Synchronous rectifier

A field effect transistor (T1) with gate, source and drain is connected between the anode and cathode of the diode, the cathode being connected to the drain. The non inverting input (+) of the operational amplifier (OP1) is connected to the anode and its inverting input (-) to the cathode. If necessary, its output is connected via a resistance (R2) to the FET gate, to control the gate voltage (UG) in accordance with the potential difference between cathode and anode.