Has anyone achually damaged a 7135 chip to the point it won’t work? I’m not talking about breaking off a leg or letting your dog chew on it. I’m talking about overheating it with a soldering iron.
I ask because I’ve started stacking some and while my first couple of attempts were ugly, my third try looks perfect. I added 2 chips for a total of 10 and the current only went up .15 amps with a protected Panasonic 3400.
None of the legs are bridged or anything and it looks perfect under a magnifying glass.
I have cooked one in extended operation due to poor heatsinking. It failed in a partially on state so that the emitter was permanently stuck in mood mode
This would only be noticeable in a momentary switch driver where the 7135 acts as the primary power switch between batteries and led.
Otherwise I’ve never damaged one during soldering, they’re quite sturdy.
If you’re current is not going up by adding chips, the bottleneck is somewhere else, make sure you have a very low resistance path everywhere and aren’t using thin wires in a bench setup to test this.
I had a few which didn’t work when I first tried stacking these. I am unsure if they died because of to much soldering or by shortcuts and powering them…
I also had one with broken leg after bending it to much…
I also have drivers on which I have one 7135 not working but since these are so cheap and it is hard to find the defective one I just stacked one more…
But all in all they are very rigid and since my soldering skills became better no 7135 died anymore.
I also had a nanjg clone from kaidomain bought before some years because you could disable memory with one of the stars and this one is half defect, it only gives 1.4A…Probably some trace broken but since it’s in an old crappy headlight I have no ambition to take a further look into it
Your problem is probably related with the battery and resistance in switch and springs. Try to braid springs and a imr battery(the samsung25R is very affordable)
When I first started stacking 7135s I overheated more than I care to think about. Usually from too much time spent trying to get the solder just right.
I started checking driver output after installing each 7135 rather than after stacking 4 or 8. With practice I’ve found quick soldering with a very hot tip seems to work best.
To test I’m using my extech 330. Multimeter it’s a decent multimeter, but it’s still no fluke. And I haven’t put larger leads on it yet.
When I test my convoy c8 with 8*7135 it comes pretty close to the correct current.
I’m just going to remove all my extra chips, test, then install them one at a time. I’ve stepped my heat down quite a bit on my soldering station so maybe I was frying them because it was pretty high.
I’ve got 100 7135s and 5 105 drivers coming tomorrow so I’ll be able to start over fresh anyway.
Yup. I’m out of chips now, but I’ll try again tomorrow. I’ve tested for shorts and opens on all of the chips and it tests perfect. It’s not not cranking out the juice. I think I baked a lot of them.
I was doing it in the pill at first so they were hot for a while, now I’m ding it out of the pill.
I have a testing board similar to this: OSH Park ~
With it powered up I just press the 7135 into the holes and check the current drawn from the power supply. I’ve checked a lot of 7135s prior to mounting and they’ve all drawn exactly what they have supposed to draw. The ones I took off from the fried driver board could show anything up to 400mA.
