Introduction
Railway electronics operate in one of the harshest DC environments of any industry. Traction events, regenerative braking, and long supply cables create deep voltage dips, short surges, and high noise. Standard DC-DC converters are rarely designed to tolerate this.
Ultra-wide input DC-DC converters provide a proven solution. Designed specifically for rolling stock and railway infrastructure, they can accept a much broader input range, deliver stable regulated output voltages, and meet the stringent requirements of EN 50155, EN 50121-3-2, IEC 61373, and EN 45545-2.
Cincon’s 12:1 input range railway converters, capable of operating from 14.4 to 160 Vdc, give engineers the freedom to design equipment once and deploy across multiple fleets and systems.
Why Ultra-Wide Input Matters in Rail
Every rail operator uses different nominal DC bus voltages depending on train type and age. Common supply classes are 24, 36, 48, 72, 96, and 110 Vdc, each with its own voltage fluctuation range. During traction and braking, these can momentarily fall to 0.6 × Vin or spike to 1.4 × Vin.
An ultra-wide input converter remains fully operational across all these conditions, protecting downstream control systems, radios, displays, and communications gear. This reduces system complexity and eliminates the need for multiple voltage-specific converter models.
Key Technical Benefits
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Wide input voltage range – supports all standard rail DC buses.
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High reliability and long service life – conduction-cooled, baseplate designs with no fans.
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Strong EMC performance and galvanic isolation – compliant with EN 50121-3-2 and EN 62368-1.
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Shock and vibration resistance – tested to IEC 61373 for rolling stock environments.
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Temperature and environmental resilience – operates from −40 °C to +100 °C baseplate.
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Redundancy and protection – features include UVLO, OVP, OCP, SCP, and OTP.
EN 50155 Input Voltage Classes
| Nominal Voltage | Continuous Range (0.7-1.25 x Vin) |
Short Dip (0.6 x Vin for 0.1 s) |
Short Surge (1.4 x Vin for 1 s) |
| 24 V | 16.8 – 30 | 14.4 | 33.6 |
| 28 V | 19.6 – 35 | 16.8 | 39.2 |
| 36 V | 25.2 – 45 | 21.6 | 50.4 |
| 48 V | 33.6 – 60 | 28.8 | 67.2 |
| 72 V | 50.4 – 90 | 43.2 | 100.8 |
| 96 V | 67.2 – 120 | 57.6 | 134.4 |
| 110 V | 77 – 137.5 | 66 | 154 |
A Cincon 12:1 converter (14.4 – 160 Vdc) covers every range in this table. One part number can therefore be used across both 72 V and 110 V rolling stock fleets, greatly simplifying product standardisation and certification.
Mechanical Formats and Power Classes
- Quarter, half, and full brick modules – 20 W to 600 W power ratings with baseplate cooling.
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Chassis-mount and DIN-rail versions – pre-enclosed, easy to integrate in cabinets.
- PCB mount modules – ideal for low-power logic rails and signal conditioning.
- Output voltages – 5 V, 12 V, 15 V, 24 V, 28 V, and 48 V single outputs, or dual ±12 V and ±15 V.
- Trim and sense – typically ±10 % voltage trim with remote sense for load-side regulation.
Designing for Original Equipment Manufacturers (OEM)
If you are an equipment manufacturer supplying subsystems such as train radios, surveillance cameras, passenger information displays, in seat power or telematics gateways, integrating an ultra-wide input DC-DC converter into your product design allows it to operate natively across multiple DC bus voltages.
Instead of producing separate 72 V and 110 V versions, one design using a Cincon 14.4 – 160 Vdc converter will work across both. This dramatically expands your product’s usable market while reducing your engineering and certification overhead.
Commercial and Technical Advantages
- Universal compatibility: A single PCB assembly suits both 72 V and 110 V fleets.
- Simplified compliance: EN 50155 input tests only need to be passed once.
- Reduced inventory: One SKU simplifies procurement, stock management, and after-sales support.
- Longer product lifecycle: Future projects or export contracts can use the same design without modification.
- Improved resilience: Built-in transient and surge immunity ensures stable operation across fleets and networks.
Example Applications
- Onboard radios and communication routers – regulated 24 V logic rails maintained during traction transients.
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CCTV and DVR systems – reliable operation across 72 V light rail and 110 V heavy rail with no hardware change.
- Passenger information displays – single design suitable for mixed fleets and depots.
- Condition monitoring systems – operate from both traction and depot auxiliary supplies without re-engineering.
Powerbox Support for Rail and OEM Engineering Teams
Powerbox Australia provides local engineering support for the selection, testing, and integration of Cincon ultra-wide input converters. Our team works alongside Cincon’s FAE team to assist with:
- Module selection by voltage, current, and cooling type.
- Assistance with pre-compliance thermal and EMC analysis.
- Local stocking and lifecycle management for production continuity.
With more than 40 years of experience in power electronics, Powerbox helps Australian and New Zealand manufacturers design products that are reliable, compliant, and ready for deployment across the rail sector.
Ready to simplify your rail power design?
Contact the Powerbox engineering team to discuss your next project or request a shortlist of Cincon railway-qualified converters suited to your system.
Frequently Asked Questions
What is an input ratio and why does it matter in a DC-DC converter?
The input ratio defines how wide a converter's operating voltage window is, expressed as the ratio of its maximum to minimum input voltage. For example, a 4:1 converter operating from 9–36 Vdc has a fourfold input span, while a 12:1 converter operating from 14.4–160 Vdc can tolerate far greater variation.
A wider input ratio allows a converter to remain regulated during voltage dips, surges, and supply transients. In rail and industrial systems where bus voltages vary under load, a 12:1 converter eliminates the need for multiple voltage-specific variants and ensures reliable operation across all standard supply classes.
What are the key standards a DC-DC converter must meet for use on rolling stock?
The principal requirements are defined under EN 50155 for voltage variation, temperature, humidity, and functional performance; EN 50121-3-2 for EMC emissions and immunity; and IEC 61373 for shock and vibration. In most cases, material selection also needs to consider EN 45545-2 fire safety requirements.
Cincon's railway converters are designed to comply with these standards when integrated according to datasheet recommendations.
Why use a 12:1 input range converter instead of a 4:1 or 8:1 model?
A 12:1 converter — for example 14.4–160 Vdc — can operate across all common nominal rail buses, including 24 V, 48 V, 72 V, 96 V, and 110 V systems. This allows a single design to be used across multiple fleets and reduces the need for voltage-specific product variants. It also provides additional headroom for the transient conditions specified in EN 50155.
You don't have all Cincon products listed on your website — can I access the full range?
Yes. Cincon has an extensive catalogue with more than 25,000 models, including DC/DC converters, AC/DC power supplies, and custom assemblies. Powerbox displays only a selection of popular products on its website, however our engineering team has full access to the entire Cincon catalogue and can recommend or source the most suitable part for your project.
How do I ensure compliance with EMC limits in EN 50121-3-2?
Even though Cincon modules include internal filtering, external LC filters are usually required to meet system-level limits. Layout practices such as short input leads, symmetrical Y-capacitor returns, and bonding the baseplate to the chassis ground are equally important.
Powerbox can assist with pre-compliance testing and filter design reviews.
What cooling methods are recommended for onboard rail electronics?
Conduction cooling via the converter's baseplate is preferred in rail environments because it eliminates fans, reduces maintenance, and improves reliability. Ensure there is a defined thermal interface between the module and the mounting surface, and verify that baseplate temperature at full load does not exceed the specified limit — typically 100 °C.
Can Powerbox supply Cincon modules as part of a complete power assembly?
Yes. Powerbox has extensive experience in the custom design of products using Cincon modules. These solutions can be packaged to meet the unique electrical, mechanical, and environmental requirements of each application. Options include enclosed or baseplate-cooled assemblies, DIN-rail configurations, and integrated power systems designed and tested locally to meet Australian and New Zealand standards.
About the Author
James Rutty, Director, Powerbox Australia
James Rutty is a Director at Powerbox Australia, with over 15 years of experience in power electronics for critical infrastructure across Australia and New Zealand. He works with engineers, consultants, and integrators at the architecture level, from initial load assessment and system design through to product specification, commissioning support, and lifecycle management.
