Luxeon 5 Watt - overdrive

[TTT]

Hi guys,

I got a Silva LX headlamp, with a luxeon 5 watt led.

My questions is:

The headlamp uses rechargable batteries that are included at 6v/4,5ah or optionally 9 ah.

Will the led handle using 7,2 volt packs intended for RC cars? Will this increase output notably? It seems to me that the led is not regulated.

 

[Gunner12]

A small increase in voltage would result in a large increase in current for LEDs. So I would not recommend adding a higher voltage pack. If you want, you could install a buck driver in the light and run one of the current gen LEDs. Should be around the same(or more) output for a longer runtime.

:welcome:

 

[mahoney]

The Vf of a typical Lux V at 700 ma is somewhere around 6.4 to 7.2, so there might be a boost circuit in the light already. That circuit may not be happy with the increased voltage. If the light is direct drive (nothing but wires between the batteries and LED), then you could put a good ammeter in series with the Lux and see how much current goes through it at 7.2 volts. Anything less than 1 amp should be OK, with the caveat that there will be MUCH more heat produced that will have to go somewhere. Under-driven Lux Vs are pretty efficient (as Luxxes go anyway) and if the headlight was designed to direct-drive the Lux V at 6 volts, there may not be much heatsinking.

 

[TTT]

http://www.silva.se/templates/Products____99.aspx?epslanguage=EN&productId={C8FA11CD-7FBA-43CF-9727-36C2FFFC9AEB}


Here is the headlamp. It does have a reasonable heatsink, which does get warm, but not really a problem. I guess the manufacturer would need quite a wide margin of error when it comes to temperature, as it should be able to run for an extended period in warm weather. I live in Norway, therefore temperature would rarely be a problem. I would normally operate it at temperatures between +15 celsius and -15 celsius (59-5 fahrenheit), and especially need max power while biking after dark, where wind would give additional cooling. I do not think temperature would be a problem if used cautiously under cool enough conditions (biking or cold weather).

Here is a test of headlamps (in Norwegian) but the measured output might be interesting for you guys as there are many other lamps tested, both HIDs, leds and halogen. My Silva LX is measured to 160 lux @ 3 meters:

http://www.sport8.no/stayer_lyktetest.pdf

Btw, the output is not far from my Fenix L2D Premium Q5 Cree XR-E which only has a slight egde in turbo mode (supposedly 180 lumen). The Fenix can only run for 10 mins max due to heat, but the Silva can run untill the battery runs flat.

I think it will be difficult to change the led, due to the design (nothing to unscrew or to be easily tampered with). I would also rather overdrive it untill it is burned out before changing it, as a different led will not give that much gain.

I shall mail Silva and hear if it is is direct drive or not.

Thanks for you help! :twothumbs

 

[TTT]

BTW will increasing voltage reduce longevity even if not running too hot?

 

[Gunner12]

The Fenix can run for as long as the batteries would allow on turbo. Run it for less the 10 minutes during high ambient heat, something like the middle of a desert at noon might classify as high ambient heat. Also, the LED is running at almost half the voltage of the Luxeon V in the headlamp.

Increasing the voltage even a little could result in a big jump in current. This specific LED went from 350 mA to 500 mA with a increase of 0.1v.

Running the LED at a higher voltage would reduce the life of the LED.

 

[TTT]

How do you know it's a Luxeon V?

 

[Gunner12]

The Luxeon I is usually called the Luxeon 1 watt. Luxeon III = 3 watt, Luxeon V = 5 watt, Luxeon K2 = anywhere from 4.8 watt - over 6 watt. At least that's what many manufacturers label them as.

 

[Jumi]

Here
http://www.silva.se/templates/Products____117.aspx?epslanguage=EN
it says LuxeonTM 5W

I got that L2 which I have modded with U-bin SSC and Cree 8 decree optic.
I hated original narrow beam but now it's all flood.
So it it moddable, there is small screw behind silver label which says something like (warranty ends if this label is removed ) Then swith part slides forward. But this is not needed if you only change led.
All electronics is in this area.

Light head is glued so it needed sharp knife and some force to get halves apart. In L2 emitter was glued straight to heatsink and broke when removed, I was not able to get blade under led since large circuitboard is same size as head.

In your case I would measure current draw with bench supply starting from 6volts with little steps to 6x1.4=8.4V and if it doesn't rapidly increase over 1 A then it would be ok to use. Best would be if current would decrease when voltage goes up. But then it would not be brighter with higher voltage.
Maybe better binned Luxeon V?

Juha

 

[TTT]

According to a review I read, it is supposedly a K2 led in the LX. With a forward voltage of 3,7 volts, 1350 ma would be the current needed to produce 5 watts.

With a maximum of 1500 ma up front there will not be much to gain unless one changes the led.

The difference in brightness compared to my Fenix L2D in turbo mode is minute at best, which is supposedly 180 lumen.

 

[TheCowboy]

Hello Guys,
First of all, the P7 is not the brightest LED bulb, although Surefire would have you believe it.
Our ZP20 20watt is perhaps the most powerful LED produced today.
We do sell it to companies other than Surefire, so interested parties may contact us..
We also sell the ZP10 10watt led comperable to the p7 10 watt.
We prefer not to export these outside of the US in small quantities, but
People interested in purchasing the light may contact me directly at my personal email. We will sell in quantities as low as 10.
I will send pictures, pricing, etc... These are not toys, so Please, only serious purchasers ready to buy need contact me as we have lotsof business as is.
The Cowboy

my contact email for the ZP10 and ZP20 is [email protected] I prefer this email as I will not give out our website email except to real buyers of our led products.
PS, we sell in quantities from 10 to 50,000.
Free shipping is standard
The CowBoy

 

[Drewfus2101]

Hello Guys,
First of all, the P7 is not the brightest LED bulb, although Surefire would have you believe it.
Our ZP20 20watt is perhaps the most powerful LED produced today.
We do sell it to companies other than Surefire, so interested parties may contact us..
We also sell the ZP10 10watt led comperable to the p7 10 watt.
We prefer not to export these outside of the US in small quantities, but
People interested in purchasing the light may contact me directly at my personal email. We will sell in quantities as low as 10.
I will send pictures, pricing, etc... These are not toys, so Please, only serious purchasers ready to buy need contact me as we have lotsof business as is.
The Cowboy

my contact email for the ZP10 and ZP20 is [email protected] I prefer this email as I will not give out our website email except to real buyers of our led products.
PS, we sell in quantities from 10 to 50,000.
Free shipping is standard
The CowBoy

Not that I should even have to comment, but I feel the need too. I'll just quote what I replied with in another thread:

It looks like every one of your post so far are the same 2 posts you have made in this thread just copy and pasted into other threads.

Then you use a free and untraceable email account. Not an account linked with a company that is producing these wonderful new emitters. Whatever company that is.

You offer no proof or evidence of anything. When the P7 hit it was the talk of the science community. If your company has something that is more efficient you would have front page news, not some black market item. This could not be a more obvious scam. I just hope that some of the more trusting (gullible) people on this board don't fall for it.