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How do you go about finding high-quality LEDs? Are they easily available in standard bulbs?

toss1 8y ago
Just tinkering, I've found several factors are important. First is the color temp and CRI of the bulb/chip; make sure they match your application. Sometimes mixing bulbs/chips works well to get a more pleasing & usable spectrum. I've also found that the strip LEDs with multiple colors and a tunable controller produce good results. Second, find a power supply/controller that has a very high frequency. LED's don't inherently flicker, and when powered straight from a source like a battery provide a completely steady light. The flicker is typically from a time-chopping brightness controller. Cheap ones may use 60Hz, which the eye can still see, especially in the peripheral vision areas (rod cells, sensing only grays detect motion much better, whereas color-sensing cone cells at the center of the visual field have a slower response so detect flicker less well). Ideally, get a controller well above 25KHz to also eliminate any audio artifacts. I'd very much like to see someone more expert chime in!
- iainmerrick 8y ago
  Are there any dimmable LED strips that operate by fully illuminating X% of the LEDs? As opposed to time-slicing all the LEDs. I don’t know enough about hardware to know if that would be feasible. The flickering and whining is pretty bad in all the dimmable LED bulbs I’ve used (but I haven’t yet looked hard for high-end ones).
  - dbuder 8y ago
    For long life, LEDs need to be off some of the time, better to run at 20mA 50% of the time than 10mA 100% of the time. That always on warning light on your cheap electronics runs at low power and has a relatively high failure rate. You need to tune or shield the drive to avoid troublesome EMI.
  - thatcat 8y ago
    Yea, my desk lamp does that.
  - OnlineCourage 8y ago
    That severly shortens the lifetime of an LED, like by a factor of 10. So I would guess it is not common because much of the benefit that gets marketed is the longer lifetime. It is possible to build a better dimmer switch which actually works across the full profile of voltage variation but the problem then is you have to pay an engineer money and why do that when you can spend money on booze and dinners to win more sales contracts with your lighting distributors and get a higher ROI? The lighting world is a very consolidated place.
lotsofpulp 8y ago
I haven't had any problems with the GE Classic LEDs: https://www.lowes.com/search?searchTerm=ge+classic+led https://www.lowes.com/search?searchTerm=ge+classic+led
- sydd 8y ago
  Sorry, they are likely crap. If there is no Ra/CRI value given its 80.
sydd 8y ago
Yes. Just google for stuff like 95 CRI or high CRI bulbs. They are a bit more expensive than normal bulbs though. Some examples of good ones: https://www.waveformlighting.com/home-residential https://www.waveformlighting.com/home-residential https://www.mueller-licht.de/ https://www.mueller-licht.de/ And surprisingly IKEA Ledare bulbs are pretty good too (although not as good as the ones above)

Just tinkering, I've found several factors are important. First is the color temp and CRI of the bulb/chip; make sure they match your application. Sometimes mixing bulbs/chips works well to get a more pleasing & usable spectrum. I've also found that the strip LEDs with multiple colors and a tunable controller produce good results. Second, find a power supply/controller that has a very high frequency. LED's don't inherently flicker, and when powered straight from a source like a battery provide a completely steady light. The flicker is typically from a time-chopping brightness controller. Cheap ones may use 60Hz, which the eye can still see, especially in the peripheral vision areas (rod cells, sensing only grays detect motion much better, whereas color-sensing cone cells at the center of the visual field have a slower response so detect flicker less well). Ideally, get a controller well above 25KHz to also eliminate any audio artifacts. I'd very much like to see someone more expert chime in!

iainmerrick 8y ago
Are there any dimmable LED strips that operate by fully illuminating X% of the LEDs? As opposed to time-slicing all the LEDs. I don’t know enough about hardware to know if that would be feasible. The flickering and whining is pretty bad in all the dimmable LED bulbs I’ve used (but I haven’t yet looked hard for high-end ones).
- dbuder 8y ago
  For long life, LEDs need to be off some of the time, better to run at 20mA 50% of the time than 10mA 100% of the time. That always on warning light on your cheap electronics runs at low power and has a relatively high failure rate. You need to tune or shield the drive to avoid troublesome EMI.
- thatcat 8y ago
  Yea, my desk lamp does that.
- OnlineCourage 8y ago
  That severly shortens the lifetime of an LED, like by a factor of 10. So I would guess it is not common because much of the benefit that gets marketed is the longer lifetime. It is possible to build a better dimmer switch which actually works across the full profile of voltage variation but the problem then is you have to pay an engineer money and why do that when you can spend money on booze and dinners to win more sales contracts with your lighting distributors and get a higher ROI? The lighting world is a very consolidated place.

lotsofpulp 8y ago

I haven't had any problems with the GE Classic LEDs: https://www.lowes.com/search?searchTerm=ge+classic+led https://www.lowes.com/search?searchTerm=ge+classic+led

sydd 8y ago
Sorry, they are likely crap. If there is no Ra/CRI value given its 80.

sydd 8y ago

Yes. Just google for stuff like 95 CRI or high CRI bulbs. They are a bit more expensive than normal bulbs though. Some examples of good ones: https://www.waveformlighting.com/home-residential https://www.waveformlighting.com/home-residential https://www.mueller-licht.de/ https://www.mueller-licht.de/ And surprisingly IKEA Ledare bulbs are pretty good too (although not as good as the ones above)