Seen a 7805 open up once, guess the shutdown had an issue. I also learned it's also a good idea to pay attention to voltage and polarity with tantalum caps. Anybody got any really good incendiary stories?
So this set up is losing 7V @ 500mA for a power dissipation of 3.5W.Without a heatsink, that 7805's temp shot to 110C in mere seconds. I turned it off then, since the datasheet said 120C tops.