Abstract: An uninterruptible power supply circuit includes an inverter circuit configured to be connected to a first AC power grid, the power supply circuit moreover being configured to adopt a first configuration for supplying power to the first AC power grid from a second AC power grid, wherein first configuration a power factor correction circuit is configured to be connected to the second AC power grid so as to deliver a DC voltage to the inverter circuit, the power factor correction circuit comprising an inductor, and a first switch branch pertaining to the power factor correction circuit and the inverter circuit; and a second configuration for supplying power to the first AC power grid from a DC voltage source, wherein second configuration a DC-DC converter circuit is configured to be connected to the DC voltage source so as to deliver a DC voltage to the inverter circuit, the inductor moreover pertaining to the DC-DC converter circuit.

Abstract: The monitoring device is configured for monitoring a converter comprising a first and a second input terminals, two output terminals, a first filter branch connected between the input terminals, a second filter branch connected in parallel with the first branch, two switching branches connected in parallel with the second branch, each switching branch including two switching half-branches connected in series and in an intermediate point forming an output terminal. The monitoring device comprises a detection impedance configured for being connected between the first and the second branches, and a detection module configured for comparing the voltage across the detection impedance with a predefined threshold, then for generating a detection signal as soon as said voltage is greater than said threshold.