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I have an device to design on a low power budget, and I would like to have indicator LEDs on the front panel. What should I choose to be as visible as possible with the lowest possible power consumption? The instrument will be used in a typical office/lab setting.

Can do better than a green LED, with as much current as I can spare? Is there another technology I should look at?

Jack B
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    Blink them. Low duty cycle saves power as well as being more visible than steady. –  Oct 05 '20 at 13:13
  • Have you searched other questions here? I found answers to https://electronics.stackexchange.com/questions/505444/led-visibility-calculation have some good suggestions. –  Oct 05 '20 at 13:18
  • Include alternating position, nearby, to Brian's suggestion as the human brain is arranged to notice "motion." – jonk Oct 05 '20 at 13:22
  • @CharlesCowie Yes, I think that is mostly about LED visibility which I am reasonably familiar with, I was more wondering if there was something else to consider as an alternative to LED. – Jack B Oct 05 '20 at 13:45
  • @BrianDrummond Good idea, thanks. – Jack B Oct 05 '20 at 13:47
  • Also consider a "test" button. LEDs are completely off until button is pressed. – rdtsc Oct 05 '20 at 13:51
  • @rdtsc good idea, but these lamps will be at their most useful when the user is poking and prodding other things at the same time, and that might get frustrating. I guess I could hold them on for 20 sec after a button press. – Jack B Oct 05 '20 at 13:57
  • Two button presses - ON full time til one button press, when it reverts back to 20s. Allows trouble shooting. – StainlessSteelRat Oct 05 '20 at 21:02

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High-brightness LEDs (those with a zillion candela) are noticeable with a tiny current, a fraction of a milliamp... So that could be a good choice. This is thanks to the optics concentrating the light in a tiny cone angle though, which means they lose visibility when you look at them from the side.

Make sure they sit against a dark background.

If they blink for important stuff, okay. If they blink all the time, someone will get fed up of it and stick black tape over it.

bobflux
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