10mm LED diffusing experiment

[gotwind2]

I bought fifty 1000Mcd 30 deg viewing angle 10mm leds off eBay to experiment with.

The led's were run from a dieing 9v pp3 battery with 390 ohm resistor on each. Current 15Ma each.

Filing the dome flat had some effect in diffusing.

I was surprised what difference frosting (light grit papering)made.

A cluster of about 9 frosted lenses could provide a good volume of light for minimal current (135Ma) in my opinion.

[ghurd]

Ben,

Double the light for the same power. Try 2 LEDs in series and 180 ohms.  

Cluster 18 LEDs for for the same 135ma, or 10 LEDs for 75ma.

G-

[gotwind2]

Hi Ghurd.

Yeah, tried 2 LEDs in series and 180 ohms resistor, works well.

I am going to make 12v shed light using 18 frosted 10mm leds, leaving a bit of length on the led legs to angle outwards.

Thankyou.

Ben

[Norm]

  Been doing some Google ing on LED tube lights

and as far as experimenting is all right but

seems like if you really want to experiment

with LEDs for some serious lighting...   maybe

just some of these Christmas lights at 70 for

$6.99 would be cheaper they are colored, but that's

just the plastic covering, inside are the white

LEDs ?

    Unless you can buy them cheaper than that?

    LEDs seem to be headed for a great future

Few years from now...maybe we'll be swapping

CFL's for LEDs ?

          ( :>) Norm.

[richhagen]

I built a light a few years back that always stays on in my laundry room.  I don't recall the exact number of leds, I think about 120, they are not as efficient as newer ones such as the ones I got from Glen, and also not nearly as efficient as a small flourescent would be, but they've been there for quite a while there, strung 3 in series with a 120 ohm resistor, run off of a 12V bank between about 11.5 to 15 volts, depending on the time of day and year.  

They were mostly 20 degree leds, and give a harsh spot light effect.  I put the light in a fixture with a frosted glass dome to accomplish the same thing as you with the light sanding.  Probably not quite as efficient, but it was quick and easy, and is still there, although I could do with updating it to make it a bit brighter, especially when the batteries are really low.  



Anyway, I don't have any hard data on the light output vs. power or anything, and I don't claim to be an expert, but it works for me.  Rich

[stop4stuff]

rather than diffusing the harsh LED light, have you tried reflecting the LED light off of something... here's something i tried a while ago http://www.fieldlines.com/story/2004/6/4/8457/26205

paul

[RP]

Duh,  I just got confused and responded to that post from 2.5 years ago.  :-(

I was going to suggest using "bright white" printer paper as a diffusing reflector.  I've used this at work for a lit logo sign on a machine and it's pretty impressive stuff with the white LEDs.