1W Luxeon underdriven VS. 5mm LED of 20,000 mcd?

I found some 5mm white LED of 20,000 mcd on ebay(spec. in the latter part of this post).

I am planning to mod a Solitaire to the brightness somewhere brighter than a CMG Ultra. Due to the battery life and heat factors, I was thinking to underdrive a 1W/3W Luxeon at 150 mA or between 100 to 250 mA. Until I found these LED I had these questions:

How big the difference of brightness will be to drive this 5mm LED at its max IFP 80 mA(or a Nichia 5mm LED) and the 1W/3W Luxeon at 100/150 mA?
Compare this 5 mm LED with Nichia 5 mm LED, which has the better performance?

What I am thinking are:
A CMG Ultra is good enough to many people.
The CMG Ultra is made with a Nichia 5 mm driving at 65 mA(correct?).
A Solitaire which is modded to a 5 mm LED driving at 80 mA is much brighter and smaller than the Ultra(it would be better if the LED produces more mcd than the Nichia under same conditions).
With a 5 mm LED, we can easily mod the Solitaire and keep the candle mode and focus adjusting features which we can't find on an Ultra.
As refer to the Arc AAA, I guess the mod should have at least 3 hours of runtime.
If the above are true, I believe that this mod would be much better enough to more people.
An underdriven(100mA/150mA) Luxeon does not perform too much better than the 5 mm LED(need comments).
A 5 mm LED is much cheaper than the Luxeon (under $2 vs about $15).
It is a kind of waste if the Luxeon does not perform better than the 5 mm LED with the same driving current.
Compare to a 5 mm LED, a Luxeon is harder to fit into a Solitaire due to their form factors.
If these are correct, I should mod a Solitaire with a 5 mm LED instead of a Luxeon.

To make it simple, I am looking for a Solitaire mod solution regarding economic, battery life, heat and the easy to mod considerations. Any comments are welcome.


5 mm LED, 20,000 mcd spec.:

Absolute Maximum Ratings (Ta=25°C)

Item Symbol Absolute Maximum Unit
D.C. Forward Current
IF 20 mA
Peak Forward Current (1/10 Duty Cycle, 0.1ms Pulse Width) IFP 80 mA
Reverse Voltage VR 5 V

Power Dissipation PD 100 mW
Operation Temperature TOPR -25 ~ + 85 °C
Storage Temperature TSTG -40 ~ + 100 °C
Soldering Temperature TSLD 260°C for 5sec.

Initial Electrical / Optical Characteristics (Ta=25°C)

Item Symbol Condition Min. Typ. Max. Unit
Forward Voltage VF IF=20[mA] 3.0 - 3.8 V
Viewing Angle 2?1/2 - 20 - deg
Luminous Intensity
Rank A IV IF=20[mA] - 20,000 22,000 mcd
Rank B IV IF=20[mA] - 16,000 18,000 mcd
Rank C IV IF=20[mA] - 12,000 14,000 mcd

* Luminous Intensity Measurement Allowance is ± 10%.All LEDs

I bought a bunch of these some time ago and they give a underdriven LS a good run for the money.

But, you cannot focus these leds, the beam is pretty tight, they dont even need a reflector because the residual sidespill is minimal.

This actually is good for small size keychain lights /ubbthreads/images/graemlins/grin.gif

I like them and I use them /ubbthreads/images/graemlins/smile.gif


Pablo

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

I have an under-driven Luxeon in a (former) 3LED 1AA Dorcy flashlight, built by MR Bulk. It has a 1 watt Luxeon and a focusing optic. It's quite bright and focussed and given a choice between a Dorcy 1AAA 1LED and the MR Bulk light, I'd always pick the MR Bulk light because it has more throw.

Most 1 LED 5 mm lights have very poor throw with the exception of the 1 LED 4AA Dorcy light which has a combination of a specially ground-down LED and a large reflector -- IIRC, it has a lifetime of about 200 hours.

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

send a PM to DJpark he's the guru of 5mm mods, uses them vs lux all the time.

I have run a lux 3 as little as single digit mA... the nano i'm building has a dial for brightness and i can dial it down as little as i want. They don't recommend constant current low current for color reasons but i had no problem with the color... efficiency drops a lot... i have a different circuit made for low power made by TI... and would recommend that route for a low power solution.. it's 95% efficient below 100mA. Nonetheless.. i can probably get 4 hrs runtime at 70mA or so from a single charge if i cranked a nano down that low and had the patience to runtime test it. (normally i burn a battery out in 1/2 hr at 1 1/2W).

Do they have 3mm LEDs that have brightness similar to 5mm? the lux is like 5.6mm.. not really terribly fatter, although you do have to accommodate the much larger 'shoulder'.

Good luck and have fun with your mod.. post pics when you can.

-awr

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

Thanks for the comments.

andrew, the brightest 3mm LEDs are below 10,000mcd. But they have a lot of other good prize LEDs may be you like to look in. Like 8mm/10mm LED of 13 Lumen, UFO LED of 20 Lumen(like LS), etc. I just bought 50pcs of 5mm 20,000mcd white LEDS for $14.99, 2pcs of 8mm 13 Lumen high power pure white LEDs for $2.15 and 5pcs of 1W high power white UFO LEDs for $13.99.
The ebay store name is http://stores.ebay.com/LCK-World-Trade-Centre_W0QQsspagenameZl2QQtZkm
The link was corrected by coping from PEU.

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

I am not as strong in the 5mm LEDs, but basically, you are always better off under driving an LED when you can. Reasons:
- The large die area of a Luxeon helps get the light out of the package relative to a 5mm LED
- The Luxeon has a better / separate heat removal path. Even if you do nothing to help it, it will get the heat out better. Heat not only shortens LED lifetime, but dramatically impacts brightness for a given power level.
- The package for a Luxeon is larger, which is a distinct disadvantage from a packaging perspective.
- The color consistency across the emitted angle is usually better from a larger die, but especially in the case of the higher end packages, the phos coating process is much more uniform.

Price - I am not sure why anyone would pay $ 15 for a Luxeon 1 watt emitter. You can buy them directly from their distributor, Future Electronics for around $ 5 / each. $ 15 / each is more like the price of a bin specific Lux III. (If you need a lot of them and want to pay $ 15 / each, I will be happy to buy them and re-sell them to you for $15 /ubbthreads/images/graemlins/smile.gif - yes, I am just joking around.)

I am guessing that you can put a post in the buy / sell / trade with a want to buy a Lux III - low end or Lux I LED and have no problems staying well under $ 10.

Have fun with your project.

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

Just checked the ebay link, it seems the ebay store is no linger in operation.
Jeff

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

The correct link to the store is: LCK-World-Trade-Centre


Pablo

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

I just hooked up a tx1j and an mj's microconverter from the shoppe and was quite disapointed. My Dorcy mod blew it away straight up( after I rigged it into a modded solitaire(the micro converter)) So $45-$50 owned by $8 mod. Anyone want to buy a solitaire mod for, say, $50 shipped? /ubbthreads/images/graemlins/grin.gif Please? /ubbthreads/images/graemlins/icon23.gif

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

Just a quick comment on runtime... I have a 400 mA Lux 1 modded ARC AAA and on a single 800 mAh Raoyvac NiMH it lasts for over 1.5 hours of continuous use.

I want to do a similar mod as you Mike101... I have a couple Garrity Stainless Steel 2xAAA penlights and I love the form factor. I've put a couple various red LEDs in there (had to drill the hole open to get a 5mm in) and am wondering how well one of these 20,000 mcd LEDs might work. I don't care about focus... actually, I'd probably gravitate towards one of the narrower focused LEDs if given the option.

Be sure to let us know how it turns out.

Re: 1W Luxeon underdriven VS. 5mm LED of 20,000 mc

There seem to be a few manufacturers of such power leds (5/8/10/11mm) including ISP.

Most 5mm leds (100mA) I tried from ISP has 20 degree beam angle and this narrow beam produces very tight focused beam which throws much farther than the regular 5mm. Also as the light output is concentrated, the tint is very white.

With lack of the side spill, the overall light output may be seen as not much and may not be very suitable as close up task light with single led, but it sure makes a good light if bundled together.

For a single led light, I'd prefer using 40mA version which has 55 degree beam overdriven to 80mA. A good replacement for regular Arc-AAA/AA.

-- dj