POWER PACK

摘要

A mains power supply unit for the purpose of supplying consumers that are connected directly or by way of a voltage system converter to a direct voltage branch of a mains power supply unit comprises a buffer capacitor (C) that can be charged from the mains supply and that still supplies the direct voltage branch for a predetermined minimum period of time in the event of a failure or interruption in the mains supply. In such an event, the buffer capacitor (C) can be charged by way of a dedicated charging circuit (3) to a voltage (U2), which, regardless of the voltage fluctuations in the direct voltage branch, is substantially constant and corresponds in a substantial manner to the upper limit value of the direct voltage (U1) to which limit value the mains power supply unit is dimensioned. The buffer capacitor can be connected onto the direct voltage branch by way of a controlled switch (S) in the event of undervoltage in the mains supply or in the direct voltage branch.