I want to have a green light on my microscope that shines from the backside. I will utilize a Convoy S15 head and an external driver with probably 350-500mA plus a switch.
I would like to have a “proper” green, no blue emitter + green phosphor - but I’m having trouble of finding some at 5050 size?
There are the XML-Fakes on AliExpress and the Getian GT LED from Convoy - that’s all I can find?
Is the market for green LEDs so limited that essentially noone is producing LEDs for it other than some rare 3535 ones?
Or am I just overseeing things?
Has to be on AliExpress, some US Store has no use for me here in switzerland
What’s the reason for the 5050 footprint requirement? Since you’re using a Convoy S15 head, the footprint shouldn’t matter as long as you can find compatible parts.
If you can relax that to 4040 or 3030, you can use the Osram verdure emitters. If you have a secondary optic designed for 5050 emitters, it shouldn’t be difficult to make an adaptor that makes your existing 3535 work.
If you must stick with 5050, the Getian is certainly monochromatic, but you might be unable to use it on a standard MCPCB. Ask Simon for a datasheet or solder pad layout to be sure.
I need a somewhat wide beam profile, sonce the flashlight head will be fixed but I want the green light not just in the center. So an LED with a larger LES would be better than the tiny Osram Emitter or 3535 ones.
SImon answered that he doesn’t have 16mm boards for the Getian LEDs, so they must have a special footprint. I will wait for the Osram verdure and decide afterwards if I try to grind the Getian-MCPCB down
So you’re looking for a wide beam, not a large footprint! A large LES certainly achieves that, but also, Convoy has lots of beaded TIRs that can generate a wide beam from a small LES.
I happen to prefer TIRs for compact lights like the S2+, and ended up with a large collection of them. It’s great fun playing with them and seeing which TIR/emitter combinations work well.
If a heavily beaded/floody/diffused TIR is used, the size of the emitter becomes essentially irrelevant–a 1mm^2 die would make the same beam as a 2mm^2 or even 4mm^2 die. The LES only correlates well with beam width if a converging/smooth/clear optic is used.
Intuitively I’m inclined to agree. Since OP wants both wide beam and dust spotting, perhaps a single small emitter, mule-type light would work well–the low etendue allows dust to cast sharp shadows. I’ve built such configurations by putting a convex lens inside an S2+:
It makes a 60-degree uniform beam that casts sharp shadows.
I vaguely recall having a similar discussion to this post on reddit a couple years ago, and the possibility of a diffused/diverged green laser came up, but was dismissed because of splotchy interference patterns.
With, say, a 60-degree beaded TIR, it won’t matter. I’ve played around with these TIRs enough to observe this, and you can even run the math:
If the 1mm^2 emitter makes a 5-degree beam, then applying a 60-degree diffusion gets you a 65-degree wide beam. Under the same setup, the 4mm^2 emitter makes a 10-degree beam, the same diffusion gets you a 70-degree beam. Not so different after all.
In other words: if you have strong diffusion, then “noise” (i.e., the diffusion) overwhelms the “signal” (i.e., the size of the un-diffused beam).
I’m not discussing hypothetical scenarios, i’m looking at parts he is using. and they will give him a very poor flood, regardless of angle of the reflector.
He posted parts list.
What is your experience? I’ve build from scratch, and moded well over 100 lights, most of them well documented on blf cpf and fonarevka.ru. where can I see your builds?
