I’m sure, like me, you have lots of electronic gadgets that have status LEDs on them. Some of these just show the thing is on, some blink when it’s doing things. Of late, as blue LEDs have gotten cheap, it has been very common to put disturbingly bright blue LEDs on items.
These become much too bright at night, and can be a serious problem if the device needs to be in a bedroom or hotel room. Which things like laptops, phone and camera chargers and many other devices need to do. I end up putting small pieces of electrical tape over these blue LEDs.
I call upon the factories of Shenzen and elsewhere to produce low cost, standardized status LEDs. These LEDs will come with an included photosensor that measures the light in the room, and adjusts the LED so that it is just visible at that lighting level. Or possibly turns it off in the dark, because do we really need to know that our charger is on after we’ve turned off the lights?
Of course, one challenge is that the light from the LED gets into the photosensor. For most LEDs, the answer is pretty easy — put a filter that blocks out the colour of the LED over the photosensor. If you truly need a white LED, you could make a fancy circuit that turns it off for a few milliseconds every so often (the eye won’t notice that) and measures the ambient light while it’s off. All of this is very simple, and adds minimally to the cost. (In fact, the way you adjust the brightness of an LED is typically to turn it on and off very fast.)
Get these made and make it standard that all our gear uses them for status LEDs. Frankly, I think it would be a good idea even for consumer goods that don’t get into our bedrooms. My TV rooms and computer rooms don’t need to look like Christmas scenes.