High efficiency semi-encapsulated DC-DC converters meet railway standards

March 06, 2012 // By Paul Buckley
Sunpower's has introduced the company's new RSD-150 series which features high-efficiency, semi-encapsulated 150 W DC-DC converters with EN 50155 and IEC 60571 railway standard certification. Featuring built-in constant current limiting, the RSD-150 series products are just 36 mm high and therefore fit within a 1U enclosure.

The rugged products have an operating temperature of -40 to +55˚C, or with base plate cooling, to +70˚C without derating.     

The semi-encapsulated design provides further ruggedisation, with basic anti-moisture and anti-dust PCB protection as well as anti-vibration protection to 5G, and heat dissipation. Along with a high efficiency of up to 91%, this eliminates any need for forced air cooling and fan reliability issues. The series is also highly versatile, with 2:1 (± 40%) wide input voltage ranges, from approximately 14 – 34 VDC to approximately 58 – 154 VDC. Different models offer output voltages from 5 V to 24 V, with 30 A to 6.3 A output current ratings.     

All models can support an overload of up to 135% of rated power, using a constant current limiting circuit providing auto-recovery. All offer input/output isolation of 4000 VDC and all use 105˚C long life electrolytic capacitors. Protection for short circuit, overload and output overvoltage is designed in and the units can be subjected to reverse polarity input without damage. They have CE EMC approval with an EN 50155 test report.     

As well as being certified to railway standards EN 50155, IEC 60571, IEC 61373 and EN 50121-3-2, these new converters comply with ITE standards IEC 60950-1 and EN 55022. This qualifies their use within a wide range of vehicles operating on DC power, in applications such as railways, metro rapid transit systems, subways, buses, leisure trailers, vessels and others. The series is also ideal for use together with a battery-driven external DC power source in harsh environment industrial installations such as security systems, DC UPSs, telecom equipment and other applications where ambient temperatures, moisture and dust are issues.     

The RSD-150 series is a second-generation expansion of Sunpower's RSD-100 series of 100 W enclosed type single output DC – DC converters. The new units have dimensions of 189 x 77 x 36 mm (LxWxH) and carry a