A method for operating a switch in a power converter, a drive circuit for operating a switch in a power converter, and a power converter are disclosed. The method includes: driving an electronic switch coupled to an inductor in a power converter based on a feedback signal (SFB) and a crossing detection voltage, wherein the feedback signal is dependent on an output parameter of the power converter and the crossing detection voltage is dependent on a voltage across an auxiliary winding coupled to the inductor; clamping the crossing detection voltage; monitoring an auxiliary current (IAUX) associated with clamping the crossing detection voltage; and detecting an overvoltage when the monitored current reaches a predefined threshold.