New Industry Products

MEAN WELL Announces New DBUF20/40 20A/40A DIN Rail Buffer Modules

January 12, 2020 by MEAN WELL

MEAN WELL Announces New DBUF20/40 20A/40A DIN Rail Buffer Modules.

MEAN WELL newly introduced the DBUF20/40 series of DIN rail-mounted 20A/ 40A buffer modules, which can be used with DIN rail power supplies to provide short-term backup for the load. DBUF20/40 will enter the buffer mode when the AC mains power is temporarily suspended or interrupted. The buffer function provides stable 24Vdc to extend the system operation time, and the buffer time depends on the load current. The DBUF20 can sustain 20A load for 350ms, and the DBUF40 can sustain 40A load for 250ms.


Image courtesy of MEAN WELL.

The DBUF20/40 can provide similar functions as the DR-UPS40 uninterrupted power backup function. The main feature of the DBUF20/40 is to provide a short buffer time through the internal electrolytic capacitor energy storage. There is no external battery in the system, and the system maintenance costs reduce significantly since no battery replacement is needed. On the other hand, the DC-UPS40 requires an external battery. The backup time can be longer, but the battery needs to be replaced regularly. After the launch of the DBUF20/40 series, MEAN WELL's DIN rail power solutions have been completed, as MEAN WELL can now provide 10~960W DIN rail power supplies and various peripheral accessory modules in one-stop-shop!


Image courtesy of MEAN WELL.



  • Buffering with electrolytic capacitors instead of batteries saves maintenance cost
  • Suitable for 24Vdc systems
  • Buffering time:
    • DBUF20: 350ms at 20A load
    • DBUF40: 250ms at 40A load
  • Buffer mode selectable by switch:
    • 22Vdc (fixed, the default setting)
    • Vin-1Vdc (dynamic mode)
  • Supports parallel connection of multiple DBUF20/40 to extend the buffering time
  • Operating temperature: -25~+70℃
  • LED indicator for operation status
  • Protections: short circuit/overload/over voltage/reverse polarity (no damage)
  • Class I installation available (includes grounding pin)
  • Passes CB/UL/CUL/EAC//CE international safety approval
  • Dimensions (WxHxD): 63 x 125.2 x 114.9 mm
  • 3 years warranty



Founded in 1982, MEAN WELL is one of the world's few manufacturers dedicated to standard power supply products. It is ranked the 5th in global power supply (DC output) makers according to a report by Micro Technology released in March, 2019. 99% of MEAN WELL sales are of standard power supply products sold under the MEAN WELL brand name. The other four companies' products are ODM/OEM.

MEAN WELL has been working as a "reliable partner" with customers, suppliers, contractors, and employees to build long lasting mutual trust relationships based on the spirit of "good intentions."

Robust partnerships with 200 plus authorized distributors around the world, MEAN WELL has been growing and getting stronger for three decades. With 2,800 employees located at its global headquarters in New Taipei Industrial Park, Taiwan, branches and sales offices at Guangzhou, Shenzhen, Suzhou in China, California USA, and Netherlands in the EU, four advanced production bases in New Taipei City (Taiwan), Tianhe District and Huadu District in Guangzhou, and Suzhou City in China, MEAN WELL had a combined revenue of USD 1,007 million in 2018.