The 48W calculation was determined by multiplying the shipping carton size (8 pcs.) x the wattage (6W) per unit. I don't see why that would be difficult to infer.
I have the 6-led UV panel you did a video on years ago, from the same brand, and it likely uses the same LEDs - I've sacrificed once of the LED chips and and additional one of the phosphor domes/blobs. It appears to have two LED dies on each chip, one bonded with two wires to each end of the module, and one bonded directly downward with only one bond wire leading to it. The 2-wire die (presumably 405nm) lights a visible purple at a lower voltage (just under 3V), and the 1-wire die takes greater voltage to light up. The 1-wire die looks identical to the large one in a 365-nm LED flashlight I recently bought - the surface of the die itself seems to phosphoresce in white, and any color from the semiconductor itself is invisible. Looking at an individual LED module under magnification while powered at about 3.2V makes the two different dies obvious without being too bright to look at.
I wonder if the 48W on the box is kind of like with normal LED bulbs where they say "60W" very large and then "...equivalent" much smaller, and the light output is equivalent to a traditional 60W bulb.
The chinese are sneaky with model numbers like that, that will make you think it's a power rating at a quick glance. I've ran into that several times with their products before. No more trickery on MY behalf anymore though.... I've learned.
though I had some problem with sea water It also th-cam.com/users/postUgkxa-FNYUOM93a388gi9a4brtSCEVmrHgJH land for finding any things very easily. (thought it would work as normal due to it being water proof within certain parts of the detector), on dry land and sand worked well. My first one, so still have lots to learn
Me and my friend, we sometimes use such gels for nail extension, and in my opinion these substances, especially when introduced to machined nails and skin, can get into the body and cause some problems down there. And yes, because of people like Big Clive I already know the difference between the ionizing ultraviolet subtypes starting at UVC and more safe ones of it. I mentioned earlier that I tried playing with some UV-cured resin (bought a big bottle of it), and I have to say in constant UV it solidifies mostly in like ⅔ of the curing period, and if you don't want it to have sticky surface, you _need_ to treat it with UV much longer: when it's mostly not polymerized, it absorbs photons easily and across the whole volume, but the more it solidifies, the less efficient this process becomes. In short, you need to prolong the process until it is not sticky.
There are two types of photoinitiators; cationic and free radical. Cationic photoinitiators are used when light cannot reach all of the resin, as here, light starts a chain-reaction that keeps going on in darkness. Makes storage more complicated, so I guess that nail-polish is generally using free radicals. These are inhibited by oxygen, so if you have a nitrogen supply and put a flap on the opening of the UV-unit, you can just get rid of the oxygen in it and thus avoid the sticky surface. Cationic photoinitiators can for instance be inhibited by water, so here humid air is problematic. It's certainly not worth the hassle if you're just treating your nails, and you should make sure that you don't use so much nitrogen that you run a risk of asphyxiation, but I've used such a modified lamp in a lab to do some quick tests with UV-inks and it worked just fine.
As someone else mentioned, I think the outside being sticky is likely due to oxygen inhibiting the curing process, leaving some uncured resin on the outside. One thing I've tried recently for using UV cure resin for filling in some etched metal is to do a quick exposure just to firm things up a bit, and then proceed to do the main curing by putting the design in a little tray and submerging it under a thin layer of water, and then doing the main exposure that way (so it's not got the oxygen from the air to inhibit it). So far doing the main curing underwater has prevented that outer layer of sticky uncured resin like I had been getting previously. That's relatively easy to do with a nice flat thing you just need to expose from the top, but it's probably not exactly easy to do with larger things. Perhaps if you need to cure something larger 'in-place', you could try and spritz the outside in something like VG or PG to create a protective barrier layer which you could wipe off afterwards (although I've no idea if they'll mess it up in some other way).
@@bluesatin tbh, first I tried washing it in IPA, but soon discovered that solely prolonging the exposure to UV I get rid of any stickiness. For whatever reason, it's the simplest method for me so far, but I will keep in mind those advices you folks gave us. Experimenting is fun indeed! Thanks!!
@@jkobain Ah yeh, I assume just blasting it with more UV over time will eventually overcome the oxygen inhibition issue. Mine still tended to be sticky after quite a long time exposing normally, but the water trick seems to be very easy/effective in preventing the issue for my use-case. I assume there's probably a bunch of different additives that various UV resins use to try and reduce or prevent the problem, but trying to find any info on that sort of thing is a bit of a nightmare.
@@bluesatin What also helps is just using more power; the reaction is faster and leaves less time for the oxygen to interact with the resin. When I switched to an industrial lamp, I had no problems with sticky surfaces anymore with that partiular ink - though there are UV-inks that require an inert atmosphere even when you blast them with a lamp that has 180 W/cm.
They may be made specifically for curing nail varnish on nails, but they’re *perfect* for PCB reworks (specifically when you need to cover over exposed traces with conformal coating).
My roommates had a box for an old phone cover in a closet in the house that I discovered that came with a UV cured screen cover and the package actually came with a USB UV light like what you've got there. It's not as big. It only has 6 large LEDs in it, but it has the same purpose. To cure UV setting resin. I nabbed it. It's disposable. It was to be used to set the screen cover on a phone and then be discarded. Incredibly wasteful, but I rescued it. It's labelled Whitestone dome glass.
the more "extreme" version of that is used for phone display glass replacement (if the glass is cracked but the display itself underneath is still fine). You get the original glass off, clean up the display, blob on some UV glue commonly referred to as "UV LOCA", set the glass on and make sure there are no bubbles or uncovered spots between the LCD panel and the glass and if you're satisfied, you cure it with UV light for several minutes. When done well this will be indistinguishable from an original
@@Knaeckebrotsaege The HARD part is getting all the old glass and glue off without damaging the LCD underneath of it. Ive done it a few times, and then said "NO more" to that ugly task.
@@davelowets In some cases like with Samsungs it's still worth it, mainly because a replacement service pack (screen pre-attached to midframe) will cost you more than the entire used phone in functional state is worth on the used market when the phone is more than 1-2 generations old, despite still being very much usable. if the choice is 200eur for a service pack screen vs 20-30 for the glass + extra work, guess what I'd rather pick?
My wife has one of these, it says 365+405nm, I have a 365nm and a 395nm flashlight and the 365nm light does not cure UV resin better, it is actually slower by quite a bit, might just have been marketing and now everybody says they have double LEDs not to lose out. The LEDs in the one she has have two light sources, but more like 385+405 than 365+405. The 48W is an equivalent figure, as in equivalent light to a 48W UV tube. Older curing stations had the black UV tubes. I have also seen some with the mercury tubes, those will definately give you cancer.... Thank you for showing the insides of it, I am not allowed to open it.
1:35 I have a curing/cleaning station for my resin printer that has both 385 and 405nm LEDs and the difference is clearly visible when lit. The difference between 365 and 405 is even greater so it should definitely be visible.
And your printer is also probably covered by an Orange shell to block that light so you don't damage your eyes. Lots of newer LED's use ultra Violet light leds in conjunction with phosphorescent materials to convert that dangerous UV light into visible light. My point being you can have 2 different wavelengths of ultraviolet light hitting identical phosphorescent materials and producing the same light.
@@buddyguy4723 But why on earth would they be converting the NEEDED U.V. in this product into visible light? It wouldn't cure nail polish if it did. So, yes, there SHOULD be 2 easily distinguishable LED "colors" in this unit if it does, in fact, emit 2 different wavelengths of U.V.
Note that your eyes can't see ultraviolet. What you're seeing is a difference in the phosphor they use to add some visible light (so people can tell when it's on).
I expected you to investigate the LEDs, to explore the function of that extra piece of silicon in it. No problem, @restorer19 explained it in the comments. Fun fact: The power rating of products like this is not depicted in the SI unit 'Watt'. The 'W' stands for 'Whatever', or 'Wat' in short. Unscrupulous product devs sometimes add an extra T to it.
I bought a 'premium' one of these recently for the intended purpose and the response i got to my complaint of the power supply only being 24W when they claimed the unit was '54W' is that "there is xW per LED and x LED's, multiplied together = 54W"
I'm assuming you can just block the IR any way you want (tape over receiver/sender) or even clip wire from sender to make it on all the time. That device seems useful for lots of things like curing solder resist or other uv curing glues/resins.
Well, they actually say these UV chips have a protection diode in them. I got some spare LEDs for such UV nail lamps, and they all have two dies in them (two different wavelength), but some of them actually have a third die as well, and they had in the description that it is some protection diode. But who knows what it in reality is.
We have a tiny one-fingertip-sized capsule for curing nail extension gels and UV varnish. It has a button on the floor, so you can put your finger in, press the button and enjoy your nail being flooded with violet light with some UV in it. If you press the button once, it will shut down the light in thirty seconds; if you press the button once more while it's on, it will add thirty seconds more. The third press switches it off immediately. It has a couple of tiny resistors, a couple of power resistors, three (or five in some variants) LEDs, a transistor (for instance, A2SHB, I just checked) to drive them, and a mysterious eight-pin chip. Such capsules, like flat whole-hand lamps with folding stands, usually work off of USB cables because of low power consumption.
LED switches can be activated by sunlight, so if the device is by a window and cloud floats by can activate the device. The plastic is not that thick and from brightness to darkness it can be activated by clouds floating by. I used to repair photocopiers with automatic sheet feeders and got complaints of them switching on by themselves. Ther ones complaining always had the photocopier by a window and the led receiver was well covered.
I took one of these apart gluead the led plates around in a old resin printer hood voila 5volt uv curing station. I just wired a switch and then directly feed the 5volt to the leds
I considered getting one of these for post-curing resin prints, but a rather beefy UV spotlight was about the same price, and I already had all I needed to make a turntable.
Hello Clive, I just received a 24V, 288W(!!!) version here from an Amazon sale (Aussie $18), it came with a 24V/2A wall tx. I haven't measured the actual wattage but it certainly feels warm when you put your hands under it. Very similar to yours, but having a 16pin microcontroller, 63 LEDs and a three digit LED readout (countdown timer) with the same functional buttons. Uses the same A09T FET to switch the LEDs and has a 'hand present' sensor. About to get some UV cure resin to experiment with.
For several years I've had a similar "SUNUV SUN[2C]" UV LED unit with a 24V/1.5A (=36W nom.) power supply and _it really does_ use *_29W_* on its 10S, 30S, 60S modes, and 5.6W on 90S "Low heat mode". I don't recall whether a specific power rating was advertised. That's spread over 33 LEDs: 18 on the top panel, and groups of 4,2,3,2,4 on 5 angled side panels. I can see through ventilation holes several aluminium-core PCBs, the central of which has at least 10 large SMD resistors (“2512”-size, 1W typ.), 5 each to the left and right of the central LEDs, marked: Left: “330” (33Ω), “330” (33Ω), “……0”, “24…”, “2……” Right: “330” (33Ω), “330” (33Ω), “4R0” (4Ω), “…R0”, “24…” There are also some smaller “1206” resistors whose labels I can't see. I did consider that the resistors might only exist to boost the power consumption :) but the 33Ω, at least, are inline with the LEDs. I can't tell for the others. Unfortunately I can't open it up non-destructively because the screws are covered by magnets secured with a glue that's unaffected by all of my nearby solvents (isopropyl alcohol; acetone; limonene). My attempts resulted in chipped magnets and the surrounding plastic breaking apart (perhaps weakened by the solvents). I might try again tomorrow with Extra Solvents™ :)
Cosmetic industry has often had a bit of a blind spot about bad effects from chemicals used in the products. As you said, in the currently fashionable nails finishing industry people gladly submit to various glues resins and solvents, but when cancers occur, industry claims it must be from other factors like UV exposure. (?!) It was bad enough when Madge the manicurist had people soaking their fingers in dish soap in the old Palmolive commercials on TV - but now she'd need an organic solvent canister respirator , cause the people would be soaking in acetone (or worse)! re the 48 W claim - maybe they are counting the glory, visible light, and Q ray emissions as well as the UV emissions.......8^) Cheers!
The monomers used in UV resins are often cancerogenic. I guess that being very small and organic they can easily diffuse wherever and do their nefarious work. Acetone certainly helps with reducing any barriers for unhealthy stuff to enter your cells. My wife sometimes uses UV-cureable nail polish. To make sure that it's not straight poison, I insisted on getting the MSDS before selecting a brand. It was an interesting experience. "What's that!?", "Sorry, the boss is on vacation and I don't know where to find it" and in some cases simply no reply. I certainly wouldn't recommend any cosmetics sold from china (or resold via fulfillment by amazon or similar crap).
i remember seeing some articles about the potential dangers of UV in nail salons and the comments were certainly a thing to behold. lots of nail stylists going to bat for cosmetics conglomerates with all the info they were given in their short (company sponsored) class on how to use a UV hood and how safe they are. like, yes, 6 watts is a negligible amount of energy and they're probably right. but when they lead with "It's not UV, it's LED, so it's safe" as if LED is a light spectrum, and claim they learned all about it in cosmetology school... that industry doesn't exactly have a great track record, historically, when it comes to telling the truth and not poisoning people.
Entertaining and educational, as always, especially that resistors can be mounted upside- down (6:34), ho, ho. As you say, I suspect bucket-loads of Acetone are doing more damage, anyone for gastrointestinal haemorrhage?
I sell UV epoxy that cures at 365nm and I can tell you I really doubt these are 365nm, they all seem to put that for sales reasons. The 365nm LED's are like 10x the cost of the 400-405nm versions. If these were truly 365nm I would be selling them for my customers. The cheapest 365nm at like 20w that I can get wholesale are like $100 for a little tiny one.
did you put a meter across the LEDs to see if the voltage is reduced inside the package with a secret resistor inside or it is all just in the flimsy wires and tracks
watts come in different forms. electrical watt is easy to convert to other units using ohms law. optical watts that lasers use i think apply to all forms of light so the uv curer could be 48 optical watts. then there is heat watts witch is the unit for electric heaters. uv is invisible though there are some people who can see into the uv range and many tv cameras can show uv that is the blue to purple glare you see when watching shows where arc lights and welding is shown. because uv is invisible they probably add some visibling phosphor to make the leds visible so the user can see it working.
Btw, I have one of these for doing my nails (which I haven't used in ages, in a bit of a slump atm). I never use solvent to remove the old gel, I tend to peel it off and file the nails to remove anything left over. But it tends to peel off in one piece.
I bought my wife one of the more powerful models, she says it's radically improved the speed with which she can do her nails. As you say, there are bigger risks than the light in the process
Perhaps worth noting the British Association of Dermatologists (they’re BAD) article on gels and skin sensitisation called “Dermatologists reiterate artificial nails warning and risk of at-home kits” from April this year.
Hello Clive, slightly off topic, great channel and your videos are brilliant, although I am not that knowledgeable in that field. Could you answer me a question please? I have an old sky dish on the rear of my house that I am about to remove. I have a couple of sat cables running to it from inside the house. Could I run 240v through this sat cable to a small 30w LED light in its place? Thank you. (I hold you in no way responsible for any advise you give. Lol.)
I have this same light. I used to have 2 lights, a UV and LED because some products require UV to cure and others LED. This light cures both types of nail products. Sometimes the infrared sensor messes with the timer buttons on top. Sometimes when the timer runs out, it switches of and sometimes not. Why? I TRULY enjoyed your video!
Wonderful video again, You almost always manage to learn me something while I'm being amused in the way you do it. if all teachers were like you education would be much more effective. I never was good at math because my teacher was a narcistic self centered ahole. my electronics teacher was more like you and now I am a successful electric/it engineer .
Is the IR receiver really a photo diode, or is it a photo resistor? I greatly enjoy your phraseology, sense of humor! Well worth the cost of admission :)
Don't see an email in your about section, but would you be interested in looking at a 100W GaN charger that died? It let out a loud fizzling sound, then a stream of smoke as I was leaving the room. I've opened it and the failure point is obvious, but I don't know nearly enough to say why it actually failed.
I got me a cheap model to cure my 3D Resin prints. Works nicely. Though I think I will upgrade it eventually with a µC for control instead of the simple timer.
Is there an at-home test to figure out the wavelenght of UV diodes? I got a bunch of different and dont trust the vendors information and want to test myself.
If the light from the LED is detectable from a camera, you can diffract the light off of a DVD. Use a CFL for a reference to get the wavelengths and you can usually distinguish the 405-395 nm ones from the 365nm.
IIRC it has something to do with the way they are using the I/O pins on the micro to both control the idiot lights and read the buttons. The micro has to be run at a lower potential than the LED supply rail. Also, the zener diode is probably supposed to be 4.3V and the measured 4.4V is within the 5% tolerance band (4.085V to 4.515V) the diode is rated for.
No need for the micro to switch the selector switch lines from input to output on a timer. Just leave it as an input until the button is pressed, then change it to output and pull it down.
Solvents I'd say too. My uncle used to splash car parts cleaner around to get oil off in a lorry shop. He got away with it for about 25 years till her got skin cancer, the one that goes all over, metastasized, in your bones, in your lungs. Caught it soon enough radiation did the trick though. He's still tickin. He just went through a long few years of them thinking he had some severe rapid onset dementia. It wasn't. It was his thyroid or something. They fixed it. He can remember again. Very strange and stressful for them.
My dentist uses UV-cured adhesives, resins, whatever and the dental-grade lights seem very stylish but effective - probably well-built and expensive. Only UV curing I’ve encountered in person.
I got some composite bonding on a tooth yesterday and I'm always fascinated by how fast it's curing even though the composite is opaque. Like five seconds with that extremely bright, science fictionish UV wand and it's done. Impressive.
I luurv the uv glue mrsW keeps ripping half her fingernail off and a drop of glue will repair the rip until the nail grows out. I found a kree lookalike uv led in a random selection on Ali and it cures the glue fast enough to make stalagmites. Trouble is I don't know what it was so can't get more.
UV cure nail varnish used in these booths where people do it daily seems to all be "soak off" now. That means they just have to soak fingers in water for the stuff to come off again. Not for going swimming with in other words.
Soak off usually refers to using acetone or similar. Never seen or heard of water being used to remove the nail polish. Other types of polish have to be buffed or ground off.
@@networksdude Soak off now refers to water. I bought some color changing to play with and put it on some on some metal pieces. Even if sanded first it comes off in sheets after a time in water.
I had a moment when I realized walmart sold 100% acetone. And it said soak your fingers for 15minutes and remove gel nails. If needed soak another 15minutes. Compare that to the MSDS datasheet for acetone.
It is well known that the gels and resins used in uv nail tech can cause serious skin reactions (and worse for those sensitive to them). That's why using salon materials in the home environment is discouraged.
One has to love the pandemic for abundant UV devices. I just bought a UV phone sanitizer from Lidl for 7 euros. It has 2 LEDs which look like some kind of brass body things with 2 elements inside. I'll try it for erasing EPROMs. If it works at all it's a pretty good deal for the money and it even has a battery so it's a take-along.
It would not be as much fun to disassemble, but Convoy flashlights makes UV torch that is just... skookum. It cures resin in amazingly quick time. It is scary how quickly you feel "heat" on your skin (and the sun tan smell) if you get in the beam. It uses a Nichia LED and because of the flashlight/reflector setup sends UV with some enthusiasm..
I put a powerful 365nm emitter in one of my LED Maglites, and YES, it heats up and bakes the skin quite quickly in the beam. It was an absolute BITCH to remove the original, and then resolder the tiny bare U.V. emitter on top of the LED module in the Maglite, but I finally managed to get it on there without mangling or cooking the emitter and the top of the plastic module I use the light for finding leaks in automotive systems in which I've put dye into to make locating small leaks easier. The fact that the Maglite can be focused down to a small, bright, hotspot makes finding and fluorescing the leaking dye MUCH easier in broad daylight than the horrible, useless, LED U.V. light that came with the dye kit.
I've got one of these (well a fluorescent one) that I got with the idea of erasing UV EPROMS or exposing PCBs with it... but never got around to testing it for either of these things... I wonder if anyone else has given anything similar a try?
I'm afraid the suspicion of these being a cause of skin cancer is in fact entirely plausible, mainly because many of these devices, if not most of them, actually don't use LEDs emitting in the UVA, but still use the old black light bulbs (not black light blue, but the white appearing black light bulbs) that are essentially just using the same phosphor as in tanning lamps and thus emit light as far down into the UV as about 300nm. See the paper "DNA damage and somatic mutations in mammalian cells after irradiation with a nail polish dryer" from 3/23 in Nature Communications. Unfortunately the authors of these kinds of papers (and this one is no different) are often just as utterly clueless and useless about differentiating between kinds of UV light sources as they are brilliant at assessing carcinogenicity and mutagenicity in cells in petri dishes, and thus they make no attempt whatsoever to differentiate between Hg discharge tubes blasting out huge amounts of UVB light on one hand, and LED based bulbs that emit none on the other. In fact they appear to be so thoroughly useless on the subject of the light sources themselves that they're unaware of any differences between the two fundamentally different kinds of lights at all, essentially rendering their findings pointless for all but the most astute readers of their paper who can read between the lines and figure out that all the potential danger is coming from just one kind of lamp: the tube discharge lamps.
Ultraviolet light is very much visible. 365nm radiation for instance causes the lens of the eye to fluoresce brightly and is easily detected even if not seen directly.
@@Muonium1 - No, it very much isn't. That's why it's called _ultraviolet._ The fact that some things emit *a different wavelength* (of _visible_ light) when hit by ultraviolet radiation doesn't mean you're seeing ultraviolet. Just like the fact you can hear your dog bark when it hears an ultrasonic whistle doesn't mean that *you* are hearing the ultrasounds. *By definition,* infrared (and any frequencies below it) and ultraviolet (and any frequencies above it) are *invisible.* If you can still see it (not "see its effects on something else", if you can actually *see* it), it's emitting visible light (ex., violet, possibly _in addition to_ ultraviolet).
@@RFC-3514 nnnnope, and most people can see infrared too out to at least 800nm. even x-rays are faintly visible. maybe read some of the primary literature instead of taking science lessons as dogma from your 5th grade teacher.
@@RFC-3514 I literally have an 850nm laser source sitting next to me right now. I've spectrally analyzed it to confirm its monochromaticity, I can see the red dot it projects plainly in a dark room. I'm an optics engineer on a high power laser fusion system. What do you do for a living? Does it involve serving a lot of fries?
The 48W calculation was determined by multiplying the shipping carton size (8 pcs.) x the wattage (6W) per unit. I don't see why that would be difficult to infer.
"Let your beauty eternal glory"
Truly words to live by
I have the 6-led UV panel you did a video on years ago, from the same brand, and it likely uses the same LEDs - I've sacrificed once of the LED chips and and additional one of the phosphor domes/blobs. It appears to have two LED dies on each chip, one bonded with two wires to each end of the module, and one bonded directly downward with only one bond wire leading to it. The 2-wire die (presumably 405nm) lights a visible purple at a lower voltage (just under 3V), and the 1-wire die takes greater voltage to light up. The 1-wire die looks identical to the large one in a 365-nm LED flashlight I recently bought - the surface of the die itself seems to phosphoresce in white, and any color from the semiconductor itself is invisible.
Looking at an individual LED module under magnification while powered at about 3.2V makes the two different dies obvious without being too bright to look at.
I wonder if the 48W on the box is kind of like with normal LED bulbs where they say "60W" very large and then "...equivalent" much smaller, and the light output is equivalent to a traditional 60W bulb.
Its just a model number and not a power rating. Its easy to confuse :P
The power ratings are obviously worked out the same way as they do audio power ratings😂 The bigger the number the better 😊
The chinese are sneaky with model numbers like that, that will make you think it's a power rating at a quick glance. I've ran into that several times with their products before. No more trickery on MY behalf anymore though.... I've learned.
Equivalence is about 7.14 times the difference,6.8 comes out to 48.552
@@agurdel It literally says "48W power." It's not a model number.
though I had some problem with sea water It also th-cam.com/users/postUgkxa-FNYUOM93a388gi9a4brtSCEVmrHgJH land for finding any things very easily. (thought it would work as normal due to it being water proof within certain parts of the detector), on dry land and sand worked well. My first one, so still have lots to learn
Thank you, now TubeYou will be thinking I need to see all the videos about nail varnish and UV curing techniques !
Marvel at the millions of views those videos get.
Your power meter also displays the power in Watts.😊
Still, a good excuse to use the Kink Palculator. 😂
It's so rare that I use that feature that I completely forgot it was there.
Me and my friend, we sometimes use such gels for nail extension, and in my opinion these substances, especially when introduced to machined nails and skin, can get into the body and cause some problems down there. And yes, because of people like Big Clive I already know the difference between the ionizing ultraviolet subtypes starting at UVC and more safe ones of it.
I mentioned earlier that I tried playing with some UV-cured resin (bought a big bottle of it), and I have to say in constant UV it solidifies mostly in like ⅔ of the curing period, and if you don't want it to have sticky surface, you _need_ to treat it with UV much longer: when it's mostly not polymerized, it absorbs photons easily and across the whole volume, but the more it solidifies, the less efficient this process becomes.
In short, you need to prolong the process until it is not sticky.
There are two types of photoinitiators; cationic and free radical. Cationic photoinitiators are used when light cannot reach all of the resin, as here, light starts a chain-reaction that keeps going on in darkness. Makes storage more complicated, so I guess that nail-polish is generally using free radicals. These are inhibited by oxygen, so if you have a nitrogen supply and put a flap on the opening of the UV-unit, you can just get rid of the oxygen in it and thus avoid the sticky surface. Cationic photoinitiators can for instance be inhibited by water, so here humid air is problematic.
It's certainly not worth the hassle if you're just treating your nails, and you should make sure that you don't use so much nitrogen that you run a risk of asphyxiation, but I've used such a modified lamp in a lab to do some quick tests with UV-inks and it worked just fine.
As someone else mentioned, I think the outside being sticky is likely due to oxygen inhibiting the curing process, leaving some uncured resin on the outside. One thing I've tried recently for using UV cure resin for filling in some etched metal is to do a quick exposure just to firm things up a bit, and then proceed to do the main curing by putting the design in a little tray and submerging it under a thin layer of water, and then doing the main exposure that way (so it's not got the oxygen from the air to inhibit it). So far doing the main curing underwater has prevented that outer layer of sticky uncured resin like I had been getting previously.
That's relatively easy to do with a nice flat thing you just need to expose from the top, but it's probably not exactly easy to do with larger things. Perhaps if you need to cure something larger 'in-place', you could try and spritz the outside in something like VG or PG to create a protective barrier layer which you could wipe off afterwards (although I've no idea if they'll mess it up in some other way).
@@bluesatin tbh, first I tried washing it in IPA, but soon discovered that solely prolonging the exposure to UV I get rid of any stickiness. For whatever reason, it's the simplest method for me so far, but I will keep in mind those advices you folks gave us. Experimenting is fun indeed! Thanks!!
@@jkobain Ah yeh, I assume just blasting it with more UV over time will eventually overcome the oxygen inhibition issue. Mine still tended to be sticky after quite a long time exposing normally, but the water trick seems to be very easy/effective in preventing the issue for my use-case.
I assume there's probably a bunch of different additives that various UV resins use to try and reduce or prevent the problem, but trying to find any info on that sort of thing is a bit of a nightmare.
@@bluesatin What also helps is just using more power; the reaction is faster and leaves less time for the oxygen to interact with the resin. When I switched to an industrial lamp, I had no problems with sticky surfaces anymore with that partiular ink - though there are UV-inks that require an inert atmosphere even when you blast them with a lamp that has 180 W/cm.
Thought you might have tried the UV test steps but resin worked even better. Thanks Clive another interesting video
I always have the urge to visit a thrift shop after watching any of your videos 😊
again, lovely UV and a small sum of money. thank you.
Thanks.
They may be made specifically for curing nail varnish on nails, but they’re *perfect* for PCB reworks (specifically when you need to cover over exposed traces with conformal coating).
My roommates had a box for an old phone cover in a closet in the house that I discovered that came with a UV cured screen cover and the package actually came with a USB UV light like what you've got there. It's not as big. It only has 6 large LEDs in it, but it has the same purpose. To cure UV setting resin. I nabbed it. It's disposable. It was to be used to set the screen cover on a phone and then be discarded. Incredibly wasteful, but I rescued it. It's labelled Whitestone dome glass.
the more "extreme" version of that is used for phone display glass replacement (if the glass is cracked but the display itself underneath is still fine). You get the original glass off, clean up the display, blob on some UV glue commonly referred to as "UV LOCA", set the glass on and make sure there are no bubbles or uncovered spots between the LCD panel and the glass and if you're satisfied, you cure it with UV light for several minutes. When done well this will be indistinguishable from an original
@@Knaeckebrotsaege The HARD part is getting all the old glass and glue off without damaging the LCD underneath of it. Ive done it a few times, and then said "NO more" to that ugly task.
@@davelowets In some cases like with Samsungs it's still worth it, mainly because a replacement service pack (screen pre-attached to midframe) will cost you more than the entire used phone in functional state is worth on the used market when the phone is more than 1-2 generations old, despite still being very much usable. if the choice is 200eur for a service pack screen vs 20-30 for the glass + extra work, guess what I'd rather pick?
@@Knaeckebrotsaege I'd still pay the $200... 🤷🏻
My wife has one of these, it says 365+405nm, I have a 365nm and a 395nm flashlight and the 365nm light does not cure UV resin better, it is actually slower by quite a bit, might just have been marketing and now everybody says they have double LEDs not to lose out. The LEDs in the one she has have two light sources, but more like 385+405 than 365+405.
The 48W is an equivalent figure, as in equivalent light to a 48W UV tube. Older curing stations had the black UV tubes. I have also seen some with the mercury tubes, those will definately give you cancer....
Thank you for showing the insides of it, I am not allowed to open it.
1:35
I have a curing/cleaning station for my resin printer that has both 385 and 405nm LEDs and the difference is clearly visible when lit. The difference between 365 and 405 is even greater so it should definitely be visible.
To add 405nm looks violet, and 365nm looks white/grey to the eye.
And your printer is also probably covered by an Orange shell to block that light so you don't damage your eyes. Lots of newer LED's use ultra Violet light leds in conjunction with phosphorescent materials to convert that dangerous UV light into visible light. My point being you can have 2 different wavelengths of ultraviolet light hitting identical phosphorescent materials and producing the same light.
@@buddyguy4723 But why on earth would they be converting the NEEDED U.V. in this product into visible light? It wouldn't cure nail polish if it did.
So, yes, there SHOULD be 2 easily distinguishable LED "colors" in this unit if it does, in fact, emit 2 different wavelengths of U.V.
@@davelowets it dosent. You misunderstood me.
Note that your eyes can't see ultraviolet. What you're seeing is a difference in the phosphor they use to add some visible light (so people can tell when it's on).
Hey, A09T is most probably my favorite AO3400 N-channel MOSFET - using it all over the place, love the little thing.
That and the A2SHB are ridiculously capable transistors for their size.
Quite a nice teardown of that Death Star apartment complex.
For a second I thought Clive was starting off June with pride nails.
There is still time, Clive....😘
I expected you to investigate the LEDs, to explore the function of that extra piece of silicon in it. No problem, @restorer19 explained it in the comments.
Fun fact: The power rating of products like this is not depicted in the SI unit 'Watt'. The 'W' stands for 'Whatever', or 'Wat' in short. Unscrupulous product devs sometimes add an extra T to it.
I’ve been looking for just such a product that will help my beauty eternal glory.
I bought a 'premium' one of these recently for the intended purpose and the response i got to my complaint of the power supply only being 24W when they claimed the unit was '54W' is that "there is xW per LED and x LED's, multiplied together = 54W"
How thoughtful of them, the box came pre-crushed.
I'm assuming you can just block the IR any way you want (tape over receiver/sender) or even clip wire from sender to make it on all the time.
That device seems useful for lots of things like curing solder resist or other uv curing glues/resins.
Taping the sender and receiver is exactly what I did on mine. Press the 30 second button to start curing resin. They do a pretty good job.
Well, they actually say these UV chips have a protection diode in them. I got some spare LEDs for such UV nail lamps, and they all have two dies in them (two different wavelength), but some of them actually have a third die as well, and they had in the description that it is some protection diode.
But who knows what it in reality is.
We have a tiny one-fingertip-sized capsule for curing nail extension gels and UV varnish. It has a button on the floor, so you can put your finger in, press the button and enjoy your nail being flooded with violet light with some UV in it.
If you press the button once, it will shut down the light in thirty seconds; if you press the button once more while it's on, it will add thirty seconds more. The third press switches it off immediately.
It has a couple of tiny resistors, a couple of power resistors, three (or five in some variants) LEDs, a transistor (for instance, A2SHB, I just checked) to drive them, and a mysterious eight-pin chip. Such capsules, like flat whole-hand lamps with folding stands, usually work off of USB cables because of low power consumption.
Intriguing circuit
I thought it was actually a 4-8W rating but due to printing issues and cost savings for expensive ink the hyphen didn't print out clearly.
LED switches can be activated by sunlight, so if the device is by a window and cloud floats by can activate the device. The plastic is not that thick and from brightness to darkness it can be activated by clouds floating by. I used to repair photocopiers with automatic sheet feeders and got complaints of them switching on by themselves. Ther ones complaining always had the photocopier by a window and the led receiver was well covered.
I would reckon the top, downwards facing LEDs are a cree XB-D variant or derivative
That housing looks so futuristic. I wonder if you replaced all the UV LEDs with blinky ones if it might make cool looking Super Computer.
Hey Clive, 1:03, your usb meter show the power consumption on the lower right corner, no need for math or a calculator. 6.755W
I took one of these apart gluead the led plates around in a old resin printer hood voila 5volt uv curing station.
I just wired a switch and then directly feed the 5volt to the leds
I considered getting one of these for post-curing resin prints, but a rather beefy UV spotlight was about the same price, and I already had all I needed to make a turntable.
Hello Clive, I just received a 24V, 288W(!!!) version here from an Amazon sale (Aussie $18), it came with a 24V/2A wall tx. I haven't measured the actual wattage but it certainly feels warm when you put your hands under it. Very similar to yours, but having a 16pin microcontroller, 63 LEDs and a three digit LED readout (countdown timer) with the same functional buttons. Uses the same A09T FET to switch the LEDs and has a 'hand present' sensor.
About to get some UV cure resin to experiment with.
I've just got a "150W" version that also has a very light 24V 2A supply.
Whoa Nellie! That thing sounds dangerous! Could be useful as a UV EPROM eraser.
@@quantumleap359 I thought the same. The eraser lamp needs to be around 255nm however. Germicidal lamp seems to be the thing to use.
For several years I've had a similar "SUNUV SUN[2C]" UV LED unit with a 24V/1.5A (=36W nom.) power supply and _it really does_ use *_29W_* on its 10S, 30S, 60S modes, and 5.6W on 90S "Low heat mode". I don't recall whether a specific power rating was advertised.
That's spread over 33 LEDs: 18 on the top panel, and groups of 4,2,3,2,4 on 5 angled side panels.
I can see through ventilation holes several aluminium-core PCBs, the central of which has at least 10 large SMD resistors (“2512”-size, 1W typ.), 5 each to the left and right of the central LEDs, marked:
Left: “330” (33Ω), “330” (33Ω), “……0”, “24…”, “2……”
Right: “330” (33Ω), “330” (33Ω), “4R0” (4Ω), “…R0”, “24…”
There are also some smaller “1206” resistors whose labels I can't see.
I did consider that the resistors might only exist to boost the power consumption :) but the 33Ω, at least, are inline with the LEDs. I can't tell for the others.
Unfortunately I can't open it up non-destructively because the screws are covered by magnets secured with a glue that's unaffected by all of my nearby solvents (isopropyl alcohol; acetone; limonene). My attempts resulted in chipped magnets and the surrounding plastic breaking apart (perhaps weakened by the solvents).
I might try again tomorrow with Extra Solvents™ :)
Cosmetic industry has often had a bit of a blind spot about bad effects from chemicals used in the products. As you said, in the currently fashionable nails finishing industry people gladly submit to various glues resins and solvents, but when cancers occur, industry claims it must be from other factors like UV exposure. (?!) It was bad enough when Madge the manicurist had people soaking their fingers in dish soap in the old Palmolive commercials on TV - but now she'd need an organic solvent canister respirator , cause the people would be soaking in acetone (or worse)! re the 48 W claim - maybe they are counting the glory, visible light, and Q ray emissions as well as the UV emissions.......8^) Cheers!
The monomers used in UV resins are often cancerogenic. I guess that being very small and organic they can easily diffuse wherever and do their nefarious work. Acetone certainly helps with reducing any barriers for unhealthy stuff to enter your cells.
My wife sometimes uses UV-cureable nail polish. To make sure that it's not straight poison, I insisted on getting the MSDS before selecting a brand. It was an interesting experience. "What's that!?", "Sorry, the boss is on vacation and I don't know where to find it" and in some cases simply no reply. I certainly wouldn't recommend any cosmetics sold from china (or resold via fulfillment by amazon or similar crap).
with each bit being on it's own little heatsink, you could make a good custom array
The question-mark chip seems to just be an operational amplifier (op amp).
It's definitely a microcontroller.
Amazing! I bought this one a month ago and did not find a lot of information on the internals
i remember seeing some articles about the potential dangers of UV in nail salons and the comments were certainly a thing to behold. lots of nail stylists going to bat for cosmetics conglomerates with all the info they were given in their short (company sponsored) class on how to use a UV hood and how safe they are.
like, yes, 6 watts is a negligible amount of energy and they're probably right.
but when they lead with "It's not UV, it's LED, so it's safe" as if LED is a light spectrum, and claim they learned all about it in cosmetology school... that industry doesn't exactly have a great track record, historically, when it comes to telling the truth and not poisoning people.
😅 Much safer now-a-days rubbing white LED onto your skin than it used to be
I had a random idea of i wonder if you could replace the UV led with grow full spectrum led and use it to grow plants for some reason 🙂?
Entertaining and educational, as always, especially that resistors can be mounted upside- down (6:34), ho, ho. As you say, I suspect bucket-loads of Acetone are doing more damage, anyone for gastrointestinal haemorrhage?
I sell UV epoxy that cures at 365nm and I can tell you I really doubt these are 365nm, they all seem to put that for sales reasons. The 365nm LED's are like 10x the cost of the 400-405nm versions. If these were truly 365nm I would be selling them for my customers. The cheapest 365nm at like 20w that I can get wholesale are like $100 for a little tiny one.
did you put a meter across the LEDs to see if the voltage is reduced inside the package with a secret resistor inside or it is all just in the flimsy wires and tracks
watts come in different forms.
electrical watt is easy to convert to other units using ohms law.
optical watts that lasers use i think apply to all forms of light so the uv curer could be 48 optical watts.
then there is heat watts witch is the unit for electric heaters.
uv is invisible though there are some people who can see into the uv range and many tv cameras can show uv that is the blue to purple glare you see when watching shows where arc lights and welding is shown.
because uv is invisible they probably add some visibling phosphor to make the leds visible so the user can see it working.
I was so hoping you'd use pink UV gel nail polish to test this...
Btw, I have one of these for doing my nails (which I haven't used in ages, in a bit of a slump atm).
I never use solvent to remove the old gel, I tend to peel it off and file the nails to remove anything left over.
But it tends to peel off in one piece.
It can be used as counterfeit bill detector.
Hmmmmm, can it detect other named persons 🤔🤔
I'd imagine that the microcontroller is pulse width modulating the MOSFET to limit the current.
By the way: The addition of white/blue phosphorous led to the UV could help reduce people staring at the curing?
Yeah, they do that so people can see it's on, otherwise they wouldn't see the LEDs glow at all (if they were emitting just pure UV).
Saturday evenings from now on, we'll be expecting Big Clive to be showing off his glittery toe nails!!
I bought my wife one of the more powerful models, she says it's radically improved the speed with which she can do her nails.
As you say, there are bigger risks than the light in the process
Perhaps worth noting the British Association of Dermatologists (they’re BAD) article on gels and skin sensitisation called “Dermatologists reiterate artificial nails warning and risk of at-home kits” from April this year.
1:15 - While the Kink Palculator is easier to see, the Ruideng USB thingy already shows the power (in the bottom right corner).
My wife has one similar to this interesting
I was thinking the 48Watts might be equivalent wattage? The LED's are equivalent of 48Watt's of tubes? Probably not, but just a thought
Hello Clive, slightly off topic, great channel and your videos are brilliant, although I am not that knowledgeable in that field. Could you answer me a question please? I have an old sky dish on the rear of my house that I am about to remove. I have a couple of sat cables running to it from inside the house. Could I run 240v through this sat cable to a small 30w LED light in its place? Thank you. (I hold you in no way responsible for any advise you give. Lol.)
No I'd not recommend running mains through a satellite cable. Low voltage would be safer.
I have this same light. I used to have 2 lights, a UV and LED because some products require UV to cure and others LED. This light cures both types of nail products. Sometimes the infrared sensor messes with the timer buttons on top. Sometimes when the timer runs out, it switches of and sometimes not. Why? I TRULY enjoyed your video!
The infrared sensor may be retriggering the timer.
@@bigclivedotcom my wife says thank you very much. She really enjoyed the video!
Wonderful video again, You almost always manage to learn me something while I'm being amused in the way you do it. if all teachers were like you education would be much more effective. I never was good at math because my teacher was a narcistic self centered ahole. my electronics teacher was more like you and now I am a successful electric/it engineer .
Is the IR receiver really a photo diode, or is it a photo resistor? I greatly enjoy your phraseology, sense of humor! Well worth the cost of admission :)
Most likely a photodiode these days, But it does change resistance according to the level of light.
Don't see an email in your about section, but would you be interested in looking at a 100W GaN charger that died? It let out a loud fizzling sound, then a stream of smoke as I was leaving the room. I've opened it and the failure point is obvious, but I don't know nearly enough to say why it actually failed.
Cured resin? Never even knew it was sick.
😀
I got me a cheap model to cure my 3D Resin prints. Works nicely. Though I think I will upgrade it eventually with a µC for control instead of the simple timer.
Is there an at-home test to figure out the wavelenght of UV diodes? I got a bunch of different and dont trust the vendors information and want to test myself.
If the light from the LED is detectable from a camera, you can diffract the light off of a DVD. Use a CFL for a reference to get the wavelengths and you can usually distinguish the 405-395 nm ones from the 365nm.
It really requires a lab grade bit of equipment.
@@greengreens9936Works better when use the "Pink Floyd Dark Side Of The Moon" CD because of the album cover artwork.
Are supermodels allowed in the sunlight? :)
Wow. With the plastic cover removed at 4:52 it looks like one of those hats they use in the psychology department to read your brain waves.
So they're effectively multiplexing the outputs so they swap rapidly between input and output? In effect PWMing the LED's as well?
Why the 4.4V Zener? Why not run on straight +5V?
IIRC it has something to do with the way they are using the I/O pins on the micro to both control the idiot lights and read the buttons. The micro has to be run at a lower potential than the LED supply rail.
Also, the zener diode is probably supposed to be 4.3V and the measured 4.4V is within the 5% tolerance band (4.085V to 4.515V) the diode is rated for.
It may be to give a slight regulation to give better processor stability when the 5V rail is suddenly loaded by the LEDs.
I think I missed the part in the schematic that controls the LED’s for half or full power. Does the chip control the drive to the MOSFET in some way?
It pulse width modulates them.
No need for the micro to switch the selector switch lines from input to output on a timer. Just leave it as an input until the button is pressed, then change it to output and pull it down.
I wonder if these can be used to cure resin used to make ink stamps with the photosensitive resins.
You might have to experiment with that.
Solvents I'd say too. My uncle used to splash car parts cleaner around to get oil off in a lorry shop. He got away with it for about 25 years till her got skin cancer, the one that goes all over, metastasized, in your bones, in your lungs. Caught it soon enough radiation did the trick though. He's still tickin.
He just went through a long few years of them thinking he had some severe rapid onset dementia. It wasn't. It was his thyroid or something. They fixed it. He can remember again. Very strange and stressful for them.
The 1kΩ resistor from each of the push button switches to the common rail seems unnecessary to the function of this circuit. Your thoughts?
It's probably to limit the current when a button is pressed while the microcontroller pin is assigned as an output and in the high state.
My dentist uses UV-cured adhesives, resins, whatever and the dental-grade lights seem very stylish but effective - probably well-built and expensive. Only UV curing I’ve encountered in person.
I think it's blue light cured glass isomer. Very impressive.
I got some composite bonding on a tooth yesterday and I'm always fascinated by how fast it's curing even though the composite is opaque. Like five seconds with that extremely bright, science fictionish UV wand and it's done. Impressive.
I was expecting him to apply some pink nail varnish and test the uv light.
I have a roll of strips that claim 2 wave lengths. I used cobs instead
This light out of one of these might be the solution to replace useless uv lamp in a fly-zapper I bought yesterday.
Dentists will use glycerin to cover the resin as an oxygen inhibition barrier, this way the resin cures to the surface without leaving goo.
I luurv the uv glue mrsW keeps ripping half her fingernail off and a drop of glue will repair the rip until the nail grows out. I found a kree lookalike uv led in a random selection on Ali and it cures the glue fast enough to make stalagmites. Trouble is I don't know what it was so can't get more.
They might have missed out on the dot in between 4 and 8.
Awesome Video big clive
UV cure nail varnish used in these booths where people do it daily seems to all be "soak off" now. That means they just have to soak fingers in water for the stuff to come off again.
Not for going swimming with in other words.
Soak off usually refers to using acetone or similar. Never seen or heard of water being used to remove the nail polish. Other types of polish have to be buffed or ground off.
@@networksdude Soak off now refers to water. I bought some color changing to play with and put it on some on some metal pieces. Even if sanded first it comes off in sheets after a time in water.
Okay. Never seen that and they certainly don't have that in Cyprus.
I had a moment when I realized walmart sold 100% acetone. And it said soak your fingers for 15minutes and remove gel nails. If needed soak another 15minutes. Compare that to the MSDS datasheet for acetone.
I don't like the way it uses the USB cable to limit the power. If you used a good quality charging cable, could you blow up the mosfet?
I can’t understand it’s actual use but I can sure think of a few other uses for this it’s not terrible.
How are they doing the low power setting? PWM?
Yes.
0:26 Brilliant! 🤣
3:18 "that's well 'ard, innit?"
what's the wattage value in the bottom right of the usb killowatt (forgive me I forget the name)? showed .745?
Ruideng meter. It's watts. I forgot that it displays that.
How Clive does his Friday night nails.....
No current limiting resistors for the LEDs, it doesn't look good... Interesting device though.
Looks like it could be good for parts.
Parts ??, other body parts ???🤔
It is well known that the gels and resins used in uv nail tech can cause serious skin reactions (and worse for those sensitive to them). That's why using salon materials in the home environment is discouraged.
One has to love the pandemic for abundant UV devices. I just bought a UV phone sanitizer from Lidl for 7 euros. It has 2 LEDs which look like some kind of brass body things with 2 elements inside. I'll try it for erasing EPROMs. If it works at all it's a pretty good deal for the money and it even has a battery so it's a take-along.
It would not be as much fun to disassemble, but Convoy flashlights makes UV torch that is just... skookum. It cures resin in amazingly quick time. It is scary how quickly you feel "heat" on your skin (and the sun tan smell) if you get in the beam. It uses a Nichia LED and because of the flashlight/reflector setup sends UV with some enthusiasm..
The skookum output lends credence to the term "torch" Ha!
I put a powerful 365nm emitter in one of my LED Maglites, and YES, it heats up and bakes the skin quite quickly in the beam. It was an absolute BITCH to remove the original, and then resolder the tiny bare U.V. emitter on top of the LED module in the Maglite, but I finally managed to get it on there without mangling or cooking the emitter and the top of the plastic module
I use the light for finding leaks in automotive systems in which I've put dye into to make locating small leaks easier.
The fact that the Maglite can be focused down to a small, bright, hotspot makes finding and fluorescing the leaking dye MUCH easier in broad daylight than the horrible, useless, LED U.V. light that came with the dye kit.
Waits to see Clive to get his nails done...
I've got one of these (well a fluorescent one) that I got with the idea of erasing UV EPROMS or exposing PCBs with it... but never got around to testing it for either of these things... I wonder if anyone else has given anything similar a try?
Suitable for PCBs, but not EPROMs. Although with PCBs it's better as a source directly above the PCB and not at the sides.
The "Kink Palculator" 🤣
I'm afraid the suspicion of these being a cause of skin cancer is in fact entirely plausible, mainly because many of these devices, if not most of them, actually don't use LEDs emitting in the UVA, but still use the old black light bulbs (not black light blue, but the white appearing black light bulbs) that are essentially just using the same phosphor as in tanning lamps and thus emit light as far down into the UV as about 300nm. See the paper "DNA damage and somatic mutations in mammalian cells after irradiation with a nail polish dryer" from 3/23 in Nature Communications. Unfortunately the authors of these kinds of papers (and this one is no different) are often just as utterly clueless and useless about differentiating between kinds of UV light sources as they are brilliant at assessing carcinogenicity and mutagenicity in cells in petri dishes, and thus they make no attempt whatsoever to differentiate between Hg discharge tubes blasting out huge amounts of UVB light on one hand, and LED based bulbs that emit none on the other. In fact they appear to be so thoroughly useless on the subject of the light sources themselves that they're unaware of any differences between the two fundamentally different kinds of lights at all, essentially rendering their findings pointless for all but the most astute readers of their paper who can read between the lines and figure out that all the potential danger is coming from just one kind of lamp: the tube discharge lamps.
what is the nano metre of this uv light
Unknown. Probably 405nm.
Maybe 'eternal glory' is to make this appealing to corpses. (I'll show myself out now)
1:47 - Well, no, real ultraviolet would in fact be invisible.
Ultraviolet light is very much visible. 365nm radiation for instance causes the lens of the eye to fluoresce brightly and is easily detected even if not seen directly.
@@Muonium1 - No, it very much isn't. That's why it's called _ultraviolet._ The fact that some things emit *a different wavelength* (of _visible_ light) when hit by ultraviolet radiation doesn't mean you're seeing ultraviolet. Just like the fact you can hear your dog bark when it hears an ultrasonic whistle doesn't mean that *you* are hearing the ultrasounds.
*By definition,* infrared (and any frequencies below it) and ultraviolet (and any frequencies above it) are *invisible.* If you can still see it (not "see its effects on something else", if you can actually *see* it), it's emitting visible light (ex., violet, possibly _in addition to_ ultraviolet).
@@RFC-3514 nnnnope, and most people can see infrared too out to at least 800nm. even x-rays are faintly visible. maybe read some of the primary literature instead of taking science lessons as dogma from your 5th grade teacher.
@@Muonium1 - You are clearly posting from a different universe, where physics, biology and word definitions are radically different.
@@RFC-3514 I literally have an 850nm laser source sitting next to me right now. I've spectrally analyzed it to confirm its monochromaticity, I can see the red dot it projects plainly in a dark room. I'm an optics engineer on a high power laser fusion system. What do you do for a living? Does it involve serving a lot of fries?