LEDs Browning Out - Not just Violet, now RB

[jack1978]

Yes, no problem with silicone coverage.

 

Awesome, thanks for the info!

Brand you would recommend?

[nady]

There are many, for example, ac-rc, leds-global, ....

[evilc66]

This is a common problem with the generic LEDs under 430nm. The material that is used for the lens isn't rated for such a short wavelength, and as a result, discolors. I've seen this on 400nm, 410nm, and 420nm LEDs. That's not to say that all generic LEDs are built with the same defect, but it's more common than not. On the newer violet LEDs (XP style) that LEDGroupBuy and RapidLED sells (not sure about Steves at the moment), the silicone material that is used is very high grade, and shouldn't discolor over time. The lower the wavelength, the greater the chance for problems. All LEDs under 400nm will have glass lenses.

 

The theory that the violet LEDs were discoloring the royal blue lenses is a pretty good one, and probably the best option to date. 455nm shouldn't create issues with the lens material.

 

Bottom line is (and you've heard it already), you get what you pay for.

 

 

 

And don't worry about the thermal pads. While the ones you used were a little on the thick side, you correctly used them with screws to increase the clamping pressure. While not quite as good as thermal paste, they are more than adequate. I've been using Bergquist Bondply adhesive thermal pads for years (no screws) without any issues, and are great for prototyping.

[jack1978]

Evil,

Can't thank you enough for chiming in with all the detail, so thank you!

Glad to see you around here again. You're builds were what got me going the LED route.