LS quality/availability

I didn't hit this site for awhile, and now I occasionally see something about the LS quality going down; it's pea-green. I can't find the original threads discussing this, so bear with me and please explain. Are bright white LS's completely unavailable? If they're available, where? I can't find a link on the Arc site. I'd like to wire two in series and stick them on the front of my bike...

Try this site if all else fails:
http://www.nwlink.com/~mhannah1/

Dual LS in series (and properly heatsinked) kicks some SERIOUS butt! Try driving it with an 8.4v Nimh and see for yourself. Gang the batts for more runtime. It actually almost feels like an HID floodlight for the bike! Throws well to about 60 feet. Brightest non-incandescent/non-HID bikeheadlight possibility I've seen.

BTW, even the pea-green LSs become nice when slightly overdriven as I had described. Their beamcenters are still a very nice warm white, only the outer bits are tinged that awful green. When drive at spec or under, that green becomes much more obvious. Anyway, after you've seen what overdriving can do - you *won't* want a stock setup.

I concur totally.

I just received a batch from Mark Hannah and the white LSs I got are all OK. These do not exhibit the green hue cast.

I've got three batches now. I still think the slight green ones are very usable. Especially if slightly overdriven.

From what lamba has seen if you use the bare emitters ones of the green variety it gets worse. The LS/O are not that bad.



I could not resist. I ordered one of every color of the LS/O version. I'm now a proud owner of RED, AMBER, BLUE... The works.

How much do they have to be overdriven? I just recieved about 5 LS/O from Mark Hannah surplus, and they all have that greeh hue around the edges. The centers are still pretty white though, but it makes the overall beam look pretty ugly. Would 400 mA be enough, because I plan on cutting down the heatsink some, so I don't want to overdrive it too much.

InTheDark,

If you have a regulated adjustable DC power supply you can test the LED and adjust the current up or down to see how much overdriving affects the light quality.

Look at the beam 3-10 feet away cast on a white wall or something similar. Shine a regular flashight next to the LS for color comparison and beam quality. I'm not sure what you plan on doing with the LSs but for me the slight green ting on the outermost fringe has not been perceived when using it in a real flashlight application.

Additionally, I highly recommend you apply 350mA or less and let it warm up. The LS/O gets quite warm at the 350mA setting which translates to about 1W of power. You should provide addtional heat sinking even at 350mA drive to keep the LS/O from getting too warm.

Overdriving beyond this will require some experimentation. Especially if you plan on cutting the aluminum down. I think this might become a problem since there will not be enough heat sinking for the LS.

In the mini MAG mod that I did with the ZLT+ board I followed other CPF member suggestions and provided thermal heat transfer from the LS to the aluminum case of the flashlight. The flashlight gets pretty warm in around the area where the LS is located.

Have fun! Don't stare into the LS they are too bright to look into directly.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Mcd:
I didn't hit this site for awhile, and now I occasionally see something about the LS quality going down; it's pea-green. I can't find the original threads discussing this, so bear with me and please explain. Are bright white LS's completely unavailable? If they're available, where? I can't find a link on the Arc site. I'd like to wire two in series and stick them on the front of my bike...<HR></BLOCKQUOTE>

I just made a statement about this in another thread, if you are going to use two just get one white and one 470nM blue, that will raise the overall color temp(drown out the yellow/green).