Are 1W LED's inter-changeable with 3W LED's ?

On an average 1 Watt Led light , can the 1W star be replaced with a 3W star without doing any further modification ?

Would the 3W probably then be DIM ?

Do you have to make other changes to the circuit , to go from 1 Watt to 3 Watt ?

Exactly WHEN are 2-batteries required - rather than 1 battery , to power a light ?

What causes a 1W or 3W emitter to be OVER-driven so that it is much brighter - such as a 7W Golsten light ?


Who do we contact , to take a flashlight modification class (101)?

thankyou .

Re: Can 1W LED's be replaced with 3W LED's ?

Dropping a Lux III in place of a Lux I won't make too much of a difference, unless you're going from an exceptionally poor Lux I bin to an exceptional Lux III bin.

All things being equal, if you drop a Lux III in place of a Lux I, not much will change. It'll be about the same brightness, have about the same Vf, and about the same amount of current will flow.

You would need to increase the current to the Lux III to see a huge difference. Just dropping it in place of a Lux I won't do that. So you would have to modify the circuit to take full advantage of the Lux III.

The number of batteries required depends on the LED, circuit, runtime you want, etc.
For simple resistored setups, you need more voltage than the Vf of the LED. Then you pick a resistor that will drop the appropriate voltage at the required current. You can drive LEDs off a single cell if the right circuit is used (boost), and you can use many many cells if using a buck circuit.

The rediculous "OMG X WATTS!!!" lights are quoting the power consumption from the batteries, not the amount of power being dissipated in the LED. It's easy to make any light with any power dissipation, all while producing the same amount of light as lights using much less power. The LEDs in those lights aren't significantly overdriven compared to other lights, they are simply wasting battery power (and consequently your money) in big resistors, just to have a huge number that they can market...because more watts must be better, right? It's purely a marketing gimmick, and is bordering on false advertising.

I can make a 12W luxeon light by using 4 123As in series and a resistor, and running it at 1A. The resistor would be 8.2 ohms. 3.8W would be used by the LED, and 8.2W would be burned up in the resistor and wasted as heat. That 8.2W is a total waste, and would just be making people spend twice as much on batteries as they should be for the amount of light...but hey, I've got a "12W" light, so it must be better than some "3W" light, right?

Re: Can 1W LED's be replaced with 3W LED's ?

I usually replace good bin 1 watt to stock luxIII and found that some luxI is brighter than 3 watt.

Re: Can 1W LED's be replaced with 3W LED's ?

A Lux III LED is basically a 'new and improved' Lux I LED since I believe the only difference is it's capacity to transfer heat away from the LED die. They say it can handle 750mA compared to 350mA because of that difference.

Re: Can 1W LED's be replaced with 3W LED's ?

eebowler said:

A Lux III LED is basically a 'new and improved' Lux I LED since I believe the only difference is it's capacity to transfer heat away from the LED die. They say it can handle 750mA compared to 350mA because of that difference.

Click to expand...

My take is that there is no longer any actual difference between the Lux I and the Lux III, they are just binned at different currents. There used to be visible physical differences in the phosphor coating, but no longer is that true. This is how they are treating the new K2. Same animal, binning at different currents.

Re: Can 1W LED's be replaced with 3W LED's ?

The K2 is most certianly NOT the same animal in any way to a Lux I/III.

Allow me to demonstrate:

Regular Lux III:



K2:



There are substantial packaging differences, and substantial fabrication differences of the LED chip its self. The K2 is quite a different beast than a Lux I/III

Re: Can 1W LED's be replaced with 3W LED's ?



WOW..Evan9162 , those are some REALLY great and clear pictures . How much did that camera cost ? I want one !


But just what do you have to do to a Single cell, 1-Watt light,to increase it's brightness substantially??


Thats what I don't understand about modding.

Do you have to increase the current to the 1-Watt emitter ...... and how do you do that ?

Or do you have to change it out, to a 3 Watt emitter with a lower voltage rating so it is being overdriven ? This all confuses me .


Thanks ....TMG

Re: Can 1W LED's be replaced with 3W LED's ?

For a single cell light, you must modify the driver circuit to deliver more current to the LED, or replace it all together with a new one that delivers more current. Simply replacing the Lux I with a Lux III won't really do much, unless the Lux III you're putting in is exceptionally bright, at which point the brightness increase is from the individual LED, and not because you're driving it with more current.

My camera is a 3 year-old Canon PowerShot G3 with a stack of accessory macro lenses. It's got about a 7mm field of view with that setup.

Re: Can 1W LED's be replaced with 3W LED's ?

Whoops! I didn't mean to imply that the K2 was the same animal as the Lux III.

What I meant was that they are binning and selling K2s at two different currents.


Sorry for the confusion.

Re: Can 1W LED's be replaced with 3W LED's ?



So......If Lux-III emitters are not inherently brighter than Lux-I .......what is the real purpose of a Lux-III ??

I thought Lux-III was the progressive improvement step in the evolution of emitters .

Some people say a Lux-I can be as bright as a Lux-III .


I think I just don't get it .

:candle:

Re: Can 1W LED's be replaced with 3W LED's ?

A Lux III is spec'ed to be powered at 700mA or 1A (running at 1A significantly reduces the lifespan). The max spec on a Lux I is 350mA. The Lux III also (according to specs) has lower junction-slug thermal resistance, so it (supposedly) scales better relative to current. Finally, bins for a Lux I are measured at 350mA, whereas bins for a Lux III are measured at 700mA.

In a sense, the Lux III is a progressive step, albiet a small one. It allows the LED to be run at higher current, producing more light (naturally), while preserving the expected lifespan (50K hours).

The data I have in front of me, gathered from the ~30 Luxeons I have (a mix of Lux I and Lux III) shows that the Lux IIIs don't really scale any better than the Lux I - which begs the question if they are really any different at all. There's much speculation that the two are really built exactly the same, and that the Lux III simply has a slightly different star board, and is binned at 700mA, rather than 350mA.

Re: Can 1W LED's be replaced with 3W LED's ?

so funny... i've been around here for so long i forgot that a luxIII is rated @ around 700ma... i thought running a luxIII @ 1amp is a given

Re: Can 1W LED's be replaced with 3W LED's ?



I just realized - ??

Is my TITLE to this thread technically incorrect ?

Should I have asked.... > Can Lux-I Led's be replaced with Lux-III Led's ?

they are not actually 1-Watt and 3-Watt .......... Are they ?? ( I'm asking )


Why do we refer to LED flashlights as 1-Watt , 3-Watt , 7-Watt.......etc.

TELL ME if I should go back - and change the TITLE question of this thread ?

Does the title - as it is - appear to be an ignorant question ?

Thanks.............. TooManyGizmos .. :laughing:

Re: Can 1W LED's be replaced with 3W LED's ?

I would say that when you are referring to Luxeons that you should use LuxI, LuxIII, or LuxV.

Often flashlights that state 1watt, 3 watt, etc. are referring to the drive level of the LED and whether or not they have a LuxIII in them may be another issue.

Your right though, alot of times people call the LED by 3watt luxeon instead of LuxIII. No real problem though, we usually know what they mean.

Re: Can 1W LED's be replaced with 3W LED's ?

umm... can anyone calculate the area of the black non light emitting portion on both dies? i think the k2 has less of that black part,which makes it emit more light.

Re: Can 1W LED's be replaced with 3W LED's ?

Why do we refer to LED flashlights as 1-Watt , 3-Watt , 7-Watt.......etc.

Click to expand...

Marketing.

Don't get me started on the "7-watt" ("8-watt", "10-watt", whatever) LED lights. Those are borderline false advertising. While everyone else is quoting the (approximate) power to the LED, these guys are quoting the total power draw on the batteries, which is rediculous. They just bump up their power "rating" by adding more cells in series (i.e. making a 6V light a 9V light), and making the resistor bigger. The result: same brightness, but the extra voltage is just burned up in heat. You would get the exact same result by using a proper 2-Cell light and just throwing away a new battery (unless you need an expensive hand warmer or something).

What they are doing is as if I was doing the following:

1) Take a car that goes 400 miles on a tank, and who's engine can produce 200hp. But instead of quoting actual power output of the engine, take the actual energy in the gasoline that's being burned and call that my "HP" number, since that's how much is being consumed. So instead of 200hp, I'd say it's an 800hp car, since the engine is about 20% efficient. Same exact car, now it's called "800 HP". That's what the 7W lights are.

2) Now I take the above "800 hp" car, and run a fuel line outside, so it simply dumps some gas out the back of the car. The car now consumes about 25% more gas than it did before. Tah-daah! "1000 hp" car. Oh yeah, I now must make the fuel tank 25% larger, so it still has a 400 mile range. That's what the "10W" lights are. More energy is being consumed, but with no benefit at all, and the end user pays more for batteries with zero gain.

Re: Can 1W LED's be replaced with 3W LED's ?

chesterqw said:

umm... can anyone calculate the area of the black non light emitting portion on both dies? i think the k2 has less of that black part,which makes it emit more light.

Click to expand...

The "black" (or non-emitting in the case of the Lux III) portions are the top contact areas.

On the Lux III, the contact portions cause about 40% blockage of the junction, meaning that only 60% of the die can emit light directly.

On the K2, the contact portions only block about 8% of the junction, so 92% is unblocked and able to emight light directly.

Both dies are supposed to be 1mm^2, so the Lux III has about 0.6mm^2 of unblocked emitting area, while the K2 has 0.92mm^2 of unblocked emitting area.

Are 1W LED's inter-changeable with 3W LED's ?
Sometimes, but not always

I've interchangeably used Lux I and Lux III's (I prefer not to make any references to watts) in many lights. I've overdriven Lux I's (batwings to be exact) to 700mA long before Lumiled's came out with the Lux III's. The only difference between the two that the typical user may care about is that the Lux I's are spec'd to run 350mA and the Lux III's at 700mA. Running a Lux I at Lux III currents will give very good results if you heat sink properly. Bottom line is what you want to drive the LED at. If you want to run 300-500ma (-ish) go with a Lux I since they're characterized (tint and output) at those levels. If you want to run at 700mA and above, go with a lux III. I found that underdriving a Lux III can result in severe shifts in color temperature to the "undersireable" side. However overdriving a Lux I does not have such negative effects except maybe a shift towards the cool side--something most people don't mind. If you want to make similarity comparisons, an R bin lux I driven at 700mA will give you a T rank Lux III output. An S bin Lux I driven at 700mA will give you a U rank Lux III output. Tint will shift when you underdrive and overdrive accordingly.

Using a DMM - on any given flashlight....

before changing out the Lux-1 , with a Lux-3 ........

How do you determine how much current ( 350ma or 700ma or 1a...etc.) is is being delivered to the emitter that is presently in the light ....

so that you will know if changing to a Lux-III will be any brighter.......or if you are about to over-drive something.

:huh2:

TooManyGizmos said:

Using a DMM - on any given flashlight....

before changing out the Lux-1 , with a Lux-3 ........

How do you determine how much current ( 350ma or 700ma or 1a...etc.) is is being delivered to the emitter that is presently in the light ....

so that you will know if changing to a Lux-III will be any brighter.......or if you are about to over-drive something.

:huh2:

Click to expand...

If you are going from a Lux I to a Lux III then there is little chance that you will be overdriving the Lux III.
Measuring current with the LED in the light can be a challenge and a risk to the driver. You will need to de-solder one of the lead wires from the emitter/star and place your DMM leads in series with the LED (one meter lead on the wire you de-soldered and the other meter lead on the terminal that the wire was on.) The risk comes in during the powered stage, if you slip and one of your connections breaks contact then you will most likely fry the driver circuit. Most converters do not have "open load protection" and will die if they are powered and don't have the load of the LED on them.
You can measure current drawl at the battery but that will be the current drawl of the converter/ driver circuit and not the actual current going to the LED.