DISCLAIMER: I know nothing of electrical engineering I just seen this as the best fit category for my question.
I have a solar panel that is being run to a controller switch (for lack of a better name) the controller switch then has a hookup for a battery and a hookup for output. I have the battery connected and its supplying 12V - 12.8V to the output.
I want to hook up a female USB end to the the output. But I know that a USB port should only provide around 5V.
Before I had the controller and battery I had the solar panel hooked directly up to the guts of an old cigarette lighter phone charger. It worked great. But when I tried to hook up that same little circuit board to the output of the controller it just arced and so I removed it.
Have no idea what I'm doing wrong here. I hooked a voltage meter to the output and sure enough, 12V. Hooked a LED light up to it and it lit up real bright. But whenever I hook up that little circuit it arcs and if I hook up the circuit board from the inside of a USB wall charger... Nothing, no power coming from the USB port (measured with voltage meter).