Designing electronics for trains presents an array of additional challenges, both in terms of reliability and the features required by the regulator. With the THN 15UIR family, TRACO POWER ships a set of converters designed explicitly for this fascinating market.

DC/DC converters are beneficial in various applications due to their ability to transform voltages with minimal losses. In the case of the UIR15 family, an efficiency of 88% is reached, which is superior to all linear regulators.

Step-Down Conversion for a Wide Range of Voltages

All members of the railway DC/DC converter family discussed in this article are buck converters: their output voltage is lower than the input voltage. In terms of input voltage ranges, TRACO then specifies two groups: one works in the range of 9 to 75VDC, and the other covers 14-160VDC.

Inside these voltage ranges, a variety of SKUs provide different voltage levels. As an example, the \"low voltage range\" THN 15-3611UIR delivers an output voltage of 5.1VDC and a maximum output current of 3000mA. The THN 15-3623UIR is a dual-output unit that provides both +15 and -15VDC.

In some cases, adding a heatsink can be recommended to mitigate thermal issues. In this case, the SKU THN-HS2, also provided by Traco Power, is suggested. Its physical design mates the DC/DC converter perfectly, thereby ensuring easy bring-up of the solution.

Holdup Capacitor Integration Available

Advanced railway electronics often need to withstand power outages. This is accomplished via holdup capacitors, which - usually - need to be connected to the converter input via a network of passive components (see https://www.tracopower.com/int/simple-hold-time-implementation-railway-power-supplies for detailed information).

In the case of the THN15, Traco provides a dedicated set of input pins, as shown in the figure below. This leads to a simplification of the power supply\'s schematics and a cost reduction.

Certification by Various Industry Standards

Heavy industries often require advanced certifications to minimize potential liabilities. TRACO POWER certifies the 15UIR by the vast array of industry standards outlined below.

Additionally, EMC/EMI compliance is ensured by various standards and regulations. Obtaining a COTS design certified to these quality levels is a notoriously challenging task -- deploying the DC/DC converter outlined in this article sidesteps the issue.

Conclusion

If a railway-bound design needs a DC/DC converter, the THN 15UIR family should be deployed at all costs. Its wide range of certifications ensures that the test house will not focus on the power supply, thereby shortening time to market.