A story about the op-amp precision rectifier
My comments under SE EE question Understanding how the simple precision rectifier works This is a story about the famous circuit with a figurative name "ideal diode". I started my contribution by writing comments under the first question. Question 1 My comments Consider the circuit as a '"disturbed op-amp follower". Here is a Wikibooks story about this phenomenon observed in negative feedback circuits. Try a simple experiment - apply some negative input voltage (e.g., Vin = -1 V) and put yourself in the place of the op-amp. What will you do to make the voltage of the inverting input equal to the voltage of the non-inverting input (the "golden rule")? What will be the op-amp output voltage? The so-called "golden rule" is introduced in the famous book of "The Art of Electronics". It says that an op-amp with negative feedback does its best to maintain equality between its two input voltages. In your circuit, it will make Vout = Vin. ...