This rugged, industrial quality step down DC-DC regulator uses field-proven technology to generate the required output power. The design is based on topology that has a proven track record in numerous heavy-duty applications. The unit steps a 400–800Vdc input voltage to 300Vdc, or similar voltage at very high efficiency. The use of the latest silicon carbide semiconductor technology contributes to 97-98% conversion efficiency, allowing low heat dissipation and high power density in the existing F3W enclosure size. Cooling is by two long-life built-in fans on one side of the unit, with additional conduction via base plate to a heat-sinking surface. Applications include generating a stable regulated output voltage from a wide range input voltage, stabilizing the voltage at the end of a long cable, or generating a stable suitable voltage for motor drive units. A fully encapsulated version of this design for operation in extreme environments is also available.