Hello all! Ryan here. I've got a question... I'm powering my arduino with a 10.5V DC wall-transformer that I procured from my local thrift store. Is it ok to leave my arduino on for extended periods of time with this input voltage? I know that the hardware page for the UNO (http://arduino.cc/en/Main/ArduinoBoardUno) says that 10.5V is within the recommended input voltage range, but is it ok to leave my arduino on for a long time with this input voltage?
I am having it drive a 9x9 LED matrix. needless to say, there is considerable current draw from the transformer. approximately 50% of all of the LEDs will be on at the same time. also, I'm using POV so only 9 LEDs are on at any given time. After letting my UNO run for around 5 minutes, I pressed my finger against what I assume to be the 5V regulator and found it was warm. Not hot, just warm.
So my final question is this: What is the maximum period of time you would allow your UNO to run under these conditions? I would greatly appreciate any advice/help that you could give me.
Kind regards, Ryan