Hey lads so yesterday i re-flowed a XML2 into my Nitecore EA41 a nice 4500k tint. Any ways i ended up having to connect the power wires in reverse to get the LED to work. positive to negative as you do lol.
My question is can i re-flow the LED backyard? If so would the polarity be reverse? Or I am on drugs?
I am sure i done it the right way around? The small dot was facing the negative side?
Is it because i am in Australia and we are upside down i had this issue
The LED works but will there be any issues in the future?
It doesnât matter what way round you reflow the LED as long as the connections are right. It will work or it wonât. I always test polarity before re-installing just to be sure as iâve done it myself.
I did my E14 in reverse due to the board design
I really canât comment on your pharmaceutical status though :laughing:
Doesnât matter at all with a single emitter as long as you are aware of it and switch the wires.
I have a couple lights that came built with swapped wires because the emitter was backward on the MCPCB.
I always test before soldering to make sure since the dots and triangles sometimes confuse me, not to mention anode/cathode conventions. With multi-emitter mcpcbâs if I can make them all the same then right or wrong theyâll all still work.
180 off isnât a big deal. It can still work as normal with the wires reversed. The no-noâs are too much/too little solder and 90 degrees off. Too little and It might not work or heat pad insufficiently bonded, too much and the led floats too far off the heat pad and more in jeapardy of dedoming by optics. Too little solder is almost certainly worse than too much as for as heat goes. Off by 90 is a short bypassing the led. Wonât hurt the led with a 7135 driver but can easily overheat 7135 chips forced to regulate full battery voltage and is basically a dead short with an FET driver and could melt springs, switch, or overamp the cell. Not sure what that kind of current does to the led die contact pads but theyâre sure to get hotter with an FET DD driver than a 7135 driver.
May want to use a sharpie to make a big (as possible) â+â and ââ on the MCPCB if you can, for future reference just in case you have to open it up again sometime in the future. Or at least I would, but Iâm anal and like to document everything probably because Iâm incapable of remembering itâŚ
I re-flowed a new emitter in a IMALENT HR20 it also had to be the oriented âwrongâ way, because the wires coming from the driver was reversed.
I tested the emitter before putting it in, worked fine put it in tried again didnât work, took it back out tested it again worked fine, scratched my head put it back the other way around worked fine.
Led wires are the all the indication I use at that point. When I use a single color for both(I have 20â of white Teflon #26) I mark the + wire where it passes through the mcpcb, otherwise itâs red/black already so additional markings arenât needed.
Yeah, but what happens when you take that star out of the head/pill and no longer have the lead wires to help identify?
I can guaranty that - for me - if I pulled that star out of a light, thereâs a fair chance that when I put it back in the next day, or next week, or the next month⌠after who-knows-how-many other projects in between⌠there is a REALLY good chance Iâd not remember the special reveresed polarity and I would just go ahead and solder red-wire to â+â and black wire to â-â and wind up putting it in âbackwardsâ.
I just have an awful memory, I admit. :person_facepalming: Some (most) guys have better memories and maybe they could rely on that. I could look at the tiny little dot or bond wires, but 1) I have to remember to do that, and 2) what if you are like me and donât remember that type of stuff so easily either, then it is (very mildly) annoying to look up.
Taking out the marker now and putting a nice red â+â over what used to be the tiny little ââ takes zero time or effort if you do it at the time if I had to re-disassemble the light that might change my mind. And it could potentially save you time/headache/damaged LED in the future. Why not? IMO. But maybe thatâs just the QC guy in me talking.
What happens if one puts a led in the wrong way and tests it with a direct cell connection?
Would putting the wires correct make it work or would it fry?
The same caught me in my Klarus XT11GT mod with the XHP35 HI E4-3C NW mod.
I reflowed the LED as the star is marked
Build it in light not working
Ckecked a photo I did during mod from old emitter
The bond wires were on opposite site, so in original light the LED was soldered in reverse.
As the star had different shape I had to reflow the LED again to fix it
Well, the easiest way would be using a DMM and checking polarity with the continuity feature. single emitters and even some triples will light up a bit if connected the correct way.
I have yet to hook up an LED backwards to full voltage/current. I always test mine with 3V, 0.03A before they go in the light. I have applied 3V 0.03A backwards (from curiosity the first time, and accident the subsequent times) and nothing bad has happened that I can tell, the LEDs all still work great.
But I have to imagine that hooking it up to the driver backwards and hitting it with several amps would not be good for itâŚ
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Iâve tried that on several different LEDs and it just doesnât work - do I just have a crappy DMM? The continuity function seems to work normally otherwise.
Being a diode if you hook it up backwards you wonât get several amps, at least not from a linear driver. I donât know enough about boost/buck but Iâm guessing it would be bad. Itâs high reverse voltage that kills LEDs hooked up backwards since you wonât get any current otherwise.
