LED (makototsai style) Testing

[Strydur]

Anyone try using the EL diffuser and tubes for Mak's LED's? It looks like they would fit pretty good.

[xwingband]

Probably. He uses an MR like foam inside a thin PolyC tube. I'd personally throw that into a nylon tube which is what I've done with MR strips.

[Jase Kala Maris]

Ok where to start... Hmmm

I went on ebay and bought some Flat head 5mm 13,000 mcd green led viewing angle of 120 degrees... there bright but 13,000 mcd hard to say.

I followed the directions of those before me and put them in a string and powered them off a flashlight led driver at around 3.6v and 2800mah.

That is what the led driver says I have a multi meter but I can't get a satisfactory reading off it so I can't confirm this...

I have a string of 66 leds running at the 2800 mah so thats what 43ish mah per led. These are rated for 25 mah but I've heard of peeps overdriving these things crazy so I figured what the heck. and I can't believe I'm getting 2800 mah outta this thing

Also a package of 100 of them only cost me about 15 bucks with shipping off ebay.

I clear packing taped them all up then rolled them in bubble wrap then shoved them in a TCSS sanded blade and... what you want pics ok sure.

but first my MR Anakin ROTS is about 45 lux on my meter...

this on is about 275 lux

Pics ok here...



Makototsai is finishing up my MKTT FS V2.0 hopefully this week then a week shipping, so two weeks I'll have that to show some comparisons and get some Lux readings...

and a Video on youtube...

http://www.youtube.com/watch?v=VGgEKyKCjmk

[Novastar]

Looks great, Jase... and just so you know-- ~3A is not totally insane from this kind of thing! H-blades were probably always meant to spit out far more than 1A, and certainly Mako's blades must run at much >1A as well.

Also--I don't think you're doing anything crazy by going ~40mA vs. ~20mA for the little indicator LEDs. It depends on a lot of things of course, and I believe the industry standards try to use data that allow "good" light output with very good lifespan. Additionally, depending on the LED--it may be one that is meant to be "always on", or one that was never intended for that. Although most are meant to have a "max continuous current" rating.

If possible, you might set up a dedicated power supply to "crank it up and down" and see what the difference is in feeding 20mA, 30mA and 40mA (etc.). In some cases, moving from 20mA to 40mA will affect things... and in other cases, it could be barely noticeable.

[Jase Kala Maris]

I really wish I could afford to get one of them Varible Power Supplies. Like the ones I see in Xwings Videos, but the cheapest I've seen one is 75 and 15 shipping and handling. Just can't drop the money on that right now.

I totally think it's a must have! Trial and error setups to find what mah runs best is just ridiculous! Would be so much more effiecient to just wire it up to one of those and be like... Ok 25mah gives this lux 30, 35, 40... and so on.

I know what you mean about the light output just staying the same no matter how much amp I put through these little suckers. I bet they have a sweet spot someplace around 30-35mah so I'm just waisting the power-I could be putting more led in the string!!!

Maybe I'll suggest Tim carry those Varible Power Supplys, maybe he could get a deal on them.

and as always thanks for the support Nova

[Novastar]

Hey, I hear ya. *I* don't have an adjustable/variable PS... and neither do I have anything but a BEAST of a soldering iron... So don't sweat it. I'm just saying... for your projects--you might even hook up a POT to a battery source and see if you could "dial it in", heheh.

Also--I don't know IF you are wasting power/amperage... I'm simply saying--yup... you'd want to find out I'd guess!

For example--there *IS* such a thing as "overdriving TOO far" on a Luxeon LED (for example)... and I don't mean the obvious "too much" when it blows up. I mean, sure standard maybe 1000mA... then, you give it 1200 and see some more brightness... yum!! But then you go to 1300 and only detect minimal improvement... plus it starts getting HOT... and you even try 1350--and you don't feel it's a good move any more.

So... that LED is probably best @ ~1200 to get some "pimped" results--at the cost of a little lifespan... whereas going to 1250 or 1275 or 1300... might just SEVERELY cut the lifespan (via tons of heat)... and add a measely 20 lumens or whatever. Not worth it.

So... yup... sometimes ya gotta pick yer pony! You may be right that adding more LEDs (and lessening the current per LED) MIGHT actually be "more ideal" electronically vs. driving the whole shootin' match harder. It depends.

[xwingband]

Actually a large honking pot would probably be pretty decent for a variable power supply. If you could get a fixed output like from a "wall wart" it could work with a meter. You could even get gator clips and a project box to make it look nice.

I actually did that for a circuits class. Our PSU had two variable outputs and a fixed 5V... we needed +12V, -12V, +5V, -5V and a variable one to act as our trigger voltage for the sensor. We had to take the two variables at 12V, the fixed for 5V and parallel the 5V with a pot for our variable output.

A PSU is not a huge need for everyone, but for us hardcore builders that pump out a lot or do complicated things it's something I wouldn't do without. I've manually charged batteries. I use it all the time in place of batteries because who always has fresh batteries out all the time? It's great for measurements too.