PULS GmbH (Munich, Germany), a manufacturer of switch-mode power supplies for DIN rails, unveiled its new SLV20 buffer module for uninterruptible power supplies (UPSs) based on electrolytic capacitors. The buffer module supplies standby voltage without batteries or ac connection, and is simply connected in parallel to provide a regulated 24 Vdc power supply in the load circuit.
In contrast to dc UPS modules, the SLV20 is maintenance-free as no batteries are used. The ride-through time for a 20 A current load is typically 0.31 seconds (0.2 seconds guaranteed) and for a 100 mA load, the unit provides voltage for 43 seconds. Until now, the maximum hold-up time of the SLV20 was limited to 4 seconds irrespective of the current draw. The permissible operating temperature range of the SLV20 has also been extended and will operate reliably from -10 °C to +60 °C. The PULS unit can be connected to any regulated 24 Vdc power supply and can be matched optimally to the voltage source in the particular dc circuit.