsolescence as they could of used thicker metal for higher heat transfer. And there is room for that little bit more of aluminum would make this last way longer.
I like your presentation and explanation of the whole unit itself. Job well done.
I had a couple of these. Very bright and ‘if’ installed correctly they caused no dazzle to oncoming drivers. The problem is, is that they can be rotated within that securing collar. People don’t know that they need to be positioned in the right orientation. Also those fans have no suppression and could be heard on the radio, all the time, which is very annoying. 👍
I learned that when I put my H7 LED's in last year (2021). Yo be fair it was in the instructions but only refer to those as a last resort. I have had DAB dropouts from phone chargers so I'll have to check the bulbs for RF noise.
Too many people "really" have no concern, or maybe its just ignorance, as to proper installation and proper adjustment, of their headlights. Just because a vehicle sits higher from the ground, does not mean that the headlights are aloud to be aimed farther forward. No!
There are calculated settings for the safety of all drivers.
When was the last time that you, or anyone else, heard or saw any kind of announcement or advertisement stating the importance of proper headlight adjustment?
Check your tires and air pressure. Check your air filters...oil filter...coolant and oil levels.
Make sure your mirrors are adjusted...
I've changed to LEDs on a few vehicles. Some LED units are better than others due to the circuit board thickness and positioning.
The last one I did involved changing to projector lamps and due to the day running design, I modified the earth circuit to switchable 3 ohm resistors (50 watt rating) to reduce intensity and increase lifespan. It also reduces daytime and urban use glare for everyone else just as dim dip systems did.
@@idonotwantahandle2 can you recommend any Led h7 please
I was bewildered at the thumbnail for this for a couple days before finally watching it. I couldn't figure out how I'd wear this thing on my head...
You can clean the phosphor off these with PCB flux cleaner, and you get a lovely royal blue colour which causes a lot of brightly coloured things to fluoresce!!
so it wil emit a light close to UV frequencies.
🤔 I have a set of these shoved in my partners fog lights in her mini because they were useless with 22w halogens I'm tempted to try this now 😂
True, but it's pretty bad for your eyes.
Awesome video!! The fact that you used HD pics instead of trying to zoom and focus is brilliant!! I liked and subscribed for that reason. But your review is very detailed I love it!!
Dear Clive, glad you touched the subject of automotive lights with which I had to fiddle for a while. I have had such bad experiences from small 5watt replacement parking light led to Main led headlights like those.
Often the problem is that the reflector is not adapted to the LED because it is designed to have a small halogen filament in its focal point. Also the life span is not very long.
this is why you should never replace headlight bulbs with LEDs.
The final point you made is almost correct in your lovely sense of intuition. Really though, it's even more industrious than that: The bipolar modes of LED modules that are increasingly common on the Chinese market is a matter of a lack of documentation.
Chinese and American system integrators who make these modules don't always touch their designs. The circuit designer was clever enough here to make it almost impossible to break this from a documentation perspective. It's very easy to publish Input and Output voltage in an Ebay listing, but it requires a proper datasheet or a visual inspection of the circuit card to get correct polarity. There's probably a few different companies using that LED circuit card, provided by five different circuit integrators. The companies that put a module in to a heatsink casing sell to fifteen different wholesalers, in five countries. The integrators offer the same LED in four different headlight configurations, and the sellers retail through nine different brick and mortar stores in three countries. The customer just wants it to work. The mechanic just wants to see the customer happy, so he plugs it in and hopes for the best. The wires won't be wrong polarity, because Toyota is leaps and bounds ahead of this aforementioned anonymous undocumented nightmare and knows how to wire up a car's headlights for proper polarity. So yeah, the Chinese engineer deserves some credit, maybe it belongs to a fourth year engineering student from Minnesota... but whatever the case, the big whoop goes to the guy who designed that circuit card.
That's more insightful than all of the marketing material for all of these products based on that one design, combined.
I love the dual diode per phase idea and will remember to use four the next time the user inserts power wires. They can insert them with any polarity, doesn’t matter because the diodes will route them to the correct spot.
I wish you'd start putting together cool "recipes" of circuits you've backwards engineered. Why should the Chinese do all the stealing; It's our turn! :) I wonder if this light failed simply due to cheap sourcing of factory-seconds binned LEDs.
Everybody steals Bill Gates stole from Steve Jobs. If it wasn't for the Chinese you could not reply to this post.They supply your PC, Phone and everything electronic in your house. These lights are cheap and nasty and you always get what you pay for.
Robert Nitschke don't be stupid. China on my makes these things because they are the cheapest option for manufacturers. If companies weren't so obsessed with ridiculous profits and were more focused on community, like they used to be, all this manufacturing would be done at home, where ever home is.
Every country has the ability to manufacturer everything that China makes its just that their very poor work safety laws and the very very poor wages they can pay moat people allows them to corner the market... for now. I imagine Taiwan and India thought they would always be making the world a electrical goods but look what happened to them!
Martyn, It's just too bad people here in America, and other places, are so obsessed with the cheapest prices. that's why so many shop at Walmart and online at Amazon. Also here in America everyone wants to be rich; everyone wants & expects to be paid top dollar, so that drives prices up from manufactures causing shoppers to look to the East because we're way to self involved. Sure all companies want to maximize their profits, that's just normal business, but the consumer really drives the economy. That's why every year the minimum wage goes up, prices increase, and we have to pay more in taxes. It is an endless hill battle we all climb.
Personally I would be content earning less if all pricing everywhere would decrease too. Keep everything in balance and that would be the best compromise; in my opinion. Also I will always pay a little more for quality over quantity. That kind of mindset across the country would bring a lot of those over seas jobs back home. That would "Make America Great Again"!
@@robertnitschke89 - Bill Gates stole his original BASIC compiler from Dr. Dobbs. Then he had the audacity to write a letter to the Bay Area's Homebrew Computer Club appealing to their sense of morality to NOT steal HIS compiler. Amazing!
@@SherwinGooch Sounds just like the feminists today ! "We are fighting sexism and racism" and "kill all men", "kill all white people".Completely brainwashed ! No logic or reason.
But they can say "Hey Hey Ho Ho" after 4 years of college !
I finally got it! You are Scott Manley and AvE's illegitimate lovechild. Right? They released the shmoo and out came you. :D
The standard halogen bulbs are not polarised as they are just a filament. Some vehicles use common negative and others use common positive which of course makes no difference to these. This is why any replacement has to be universal to.
I did probably 20x the research than a normal person before buying a cheap Chinese headlight set, and I reaped the rewards. I deduced that the ones I settled on were in fact engineered identically to repacked models selling for over $100 on Amazon, for only about $25.
The ones I settled on have an external driver box, rather than internal circuitry. Whatever is in the box allows the entirety of the 4 COBs to be powered at once, thus resulting in very low relative heat on standard beams, thereby maximizing lifespan. I can only assume the high beam setting simply increases regulated current. The 4 chip design allows equal scatter, similar to the original bulbs. These things are incredibly bright, and they've worked successfully for almost 2 years now.
"Light" needs a fan and a heat sink now! Improvements! ¬.^
Oh, great... Candle-flicker headlights.
so you can eat the deer you've pancaked on a romantic dinner table :)
Well, we've had LED flickering cats eyes (lasted about 2 years then replaced with proper ones). You could drive along that section of road with all your lights off at night and still see where you were going !
I never realised a car headlamp bulb could be so complex!! You are a great teacher and what an interesting thing to listen to as well.
You might also be surprised at the design effort and technology that goes into a normal H4 Halogen Globe and the headlight reflector and lenses.
A complicated mix of mechanical, electrical, optical, production engineering and material science.
Toyota used switched ground, instead of switched positive, for their headlights and horns. Effectively, these were wired as "positive ground" circuits, for all purposes. Which makes it very smart for a "bulb" supplier to build an assembly that doesn't care about reverse voltage, for ground or supply. Very smart bulb maker.
This is beautiful example of how todays products are perfectly made to last only just untill their warranty ends :)
why do you think so?
Well, isn't that basically what a warranty is? The company says, we promise you that it will hold at least this long, or you get a new one. Who would be suprised when the product actually holds for as long as the promised?
Everythings on a cobb! the WHOLE PLANETS on a COBB!
R&M
I have no electronics education other than Big Clive and a couple other RUclips channels but I love this stuff. I got to mess with one of those one time and they are very interesting engineering. Love the channel.
the error proofing technique you are referencing is often called poka-yoke and is a sign of thoughtful engineering
Somehow I always end up on these videos at 1:00 AM
I have led’s that look like these, but they are not the high and low beam kind, and the polarity only works one way. I got lucky, because mine work perfectly with my headlight housing. The beam quality is better and lower to the ground than a traditional light, and blinds traffic less! It is possible to get a good LED setup, it’s just very difficult to find a perfectly positioned diode that works with the housing and reflectors.
In my experience of vehicle electrical systems, I found that most European vehicles fitted with H4 headlamps would have common negative and switch the positive to the dip/main beam pins. Whereas a majority of Japanese/Asian vehicles would be common positive and switch the negative for dip/main. I think someone clever thought this through to cover as many markets as possible. Clever circuit arrangement. 👌
Heh, not just that, but the American market, you could have two different model cars from the same manufacture, but one be switched negative, and the other be switched positive. It can make wiring things on cars a PITA at times.
LED Headlight bulbs could use passive cooling via heatpipes, so that even if there is no power available and the vehicle is pointed at the sun, the LEDs will still have cooling enough to survive that inadvertent solar furnace. Alternatively, bundles of *tapered* light fibers could route the light in from remotely-located LEDs that feed into the large end of the light fibers. Sunlight attempting to enter the tiny apertures on the other end of the fibers would not be able to get much light into the tiny areas of those fiber ends, and what light did get in would be spread out to a larger area at the LED end. This fiberoptic approach also relieves the area and volume constraints that make intense heating a problem when the LEDs are powered.
As cool as this is from an electronics point of view, seems like it's far too complicated and failure-prone for the application. Having that sort of fan on something subjected to fairly severe conditions (engine bay heat, engine bay fluids, and outdoor environment) already makes me wonder how viable these are, before considering the lifespan of the LEDs weighed against the amount of electronics circuitry and the fairly sophisticated housing that are essentially made disposable.
I live in a climate that's probably much dustier than these things were in (assuming they were used in the UK) and I have no doubt that fan would start chattering in a matter of months and be seized-up in a couple of years. If in a 4x4 truck that actually goes off road it would probably be even faster.
Yeah, if you're primarily relying on a fan then these should have have water resistant fans or at the very least, get rid of the fan entirely, stick a heat pipe on it and find somewhere on the outside of the vehicle to have the heatsinks protrude from, that way the motion from the car itself provides most of its cooling.
The thermal resistance of that long stalk also seems to be problematic. One might need a heat pipe in there. The design leads itself very well to a heat pipe.
However the 'cool' end of the heat pipe is in teh engine pay, in a location which might nog be cool at all. Just like that tiny fan could suck hot air...
TWX1138 .....You speak of the electronics in this light.. And I'm assuming you're probably driving a car with computerized everything.. From fuel injection and ignition to what ever else..... That stuff is much more sophisticated and complex than any LED driver circuitry! Even a modern day car stereo is more complex....
Brett Ison Gooseknack, I am well aware of the circuitry int the various automobiles I've owned over the years, starting with the very poorly-designed and poorly-implemented Electronic Lean Burn system in my '78 Chrysler, a computer potted in epoxy and then strapped to the side of the air cleaner housing where vibration and engine heat would kill it if the physically-worn engine tolerances didn't make it perform poorly.
The various controllers in modern cars are usually located where heat won't destroy them, or they're especially hardened to the effects of heat. Often that means they're in front of the engine and off to the side where cooler air passes over them, or else they're located through the firewall and inside of the passenger cabin and away from the heat of the engine and exhaust. Additionally automakers both take steps to electrically isolate systems where needed and to test them rigorously to reduce failure due to faulty design.
I am not happy with the direction that modern automobiles have gone. Too many body-control functions are too closely integrated as systems that must be operational for the vehicle to work, and too many formerly optional accessories and systems are now standard and unavoidable. Highly-optioned cars have poor track-records when it comes to durability over the long term, lots of fancy or sophisticated systems break-down over time and contribute to a vehicle being prematurely taken off the road when most of the rest of the vehicle is intact and even in fairly good condition; it becomes too expensive to repair these overly complex systems and a vehicle is functionally-totalled when the cost to repair exceeds the value of the running vehicle.
Honestly, peak design as far as avoiding overcomplicating vehicles while being freed from the problem of poor emissions due to carburetion seems to have been in the late nineties to early 2000s, and even then some vehicles are overly complicated already.
There are a lot of designs available now with passive cooling only, slightly larger heatsinks. Still problematic because you can't attach the rear cover to the lense anymore, and dust will get in, and also LED lights do not work properly in reflector housings.
The failed end of the cob seems to be the one furthest from the main heatsink and fan which I guess makes sense, since that end will be hotter.
While that is a fair assumption, I believe it's more likely due to the fact that the LEDs at the furthest end are the dipped beam (which is used most of the time). The uncovered section is the main beam, which is rarely used, except for country roads etc.
I love those aftermarket LED-Headlights ... we're driving a Toyota C-HR with these modern HIR2 Lamps. The stock ones burned every 3 month. After 4 changes we decided to switch to those LED things and et voila ... 14 month and still going strong.
Except in most countries it's illegal to retrofit without completely replacing the headlights specifically designed for them. So basically your car is nolonger road legal, your blinding other road users and voided your car insurance.
@@user-zt4ry9hm9uI had one with this exact design and I agreed. Its LED position is not in the same position as halogen counterpart. Made my low beam too high, even if I adjust it down, it still doesn't looks right.
I then found one that has its light position that spit out the same beam pattern as halogen one, but a bit brighter, not much. There are many types of these LED bulbs, you got to find one that met the same dimension as halogen one for the same socket.
@@worawatli8952 Best off buying high quality branded bulb's perhaps with a blue tint if you like white lights or if your car was sold OEM with HID, LED headlights as an extra you can buy them used and fit them, tho not always straightforward do your research first. Once done they would be completely legal provided you tell you insurance and have will correct light pattern plus overall better results.
Oh and don't buy bulbs with higher wattage then standard, while they are significantly brighter they are also hotter, thus you can melt your plastic housings, burn out wiring etc...
@@user-zt4ry9hm9u Yes, that's why I bought one that use less power than halogen one, brightness is almost identical, just a bit different light temperature. (It's warmwhite that is in odd yellow, not daylight or blueish one, I hate them. lol) It has worked well for almost a year now, the one that is identical to in this video just last 2 months, really bad cooling system, it burnt itself out. A better one I bought they say it has copper plates under the PCB to transfer heat to the back better than this only aluminium design.
To be completely honest here. I sometimes dont have any interest or care in what it is that you're doing in your videos, I just love to listen to your voice. It is very soothing and captivating indeed. Keep doing what you're doing! ✌
good informative video. loved the idea of the polarity protection. I just wonder how much extra they charge for the polarity protection
BillyNoMates1974 It's a cost saver so they can sell the same "bulbs" to more different cars. They could even put multiple adapter rings in the retail package to further reduce the needed inventory.
With the dual filament ones I've always had the dip beam go first too cos it's got the majority of the work to do for me.
Quite a task getting a LED unit to work at all in the constraints designed for a halogen - I suppose we'll eventually either get a new standard shape for changeable LED headlight bulbs (which will be quite different to H4) or the manufacturers will be putting sealed beam units in.
The problem there is that headlights are contract manufactured items. The cost of retooling (principally new injection moulds), and type approval for current production lights would be bad enough, but when you include recently discontinued models ("new" headlight designs are a cheap and popular route when "refreshing" an existing car model is concerned), it may be cost prohibitive to manufacture redesigned enclosures for older vehicles.
Love the close up pictures for talking about circuits!
I managed to salvage of a couple of carbon arc searchlights that were used in the defense of London during the second world war. I've mounted them on top of my pickup, and have a heavy duty switch in the cab to feed the power from a bank of batteries I pull along on a trailer. If some bastard dazzles me I just turn them on in their face. The survivors never do that again. They were handy once when I was attacked by a zeppelin, the bofors gun I carry round soon brought him down in flames.
The "Vice of Knowledge..." lol
The aluminum housing looks like a mini Mr fusion
*"I NEED FUEL!"*
Auto/Truck LEDs are one of my favorite subjects right now, as I get my custom 77 Toyota Hilux (pickup) ready for the streets again in NM. And though it came with 4 round headlights from the factory I took those out and converted it to 4X6 rectangular headlights in the mid 80s, which were seal beams.
But seal beams seem to be made to go out with time, as I found out when removing mine recently, as the glass was no longer bonded to the reflective back part at all. Any leak and they will go out fast, but I was already seeking the best current lighting and on my way to LEDs. So I searched and searched and experimented.
For a halogen housing type bulb LED, the new Evitek F2 might be the hot set up, with shields and LEDs placed the same place and size, as the halogen bulb filaments. Its rated at 36w, but is actually uses 30w. For design cooling it is like the one Clive took to bits, but uses a copper bar under the LEDs for heat transfer. The light seems to match halogens perfectly in the housings in placement, but whether it has long life only time will tell.
Another solution for old lights like mine are the all in one replacements like these. I bought one to test, but this is not my video. Notice the cutoff like the halogens.
ruclips.net/video/wDJrn0JD_wM/видео.html
There is even a lower priced one (4X6), that looks like chrome on the front, with 45 LEDs and claims 45w I also bought. My testing showed about 14-16w on low for both, and about 36w on high for both. But more of a spot beam without a halogen cutoff, and the light out put in lux at the same distance was about 50% brighter then the one in the video I posted on low and high. The housings on these are massive aluminum shells without fans, and the covers are clear plastic.
The safety on these depends on the correct aiming mostly on these, and the legality is variable according to local laws. No inspections generally means legal if aimed properly for the locale. Where I live it states the main spot of the beam must be aimed to hit the ground no further than 75 feet, in front of the vehicle. And no excess glare or red lights. No inspections in most of the state.
I do not like the light given off by HIDs, and many HID kits seem to be prone to failure in months. The LEDs are a softer bright light, and can be even brighter than 35w HIDs. Dim factory lights or pointed wrong, or both, are huge safety issues.
It is uncanny how those beautiful photographs of yours look 3D (at least to my eyes) even though they are just photographs (and viewed on a normal display of course)! Especially here where the capacitor and coil are relatively high above the PCB.
A lot of smaller motorbikes run the headlight on AC, pretty much directly off the alternator coils. That's more than likely why this LED bulb is made to work regardless of polarity IMO.
These would have been great "back in the day" when I used to ride a Honda Cub. The very "non-Halogen" bulb was less effective than a torch . . . . . . (and used to blow very frequently!)
Still the same on many modern bikes.
I.e.: Honda Wave / Honda Innova
Some older vehicles have a ➕ as a ground, so these lights will work on those vehicles as well.
@@bara2ban Not just older vehicles. Some newer ones too. My car switches the common (+) through the light switch, and connects the high or low beam pins to ground.
@@jussapitka6041 not sure what kind of car you have, but don't forget that your light switch is only activating the relays and from relay could send a + to a bulb.
Wanna check what kind of ground you have? Take a voltmeter or bulb with wires, touch one end on the vehicle body and other directly on the battery.
As someone who has installed a few aftermarket HID systems. That multiple polarity would've come in handy in the past. Most of my HID installs were 9005 (high beam) and 9006 (low beam). The first systems, the 12VDC harness was already wired up. Which was a bad idea. Because I had to swap the wires around to make it work. When I removed that first HID kit and installed in in a different car, made by the same manufacture but just different model and year. I had to swap the wires back.
Both cars, obviously, were factory halogen. (9005/9006 are never HID). With that said, car manufactures do not care what polarity the light harness is, as it feeds a halogen bulb.
You must look at the other point, just by changing the ring on the outside they can sell it as other type of fitting. No fuss.
i was surprized to see the LED coming with an actual H4 connector, normally they come with 2pin connectors.
sayan das if a LED for automotive use comes with 2 pins. It’s not for a set up like in this video. This video shows a LED where low beam and high beam are built into one “bulb”. Where as a 9005 and 9006 have different bulbs for the low and high. A set up that has four bulbs, 2 low and 2 high, only 2 pins are needed for each bulb. For a setup that uses two bulbs, low and high in the same bulb. 3 pins are needed. A common, a low beam and a high beam pin.
It sounds nice, but it is really a pain in the rear. Some vehicles may not have an issue, but i've run into several cases where LED headlights have caused issues with the vehicle electrical system. Namely with the high beams and fog lamps. I had an 01 Ram with LED housings, at first they were fine, but after a few months, the high beam indicator started dimly glowing all the time, and anytime I tried to turn on the fog lights the high beams came on. The reason was due to the lack of a low resistance filament between battery positive and the high beam rail. Instead it was now a diode bridge with small resistors to pull the rail high to be compliant with newer floating rail systems. When the under rated resistor blew out, the fog relay that draws battery voltage through the high beam rail now had to source its current through the quad beam relay and dash indicator.
I've seen a couple fords whose high beams would never shut off, I've seen Chevys where the headlights would never shut off (Some DRL issue?) So I just said screw it and trashed the LEDS. Its really just a pain.
Yeah but leds Are todays technology
I assume you also angle the reflectors up as well to maximize on the glare aspect of HID, further blinding other nighttime drivers.
I've heard from mechanics that the two LED strip style will fail quickly. The triangle LED style is suppose to last longer.
I love your blown up pictures and your easy to follow circuit breakdowns. I've only watched a few videos but they've been a lot of fun.
Could you turn it into a powerbank powered non-death camp light with optional fan setting type of thing on video?
Seems a shame to not use that nice machining for something and it might even come in handy.
I think I know why they designed it so any polarity would work. When they sell these as a 9004 or 9007, they are the same part, but a 9004 and a 9007 use different pinout.
That machined housing with the heat sink veins is remarkably attractive. Looks very pleasing to the eye, and well machined.
On the subject of vehicle High Beam LED lights, quite a few vehicles use resistor packs to lower the voltage of the Halogen bulbs from 12 ish volts to about 8 volts for the Daytime Running Lights; this is great for Halogen bulbs but nightmare for LED's. One LED manufacture told me that they cannot make a car headlight run on dual voltages, but I think with a simple-ish diode arrangement a LED High beam light could be created to have say the 6 LED's like mine has for 12 Volts (High Beam), and 2 smaller LED's for 8 volts (DRL's), making the Headlight more of a two in one LED Light that can do High beam and DRL's with a minimal of fuss. Since we are closely approaching winter, it would be great if you could re visit this and shame Car LED Light manufactures :-)
I have brought tons of led bulbs specifically 501 led bulbs and they always start flickering my theory was the absence of a constant current driver which is funny because yours appears to have this.
I got to get me some CFL headlights... shame they never really caught on eh? ;-)
CFLs are old hat - REAL headlight performance enthusiasts use carbon arcs. I just tow a small generator behind to carry the necessary generator-set...
@@railgap Intrigued by the term 'generator behind'. Thus far my only use for it would be as a description of my post-curry gas vent.
@@railgap I bet you need long arms to adjust the Carbons! (Ex Projectionist here!)
No one uses HID or carbon arc anymore hahahaha jesus are you a dinosaur... Laser projectors are the latest ones. One of our cars has them. Interesting and a lot more reliable than replacing leds or hid ballasts.
Cfls make better halos than leds do.
Somehow I missed watching this video four years ago, but not to worry, I just did watch it. Interestingly enough, your remark about reducing the voltage on the LEDs to prolong their life is so similar to reducing the voltage on an incandescent lamp, therefore prolonging its life.
Thank you Clive. Just made me realise these lamps make a great source to salvage components from.
Thanks for this amazing video! Do you think it would be possible to add a potentiometer into the circuit to make it dimmable? (for a diy DC light)
Not good on circuit schematics or electronics in general beyond really simple stuff. But Possibly substitute one or all of the high current resistors might work.
100% space allowing. fit an adjustable buck converter to the supply. As seen on video Clive reduced the supply voltage at around 7.50 in video from the bench supply to dim down the light.
Must ask lads in local garage to keep any of these bulbs they replace. Great source to salvage various components. Heat sink, fan and various smd components
Thanks Clive another very interesting video.
That is as stated a H4 lamp and those are almost always found in reflector type headlights. But the full rectifier making it polarity insensitive is an important feature since there are cars out there that feeds the H4 bulbs through the common and then selects high/low by grounding the high or low input. Subaru has that solution. So it's not just with oddball British cars with positive ground/earth that this might be a factor to count on.
8:35 The reason for this sophisticated diode arrangement is because many vehicles use ground controlled headlights instead of the most common which is positive controlled. Ground controlled lamps will always be connected to B+ and are grounded trough circuitry controlled directly or indirectly by the low beam high beam switch.
Yes, I had that very issue when replacing Sealed Beams with Halogen Fittings on a 1980's Toyota.
It caused the high/low beam relay to lock into high beam mode if you select high beam.
I had to install independent relays in the High Beam circuit.
Remove one of the 0R250 resistors to reduce the current, reduce heat and extend lifetime a lot.
That did go through my mind as a possible life extender.
I noticed it isn't three 0R25 resistors. It's two 0R25s and one 0r22. Probably not a huge difference, but slightly more current.
Yes I saw that too. I guess it was to fine tune the current to a specific value, or it's a mistake, or they didn't had enough 0R250 available in the factory...
It almost sounds like Clive was in love
European manufacturers usually use a live switching system for dip/main but many Japanese manufacturers use a switched ground method. They feed 12v to the common pin and the the dip switch grounds either dip or main as required. Hence the need for a full bridge rectifier in the unit.
Nothing better than a fetching pink colour anodized alloy cnc offering one must admit!
"Oh, blimey."
5:00
I was thinking for sure we would get "bonus footage" and Clive would have hacked them in a way got RGB out of them, but not the dodgy quick flashing the nice Slow Rolling RGB. Great video.
Pink headlights in cars are forbidden.
Frank Gormanns Not if you have the right paint job (yellow, red or black/white).
John Doe, yeah, right.
Seeing some reviews of LED headlamps have kept me away. The only LED lamps I have in my van are backup lamps.
Very good descriptive narration. I like the way you photographed it and blew it up so we could see the componants. That's coming from a non-electronic speaking auto mechanic, or should I say "limited electronic speaking". I've been switching over to LED's in my cars that can be retrofitted (due to space or type of bulb limitations) and I like to know how they work and now I know the degrade over time. I have automatic headlights on one of my cars that I switch off when they aren't needed to preserve the LED bulbs. One thing, I have found that a lot of manufacturers of LED replacement lamps are starting to place the LED element in the same location as the original Halogen filaments so the beam focuses correctly off of the reflector and you don't end up with a scattered beam. They work much better. I think the one you dissected may be that type. Any LED replacement will work in a projector type housing/lens, from my experience, and give you the correct flat focused beam.
Leds dont like heat. That's why I prefer old fashion incandescent lamps next to that hot engine baking in summer sun. Those tiny cooling fans cant make hot air they suck in any cooler.
Good points. Moreover, if the fan uses a cheap sleeve bearing, it is most likely the first thing that will fail, causing the LED array to fail as well, unless it has a temperature sensor and over-temperature shutdown circuit. Using a maglev bearing fan might be too much to ask of the vendor.
With no cold airflow the effect of all those fins and the fan would be pretty limited. It's just recycling the same engine bay heat. It's not a great idea and halogens last so long I don't see much need for it.
Closed enclosures, lots of heat needing to be dissipated, small heatsinks, not the ideal situation for retrofitting LEDs really... :\
The fan fixes all that.
Spiritpoweredinternet Sealing it up would prevent repairs and also prevent the fan sucking the moisture out of the headlight and into the warm engine compartment. It looks like you could solder in two fresh COB boards, put it back together and use it for another 2 to 5 years, using nothing but a screwdriver, a soldering gun and some thermal grease (not braking grease though).
Meh. I saw that fan and thought, 'hmm, LED headlights, 2 steps ahead, but a mechanical fan to cool? One step backwards'. Steampunkishness.
Until the fan stops....
it's not just the heat sink/fan. The thermal resistance between the diodes and the heat sink is likely large enough that it will dominate the thermal behavior. A heat pipe might help, but I question whether any manufacturers actually care about thermal design.
If they cared enough to do a cursory thermal analysis, would they then bother designing in any non-negative safety margins? I'd be willing to bet that thing has junction temps >120C at 25C ambient -- just like every other high power LED lamp product I've ever tested. Add to that the fact that it will typically be operating right next to a radiator at >>25C, and add to that the accumulation of dirt and (in my case, gravel dust and wasp nests), such a product will live a pitifully short life. The longevity of the fan itself is kind of moot.
I have XKGlow devil eyes in my car and I absolutely love them! The original ones from the company did fail in about 8 months with the same sort of flickering issues, but the replacements they sent me had a design change of some sort. I would have liked to take them apart to see what exactly was the issue but the requested I send them back Love your stuff bigclivedotcom and thank you for making everything interesting!
What goes round comes round. I'm an old man and I remember quite clearly when halogen light bulbs were introduced in the mid-1960's (they were called quartz-iodine bulbs then). Our local car accessory shop had a pair of auxiliary lights, made by Joseph (Prince of Darkness) Lucas, mounted on a display stand and working. We were amazed at just how intense and bright the light output was, especially compared with the "fag end in a jam jar" lights fitted to most vehicles in those days. I found that if I looked at the light for long enough it began to take on a pinkish hue. No dual-filament bulbs at that time of course; it took several years for the technology to evolve to allow manufacture of these. Now, compared with LED light sources, these halogen lights look quite yellow and feeble, much like the old filament bulbs in the 1960's...
I hate LED and HID retrofits equally. Most of the time, they blind me at night. Just as bad as using highbeams. I always flash the worst offenders. What the hell is wrong with replacing a standard bulb with another standard bulb or for a high performance one if you are concerned with quality of light?
I have an HID Retrofit in my car, never once I got any complain. My brother has H7 hid leds in regular headlight ...damn it's not very good. But regular HID on a regular headlight is a nightmare
I aim them properly,as much as possible, but you're replacing them cuz the original isn't any brighter than when candles or gas was used with a reflector.
I had to add a led retrofit to my truck because the lens were soo fogged, replacements cost a pretty penny, and high brightness bulbs drew too much current that it would heat up the switch (no relay in this vehicle) and cause the bulbs to flash on and off which is no good.
agreed
Typically a retrofit is refereed to swapping in the proper projector and bulb into a standard headlight. It gives you the same output as high end models and doesn't blind others. What is being shown here is plug and play garbage, better know as poverty lights
The light pattern from these is so awful they need to be prohibited from sale. The reflector is designed around a specific position for the light source, these type of bulb through all of that engineering out the window. The light pattern and cutoff is atrocious and potentially blinding to other drivers.
Not if they are set up properly as a lot of people don't think of that and just put then in.
Interesting vid. The three grooves on the house you mentioned allow the h4 adapter ring to be removed without force. If you had twisted the silver h4 base the dimples on it line up to the grooves on the alloy housing and it separates easily.
I always wondered how the head lights worked when I turn the light switch on ! It was because of the QX9920 all this time ! Bloody genius !
I thought about adding some of these to my truck. I think I'll stick with the incandescents for now!
Indeed ... this one tried, but a better way of cooling the LEDs is clearly needed.
If you do get these (they're actually pretty cheap now) then also keep some halogen ones as spares in case the LED ones fail at an inappropriate time.
Also keep in mind they aren't road legal (at least not in Europe) - so they're great, but only for off-road or track use.
they dont focus properly and you will fail your mot and notice on the road anyway
what is the point of led in a truc? it's not like you would actualy care about saving power!
AFAIK it's illegal to use retro-fit lights like that in on public roads in EU.
You are right, EU is good at banning things. I can even buy these where I live, on the other hand, there are 100w xenon retrofit lamp sets to buy everywhere. Are they so much safer? Or has the EU not found out about them yet?
AFAIK retrofit xenons are also illegal. Retrofit LED lights are not banned, you can buy them for private and track use no problem - even Philips has them on offer. The issue is that everything that impacts road safety has to have ECE approval and retrofit LED sources don't have it as of yet. Retrofit xeons on the other hand were proven to be dangerous (blinding other drivers) and will probably never get certified. There are some cars that you can get ECE approved xeon reflector assemblies for (usually when manufacturer offered xenon as an option, and they require replacing the entire assembly not just the light source) but that is not what I would call retrofit.
I can not find Philips led for sale.Has searched for H7 Philips retrofit. Philips only says they are illegal.
Only available on eBay in the United States but they will be expensive shipping and duty etc.
So you mean they sell within the EU somewhere :-) Living in northern Sweden, dark 6 months 1.5 meters snow o no police who care about what light you have on the car.
You can only do it if the entire lamp enclosure is specifically approved, otherwise it's illegal (ie. you can't just replace your halogens with leds).
Peter Johansson these are also technically illegal in the USA, the DOT doesn’t allow this sort of headlight modification, but many states aren’t as strict so there’s no one to enforce it.
These are also typically dimmer than the halogens they replace.
There's a rectifier because many old motorbikes use ac voltage to power the headlights so it makes them compatible with those bikes without doing any wiring or dc conversion .
It would be awesome if you put together a collection of some of the most clever designs you have come across over the years.
Wow, 30W in about 0.5sqcm. That's considerably more than a lot of CPUs, and CPUs have way better cooling. It would have been interesting to measure their temperature after they had been running for 30 mins.
Paul Grimshaw Although cars typically have more airflow (due to driving at speed) so it probably evens itself out unlike a CPU which is stationary in a box with other hot components.
Also, a CPU turns almost all of that energy to heat. An LED shoots a good portion of the energy out as light, so has less heat to deal with.
Oh yes, i am pretty sure there is a lot of airflow going inside my headlight. Also dont forget we fill up our headlights with headlight fluid from time to time.
This is a good explanation.
No, LEDs are not that efficient in absolute terms. The vast majority of the power, typically over 80%, still gets wasted as heat.
Living up North ,I was told dont use them in snow conditions because they tend to create white out conditions in a snow storm. Which is sad because my Subaru Forester goes through headlights at an astromomical rate. With it being the middle of April and we are STILL getting snow, those would be a poor choice anyways. Norther Michigan is called that for a reason, Northern...mabe should have been called Artic region south instead.
Also don't use white in fog. You can get different color temperatures though
Check your alternator voltage (should be below ~14.5V) perhaps the regulator is fried...
Going through lamps is either poor light bulbs ( buy Osram but avoid the blue tip versions as they are crap, the brown or black tip ones last) or poor connections in the socket, or just a bad headlamp mount that allows the light to vibrate too much. I get 5 years plus on my car, and I have headlamp bulbs that are over 10 years in use in it. If you are using them as DRL then yes a year will be about the life, just buy a box of the right lamps and keep it for use.
RC Hobbyist Extreme had them in Forester (great car by the way) and they worked great. Only snag was the radio interference from those fans.
That's abnormal in my experience...
I live in interior Alaska.
My folks have a '12 and I don't think the headlights have needed changing for 4 years.
I run an '02 forester on a set of yellowspeed dps coilovers which are about as close to comp grade drift shocks as i could find in budget locally. The front end is mostly wrx/sti bits that corrected suspension geometry and some strut tower braces and modified frame braces for stiffness because i was popping windshields with frame flex and got sick of it.
Have to change headlights (sylvania silverstar ultras the last few times) every 1 - 2 years or so, if one goes i do both.
This said, my ride comfort could be described mildly as 'spine shattering' and I've got a tendency to drive it appropriately. It gets off the ground not irregularly.
could be an electrical issue or just plain bad luck. Also the retention clip that holds the bulb housing in (depending on year model) does get weaker the more you have to undo it and can allow unwanted rattling which definitely would destroy filaments regularly especially if you've got good washboards around your area.
my personal fear with led's is that the drivers will get fucked by the horrible brine they put on our roads or just normal moisture since I have no skid plate to speak of and a lot of our roads don't have that pavement stuff I hear about.
best of wishes and sorry for the ramble.
Great video. Very informative.
These 6 pin buck regulators are very common. Many different brands. They all work about the same no matter which brand.
I use my cheap Android tablets to read books. Often even the lowest light level for the LCD is too bright for dark rooms. Plus the brighter the LED backlight the more is sucks down your battery. So I get out my guitar picks and pop open the tablet. It's pretty easy to locate the 6 pin buck regulator. The backlight wires go right to that section. And the current sense resistor is going to be a large one or as in the case above, 3 in parallel. You can assure you found the resistor if one end is connected to ground and the other connected to a pin on the chip and the transistor. You can always turn on the tablet and observe the voltage on the current sense resistor. In this case the data sheet indicates 0.25V. And 0.2V to 0.6V is typical for these chips depending on the brand. Or find the data sheet which can be very hard for some of these Asian chips. I congratulate Big Clive at finding the data sheet.
Remove the resistor. Measure it. Replace it with one that is 3 to 5 times higher in value. (You do have an assortment of 1206 chip resistors don't you? You can always stack up some 0603's.)
Now your tablet's lowest brightness setting is much lower and easier to read in a darkened room. The highest light level is also lower so you may have trouble in bright sunlight. But I don't read in bright sunlight anyway.
There is an android app that modulates the backlight to much lower levels by switching it on and off rapidly. But I find that the app really sucks down the battery because the CPU is having to run so hard to switch the back light on and off that fast.
Really pretty casing... you could turn it into a fancy funky flashlight, lol. Definitely stealing that polarity protection
I don’t get it. What advantage does this have over a simple 12v halogen bulb?
Higher intensity to dazzle your foes.
bigclivedotcom - oh, so they are brighter?
They give the landfill some violet hue, they are effective wallet vacuums, and they annoy other drivers.
for2utube - hahaha! ;)
They last a lot longer when driving in the bush / back roads. Have a set of xhp50 based bulbs in my work / farm truck. Used to kill a 9004 set every two weeks. That's $40 a set! The leds aren't much brighter, and distance is equal, but that's what the roof light bar is for.
Also replaced the bulbs in my sled and quad. Same problem. Halogen can't stand up to shock like LEDs can.
Also replaced a set of 9006 high beams in my car. I do a lot of night driving. A set of halogens would only last 3 months. Again, cree xhp50 droppin. Brighter with equal distance. Been running fine for more than 2 years.
Ignoring the legality of these...... Anywhere..... Mose retrofit stuff I've seen is absolute junk. They don't last, they have horrible light patterns usually, and on the occation they do work, it's typically ungodly expensive.
Silver Star Ultras and some auxiliary lighting is more than enough for 90%. Someone wants to play the high beam game? I have 6000 lumens of spot lights as a deterrent and they light up a country road for a good 1/2 mile.
Herpn Derpn That's a great idea. Head on smashes are great fun.
chris barrett
I think it's really more of a Honda deterrent. If you see on coming high beams in dense traffic at night, it's a safe bet it's a 05+ Honda Accord/Civic. Failing that, it's a 2010+ nissian Altima.
or a german badged knobhead.
not illegal at all in canada at least ive been pulled over by the dot which makes the vehicle laws and they just check to make sure your headlights work they could care less what they are and 6000 luemens thats cute i have 2 40 inch light bars at 12000 lumens a piece plus led headlights in my lows and highs which can be on at the same time
Tyler Baldwin
Sure, 6000 lumens isn't a lot, but it's more than than enough to convince a Honda driver that their high beams are on. It's also adequate to light up the roads in the country near me. Lastly, they fit neatly behind the grill of my square body Chevy.
In the US retro fitting is barely legal and using "off road use only" lights is illegal on public roads. Ever see the smiley face covers on old KC Daylighters, they are there for legality. You may not get pulled over for it, I haven't, but I only use them on back roads or to blind people trying to blind me. And most cops have better things to deal with unless you are being overly obnoxious with them.
For fun (I'm weird like that) I do have 2 army surplus VSS-1 carbon arc search lights. If I was in the business of causing permanent blindness I'd mount them to a rack in the bed of my truck. They come in at just over 1,257,000,000 lumens @ 100 amps a piece in normal power, and in emergency power 1,885,500,000 lumens @ 150 amps each. They have a range of over 5 miles. The beam can be run from 7.0° in wide to 0.5°-0.75° in narrow. It was built to find planes in air and illuminate battle fields.
If you happened to look into it, it would be like the scene in Indiana Jones with the ark of the covenant but with less skin melting.
I could be wrong, but I have a theory regarding these relatively new products coming in from China and regarding future products. I think the reason why the Chinese are so successful is partly because of their ingenuity and originality when it comes to manufacturing. They are clever, highly educated and creative people because Chinese culture is so different, that the world of manufacturing is getting a boost from this culture being applied in this way, and I think the old world of manufacturing have a lot to learn from these new kids on the block!
Ones I use have a glass outer casing over the LEDs, and the 3 slits you are talking about are under the glass so some air travels past/through.
"Amazing"?? It's obviously a piece of crap. A fan and power supply in a headlamp? This is way too complex for use in a car. How much more efficient is it than a conventional lamp? And why the need to save power in a car anyway? It doesn't appear to be reliable? Better off with halogen headlamps.
acoustic61theres noticible difference in lighting in a led vs a standard globe. I run led headlights in one of my car with a projector lense and i can see atleast a 30% increase in my eBay LED'S over the way more expensive globes i ran from a reputable brand.
Plus leds show pure white, which looks great. However white doesnt cut through fog, however that is no issue for me. There hasnt been fog in my area of Australia in 10+ years.
HID headlights are great too unless you're the person coming from the opposite direction who's blinded by the light. I suspect LED lights would be as bad or worse than HID because of the directional emission of LED light. LED street lamps around here are retina burners, and they're not aimed directly in my eyes.
In the USA we probably couldn't use something from ebay. Because they likely aren't DOT approved.
>And why the need to save power in a car anyway?
It dramatically increases how long you can go with your headlights left on before they drain the battery too low to start. I once went 4 hours at a job site and forgot to kill the lights and it still started right up.
Also all power used has to come out as increased resistance on the alternator and in turn increased resistance on the belt, and in turn, increased resistance on the engine, meaning power usage == fuel usage. Small, but power isn't "free" in a car.
These should be banned...all they do is blind other road users!!!
They technically ARE banned.
A lot of the newest cars in my area are already blinding straight from the factory
Yeah especially with those "brights auto-off" feature that barely works. Supposed to detect oncoming directional light and dim your brights for you, except it never does, and trains us to rely on it.
J Walker that sounds like such a pain in the ass. New cars are nice, but there's just too much tech these days for me.
J Walker the civic type r (and probably standard civic too) has auto high beam too which can only be turned off if you turn all the auto headlights off which kinda renders them pointless... But it's a nightmare when you end up flashing random road users who are just far enough down the road to not register on the system
LED aftermarket bulbs for the headlight aren’t usually polarity sensitive, but are dual voltage which makes it easier for 1 bulb different vehicle ( car 12v or truck 24v) 10-30vdc. Some can actually be brighter than standard halogen equivalents but won’t always provide a legal beam pattern.
Okay that’s very elegant. So now I understand why they’re still as expensive as they are. I have always been put off by the fact that they are quite costly and don’t always seem to last for very long. That and the fact that I cannot close the rearward bulb changing access door to my CRV headlights when I fit them because of the fan and so they will get moisture ingress issues. Can you easily modify them to a lower rate for increased life?
This circuit while is fairly simple and clever does have a easy fixed disadvantage, no output capacitance. While the switching regulators job is to control the average current through the LEDs it does it by constantly turn on and off and adjusting the duty cycle to maintain the average current. The current flowing through the LEDs when the inductor discharges will spike as the inductor dumps through the free-wheeling diode and then falls as the energy in the inductor is consumed. The spiking will cause stress of the LEDs that are already being run at maximum output. A simple capacitor across the LEDs would smooth out the current flow and keep the LEDs lite for a larger portion of the cycle. That would also reduce the noise reflected back to the input which would allow for a smaller input capacitor and lower losses in the input diodes. The second thing that would help is to use a MLCC capacitor in place of the electrolytic capacitor which would give the entire circuit a longer lifetime. Electrolytic capacitors are not long lived components and heat that they will be subjected to in an automotive environment will shorten there lives considerable. Failure of the input capacitor in this type of circuit will cause the switching regulator to operate much less efficiently and lead to much higher surge currents as the regulator tries to compensate for the inconsistent current flow through the load.
The really sad things about most LED lighting intended to replace existing bulbs is that the form factor is a poor fit for LED life. The LEDs should have more space to dissipate heat and prevent the thermal stress that causes the LEDs to break contact with the PCB. A few more LEDs would increase the cost slightly but would allow the desired light intensity while running each of the LEDs at a lower current that would improve the life span. The optics for the LEDs needs to accommodate for the different type of light source so it does not blight people. The electronics and the LEDs should not be heating each other up and using a fan of such a small size is a joke and it just another lower lifetime component.
Unfortunately, the reality is that LED lighting can be design to be very reliable but because manufacturing cost is the motivating factor, manufacturers would rather save a few dollars even on components they charge premium prices for. The devices will typically live long enough to get through the warranty and that is good enough for them.
If anyone is looking to upgrade to led headlights things to look for are: Narrow leds, copper heatsink and external drivers. This style will get hot and cook its driver. And led themselves will cast a unfocused beam because they are too wide
Love the DFW thing! I do alot of maintenance on electric guitars for people and always use DFW for Doesn't Fekkin Work...
A huge problem with most COBs is that the LED arrays are parallel connected. Thus, any temperature difference across the array is amplified by thermal coefficient instability. This leads to thermal run-away and failure.
It would be much better if the diode arrays were in series. A COB temperature sensor input to the voltage/current regulator is desirable. (Better to have slightly dimmer headlights during a heatwave, than permanently dimmer headlights after damages.)
Also, if the thermal conduction was done with heat pipes, the LED temperature would be much lower.
Wow, great video. I would love an extra video where you show us how you figure out what everything is doing. You could post them on a separate channel, if you're concerned about it affecting your view statistics.
It just seems to be a lot of stuff (technical term there) to make light from 12vdc supply.
Thank you Clive for all your investigative reporting.
Replacing the core with a vapor tube would transfer the heat so much better!
Oh! Fan ! So it is because it breaks down very quickly, headlights can be provided in Iran, none of them have a fan, it was great, thank you👏👏👏👏
take a look at your video.. the photos look like they are 3d. they look like they jump out. love it
Hey Thanx Clive! it was very interesting to see how these are put together, and how the circuit works. a friend of mine just bought a set of them for his Honda, I had never seen these b4.
I did not realize this was for a vehicle until I read the comments. I was thinking that was a very large and probably hot "Head" lamp, perhaps for hunters or miners.
Here in Australia, I'm not aware of any aftermarket LED Headlight globes that meet Australian Design Rules (ADR).
It's actually illegal to install H4/H7 Aftermarket LED Globes in the Low Beam housing because of the lack of Compliance with the Regs and poor beam pattern.
It is however okay to put them dipped light housings such as High Beam or Driving Lights, if they are switched correctly.
Personally, I have 25 watt Fanless LED H7 fitted to the High Beam Fittings, adjusted correctly and throwing heaps of white light in the right places.