Built another light last night, pop goes the xml2. ????????
Found the reason, but not sure why it is doing this.
Let me explain........................
5A buck driver from Mountain Electronics
XML2 on Noctigon lite coat of AA paste to a chunk of copper.
2x Panasonic NCR18650PF(protection did not trip surprisingly)
I swapped the led leads to slightly (maybe 1/2") longer 18g to reach thru my copper heatsink.
Trial fitted the driver, and hooked up the MM to check function before I potted it. All good, with 4.98A on high.:twothumbs
Continuing on, thinking all is fine, I potted the driver with AA aluma epoxy. Mounted and soldered the XML2. Assembled the light and then stopped for a smoke before putting my tools away, to kill time while the AA cured out some.
On to the problem.............
Turned it on for the first time, low......check, medium..........check, high........check.
I left it on high as I stepped out of my shop to play with the zoommy and about 30-60 seconds in ...............................
..........................."POOF" ..........................
:thinking:
I quickly pulled batteries, then the "pill". First thing I notice is its barely warm yet, so nothing got very hot. No visible damage.
Put everything back in, left top of led star exposed, probed for current there.
4.8A for a couple seconds then UPPPPP, tops out around 10.5A then comes back down. Then steady for a few and suddenly back up to 10.something.
When it jumps it dont stay there, just up then back to normal.
Also note, I dont think my MM was showing what it really topped out at. It seemed to be moving faster than my meters display can change, because it skipped about every other full digit. Top current could well have been several Amps higher
So.........
what would cause this? I cant take the driver out now to look at it without destroying it.
Did I do something wrong here, or just a random bad driver?
Was the AA maybe not cured yet and causing issues?
Maybe I got something hot changing the wires?
Best guess, or ideas anybody?
Jim
Found the reason, but not sure why it is doing this.
Let me explain........................
5A buck driver from Mountain Electronics
XML2 on Noctigon lite coat of AA paste to a chunk of copper.
2x Panasonic NCR18650PF(protection did not trip surprisingly)
I swapped the led leads to slightly (maybe 1/2") longer 18g to reach thru my copper heatsink.
Trial fitted the driver, and hooked up the MM to check function before I potted it. All good, with 4.98A on high.:twothumbs
Continuing on, thinking all is fine, I potted the driver with AA aluma epoxy. Mounted and soldered the XML2. Assembled the light and then stopped for a smoke before putting my tools away, to kill time while the AA cured out some.
On to the problem.............
Turned it on for the first time, low......check, medium..........check, high........check.
I left it on high as I stepped out of my shop to play with the zoommy and about 30-60 seconds in ...............................
..........................."POOF" ..........................
:thinking:I quickly pulled batteries, then the "pill". First thing I notice is its barely warm yet, so nothing got very hot. No visible damage.
Put everything back in, left top of led star exposed, probed for current there.
4.8A for a couple seconds then UPPPPP, tops out around 10.5A then comes back down. Then steady for a few and suddenly back up to 10.something.
When it jumps it dont stay there, just up then back to normal.
Also note, I dont think my MM was showing what it really topped out at. It seemed to be moving faster than my meters display can change, because it skipped about every other full digit. Top current could well have been several Amps higher
So.........
what would cause this? I cant take the driver out now to look at it without destroying it.
Did I do something wrong here, or just a random bad driver?
Was the AA maybe not cured yet and causing issues?
Maybe I got something hot changing the wires?
Best guess, or ideas anybody?
Jim
