I was a bit dissapointed in myself after trying to add 7135 chips to a driver, killed a few of each. So I practiced a while and built this hack set up to check my work.
Now, I have this…
There’s a lot of voltage drop in all those clips and 2 or 3 feet of wire, I’m hoping I get about 5.3 amps to my soon-to-be XP-G2 triple but wonder how fast I’ll cook the switch in my SF L2 (rated for 3A). I was really tempted to add 2 more chips but come on…
I’m also wondering how I should drive a 3-up Nichia 219. I have all the parts but need to try my first reflow. Anyone want to suggest how to reflow three LEDs at once? I’m thinking a hotplate is the best bet.
Very nice setup. Those chips are so small. The first time I had to solder one I went and bought a set up similar to yours. Some of the pictures on this forum they look massive.
I can surely understand why you are happy with this! Nicely done. Bravo!
I never had me one of those multi emitter lights. Did never care for them. But I must say that little solarforce host with the bling bezel might make a believer of me yet!
ltinifni - that setup will help, but I am no pro solder jock (had very very little experience prior to this), but I really got the hang of doing these 7135's with no failures - must have done about 10 or so, so far. The trick I think is a 10X lighted magnifier to check all your work at a very detailed level, check continuity at each step, and clean up any mess. Of course you need to bend the 3 pins down, use the smallest tip, a little flux, and steady hands. I like tipping the board back so the piggy back 7135 lays back on the bent pins - this helps seating the chip and viewing the work. I also like to do them on the side facing the star and pick positions more accessible.
But I’ll be glad to share what is working for me. I’ve added 16 chips to 4 drivers now without destroying anything (or burning my fingers).
The soldering iron I’m using is this one here it’s a cheap RadioShack 15/30 watt iron. The tip it came with was too big but I found a much smaller tip that fits perfect (p/n 64-2052). It’s a 15 watt tip but holds up well as long as I only hit the 30 watt switch for short times, and it’s only $3, I’m on my second one.
I found it’s important to keep the tip clean, I use steel wool before starting and re-clean after soldering each chip. I also learned that this iron will not maintain much heat even at 30 watts. If the solder doesn’t melt the second it touches the very end of the tip I hold off a minute or two before starting the next chip.
I bend all three pins at once with a pair of tweezers, when I first tried I bent the pins individually but found the pins wouldn’t end up parallel with each other. Bending them together seems to work perfectly.
When I have all the chips ready I piggy-back them with AA. The first time around I tried holding them in place and soldering the large ground on the back of the chips. I think that was one of my problems, it’s a large space to bridge and I probably used too much heat. By using AA and soldering the small ground pin it goes much quicker.
Once the AA sets up I put a little flux on each pin and just a little dab of solder on the tip of the iron. Put the iron on the point where the vertical pin of the new chip meets the horizontal pin on the driver and let the flux draw the solder. Hot and fast is my new battle cry!
After soldering each chip I inspect carfully, if it all looks good I check the current, it should have gone up by around 0.3a. If so I move on to the next one, if not I know where to look for problems. I had a few of those with this last driver but I knew it had to be one of the three solders I just did.
I don’t have any good pictures but this one gives you the idea. This is the 5a driver, there are 4 chips on the battery side and two on the LED side.
I’m sure this would be easier with a nice soldering station but it can be done on the cheap.
As far as the 3-up P60s, I’ve had a lot of fun making them but after I finish the Nichia I think I’m done with them. They put out a ton of light, huge hot spot with no spill at all. The only throw they provide is by sheer lumens. A well driven XM-L is a more usable light and it does it using less electrons. I do think the 3-up looks cool though.
