Railway DC/DC converters

moviatunnelbPolyamp has continuously supplied switch mode DC/DC converters to the international railway industry since 1973. The Company now has the capability to meet performance requirements of worldwide applications and to accommodate the extreme environmental demands of hot and humid Bangkok, hot and dry Australia and the arctic north of Sweden

System Applications

All Polyamp DC/DC Converters for railway applications are designed to be safe, technically compliant, reliable and cost effective.

Applications include systems for surface and underground trains powered by both electric and diesel locomotives, trams and special vehicles used by the operators and maintainers. Systems can be categorised as:

Train systems
Systems used by the driver are specifically safety conscious and a fault will either stop the train or automatically revert it to an alternative fail safe mode.

  • Driver computer
  • Train control
  • Remote control
  • Emergency starting
  • Radio
  • Head and backlight (Xenon/Halogen/LED)
  • Alarm (bells/horns)
  • Wipe washers
  • Cameras
Passenger comfort systems
  • Displays & information
  • Lamps (Halogen/LED)
  • IT-equipments
  • Sound/Communication
  • Toilets
  • Coffee & Restaurant
Railway operating systems
  • Counting devices, ticketing
  • Remote control
  • Cameras
  • Doors
  • Lifts including disabled facilities
  • Track control system GSM-R

Technical Standards
Modern trains achieve savings of weight and space by using battery voltage up to 110 Vd.c. but most system equipments require input power at 12V and 24Vdc. The DC/DC Converter transforms the basic 110 Vdc to 12 and 24 Vdc, but can also perform the inverse if necessary. i.e. convert 12 and 24 Vdc to 110 Vdc.

Train standards
Polyamp DC/DC Converters are designed to meet the railway specific standards for electronic equipment onboard trains including those specified in EN50155 and IEC60571. They are mechanically rugged for reliable operation in a very harsh environment throughout their whole life. Read more about train input voltage ranges.

Where these standards specify different levels for particular conditions, applicable ratings will be confirmed and agreed for individual customer applications.

An additional benefit of the Polyamp DC/DC Converters is that when they are used as a power source for equipments, that in themselves are not compliant with the EN 50155 and IEC 60571 standards, they effectively function as a filter and galvanic separation to shield those equipments. This allows the railway operator to use Commercial On The Shelf (COTS) equipments for such applications.

Environmental specification

Ambient temperature
The standard level is -25 to +55°C but most applications specify -25 to +70°C (T3).
Polyamp DC/DC Converters can be supplied to operate in temperatures from -40°C to +85°C.

Our DC/DC converters are compliant with the EN 50121-3-2 (IEC 62236-3-2) and also EN 50121-4 (IEC 62236-4) EMC performance specified for electronic equipments.
Our emission levels are much lower (-30dB) than the train limits. Our outputs also meet the immunity demands, which few competitors do. It means our output can be distributed and feed electronic equipment that do not meet the EN 50155 input variations.

Shock and vibration
Compliant with the IEC/EN 61373 requirements for body mounted class B.

Polyamp DC/DC converters are regularly used in military vehicles and fork lifts, which have more severe vibration requirements

Input voltage range of DC/DC Converters
EN 50155 and IEC 60571 specify a nominal input variation of ±30% including ripple but some other specifications define ±40%. For modern trains with better d.c. supply systems they can be relaxed and for markets still using RIA12 specifications, Polyamp can also supply models that meet its surge requirement of 3.5x nominal input voltage. Input voltages ranges for vehicles and railway applications.

pdf  Flyer 2006 Train (English) (1.62 MB)