Switched-mode power supply and method for driving a switch in a switch-mode power supply for improved switch-on after a waiting period or disconnection from the network

摘要

A switched-mode power supply with a switch for applying a supply voltage to a primary coil of a transformer based on the criterion of a drive signal. A pulse-width modulator has supplied a first regulating signal that is dependent on an output voltage and a first current signal that is dependent on a voltage through the primary coil for providing the drive signal. A second regulating signal that is variable in dependency on the current through the primary coil is also supplied to the pulse-width modulator in addition to the first regulating signal and first voltage signal. A method is provided for driving the switch in a switched-mode power supply.