No-compromise DC-DC converters for railway applications

Modern railways rely on a host of electronic systems in order to operate safely and provide passenger comfort and convenience. A typical railway carriage distributes either 72V or 110V DC of battery power to these various systems many of which require lower and regulated operating voltages.

Railway distributed power system designs incorporate DC-DC converters to convert the main battery voltage into the input voltage of the downstream electronic systems and DC-DC converters with a wide input voltage range can accommodate a greater number of power systems. In addition, the main battery power may also fluctuate when feeding higher power systems onboard the train, a DC-DC converter with a wider input range is better suited to handle such wide variations in voltage.

The OFQC40 and OFQC60 Series 40 and 60-watt quarter-brick DC-DC converters feature a wide 12:1 input voltage range covering potential distribution voltages of 9-75V DC or 14V to 160V DC, according to the EN50155 standard. The wide input range allows the OFQC converters to accommodate many different power systems within the railway environment.

Additional features and characteristics include:

• Output voltages of 5, 12, 15, 24, 28, 48 and 53V DC
• Isolation voltage up to 3000V AC
• Efficiencies up to 92 per cent
• EN55032 compliance
• Protection against over current, over voltage, under voltage, short circuits and over temperature
• RoHS and REACH compliance with CE Mark pending

As railways add more power systems to enable train operation and provide passenger amenities, DC-DC converters must accommodate a greater number of input voltages. Polytron Devices' OFQC Series of 40 and 60-W DC-DC converters boast a wide 12:1 input range so designers can use them in a variety of power systems for modern railways.

The OFQC Series of isolated 40 and 60-W single output DC-DC converters is available in two very wide 12:1 input ranges of 9-75V and 14-160V DC, with each offering output voltages of 5, 12, 15, 24, 28, 48 or 53V DC. The units come in a plastic case with aluminium baseplate and have an industry-standard quarter-brick footprint. Featuring efficiencies as high as 92 per cent, up to 3000V AC isolation voltage, and remote ON/OFF, these DC-DC converters meet EN 50155 standards for railway applications. Built-in safeguards include over temperature, overcurrent, overvoltage, undervoltage and short circuit protections. The operating baseplate temperature range is -40degC to +105degC, and heat sink options are available. OFQC40 and OFQC60 DC-DC converters comply to RoHS and REACH, with CE Mark pending.

Gresham's vast experience of designing and manufacturing defence power systems is available to customers to provide modified standard or full custom power supply designs when required. Gresham can also supply a new range of defence power products for land-based and vehicle applications to complement its world-class naval power systems that are utilised by over 20 different countries throughout the world.

The full Gresham Power Electronics product range includes OEM and external power supplies, including encapsulated, for medical, industrial, defence, communications, broadcast systems advanced multi-media applications and LED lighting. CompactPCI, hot-swap power shelves and products for telecoms as well as static frequency converters, DC UPS, distributed power systems and DC:AC inverters for Naval Defence markets. The product range is being rapidly expanded by leveraging the access to products of their new Coolisys Power Solutions Group partners.

For more information about the Polytron extra wide input range DC-DC converters visit www.greshampower.com.