Multiple output AC/DC converter with an internal DC UPS

The usual way to avoid a computer shutdown during a mains failure is to connect an AC Uninterruptible Power System (UPS). However, there are other possibilities, as using an internal DC UPS, that is, to allow the topology to operate either from the AC mains or from a battery. A complete design of an AC/DC power supply with an internal DC UPS is presented in this paper. Moreover, the power supply meets all the requirements needed to be used as an ATX PC power supply: multiple outputs, power and voltage ratings, size, protections, etc. A prototype has been fully developed and tested as a PC power supply. The autonomy achieved at full power is around 7 minutes.