Purple LEDs?

[pixelpusher]

So, I started the process of adding LEDs to my pok3r.  No problem with them actually working.  However, I cannot seem to find a purple LED that is anywhere near bright enough to give a good keycap underglow

I used the 2x3x4 rectangular leds.  I had a pack with 9 different colors.  http://www.ebay.com/itm/121774202618?_trksid=p2060353.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT

They're all great except purple, it's quite dim.  You can even see on the spec sheet that their mcd rating is much lower. I tried more than one LED, so it's just the nature of the color, I believe.  I also tried a 3mm round led, but quickly found out what "flangless" was... because I didn't order flangeless and the rim on the bottom of the led makes it stick up way too high so that it interferes with the key press.  It really did not look much brighter to me though.

Does anyone have first-hand experience with another purple LED option that is truly bright?  HALP!  I needZ purple BacklIghting for my HYPERfUSE set!!!   

[thatsmrdoctortoyou]

If you have a dremel you could grind the flange off of the flanged LEDs. It looks like a pain in the butt, but if you already have leds with the right color/brightness it may save you the headache of finding flange-less leds

[Spopepro]

You might not find many LEDs 400nm and below because a) you begin to have significant trouble seeing light starting around 400nm and b) there is non-trivial danger of high power leds in this wavelength due to UV radiation. If you want a bright purple look, maybe look for something in the 410-420 range. It will have a slightly blue hue to it, but will appear way brighter.

[pixelpusher]

Okay I'm not having any luck searching for 420nm leds.  Seems like I might just have to use pink or white.   Boo

[Data]

I'm seeing lots of 420nm LEDs but not as through-hole components.  Mostly SMD and light strips.

Most are 395-400nm:
https://www.aliexpress.com/item/100PCS-Purple-Color-5mm-Transparent-Water-ClearRound-Super-Bright-UV-LED-DIODE/32266780769.html?spm=2114.01010208.3.1.1XgkNe

Mouser has 428nm here:
http://www.mouser.com/ProductDetail/Lite-On/LTL42UB6N/?qs=sGAEpiMZZMtmwHDZQCdlqc2x%252b1SaW5zkfsFaqR48jiU%3d

But I'm not 100% sure if the leads will fit the standard keyboard spacing.  Might be worth a shot to buy some and see.

[pixelpusher]

Yeah I saw that too.  Lots of variety on surface mount but not on through hole 

I could try that second one you linked but they have the flange on the bottom and they are over $50 for 100. 

Maybe I'll just go with white for now and see about moving my hyperfuse set to a board with rhb lighting for purple down the road

[zeltner]

These are SMD style but they are 400nm
https://www.amazon.com/gp/product/B01CUGACAY/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Heres some pictures of them in use w/ a clear case.

[Data]

Yeah I saw that too.  Lots of variety on surface mount but not on through hole 

I could try that second one you linked but they have the flange on the bottom and they are over $50 for 100. 

Maybe I'll just go with white for now and see about moving my hyperfuse set to a board with rhb lighting for purple down the road

The 428s are T-1 3mm package.  I checked the spec and they should fit the standard 2.54mm lead spacing.  Bottom flange shouldn't cause any problems at 3mm.  Cherry switches are made to fit up to 5mm round LEDs.

[pixelpusher]

These are SMD style but they are 400nm
https://www.amazon.com/gp/product/B01CUGACAY/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Heres some pictures of them in use w/ a clear case.

Those look amazing.  I don't understand the specs.  Those you linked are rated at 20-25mcd and they look so bright.  The ones I was using show that they are Luminous Intensity:
(Unit:mcd, IF=20mA)  2000

I read that as 2000mcd if they are supplied 20mA, but that would be 5v, and I'm pretty sure the board won't put out 5v to the LEDs

But even at 1/2 of that voltage, wouldn't I see 1000mcd?  Maybe not, maybe the math doesn't work that way.

[pixelpusher]

These are SMD style but they are 400nm
https://www.amazon.com/gp/product/B01CUGACAY/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Heres some pictures of them in use w/ a clear case.

Those look amazing.  I don't understand the specs.  Those you linked are rated at 20-25mcd and they look so bright.  The ones I was using show that they are Luminous Intensity:
(Unit:mcd, IF=20mA)  2000

I read that as 2000mcd if they are supplied 20mA, but that would be 5v, and I'm pretty sure the board won't put out 5v to the LEDs

But even at 1/2 of that voltage, wouldn't I see 1000mcd?  Maybe not, maybe the math doesn't work that way.

But that little lip at the bottom keeps them from slipping down into the switch housing, or at least it did on the 3mm LEDs that I recently purchased.  There is a rounded notch in the switch to accommodate, but my 3mm led sticks up too high and can't get down into the switch unless I somehow remove the lip/flange at the base of the light.

[pixelpusher]

Heres some pictures of them in use w/ a clear case.

I'm assuming those are white LEDs on the switches?  If so, I might just go that route.  That looks pretty nice, indeed.

[Fictiouz]

What value resistors are on the board? Correct me if I'm wrong but when using higher voltage drop LEDs don't you want smaller resistors to reduce the current limitations. I'm making the assumption that the Pok3r PCB has per-key resistors, one for each LED.

IIRC 820 is the standard value for white backlight LEDs.

[pixelpusher]

I thought that might be the issue.  I don't know that I want to go about trying to change the resistors.  I'm not even sure it would help, b/c according to the spec sheet of the LEDs I bought, the forward voltage is actually the same for white and purple (avg 3v, max 3.4v)

I did find another thread on reddit that said the pok3r is set up with resistors for white LEDs.  I think I'll just take the path of least resistance (ooh, snap, all puns intended) and use white or pink LEDs.

[zeltner]

These are SMD style but they are 400nm
https://www.amazon.com/gp/product/B01CUGACAY/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Heres some pictures of them in use w/ a clear case.

Those look amazing.  I don't understand the specs.  Those you linked are rated at 20-25mcd and they look so bright.  The ones I was using show that they are Luminous Intensity:
(Unit:mcd, IF=20mA)  2000

I read that as 2000mcd if they are supplied 20mA, but that would be 5v, and I'm pretty sure the board won't put out 5v to the LEDs

But even at 1/2 of that voltage, wouldn't I see 1000mcd?  Maybe not, maybe the math doesn't work that way.

To be honest I don't really understand what all of those specs mean. I wanted purple underglow for the build and I found these. I asked in leandren group buy thread I think and someone said they should work so I tried them and that was the result.

Heres some pictures of them in use w/ a clear case.

I'm assuming those are white LEDs on the switches?  If so, I might just go that route.  That looks pretty nice, indeed.

Yeah it is the purple SMD leds on the bottom for underglow and then 1.8mm white LEDs in the switches.

[ghostjuggernaut]

Purple LEDs are actually UV, so you will have a difficult time finding bright ones. I used 1.8mm ones fro lighthouse LEDs that weren't too bad on my GON. Unfortunately I don't have a pic anymore of the board. SMD purple works rather well normally.

[0100010]

What are the specs on the purple LEDs you have now, and can you get a pic of the current resistors on the board?

[Mickkkey]

Although this is an old post I have the LTL42UB6N LEDs (mine are from Mouser though several other sites offer them also) and so I can shed some LIGHT on the subject.  This is a silicon carbide blue LED which is one of the first blue types released, predating the Nichia blue IIRC.  It emits light over a very broad bandwidth going even into the orange/red region, although very dimly.  So it looks like a lighter shade of blue similar to a typical blue power indicator LED but with a less "saturated" color appearance and a faint purplish halo visible around the point of light when viewed from a distance.  They used these in the Mackie self-powered PA speakers, and may still to this day AFAIK. 

My copies of these LEDs have a forward voltage of 4.24~4.30V @ 20 mA which is a volt or more above typical white/blue/green/violet voltage.  This is a function of the chemistry so I don't think they can ever be as low as the others.  If run from 5V at rated current this would require a 39 Ohm resistor.

Other violet LEDs (400~430nm):

They are still readily available around 400~405nm, but as mentioned previously that's not really what you want.  Ideally look for ones around 415~420nm.  Good luck. They USED to be readily available, like 7 or 8 years ago.  Nowadays they're very rare unless you're prepared to buy 10,000 or more from Alibaba.  That's "progress" I suppose. . You can still get this wavalength range readily but only in the 1 watt and above, surface mount and chip-on-board sizes.

Hope this helps! 

If anyone has other sources for 100-ish quantities I'd be interested.  Also for the 480~490nm 3- or 5mm bluish-cyan range, which has become extremely hard to get also.  Thanks!