[sdiy] Re: Other LED's

[phillip m gallo]

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


-----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.