Power supply with reduced harmonic load on mains system and corresponding equipment

摘要

The power supply according to the invention has a first switched-mode power supply and a second switched-mode power supply, which is connected in parallel with the first, and with both switched-mode power supplies having power factor correction. In this case, the first switched-mode power supply has an active power factor correction circuit, for example with a current pump which contains a coil which is coupled to a primary winding of a transformer, and the second switched-mode power supply has a power factor coil (NS) in its power supply for power factor correction. Both switched-mode power supplies are in this case arranged in one appliance, in particular in parallel and downstream from a common mains switch. The active power factor correction in this case flattens the pulsed current flow, and the power factor coil shifts the phase of the pulsed current flow. Since the current flows in the switched-mode power supplies, which are connected in parallel, are added to one another, this addition results in additional broadening of the pulsed current flow, which leads to a further improvement in the power factor for the power supply, and/or the inductance of the power factor coil can in consequence be chosen to be correspondingly lower.