@^#%&$^ Blue LEDs on equipment - Page 1
Forum section: electronics / general

author: Lightages
author_rank: Unknown
timestamp: September 13, 2013, 12:09:51 am
content: I know Dave did a video on stupid designs earlier on, but I can't help but rant about one of the most annoying stupid ones he mentioned.I HATE BLUE LEDS IN EQUIPMENT SO BRIGHT YOU CAN'T LOOK AT THEMI tried to make the above look as annoying as the problem.I would like to find all the idiots who design these LEDs into equipment and put them in a small room with 10,000 blue LEDs shining in their faces for the rest of their lives. Really, who are these idiots? Why do they all have this blue LED fetish? Have any of them heard of red, green, yellow, or orange? Are they all blind?

author: xrunner
author_rank: Super Contributor
timestamp: September 13, 2013, 12:18:40 am
content: That post was so annoying to look at I can't even respond to it.

author: ovnr
author_rank: Frequent Contributor
timestamp: September 13, 2013, 12:30:54 am
content: I've found that slapping a couple layers of kapton tape on top of blue LEDs will take the worst edge off; kapton either fluoresces weakly at the usual blue wavelength, or absorbs the lower part of it. The end result is, in any event, a slightly lighter (and dimmer) blue color.This obviously requires access to the internals of the device in question, as slapping big orange pieces of tape on the front isn't really an option. And obviously black tape is great too, but sometimes you do need to see the LED.

author: c4757p
author_rank: Super Contributor
timestamp: September 13, 2013, 12:36:42 am
content: Agreed!It's not even that they're too bright, because blue LEDs are damn near invisible if you don't run them blindingly bright - the blue isn't noticeable against the relatively bluish daylight or fluorescent light. Juststop using them, people! But the marketroids wouldn't have that - red and green look outdated and yellow looks sickly...Let's bring back neon...

author: Psi
author_rank: Super Contributor
timestamp: September 13, 2013, 12:41:56 am
content: Yep, tape works well.High brightness LEDs can require ridiculously large resistors to get there brightness down to a level that is conformable to look at.In one of my projects for automotive use i have 0-100 step PWM on an yellow led for brightness control and i needed to use a 39K resistor, seriously, 39000 ohms between the 5V mcu pin and the led to get acceptable brightness levels.Further more, for dim mode on the device (night driving) i'm driving the led PWM at 10/100.Thats 1/10 brightness with a 39k resistor from 5V. CRAZYI think this is one of the reasons why manufacture keep getting it wrong. No one expects to need that level of resistance on an LED.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 13, 2013, 12:43:57 am
content: Use sandpaper to diffuse them.

author: BravoV
author_rank: Super Contributor
timestamp: September 13, 2013, 12:50:59 am
content: It used to be red and only red available, then green, now blue, so the circle is complete akaRGB, expecting the trend will be using the blinding narrow angle WHITE colored led to burn off your retina.Agree as previous post, unless you're going to de-solder it and replace with red one, just slap in a layer or two of kapton tape and call it a day.

author: c4757p
author_rank: Super Contributor
timestamp: September 13, 2013, 01:00:11 am
content: Violently extracting it with pliers is more emotionally rewarding.

author: Legit-Design
author_rank: Frequent Contributor
timestamp: September 13, 2013, 01:02:30 am
content: My samsung monitor has brightness adjustment for power on button with blue led. It's in the OSD, I just set it to 0 when I got it, in daylight it's just barely visible. I wish my next computer monitor will have automatically adjustable power on led based on ambient lighting.Also have HDMI switch that has dim red led and blue leds, which shine through two layers of duct tape just as bright as the red led without tape. Those blue leds would light up a wall without tape.

author: xrunner
author_rank: Super Contributor
timestamp: September 13, 2013, 01:04:05 am
content: Quote from: c4757p on September 13, 2013, 01:00:11 amThat's what she said ...I know, but it's an easy joke.

author: WarSim
author_rank: Frequent Contributor
timestamp: September 13, 2013, 01:04:09 am
content: Here is more reasons.Diffused LEDs cost more, so in latter stages of design they get swapped by the bean counters."Indicator" LEDs cost more that "Hot" LEDs, therefore are swapped out by bean counters."Hot" LEDs are more thermally efficient because so are preferred in low power projects.I personally prefer wide angle hatched diffused warm blue LEDs, not to be confused with the hot clear narrow blue LEDs.If I end up with a hot LED of any colour I tape a hole punch hole over it. Very cheep.

author: c4757p
author_rank: Super Contributor
timestamp: September 13, 2013, 01:10:32 am
content: Quote from: xrunner on September 13, 2013, 01:04:05 amHave youseenmy sense of humor? I amnotabove an easy "that's what she said"

author: TerraHertz
author_rank: Super Contributor
timestamp: September 13, 2013, 01:57:00 am
content: Overly bright blue LEDs on instrument panels is nothing. The cinema near my place upgraded two of their halls to 'VMax' - their idea of luxury seating. Yes, the seats are very comfortable. But some retarded designer thought having bright blue-LED illuminated seat numbers in the armrests of every seat would be a neat idea. And no, they don't get dimmer during the movie.How could they think that was workable? Did they even try to imagine what it's like to watch a movie, with your lower peripheral field of view full of blinding bright blue dots? And for this crap we have to pay ever-higher ticket prices?Personally I found it unacceptable, so adapted by taking a roll of black gaffer tape with me every time I went there.Finally, nearly two years later, the management somehow lowered the brightness of the seat number LEDs. But not enough. I still take the gaffer tape. Resisting the temptation to take a small paint spray can.What really amazes me, is that most people seemed to be able to ignore the blue-dot torture. Or at least were too passive/inhibited to complain to management, or do anything about it themselves. Which explains a lot about the way the world is, actually.Incidentally, for annoyingly bright instrument LEDs (especially at night) I use a bit of blu-tac. Entirely cover the offending LED, then use pointy object to make a tiny hole in the blu-tac, just enough to let a comfortable amount of light through.

author: IanB
author_rank: Super Contributor
timestamp: September 13, 2013, 03:16:18 am
content: Yeah, I just bought a webcam that has a blue LED for the recording light. Er, what? Don't they know that a red light is the industry standard signal to tell you when a camera is on? Perhaps there is a world shortage of red LEDs and they have to use blue ones instead?

author: BravoV
author_rank: Super Contributor
timestamp: September 13, 2013, 03:49:49 am
content: Quote from: IanB on September 13, 2013, 03:16:18 amIts a sign, newer generation's retinas are mutating and starting to reject toward red spectrum, just wait for few decades more ...

author: SeanB
author_rank: Super Contributor
timestamp: September 13, 2013, 04:52:40 am
content: I remember the first red LED's in plastic packages, where if you ran them at 5mA you could see them in the dark. 10mA and you could see them in a shaded part of a room. 20mA they blew up....I did make a mains indicator using a 5mm hyperbright clear 5mm red LED. Straight resistive dropper with 3 39k 0.5W resistors in series and a reverse blocking diode ( wanted it to survive being connected across 400VAC as well) all potted in slow set epoxy. It was good at casting a shadow across the wall at night if the room light was off. Perfect as a power indicator that I wanted to have visible in direct sun.

author: David Aurora
author_rank: Frequent Contributor
timestamp: September 13, 2013, 05:06:37 am
content: THis shit is a HUGE craze in music equipment/pro audio, so being a musician/recording engineer I cop the blinding lights constantly. As bad as blue LED's on ANYTHING are, it's even worse on dim stages/in dark studios, I assure youThat said, I've been slowly working my way through all my gear replacing all the blue LED's with more tasteful colours and brightnesses. I'll get through it all one day haha

author: steve30
author_rank: Frequent Contributor
timestamp: September 13, 2013, 06:07:14 am
content: I had a major issue with these back in 2009 when pretty much everything I came across used them. I decided I would ban blue LEDs from my lab.When I bought my Dell U2410 monitor a couple of years ago, I was really concerned that it had a blue LED. But its actually quite dim, so isn't that noticeable

author: amyk
author_rank: Super Contributor
timestamp: September 13, 2013, 06:14:49 am
content: If you've ever been to east Asia (especially places like Shenzhen, Hong Kong, etc.) you'll notice that's probably where the fad started, as almost everything has bright blue LEDs on it (and the people don't particularly seem to be distracted.)

author: jzoeller
author_rank: Newbie
timestamp: September 13, 2013, 07:37:14 pm
content: I just got dish network and their box has a bright blue LED on it, really sucks if you have the lights off watching a movie = covered up with tape.

author: SeanB
author_rank: Super Contributor
timestamp: September 13, 2013, 08:29:03 pm
content: A lot of decoders also had a tape covering the display, but for a different reason, as the decoder would respond to random remote IR signals and either switch off, change channel or change volume or mute. Some would drop into a tuning mode which would be rather annoying.

author: Rick Law
author_rank: Super Contributor
timestamp: September 14, 2013, 01:56:41 am
content: Funny, I just finished building a board with 5 very bright blue LED's. I am so tired of Red and and yellow.So, 4 pairs of blue (+) and green LEDs , and a pair of a blue and a white.So, what state/country do you live in? I will be nice and avoid pointing my new board in your general direction.

author: Kaptein QK
author_rank: Regular Contributor
timestamp: September 14, 2013, 02:07:18 am
content: Last blue LED got the dremel treatment. I simply drilled through the die!

author: vk6zgo
author_rank: Super Contributor
timestamp: September 14, 2013, 04:16:43 am
content: Interestingly,the eyes response to colours changes between daylight & darkness.In daylight it peaks roughly in the green region,but in "dark adapted" vision,the peak shifts towards blue.That could account for the glare from blue LEDS in subdued lighting.

author: WarSim
author_rank: Frequent Contributor
timestamp: September 14, 2013, 04:29:40 am
content: Quote from: vk6zgo on September 14, 2013, 04:16:43 amVery true that is why any design should compensate, but most consumer product consider it waisted expense and omits it. It seems these days you have to be in a segments where function and safety is more important that money. Unfortunately these segments are very few.

author: westfw
author_rank: Super Contributor
timestamp: September 14, 2013, 05:17:00 am
content: Well you know, there's apparently a standard for telecom equipment that prohibits using red for anything other than "error" indication. And then you should avoid green/orange because of the color-blind. White LEDs are subject to phosphor degradation. That doesn't leave a lot of choices :-)

author: Wytnucls
author_rank: Super Contributor
timestamp: September 14, 2013, 05:24:38 am
content: This is the most annoying device I own: extra battery sleeve for Samsung phone (Not made by Samsung):In low ambient light, those blue LEDs burn through retinas like disco lights.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 14, 2013, 05:34:12 am
content: Quote from: westfw on September 14, 2013, 05:17:00 amYeah,when I worked for a Telecommunications organisation that also ran (manned) TV transmitter sites for other bodies,a directive came out that we had to swap the red & green lights on our faders.To a Broadcasting person,it looked all wrong,as red meant "ON AIR"!!A lot of equipment used green "on" lights,but there were still plenty that used red,including the "Do Not open" lights on many Transmitter doors!

author: rollatorwieltje
author_rank: Unknown
timestamp: September 14, 2013, 06:56:05 am
content: It's not just on consumer stuff, Festo also uses bright blue LEDs on their controllers. Even the 7-segment displays are blue.Bright signal LEDs are stupid anyway, not just blue ones. I currently have an alarm clock with a very good dim red display. I want to replace it because the radio barely works, but all new ones seem to have extremely bright displays. I have another one with a green display, at night it looks like someone threw a flare in the room

author: SeanB
author_rank: Super Contributor
timestamp: September 14, 2013, 07:31:02 am
content: Easy to fix the clock display with 2 100R 0.5W resistors in the 2 display AC supply multiplex lines. there might already be an unused set of pads and a switch that was removed to reduce the cost by removing the dimming capacity.

author: TerraHertz
author_rank: Super Contributor
timestamp: September 14, 2013, 07:53:53 am
content: Arrgh! Too-bright clocks! Definitely way up there on my hate list. I refuse to use any illuminated clock in my bedroom, so stick with simple mechanical ones. If I really want to know the time when woken up in the wee hours, I close eyes, turn on bedside light, turn off bedside light, open eyes. The luminescent paint on the clock hands is then perfectly visible.But why oh why can't any manufacturer produce an illuminated clock, in which an ambient light sensor dims the display right down, proportional to the darkness?Anyway, on the topic of instrument panel lights, and making them NOT annoying, here's a project in progress.It's something I want to look very, very nice when it's done. It's a long term project, and will have a lot of work put into it. Among other things on the control panel there will be quite a few LEDs. And space will be tight, so they need to be fairly small. So I looked around for nice, small panel-mount LED bezels.Eventually decided all the commercial ones I could find looked like cheap crap, or at least... kind of ordinary.What to do?Then I remembered something from long ago. My childhood actually.Remember these?They are the indicator lenses from old PMG (telephone) switchgear panels. All indicators were small plug-in lightbulbs, and to get different colours they used these small clip-in glass lenses. It's actually glass too, translucent and with slightly frosted surfaces to get a really even light distribution. They came in several colours - red, green, amber, and (fortunately for my use) white.I recalled that sometime in my childhood I'd found some old PMG panels on a tip, taken them home and dissected them. I'd long ago discarded all the bits (except maybe a few relays), except I thought I had kept the coloured lenses, just because they were pretty. But where were they?It took quite a while to find them, but they did turn up. They were in an old lolly tin (another relic in itself.)(They were loose and mixed, the sorted ziplock bags are recent.)I tried an experiment, putting a tri-colour LED behind a white one. And WOW! It's really beautiful! The effect most reminded me of the gorgeous indicator lamps in rendered games like Myst. After a little more experimenting (grinding the front of the LED lense flat and matte, and adding one more diffuser layer between the LED and rear of the glass lense, the result is a perfectly even, soft colour, that's quite luscious. The photos I've included don't really capture the effect at all.OK, so this is definitely what I want on the panels. Next question, how? I wanted to have a minimal amount of visible mounting hardware, besides the rim of the old PMG lenses. Also, needed to make lots of them.The lenses made a good press fit in a size of thin-walled brass tubing. I made a jig to part off bits of the tube to the same length in the lathe, then another to turn over a small lip on the end of each piece. That makes the main bezel body, which from panel front only shows as a tiny little lip around the edge of the lense holder.Parting off some small rings of the next size up of the tubing gives sleeves that can be slipped over the back of the bezel in a panel, then spot soldered in place. The LEDs are press fits in the back, held in place with short cut-offs of a plastic tubing size that tightly fits the brass tube.When this thing is finished, it's going to look like something out of Myst. At least a little bit.I'm not colour blind, and this thing is for my use only. So a lot of system state display will be via indicator colours. ALL the indicators will be the same tri-colour LEDs, with software control of the individual RGB LEDs.Control is via registered LED current driver chips right behind each panel section, with only the serial data lines going off to the processor.I'm glad I kept those old PMG lenses. And I'm glad this project is worthy of using such mementos.There are enough in my childhood's saved tin for the project. But does anyone know of a source for lots of these?Actually, I bet if someone set up to manufacture these, there'd be a market. They really do give the prettiest looking indicator lamps I've ever seen.

author: baljemmett
author_rank: Unknown
timestamp: September 15, 2013, 12:11:02 am
content: Quote from: TerraHertz on September 14, 2013, 07:53:53 amQuite - my 'bedside clock' is actually a little hi-fi system with a (pretty pleasant, really) VFD - but alas it can be a bit bright at night. Luckily it has a display-defeat switch, which turns off everything apart from the alarm annunciator; since it's several feet away from the bed I can't read the clock easily anyway!When I built a word clock earlier in the year (bit of a cliché, but saw one in a shop for real money and fancied trying my hand at a knock-off for my own amusement), I stuck a light sensor on the board just in case I fancied gilding the lily a bit - in the end it proved almost essential to respond to ambient light levels, otherwise it looked a bit 'how ya doing' as Dave might say. I need to revisit the brightness curve at some point to tweak the low end a little, though.QuoteThose are extremely sexy -- nice work! Of course now I want to use them for the 40-ish indicator lights on my next big project too. *sulks* Current plan is probably to use the 5mm versions of the flat-top LEDs I used ona previous project- they don't have quite the same cachet, though, even ignoring the whole friction-fit vs. proper mount thing.

author: Hydrawerk
author_rank: Super Contributor
timestamp: September 15, 2013, 12:35:14 am
content: I do not like LCDs withdarkblue underlight. It is crazy. The underlight should be white or orange, or some bright colour... And this display is also not so good.So i replaced the LCD.

author: free_electron
author_rank: Super Contributor
timestamp: September 15, 2013, 02:48:52 am
content: Quote from: Lightages on September 13, 2013, 12:09:51 amnow now. while i agree that it is annoying to have these super bright blue led's on frontpanels there is one thing where they should be mandatory : Bicolor status indicators.i am colorblind and do not see the color green. a tremendous problem for me is to tell when a bi-color led changes color from red to green or red to amber or amber to green ( amber = both red and green are on). my eye only detects the luminosity , not the colro itself. so when both led's are on the led is just a tad 'brighter' that's all.so for things like battery chargers : red is chargeing , green is done . this is a friggin nightmare. when i get a new piece of gear that uses bicolr leds the first thing is do is rip out the bicolors and replace em with red and blue. NOBODY is red/blue colorblind. does not exist. there is one version where the red and blue elements are fused. those people only see purple ....(i'm not making this up. this is real ! )if you want to see what my world looks like :http://www.colourblindawareness.org/colour-blindness/colour-blindness-experience-it/and wait for the deuteranopia slide.in short : bi color indicators should be prohibited uness they are red/blue

author: free_electron
author_rank: Super Contributor
timestamp: September 15, 2013, 02:52:59 am
content: Quote from: Hydrawerk on September 15, 2013, 12:35:14 amthe programmer that made that is an idiot.look at the refresh flicker of the display ! No wonder this lookes bad.her is first erasing all characters with blanks and then rewriting them. the proof is that the first character is bright while the last in the queue flickers badly. ( the first digit is 'off' 1/16 of a line while the last is off 15/16 of a line ....)he's not buffering his display and he's wasting cpu time waiting for the display update..<joke>plus, an iq test based on an atmel cpu ? that is already a contradiction in teminis...</joke>

author: peter.mitchell
author_rank: Super Contributor
timestamp: September 15, 2013, 03:33:04 am
content: Quote from: free_electron on September 15, 2013, 02:48:52 amTo be honest, bicolour indicators should be prohibited in general, if you look at them off angle, often you will only see one of the two colours being illuminated, even if both are, it's frustrating to most people.

author: WarSim
author_rank: Frequent Contributor
timestamp: September 15, 2013, 05:34:17 am
content: Quote from: free_electron on September 15, 2013, 02:52:59 amFree-electron what in the world made you be such a douche?Every on is in title to an opinion, but you don't need to be a tackles jerk.Responses like yours only achieves on effect. A reduction in you credibility and the respect others give you.I suggest you retract you derogatory remarks.

author: free_electron
author_rank: Super Contributor
timestamp: September 15, 2013, 10:50:10 am
content: Quote from: WarSim on September 15, 2013, 05:34:17 am<Sarcasm on>If you are going to make an iq test, at least learn to write a proper display update routine. <sarcasm off>This thing flickers like crazy. I see this kind of mistake frequently, even on commercial products, and it makes me mad. The display is unreadable and it looks bad.Furthermore, the entire display string is being rewritten while only 3 characters need updating.If i'm going to be insulted by a little program that is going to tell me i'm an idiot it'd better be done right!This is one of my 'pet peeves' just like internet schematics consisting of loose components scattered on a page with netnames on em... or wire spaghetti . nobody takes the time to make custom symbols and deliver clear, readable stuff anymore. This is a bad lcd library or bad lcd code. <Sarcasm on>I blame the arduino generation.<sarcasm off>I mean, come one, how hard is it to properly refresh a display ? It does not take a genius.Allocate 32 bytes of memory , software updates the memory. main code is not allowed to touch the display directly.A service routine shoves the buffer to the display in one go. It will be clean, although very wasteful in cpu cycles (especially if you are going to poll the display to wait sending the next character like it should be done, and not using a stupid hardcoded time). But it will be clean. If your skills grow you will code the main program as fall-thru decision logic that only touches the display, when there is an update, and only the characters needed. The code in the example above is most likely something like this :Code:For x 0 to 100Clr , print 'processing ', x , "%"Wait 100msNextChanging it toCode:Locate 1,1: print 'processing'For x = 0 to 100Locate 1,12 print x,"%"Next xWill prevent this problem.Now, it may be that hydrawerks is not the guy that wrote that bad code, then the blame falls on whoever wrote the library that implements that cruft.Put some more spit and polish on a user interface even if it is only for a run-once joke program.Another reason for my strong reaction is that there is a complaint about the blue display with white backlight. On an inverse display the flicker is more noticable than on a classic black on yellow one for example.You get these weird intermediate blue colors. The left character is white, the center character is almost a dimmed blue while the right character is like an oversaturated dark blue. Kinda like the color you get when the display isn't initialised yet and the top bar is all dark..If you are going to complain about the readability of the display ... Fix your damn display refresh routine first.I do agree that there is one point in my post where i should have put in a bit more consideration. I fixed that portion.Note to self : don't comment on pet peeves while tired and grumpy. People dont like strong reactions

author: amyk
author_rank: Super Contributor
timestamp: September 15, 2013, 11:01:50 am
content: Quote from: free_electron on September 15, 2013, 02:48:52 amResistor colour codes must be a nightmare for you...

author: GK
author_rank: Super Contributor
timestamp: September 15, 2013, 11:12:06 am
content: My "pryon" PC case has some stupid ultra bright blue LED's mounted with a diffuser designed to illuminate the entire width of the bottom of the front panel. Hurts your eyes and illuminates the whole freaking room with the lights off. I opened the case to see if I could yank out the LED's but the were out of reach behind a front panel subsection pop-riveted to the chassis. Couldn't easily identify the right wires either as they are with a bundle of wires for other things. Arggh. A layer of aluminum foil over the front panel and then tape on top fixed the problem.

author: Unknown
author_rank: Unknown
timestamp: September 15, 2013, 11:30:19 am
content: Quote from: amyk on September 15, 2013, 11:01:50 amGood for him nobody uses through-hole resistors anymore outside power supplies or cheap Chinese crap.

author: free_electron
author_rank: Super Contributor
timestamp: September 15, 2013, 11:30:46 am
content: Quote from: amyk on September 15, 2013, 11:01:50 amI started using smd in 1989... Haven't had problem sinceAnd before 1989, i had a good ohm-meter.It is actually more subtle than that. The problem is still see the brightness of a green object, just not the color.So, if you put a red object with a certain brightness next to a green object with the same brightness then both are red to me.Background is important. . The yellow/beige are ok. The dark brown ones are more difficult and the blue precision resistors are a nightmare for meIn standard E12 the problematic values are 120,150, 220 1k2 1k5 2k2The others can be 'filtered' away because the combination doesn't make sense.120 brown red brown : confused to 120 on center ring , confused to 1k2 and 1k5 and third ring150 brown green bown see 120220 red red brown here the confusion is to 2k2 which is red red red12k and 15k only confuse each other as the third ring is orange.I simply avoided t hose values in anything i designed.But with surface mounted stuff the problem disappeared completely. Yay for SMD!Whne i grew up we had to undergo some psycho-medical exam in first thru 6th grade. Those doctors said i would not be able to learn electronics because of the color code. I have an uncle who also does electronics and he simply said : use an ohmmeter if you arent sure. We found out it was only the red brown green rings that are problematice and you can 'reason' those away . You can filter out the. 'Impossibles' because they dont make sense in e12 series (which was prevalent at the time... Talking 1976 now..)If i ever encounter one of those 'doctors' that decide what a kid should not be allowed to do, he'd better hope i'm not carrying a multimeter... It'll end up sideways , with the probes sharp end pointing outward, in that place where the sun doesn't shine. He'll be walking 'funny' for months.Those guys have destroyed too many kids aspirations and dreams because of outdated viewpoints.

author: SeanB
author_rank: Super Contributor
timestamp: September 15, 2013, 12:03:34 pm
content: My father was blue green colour blind, and he was a commercial pilot for a few decades. Only difficulty he had was wiring up a 3 pin plug, there he generally would call me to check, or looked carefully to see the yellow green banding on the earth wire to differentiate them.

author: c4757p
author_rank: Super Contributor
timestamp: September 15, 2013, 12:28:43 pm
content: The resistor color bands are already bad even if you aren't color-blind... so many manufacturers use cheap inks that make colors very similar. I am not color blind and quite often have trouble with brown/red/violet on some brands, violet/grey and red/orange on others... I've even seen golds that looked like yellow... and brown-red-black-orange-brown: is that 120K or 13K?It's pretty silly of a doctor to say your colorblindness would prevent you from working in electronics... you're probably no worse than most of us at reading the damn things...

author: rdl
author_rank: Super Contributor
timestamp: September 15, 2013, 02:37:36 pm
content: QuoteYeah, I agree. I have to look at them under very bright light to see the difference sometimes. The manufacturers are too cheap to add enough TiO2 (white pigment) to lighten the color enough. Most organic color pigments appear nearly black in their pure state when mixed into liquid such as paint or ink. Of course, these resistors only sell for pennies, so I guess it's somewhat understandable.Most of the time I use a meter instead of trying to see the colors, just to be sure. They might as well leave the color bands off and just mark them with the actual value.

author: timcki
author_rank: Contributor
timestamp: September 15, 2013, 03:18:14 pm
content: I like blue leds.

author: Unknown
author_rank: Unknown
timestamp: September 16, 2013, 12:00:25 am
content: Color bands are much easier to see on the tan carbon film resistors than on the blue metal film. A reason to buy carbon film over metal film.

author: tom66
author_rank: Super Contributor
timestamp: September 16, 2013, 12:16:59 am
content: Blue LEDs can be used tastefully. The KURO plasma displays use it quite well for power indicator, and I think you can turn it off in the user menu too.But the Whirlpool washing machine we own does not use them right at all. All the indicators are over-driven blue LEDs. You know when you overdrive a blue LED and it goes white, because the yellow phosphor can't keep up? Yeah... and then after a few years the LEDs start failing and half them are completely dark now, corresponding to how often certain presets are used.

author: rdl
author_rank: Super Contributor
timestamp: September 16, 2013, 12:40:26 am
content: My 8 year old TV has a blue LED. It's a more greenish color of blue than what you see these days and it's not terribly bright. The nicest thing about it is that it only comes on when the TV is off but still plugged in. When I first got the TV I thought that was ass-backwards, but I soon realized that having a blue LED in your face while watching TV would probably have been a bad idea.

author: xrunner
author_rank: Super Contributor
timestamp: September 16, 2013, 12:44:34 am
content: Quote from: timcki on September 15, 2013, 03:18:14 pmI wonder if you really like do like them. It's easy to say so on a forum, but a lot harder to prove it.Can you post a pic of you in the physical act of liking them?

author: kizzap
author_rank: Unknown
timestamp: September 16, 2013, 04:14:05 am
content: Quote from: xrunner on September 16, 2013, 12:44:34 amPlease Don't.

author: cimmo
author_rank: Frequent Contributor
timestamp: September 16, 2013, 10:17:58 am
content: Quote from: tom66 on September 16, 2013, 12:16:59 amSorry, not sure if you're trying to make a joke here, but you do know there are no phosphors in a blue LED?White LEDs are based on a blue LED with a phosphor, but all other LEDs are monochromatic.If you meant it as a joke/sarcasm, then disregard.

author: westfw
author_rank: Super Contributor
timestamp: September 16, 2013, 04:04:10 pm
content: QuoteNah; people have gotten creative with the phosphors. Pink LEDs are also blue emitters with a phosphor.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: September 16, 2013, 04:26:37 pm
content: Quote from: westfw on September 16, 2013, 04:04:10 pmPink is not monochromatic as its a combination of colors (namely white and red, though sometimes with a bit of purple thrown in). Anything that is not a pure color is going to involve phosphors of some sort.The exception to this would be the "Magic Size" quantum dot LEDs. Where they take advantage of the surface trap emission to create intrinsically white LEDs.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: September 16, 2013, 04:29:29 pm
content: Quote from: PedroDaGr8 on September 16, 2013, 04:26:37 pm