tdaniel@hubcap.clemson.edu (tod daniels) (02/16/91)
Can anyone recommend a vendor for a tri-state LED. If possible, I would prefer one with three separate diode leads and a common anode (or cathode) in a single package with a single lens. The three colors should be red, blue, and green. Schematically, it should resemble the following: | | | | | | -- -- -- /\ /\ /\ /__\ /__\ /__\ | | | | | | ----------------- | | I know that two color LEDs are available, but they usually require that the voltage across the diode be reversed to get the other color. Is something like this available anywhere?? Thanks... -- ----------------------------------------------------------------------- "It's so lonely when you don't even know yourself" -- RHCP tod daniels -- tdaniel@hubcap.clemson.edu
smithj@hpsad.HP.COM (Jim Smith) (02/20/91)
The only tricolor LEDs that I have seen only use two elements, and you get the third color by turning on both (or using AC). I've never seen a BLUE LED. If the item you're looking for were available, you could make a GIGANTIC CGA display! good luck!
tomb@hplsla.HP.COM (Tom Bruhns) (02/21/91)
I recently saw an article about blue LED's, claiming they were likely to start getting cheaper (as I recall). I think they talked about a three- primary-color package being recently announced. Check the newspaper-type electronics journals: Electronic Engineering Times and a similar EDN- sponsered one. The article was in one of them since the first of the year.
henry@zoo.toronto.edu (Henry Spencer) (02/21/91)
In article <13140@hubcap.clemson.edu> tdaniel@hubcap.clemson.edu (tod daniels) writes: >I would prefer one with three separate diode leads and a common >anode (or cathode) in a single package with a single lens. >The three colors should be red, blue, and green. Nobody makes r/g/b LEDs yet that I know of. Practical blue LEDs are a very recent development. >I know that two color LEDs are available, but they usually require that >the voltage across the diode be reversed to get the other color. "Usually" is a vast overstatement; circa half of the manufacturers supply the three-lead version instead. (In particular, almost all rectangular bicolor LEDs are the three-lead version.) These are sometimes advertised as "three color" LEDs, but they mean red, green, and yellow. -- "Read the OSI protocol specifications? | Henry Spencer @ U of Toronto Zoology I can't even *lift* them!" | henry@zoo.toronto.edu utzoo!henry
covey@ithaca.uucp (Bob Covey) (02/24/91)
Blue LED's are also available for about $10 each from Digi-Key, discounts for large orders. It should be pointed out that these are really not a good blue color but cyan (blue-green), and would not reproduce good blues and purples if used in a graphics display/TV emulation. Bob Covey