Thanks to MR. BULK for the U3U SE's

Thanks to MR. BULK for the U3U SE\'s

Charlie, I bought 3 SE's from you many months ago. I Finally got around to heat sinking (hotlips) two of them and mounting a BB 700 in one for a 4C Mag. I mad two mistakes in my first mod ever. 1st, I clamped one of the emiters down to hard on the heatsink and deformed the emitter and had some silicon type goo get squeezed out of the die. My solution will be to mad scientist this one in a 6C direct drive and see how long it will last. 2nd mistake was to buy the wrong epoxy from Wayne Y. I ended up ordering the ceramic thermal compund by mistake, so I ended up useing this material to heatsink the BB700 and greasing the heatsink before installation into the mag 4C. I decided to use some Elmers gel superglue for the emitter bonding to heat sink which has worked very very well. My only suprise has been how much heat this assembly generates. I estimate the barrel and head has stabilized around 105F after about 15 minutes which proves to me that the emitter and heat sink have bonded well.

Now I just need to find some good high domes that wont break me and it will be time to upgrade.

Oh, I also used NaOH in removing the anodizing

I will post my runtime when the test is over. But I did get about 2 hours of use from pratically dead batteries last night when I went for a walk. The Led started to flicker when the batteries could no longer supply the current that the BB demands. I thought a had a cold solder joint but then after about 5 minutes the system dropped out of regulation.

Re: Thanks to MR. BULK for the U3U SE\'s

Doug,

I am glad to see you making use of those SEs. As to an "upgrade", from what I understand some here are very pleased with the kind of beam pattern they get from SEs.

Thanks.

Re: Thanks to MR. BULK for the U3U SE\'s

Hey Charlie, some of the oilfield workers have fallen in love with the LED modified mags around here because of more uniform beam pattern, but most love them because of the shock resistance. A 6D mag (Elekrolumens heat sink and .75 ohm resister) took a 15 foot fall on to steel deck plating of the rig and and started flickering. The Batteries were changed and it went right back to the same brightness.

My observations on my 4C mod. With fresh batteries I can get about 1.5 hours before brightness starts to drop off. by that time the batteries are very hot, the BB700 is cooking because of the 2 amps being sucked out of the batteries which are at 3.5 volts total and the normal heat starts to take its toll. With a stationary test, the whole flashlight including the tailcap and the bezel were uncomfortable to the touch (probably greater than 113F), Let the batteries rest over night and I could get 3 15 minutes runs in regulation.

My opinion is that the 4C 5 watts are a bad idea, especially if you want a good walking light. You get better current draw performances from AA's or go to a 6C if you want a regulated light. Direct drive 6C waste to much power in my book and a .47 ohm resistor is only a $1.29 from Radio Shack still allows the LED to be overdriven in the 800 to 900ma range and gives and amazing amount of light.

Now all I need is a freakish X Bin with a multi-level regulator and my 6AA Space Needle adaptor. Of Course the only think that Mr. Bulk can help with is the 6AA Adaptor ! /ubbthreads/images/graemlins/wink.gif HINT HINT HINT HINT

Re: Thanks to MR. BULK for the U3U SE\'s

A nod's as good as a wink, nudge, nudge, knowhatimean, knowhatimean.

Re: Thanks to MR. BULK for the U3U SE\'s

another man happy with the nice, bright spill from the U3U SE (in my NexNeedle)

hideo