Better hold on to your hats guy`s

[Badbeams3]

30 lumen white led at 300ma!...it` called the Shark line...other colors up to 55 Lumen!
www.optotech.com

Don`t forget...I have a retirement home for incandesants

 

[**DONOTDELETE**]

That thing gives out 24.3 Lm @ 200 mA with Vf of 16.06 V, which makes it 7.6 Lm/W.

Luxeon Star gives out 18 Lm @ 350 mA with Vf of 3.42V, which makes it 15 Lm/W - twice as good as that "opto" thing.

Oh, and BTW: the cyan LS LED gives out 30 lumens, which makes it 25 Lm/W.

And the best news - Lumileds expects these numbers to go up in the "future".

 

[Badbeams3]

Welcome Mad, your right...and I didn`t see how many volts it wants to get the 30 lumen 300 ma rating...maybe 24 volts...two car batts...or one hell of a step-up.

But I must point out that the LS white would likely be a pile of melted goop before it put out 30 lumen (I wonder what the Shark is capable of if overdriven) and I`m sure this company has plans for improvement too.

As I understand it, thier useing a differant approach...many (50) micro super bright led`s compacted into a small space, hooked up in groups and in series...this explains the lack of heat build up and the higher volt requirments...sort of like...instead of a turbo charged single piston engine thier making a 8. I wonder how many lumens it would put out at 6 volt or if it would light at all.

But I don`t think they could beat the LS price...was it $6.50 or $4.50 per unit (1000 unit purchase required).

One nice thing is the step-ups, regulators and pulse modulators are selling in the $1.5 to $3.5 range depending on manufacture and specs...by the time they trickle down to Wally World a nice powerfull led flashlight should sell for less than twenty bucks (Hmm, I heard a romour that Mag-lite was going to unvail something new soon). And I hope that day is not to far off

Anyway, I thought our members would find it interesting and it`s great to see this competition.

I wonder what Nichia will surprise us with

Welcome again and hope you post often.

 

[Badbeams3]

Just in case there are any members who do not have data sheets on the LS here`s a base.

Info from charts on page 3:

At 3.1 volts it draws 100 ma and produces 6 lumen.

At 3.4 volts it draws 350 ma and produces 18 lumen

I assume since the chart does not show it going lower than 3.1 volts the performance must fall off rapidly below that point.

I also assume since the chart does not show it going higher than 3.4 volts the lumen gains above this point must be small compared to the power consumption.

 

[**DONOTDELETE**]

The data sheets are available at the luxeon website.

 

[Steelwolf]

How does lumen compare to candela?

 

[**DONOTDELETE**]

What do you mean "compare"?

The relationship between the candelas and lumens is
dL=I*dR, where L is the quantity of light in lumens, I is intensity in candelas, and R is solid angle in steradians. So basically if you want to convert to lumens from candelas, you would have to integrate the function of intensity over steradians. But since the intensity is not uniform (except for omni-sources), it is pretty difficult (but possible) to estimate the lumen rating.

Its a pity that manufacturers always stick to one value.

 

[Steelwolf]

Thanks MS. I guess I should have been a little more explicit in my question. But you answered it well. I'm guessing that steradian is some measure of angle?

My basic knowledge was that one measured the total available light coming out from regardless of the angle, and the other was angle dependant, ie light that fell further away from centre would contribute less to the overall score of the rating. So two lights may have the same rating in one measuring system, but because the beam is wider in one than the other, it scores a lower rating in the other system. Am I right?

I can't remember which is which, but the formula you gave seems to indicate that candela is the one that is angle dependent. Did I understand that correctly?

 

[RonM]

If I understand Mad Scientist correctly: Lumens represents total light output while Candelas account for the focusing of the light energy. Seems most info is in candelas. (Is mcd a thousandth of a candela?) I was frustrated by this when trying to buy leds for a kite. I wanted ones that were bright but had wide dispersal. Reading ratings in mcd it was hard to determine if the low numbers were do to the wide beam angle or just overall low output. Lumens would have been more helpful.

 

[Go Go Gadget Flashlight]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by RonM:
If I understand Mad Scientist correctly: Lumens represents total light output while Candelas account for the focusing of the light energy. Seems most info is in candelas. (Is mcd a thousandth of a candela?) I was frustrated by this when trying to buy leds for a kite. I wanted ones that were bright but had wide dispersal. Reading ratings in mcd it was hard to determine if the low numbers were do to the wide beam angle or just overall low output. Lumens would have been more helpful.<HR></BLOCKQUOTE>

Yep, all of that.

1000 mCd = 1 Cd

Beam angle affect Candelas, not Lumens. That's why the 20 degree and 50 degree Nichias have different Cd ratings. Same basic guts, but the dome is different.

 

[Spork]

those new led's look like they have a lot of guts to go along with them. does that sacrifice durability?