Very unfortunate, and looking for an explanation and solution for the future.
I have the following setup:
Running four daisy-chained TLC5940s from my Duemilanove a la this page: http://www.arduino.cc/playground/Learning/TLC5940
I have my 5V and ground from the Arduino board (USB bus power) running the TLCs. I have 9 common anode RGB LEDs hooked up to the TLCs, and I had the anode of those hooked to a bench power supply sharing ground with the Arduino.
I did this because the LEDs pull about an amp of current in total. Everything was running fine and work great until I switched off the bench supply. It seemed to spike really high - all the LEDs went white, then went out. When I turned it on again, nothing worked. I swapped out the TLCs, and all was well, so I guess it fried them.
- What happened?
- What an I do in the future to prevent it? Cap? Surge protection of some kind? Another power supply option?
I need something to supply about an amp of current at 3V to these LEDs, and I don't want it to be something that will surge and fry these TLCs!