Overvoltage protection and power saving circuit for a switched mode power supply

摘要

The present invention relates to electrical power supplies and, more particularly, to an overvoltage protection and power saving circuit in switched-mode power supplies (SMPS) (1). It is proposed a switched-mode power supply (1) coupled to an AC voltage source and comprising a transformer having a primary side winding and a secondary side winding, said switched-mode power supply (1) further comprising a rectifier, an input capacitor and an SMPS controller. According to the invention, a low voltage blocker ensures that if a bus voltage that is lower than a certain level is measured, a band gap reference comparator that is in series with said low voltage blocker is be energized.