Smoke released

:o I made some mistake hooking up a photo interrupter (http://www.sparkfun.com/datasheets/Components/GP1A57HRJ00F.pdf) I bought from Sparkfun. I swapped 5V with GND. Some smoke was released from the transistor side. I kind of wonder which part was reponsible for this. Any ideas?

BTW, there seems to be enough smoke left in whatever part so when I corrected my connection, it worked.

An IR emitter the wrong way round is just a diode. This conducted a lot of current but was probably saved by the current limiting resistor and the feebleness of your power supply. The smoke was probably just burning plastic.

You were lucky. ;)

there seems to be enough smoke left in whatever part

Thx for the laugh :)

Thanks guys. I got the smoke joke from the “bar sport” board. Still don’t know which part of the transistor+compariter is overheating.