I'd like to create a simple circuit that makes an LED brighter depending on the amplitude of an audio signal. My idea is to use the following schematic ;
My question is this - what happens when the voltage of the AC signal goes negative? Does any current flow out of the base of the transistor? And if so, what happens to the current through the transistor? Also, I appreciate that this isn't a great circuit to indicate the amplitude of the AC audio signal, but it should more or less work right?