# Pet LED Peeve of the day



## KC2IXE (Jun 1, 2010)

Blue LEDs - why does every electronics designer seem to thing they need a BLUE LED status bar drive to levels that we don't need a nightlight? The area around my computers USB port - BLUE, my NAS Box, BLUE flickering status bar with a RED power led too

How about something simple please - the nice small round or rectangular LEDS - RED for off/fault, amber for standby, green for on - and dim enough so they don't light up the whole room at night - PLEASE


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## ninemm (Jun 1, 2010)

I couldn't agree with you more. My HP Mini had power buttons on the front of the body under the track pad. Well, when resting the netbook on your chest the blue and white leds would shine right in your eyes. So annoying.


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## JohnR66 (Jun 1, 2010)

Reminds me of the toaster my parants have. It has buttons on the side to select what you are toasting. Each button has a blue led that lights up the kitchen like a night light at night.

Same thing with these cheap closeout Ipod speakers I got from Walmart. Blue LED is like a bright keychain light!.

Perhaps the indicator circuit was designed for the standard indicator LED and someone in marketing says, "Hey. Lets use blue LEDs!". The dropping resistor wasn't changed to compensate for the high brightness of the blue LED and you get the bleeding bright blue light.


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## blasterman (Jun 1, 2010)

A few years ago a friend of a friend asked me to mod out the front indicator lights of his PC with the brightest LEDs that would work. I ended up using the brightest 100mA LEDs I could find (more concerned about the MB being able to push the current). After all, it wasn't my computer and I didn't have to look at it.

I noted that I could see if he had HD activity out in the parking lot via the room lights of his apartment flickering. I think this lasted a month before his GF painted nail polish over the front panel of his computer case. I've seen some older HP models nearly as bad.


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## Canuke (Jun 1, 2010)

JohnR66 said:


> Perhaps the indicator circuit was designed for the standard indicator LED and someone in marketing says, "Hey. Lets use blue LEDs!". The dropping resistor wasn't changed to compensate for the high brightness of the blue LED and you get the bleeding bright blue light.



Ironically, the higher Vf of blue diodes would result in a very *dim* light in such a case, wouldn't it? Seem to me that we ought to wish they did this.


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## JohnR66 (Jun 1, 2010)

Canuke said:


> Ironically, the higher Vf of blue diodes would result in a very *dim* light in such a case, wouldn't it? Seem to me that we ought to wish they did this.



Indeed the current would drop and the amount of reduction would depend on the supply voltage to the resistor and LED, however the super bright blue LEDs can be many times brighter than the standard lime green indicator LED that much more makes up for lower current.


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## Fallingwater (Jun 1, 2010)

I can definitely understand the reason for this mini-rant, but whenever I turn on my external hard drive I always surprise myself staring at the high-intensity blue status light shining from the underside of it. I just love blue light. <3


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## Lynx_Arc (Jun 1, 2010)

I have figured out how to stomp out bright blue and green LEDs on stuff. I have a dvr with a bright blue light that comes on when it records I took the plastic film label off a set of sunglasses that was a white label and stuck it over the rectangular LED and it cut it down to a nice level. I have bright blue power and drive lights on my computer I used poster putty to block them easily removable with no mess. I put a thin layer of poster putty on the blue LED on my duracell mobile charger too and some on the green "tuned" led on my stereo too. I use the blue poster putty. The flexible plastic peel offs on stuff are good to block light on shiny plastic surfaces I wish I had some that was like window film that uses static to stay on no adhesive.


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## gswitter (Jun 2, 2010)

Ten years back, I was working on souped-up network interface card, and marketing insisted that we use blue LEDs for the external status indicators. Something about our target customers willingness to pay more for an item with blue status lights than other colors. I'm sure that line of thinking had nothing to do with the company failing before the NIC hit the market. 

Blue status lights that I still need to see usually get covered with enough layers of masking take to make them barely visible. Others get blocked out altogether with electrical tape.


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## IMSabbel (Jun 2, 2010)

Reasons for this effect: 

a) for most people, still, blue LEDS "look cool".
b) because of the differences in night and day vision sensitivity, if you make them nicely visible at day they are brutally bright at night with "rod" vision active.


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## McGizmo (Jun 2, 2010)

IMSabbel said:


> Reasons for this effect:
> 
> a) for most people, still, blue LEDS "look cool".
> b) because of the differences in night and day vision sensitivity, if you make them nicely visible at day they are brutally bright at night with "rod" vision active.



If there is a real need to see indicator lights then obviously they need to be seen. If they need to be seen comfortably both in high levels of ambient light as well as low levels of ambient light then an additional light sensitive dimming circuit would certainly help but is the additional cost acceptable?


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## BentHeadTX (Jun 2, 2010)

My 2003 MiniMag with BB400 sandwich performs a function while sitting on my desk.

I have it in front of the blinding blue power light on my computer power switch--a bit ironic though. An LED flashlight to block the light of an LED.


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## GarageBoy (Jun 2, 2010)

I hate it even more on portable electronics. I don't need a giant blue ring on my mp3 player or my video camera. The indicators probably use more power than the player does


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## Lynx_Arc (Jun 2, 2010)

actually the race has been to make white LEDs more efficient than other colors and blue is pre-white. I would bet a blue LED ran at the same current as a red or green (not same voltage) would be brighter due to being more efficient. It is quite possible factories that make non blue (and white) LEDs are now producing such a smaller amount the individual cost of the non blue (white) LEDs is probably less than other colors. In other words the blue power LEDs may be a "cool" way for companies to make another few pennies off folks over the price of green or red.


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## TorchBoy (Jun 2, 2010)

Lynx_Arc said:


> actually the race has been to make white LEDs more efficient than other colors and blue is pre-white. I would bet a blue LED ran at the same current as a red or green (not same voltage) would be brighter due to being more efficient.


You might be forgetting our eyes are less sensitive to blue light than they are to green light. Even with phosphor inefficiencies white LEDs are brighter than blue LEDs and green LEDs because they make more light in our more sensitive spectral areas. However, if by "efficient" you mean the light power out, not the lumens produced, then sure.


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## bshanahan14rulz (Jun 3, 2010)

Fallingwater said:


> I can definitely understand the reason for this mini-rant, but whenever I turn on my external hard drive I always surprise myself staring at the high-intensity blue status light shining from the underside of it. I just love blue light. <3



Sounds like one of my LaCie drives... the black box? heheh. You can use that blue light to read the code that quality color printers print on stuff. I think they're called microdots?

We also had a lcd monitor come through, and just googling it turned up many results for a popular LED mod: putting tape over the blindingly blue power indicator LED.


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## tebore (Jun 4, 2010)

gswitter said:


> Ten years back, I was working on souped-up network interface card, and marketing insisted that we use blue LEDs for the external status indicators. Something about our target customers willingness to pay more for an item with blue status lights than other colors. I'm sure that line of thinking had nothing to do with the company failing before the NIC hit the market.
> 
> Blue status lights that I still need to see usually get covered with enough layers of masking take to make them barely visible. Others get blocked out altogether with electrical tape.



Oh oh I remember that card it was basically over marketed QoS and server level logic so it can offload more of the ip stack. It costs as much as a high end video card and gave 1-2 fps in performance. Overall it was considered a huge rip off


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## ^Gurthang (Jun 4, 2010)

BBB syndrome.... "Blinding Blue Bulb" 

It looks "cool" so make it brighter....

It looks like those "cool blue" HID / Bi-Xenon headlights, so make it bluer! 

Does it cause cancer? IF not.... MAKE IT BLUEST!!!!!! 

BTW, don't get me started on those &*#%@$ HID headlamps.....


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## tay (Jun 4, 2010)

Agreed.

I bought an amplifier that has this obnoxious blue power LED. Where I originally had it on my shelf, it pointed right at my eyes when I was trying to watch TV. I put several layers of scotch tape on it and it was bearable. Now, I have it on a higher shelf above eye level.


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## Ken_McE (Jun 6, 2010)

KC2IXE said:


> Blue LEDs - why does every electronics designer seem to thing they need a BLUE LED status bar drive to levels that we don't need ...



My impression is that when blue LEDs first came out they were used as indicators on high end stereo equipment. Not sure if this was because it was thought men of high-end stereo buying age could see them well or what. This usage of blue = top shelf kit seems to have spread out into marketing in general. It may no longer be true, but *you* try explaining that to marketing.


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## jtr1962 (Jun 6, 2010)

This is certainly a pet peeve of mine as well, and not just in regards to bright blue LEDs. LEDs in general have gotten much brighter, but it seems designers still insist on running them at their "rated" current of 20 mA. Most of today's LEDs, except the yellow-green ones, are plenty bright enough as indicators running them at a few tenths of an mA.

And it seems we've come full circle regarding colors. I'm sure KC2IXE is old enough to remember the "good old days" when you could have any color you wanted for an LED indicator, so long as it was dim red.  I know I remember those days not so fondly. I remember being excited when we first had orange, then yellow, and finally yellow-green LEDs. And they kept getting brighter. Then came the 1990s with blue, true green, aqua, and white. First they were too expensive to use as indicators, except on very high-end products. Not so any more, but the association with "high-end" and blue has nevertheless remained. What I don't get is why, when we have a rainbow of colors to choose from, we're seeing only blue more and more. It's like we're going back to the days when red LEDs dominated, only then it was because that's all you had. It's boring, for lack of a better word. I make projects with indicator lights which sometimes look like Christmas trees. Each color serves a logical purpose. Red might signal overload, orange or yellow might be getting into the danger zone, green might be "all is well". And there might be something neutral, like white, just to indicate power. Blue sometimes comes in if I need to differentiate further. I'd love to see more variety of indicator lights with colors related to function, and also please drive the things at low enough currents so they don't blind me. It's supposed to be an _indicator light_, not a night light! Also, what's with using narrow angle LEDs for indicators? Wide-angle ones would be much more appropriate ( and also less blinding as the light is spread out ).


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## Curt R (Jun 6, 2010)

LED Eye Safety: Cree’s testing to date indicates that Royal Blue and Blue (450-485 nm dominant wavelength) 
LED lamps pose a higher eye safety hazard than White LED lamps. Other colors of LED lamps, such as Green or Red, 
do not pose a defined eye safety risk. Regardless of LED color, Cree advises users not to look directly at any LED lamp.

All light sources have the potential to be harmful to both the skin and the eyes through UV, blue light 
(410-480 nm) and IR emission. Independent photobiological testing of Cree visible light LED lamps has 
confirmed that the only health risk of visible light LED lamps significant enough to warrant 
advisory is viewing blue light with the eyes.


*Test Results - XLamp XR-E Royal Blue*
Risk Categories Found (per ANSI / IESNA RP-27.3-07): 
Blue Light: 
RG-2 (Moderate Risk): CAUTION. Do not stare at exposed lamp in operation. May be harmful to eyes. 
Blue Light, Small Source: 
RG-3 (High Risk): WARNING. Do not look at exposed lamp in operation. Eye injury can result. 

*Test Results - XLamp XP-E Blue*
*Test Results - XLamp XP-G Cool White*
Blue Light: 
RG-2 (Moderate Risk): CAUTION. Do not stare at exposed lamp in operation. May be harmful to eyes. 

Low powered 5 mm LEDs may not pose a risk, but high powered flashlights in blue and cool white may. 
The danger of higher powered lights using the SST-50, SST-90 and the CSM-360 could be very dangerous. 

Children should not use high powered LED flashlights without instructions and warnings!

Curt


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## TorchBoy (Jun 7, 2010)

jtr1962 said:


> I make projects with indicator lights which sometimes look like Christmas trees. Each color serves a logical purpose. Red might signal overload, orange or yellow might be getting into the danger zone, green might be "all is well". And there might be something neutral, like white, just to indicate power.


My laptop uses slow pulsing white to indicate it's sleeping, green (a nice green) to indicate the power supply is connected and powering it, and orange (a true orange) to indicate the power supply is charging it. Tasteful use of LED colour.



Curt R said:


> LED Eye Safety: Cree’s testing to date indicates that Royal Blue and Blue (450-485 nm dominant wavelength)
> LED lamps pose a higher eye safety hazard than White LED lamps. Other colors of LED lamps, such as Green or Red,
> do not pose a defined eye safety risk.


I remember about a year ago a CPF member got absolutely - and shamefully - roasted for mentioning things like this, even though he posted links to evidence. Poor guy was too far ahead of the pack. Just recently I've seen mention that excessive blue and UV light can lead to macular degeneration.


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## Steve K (Jun 8, 2010)

TorchBoy said:


> Just recently I've seen mention that excessive blue and UV light can lead to macular degeneration.




Interesting! I'd heard (about 30 years ago) that excess UV could cause cataracts, so aircraft pilots should always wear some sort of UV blocking eyewear when flying (especially at higher altitudes). In general, UV light is pretty destructive, so minimizing exposure is always a good practice. 

My understanding is that UV is damaging just because higher frequency light has more energy. It's not hard to believe that blue light would have potential for being damaging for the same reason. 

so the end result is: don't spend all day out in the sun, and get rid of those black light posters from the 70's?? 

Steve K.


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## Kestrel (Jun 8, 2010)

TorchBoy said:


> I remember about a year ago a CPF member got absolutely - and shamefully - roasted for mentioning things like this, even though he posted links to evidence. Poor guy was too far ahead of the pack. Just recently I've seen mention that excessive blue and UV light can lead to macular degeneration.


Felco. Supplied all sorts of supporting weblinks.


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## gswitter (Jun 10, 2010)

tebore said:


> Oh oh I remember that card it was basically over marketed QoS and server level logic so it can offload more of the ip stack. It costs as much as a high end video card and gave 1-2 fps in performance. Overall it was considered a huge rip off


That may have been it. I honestly don't remember how they were marketing it in the end. It was designed to solve a specific problem that no longer existed when the dot-com bubble burst and the price of rack space came down.


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