New Industry Products

Absopulse Introduces 500W DC/DC Power Supplies for Extreme Environments

March 26, 2021 by Gary Elinoff

The PFC 319-D4 Series thrives even in the toughest of industrial environments, undeterred by fog, water, sand, oil or metal dust.

The 500 watt PFC 319-D4 power supplies employ active power factor correction (PFC) and operate over AC inputs ranging from 95 to 264 VAC. Outputs are either 12, 24, 48 or 125 VDC, and the company states that “custom input/output voltages are readily available.” 

The PFC 319-D4 units are available in tough D4 packages. Image courtesy of Absopulse


Did we mention that they’re Tough?

The members of the PFC 319-D4 series are IP66 rated. The IP code, also known as the Ingress Protection Code, is a part of IEC 60529. IP66 refers specifically to protection against foreign objects, including dust, and to protect against powerful water jets.

Inputs and outputs both feature circular or custom connections and sealed cable glands. The units feature application-specific vents for pressure equalization. These equalize the pressure inside the enclosures, minimizing connector strain and assuring the impermeability of the seal. 

Additionally, internal PCBs are conformal coated and ruggedized for immunity to high levels of vibration and shock. Beyond that, potting of the internal module is optionally available.


Active Power Factor Correction

We discuss active power and reactive power in our Basic Principles of Power online textbook. Power factor correction serves to reduce reactive power, which is wasted power caused by phase difference between current and voltage. This costly wasted power can also be a source of troublesome EMI if not eliminated via power factor correction

Significant power factor correction (PFC) can be achieved by simply adding an extra, strategically placed inductor within the power supply. Active power factor correction, illustrated by, involves the addition of such components as MOSFETs, producing much better results. The PFC 319-D4 achieves a PFC rating of 0.97, with 1.00 being perfect.



PFC 319-D4 is cooled via internal conduction to the enclosure’s walls and by convection occurring through the outside surfaces. The units are built with a baseplate, which will further enhance cooling.



The units feature isolation of 4300 VDC from input to output, 2250VDC input to chassis and 1000 VDC output to chassis. Because the outputs float, either positive of negative can be grounded. Spacing is 8 mm.



  • Inrush current limiting
  • Output short-circuit protection 
  • Output over-voltage protection 
  • Self-resetting thermal shutdown


Other features and specifications 

  • The power supplies offer an optional redundancy diode, allowing for parallel and N+1 operation.  
  • The units switch at 55 kHz
  • Dynamic response is a maximum of 5% voltage deviation for 10% to 50% load step. Recovery time is 1 msec or faster. 



The PFC 319-D4 power supplies are designed for the severe environments encountered in:

  • Power generation and distribution
  • Mining
  • Heavy industry
  • Offshore applications
  • Transportation
  • Telecom


Physical Considerations

  • PFC 319-D4 power supplies are available in die-cast aluminum D4 packages. Including mounting flanges and base plate, the dimensions are 230 x 113 x 448 mm. 
  • Non-debated operation is over a temperature range of -25 to +55℃.


Regulatory and Safety

  • Compliant with EN/UL60950-1 and with similar UL and CSA international safety standards
  • Meets EN55032 (EMI) to Class A, with class B available as an option