If I operated the Arduino Uno or Leonardo off of a battery such as a USB recharger battery (commercial version of a minty boost) can I pull the 5 V off of the Arduino +5V pin or doing I need to somehow power the circuit completely separately from the Arduino? Like I said in earlier post I think a single LED with a single NPN is going to be good enough for this application but if I'm going to chalk this whole thing up to a learning experience I want to learn all I can.Sea Moss wrote: It's certainly not surprising that it bonks out when presented with a load like this. Current is really limited here by the ability of the source to deliver it. For a battery that depends on its internal resistance…
My problem was that I had built a single LED single NPN circuit that works pretty well but when I built a second one I had problems with it. I think the first one had a wide-angle LED which was working pretty well for me because my distances were not too great. The one that wasn't working very well was narrow angle which of course meant that the position was critical. I was thinking I wasn't getting enough power when in fact I was getting too much accuracy of direction. I'm going to rebuild another one with a wide-angle and see what happens. I just didn't get a chance to do it today.