[sdiy] Re: Other LED's

[Simon Gatrall]

>Pulse width modulation would probably provide better control of LED
>Intensity for color mixing.  A diffusing lense would probably blur the
>point source light somewhat.
>
>regards,
>p

I worked on a project recently where we did both of those things and 
indeed the tri-color LEDs are very cool when used in this fashion. 
As was mentioned below, without the diffuser, there are very distinct 
sources for the R, G, and B which looks weird.

>
>-----Original Message-----
>From: owner-synth-diy at dropmix.xs4all.nl
>[mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of Scott Juskiw
>Sent: Tuesday, March 23, 2004 5:23 PM
>To: synth-diy at dropmix.xs4all.nl
>Subject: [sdiy] Re: Other LED's
>
>
>>I made a little board with three pots feeding an RGB LED, to
>>experiment with mixing the colours. What I really wanted to do was
>>make a purple LED :-)
>>Results were a bit disappointing. Did get a purple-ish light, but
>>despite the diffused package the three colours didn't mix very
>>convincingly and the overall shade varied a lot as you viewed it
>>from different angles.
>>Having said that, I was only briefly messing about with one
>>particular type - perhaps other types/better technique would give
>>better results.
>>Cheers,
>>Steve L.
>
>I've had a similar experience with RGB LEDs. To me the they look like
>4 tiny LEDs (1 red, 1 green, 2 blues) in close proximity rather than
>one 5mm LED with a single mixed colour. I remain underwhelmed. The
>one I tried was by Lumex, Digikey #:
>
>67-1829-ND LED T-5MM RED/GRN/BLUE WATER CLR
>
>I've had better luck with purple LEDs. I tried these Lumex ones, Digikey
>#:
>
>67-1830-ND LED T-5MM 410NM VIOLET WATER CLR
>67-1831-ND LED T-5MM 380NM VIOLET WATER CLR
>
>The 380 nm variety is much more expensive than the 410 nm. I couldn't
>see much difference between them. I used a bunch of the 410 nm in my
>synth. Looks great.


-- 
Simon Gatrall
gatrall at pacbell.net