On Friday, 6 December 2019 19:08:00 UTC, Andrew T.  wrote:   
   > I'm curious about what happens to an LED when it is exposed to a   
   > moderate overcurrent situation.   
   >   
   > This question came about as I was troubleshooting some small white LED   
   > lights I built using 3 5mm LEDs and a current limiting resistor to run   
   > on 12Vdc (supplied by a lead-acid battery charged by solar).  After some   
   > time, many of these strings would start to flicker or blink.   
   >   
   > I was about to post a question about that, when I redid my resistor   
   > calculation.  I had originally calculated that a 100 ohm resistor   
   > would be sufficient to keep the current around 20mA (assumed 12.5V -   
   > 10.5V total LED drop).  But on recalculation, that would result in 30mA   
   > (the absoulte maximum rating) at 13.5V, the low end of charging range.   
   > Adding another 47 ohm resistor seems to have helped.   
   >   
   > So now I'm curious what happens inside the LED when the current   
   > exceeds the absolute max current by a modest amount (i.e., not the   
   > obvious overcurrent of leaving out the resistor entirely).  The LEDs   
   > I'm using seem to return to normal operation when the current is   
   > reduced, and seem to produce a momentary open-circuit condition during   
   > overcurrent, presumably from overheating.   
   >   
   > Anyone know what's happening to the semiconductor material in this   
   > situation?   
   >   
   > Thanks,   
      
   Flashing I'm told is caused by wire bonds detaching & moving due to thermal   
   expansion. If so I suspect at some level of reduced i a flashing LED ought to   
   work again, just at reduced output.   
      
      
   NT   
      
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