Why did we mess up the indicator LEDs and what needs to be changed

Ah, this modest indicator LED. Almost all home electronics, all integrated modules have it, and generally everything that consumes electricity. In ancient times, a modest indicator glowed dimly from the back of the panel, and everything was fine. But then the 1990s came, and everything went to hell.

It's not about technology, but about how you use it.


With great brightness comes great responsibility.

In the 90s there was a lot of good: Nirvana, Linux, and, of course, a blue LED. Like Teen Spirit, the latter began to abuse too quickly: technology quickly became a symbol of everything new and cool, right down to the pain in the eyes of the buying public.

This decision on the level of stupidity is on a par with other controversial decisions, such as renting a car directly at the airport or invading Russia in the winter. I am sure that many will agree that the indicator LED should inform us about the current status of the device. It should shine bright enough to be seen if desired. What he does not need to do is shine with the brightness of an exploding star, or illuminate the entire room. However, in the desperate attempts of new product designers to pretend that they are at the forefront of technology, everything was flooded with new and bright LEDs.

This situation gives users a headache for many reasons. The number of electronic devices in the house has increased dramatically in recent decades, and most of them have their own indicator LED. Worse, many of them are used in bedrooms - whether it's laptops, phone chargers, televisions, and more. Due to the increased brightness of these indicators, many of which do not turn off, the middle bedroom now resembles a Christmas tree.


The charge from Samsung, which is supposed to be used on the bedside table, was so bright that the user had to crack it to mute it.

And the fashion for using blue LEDs for this purpose only worsens this problem. In the human eye there are special receptors that are sensitive to blue color, which are used not only for vision. They are also used to recognize the blue color of the sky, which coordinates our internal circadian rhythms, matching them with a day / night cycle. Observing artificial blue may affect this system, and researchers believe our sleep cycles may be affected.

Part of the problem is that most of the LEDs on the market today are bright blue. They are included in device designs, not paying attention to excessive luminosity, because it is simple to do - or the designers simply could not update their preferences for the standard rating of the current-limiting resistor.

If I see a bright glow on the ceiling because I did not turn off the Caps Lock button before I go to bed, this is a problem. The same goes for phone and laptop charges. I do not have to wrap the device in several layers of electrical tape in order to hide the light, which was originally supposed to glow dimly. If the device works reliably enough, I most likely will not look at it at all!

How to do it right

Of course, we all love the light indicators on the system unit, and there is a good use of a good indicator LED. He tells us that we are writing a very aggressive letter with frightening capital letters, that our charging really gets a delicious alternating current, and that power is supplied to our monitor, but it’s just not turned on until the end (okay, really, to whom it matters?). Although they are necessary - but this cannot justify the fact that they are so wrongly doing. It is very important to draw up several rules for their proper implementation and use.


Amiga 500 is an example of maximum brightness. And even here there is already a little busting, although the selected colors do not interfere with the work of our internal clocks.

Excessive brightness should be avoided. Small LEDs can easily be muffled by simply changing the resistor rating, so there is no excuse for LEDs that simply indicate the presence of power or go into standby mode, but at the same time illuminate the entire room. The brightness level must be adapted for the respective use cases of the device. Home computers of the 1980s had no problems with excessive brightness of indicators, so it is suggested to take an example from indicators from the Amiga 500. Their average brightness should be taken as the maximum brightness for indicators on power supplies or other home electronics. It is important to understand that you should not look at the LED at all so often, unless your equipment is terribly unreliable. And in this case, you will already have other problems.


Let's agree that “red” means “record”. If something is not broken, do not repair it!

You also need to standardize the colors, or at least choose them meaningfully, for an effective visual presentation. And although I am amazed at the beautiful pink LED on Nintendo's DSi, we have long agreed that the red color means “recording”, and there is no reason to refuse it. If your device must have an LED indicating standby mode (what, really?), Make it red or orange. And the power LEDs should be green. You don’t need this nonsense, “blue means turned on” - this is just a show. It wasn’t cool in 2001, and today isn’t cool either.

It is also necessary to question the purpose of the indicator LED. Too many LEDs or too many colors can confuse us. The laptop charger LED should have one color that indicates the charge - ideally, green. If it is orange and green, then what does that mean? Is it fully charged and charged? Broken and charged? If the user needs to go into the instructions in order to understand the meaning of the indicator LED, then you probably could have done better.


Slow flicker is not as distracting as a quick blink, but is it really necessary?

Blinking should only be used when absolutely necessary. The LEDs on the hard drive and network activity should blink, as they indicate a constantly changing state. The LED on the mixing console, which means mute, should blink, as this will save novice technicians who cannot understand why there is no sound. On the other hand, the LED on the TV in standby mode should not blink at all, because if the TV is off, this means that no one wants to pay attention to it.

I hope that these rules will be the starting point for future device developers. The charging mat, designed for the bedside table, will no longer illuminate the entire room with an ominous blue light. The TV will not blink unceasingly, preventing guests sitting on the sofa to sleep. A little change - and we can all rest, freed from the distracting radiance, and go about our business. Of course, this is just the opinion of one elderly engineer.