Integrating circuit-precision rectifier circuit diagram

As shown in the figure is a precision rectifier circuit with an integrating circuit, which can convert the input alternating signal into a direct current signal. If the input signal frequency is very low, the input capacitor C1 can be eliminated. During the negative half cycle, the output terminal of the operational amplifier IS1 is connected through the diode D1 (cutoff voltage is 0.7V) and is isolated by the in-phase addition point of the diode D2. Op amp IS2 works as an inverting voltage follower.

During the positive half cycle, IS1 works as an inverting amplifier and is connected to the summing point through R2. At the input end, resistor R3 and resistor R2 form a negative feedback loop.