Hey, finally starting to use transistors, currently I want to make a stroboscope using a 10w LED I have, for the sake of portability it will just be powered by a 9v, and draws ~150ma (rough guess based on analog meter) rather than the 900 it does at 12v. (measured constantly on not pulsed)
Anyways, that's too much for the arduino to handle so I grabbed some NPN's to drive the LED.
Now, I burnt the first arduino board (ebay pro mini and I have a few extras, they are cheap enough its not a huge deal) using a chunky transistor I found, it was either the board going bad or (what I think) was the transistor being too slow, the LED would just be on constantly, it didn't work properly. I tried directly driving it too and that is what burnt out the first board no doubt.
Anyways, second day, I figured out transistor circuitry more, grabbed a pack of NPN's (just the radio shack sort of pack) that I had laying around and wired it up like so:
10v from the supply going to arduino raw (I am fairly confident of this, though it is possible it might have been on VCC), I could use an attiny and that was the original plan but then I'd also have to use a voltage regulator, and I am using a fairly small heatsink.
Anyways, after a while it stopped working, I tested with a 5v 20ma led instead of the much larger one, no luck, tried to reprogram it and it was dead.
Anyways... I just want to double check that this is the correct way to wire it up, two things could have killed the arduino last time, either it was a current spike or voltage spike from the supply, I noticed it acting up a bit, or, and what I am thinking, is that I may just have put the 12v into vcc
That could also have been from when I was trying the 5mm LED instead, and had lowered the supply to 5v, can't remember, probably doesn't help that I wasn't awake for very long before this lol.
Anyways, I just want to verify that this is correct, and not some issue with how I wired up the transistor. I doubt it but it's one of those things where I doubt myself anyways.