What’s the proper way to attach 7350 chips to a bare board. If I had a driver with only five or six chips on it and a couple of spots that are empty.
Firelight2, the XP-G2’s in my EDC+ Triple are a very nice white tint, running all 3 at 2A (1.93A measured at the tail) They probably will change tint driven harder, but the 3 in my drop-in are a perfect white…no tint anywhere.
That’s the easy way. Pre-flux and pre-tin the big PCB pad with a small amount of solder. It should be just enough to cover the pad. Most likely, the pads are already tinned so you can just add a little flux and remelt the pad.
The using tweezers, hold the chip over the pad while applying heat to the edge of the pad and tab with your iron.
Once things melt, the chip will sit in place. Let the solder set
Finish up by soldering the other pins; heat first then touch the point where the iron and the pin meet with solder. It should flow right onto the pin and pad.
Success! Sorta…I got 4 of the chips soldered onto the new driver and everything LOOKS good. But it wouldn’t work. I don’t know if I shorted something or I wasn’t getting a good ground or what. I backed up and redid the pill, cut the recess down so the driver in original form would fit lower and the retaining ring will screw down on it and this one works. I’m getting 2.87A at the tail and have 3 solid reliable modes. I’ll check output and beam tonight.
I’m not experienced at soldering. This was the first time for anything with my new Hakko 888 soldering station. I thought it went pretty good, save for the part where it didn’t work.
Congrats! However, did you add 4 chips to an 8 chip board for 12 total? That should be 4.2A (for 350mA chips). Or is there error in your tailcap measurement (although that's an awful lot)?
-Garry
I did add 4 to 8, but that board didn’t work and the stacked chips were going to cause issues with the retaining ring. I tried soldering it in…used the solder as a threaded ring to hold the board down and it was pretty snug, but it wouldn’t work.
So a stock board is running my light with the original 8 chips. I might see if I can add 2 to the bottom of the board but first want to see how it’s performing here. The supposed 5A driver I had in it was only pulling 2.38A so 2.87A is a marked improvement.
By the way, the chips are binned at 380.
Did you test it by touching the pos and neg with leads from a battery, or with the entire assembled flashlight with a battery in it?
I was wishful and put the light back together. Click, nada.
I’ve now recessed the ledge that the driver sits on in the HD2010 pill and now the retainer ring sets on top of the chips on the spring side of the board. Can’t add chips there. I think I can add 2 chips on the inside, gonna check into that.
For now, success with the new driver! Nice lo, great Hi, no whiny mosquito sounds….none, zilch, silencio! 
Happiness!
The two military trailers in the beamshot below are pretty dang far back! The second one, where the reflector is shining, is 465 yds! The trees behind the trailers are 550 yds from the hayloft I was in. Not too shabby! The camera settings mimicked what I could see. Canon G1X zoomed to 112mm 0.6 sec f/5.8 at 1250 ISO.
I think the chips could be in the way. Perhaps a longer spring. I've been trying to stay away from adding chips on the contact side, unless the driver is hooked up to a separate larger board from underneath.
To save myself headaches, I now pre-test any driver I worked on. I have an LED that I had swapped out of another light permanently hooked up to alligator tipped leads. I attach the clips to the drivers leads and then touch the pos. and neg. with wires from a battery holder. If the LED comes on...your good to go.
That way you know if your flashlight doesn't work after installation, its something else, like a poor connection somewhere.
I actually did solder a different spring, inverted, onto the board. My 26650 LiNiMnCo cell is more of a flat top so the longer wider spring was used to ensure contact. Only one I had so I had to remove it and put it on the stock board when I went that route.
I actually have a couple of emitters on copper stars sitting right beside me, could use them to check that driver easily enough. Nice suggestion and nice set-up. Thanks.
I cut a set of wires and tried the modified driver. It works! The chip addition is a success! I’m blind!
The XP-G2 on copper star with thermal paste sticking it to a copper bar is very very bright on Hi, Med and Lo modes also work. I will find a use for this driver or figure out how to put it in the HD2010 somehow. Anyone able to make me a copper pill for the HD2010? Anybody?
Edit: Uh, perhaps I should have used 2 AA cells instead of a fully charged 14500. How long does it take for the purple haze to go away? Prince would know….
Yeah! I’m glad the driver is good. It sure is nice to know before installation, isn’t it.
I have that XP-G2 on copper, and this driver, and I’ve been wanting to modify a MiniMag. Reckon a 4A minimag is too much? Perhaps I could fit this stacked chip driver into my HD2010 and move the 3A stock version into a MiniMag, would 3A be too much? Could the XP-G2 on copper handle 3A safely? Anyone know who could make a solid copper head for the MiniMag AA light? >) >)
My first attempts at stacking went well, but my last couple gave me problems.
I ruined one driver (don’t know what I did) and the last one, I couldn’t span the gap of the last set of legs with the solder, no matter how hard I tried.
My solution: I stripped a piece of small gauge wire I had removed from a driver, tinned it, held it vertically against the two legs, touched the iron to it until it attached itself , and snipped off the excess at the top. It worked great.
Hmm, that makes me think…what if you stripped a wire a little longer than that bridge between the legs, tin it, then hold it to the legs and make that touch to connect the legs. Snip off the remaining wire right above the upper leg. Might be the easiest way yet as you’ve got the wire to hold it in place by with the tinned portion ready to grab the legs as soon as the iron touches. Voila!
Gonna have to try that next time….if I can remember!
Thanks Ouchyfoot!
I’ve done the wire trick before, works fine.
Were you trying to keep that little secret all to yourself? :quest:
I find it more difficult than just using solder. The wire has to be really thin. I wonder if solder alloy is a factor… 60/40 vs 63/37. I use the former. Maybe I will pick up some of the latter and try it.
I don’t see why the wire would have to be thin. I just soldered 2 together with 20ga silicone covered wire. Like attaching a pillar in front of the legs, lol. Of course, in this application I’m leaving the wire some 3” long and using it for battery contact and emitter contact.
Hey Ouchyfoot, do you attach the top chip before soldering the legs or do you use the ground solder to hold it in place?
I don’t have anything to attach it with first, or the patience to wait for Fujik (if I had some) to dry. So I just hold it in place and solder the wide ground on the back side first then do the other 2.