Switched-mode power supply based on the flyback converter principle, for optional operation on mains voltage or a battery voltage

摘要

A switched-mode power supply based on the flyback converter principle has a control circuit on the primary side for driving, controlling and monitoring a switching transistor, a control winding and a winding for supplying the control circuit. By means of an additional winding, an additional switching stage and a changeover switch, whose switching state depends on the presence or absence of the mains voltage, the switched-mode power supply on which the invention is based is expanded for battery operation.