jackrae:
What do you mean by "valleys" Do you mean the maximum negative peak or the lowest voltage that the "rectified" signal fall to.
Hi Jack, Yes, I am referring to the negative peaks of a sinusoidal input.
@dlloyd: I'll try that circuit. But, I am not sure that will work because the capacitor needs to discharge since the sinusoid amplitude may change and it needs to follow the negative peaks. Maybe having a resistor connected to ground to the right of the diode may work?
@fungus: That option is good but I cannot invert the signal for what I am doing.