Safety systems for the railway


Highly reliable solutions for axle counters

Azle60-W: customized DC/DC converters for axle counters in railway technology

Special solution for a customer to be used beside the rail tracks. The electrically isolated DC/DC converter supplies a safety application which energizes the axle counters and accordingly controls rail traffic areas.

Special features:

The original solutions with 24 VDC and 60 VDCin are replaced with a single DC/DC converter. The wide input range between 14.4 and 84 VDC helps to reduce the customer’s variety of models. Integrated is an active reverse-polarity protection, an active inrush current limitation as well as a hold up time of 10 ms. The continuous power is 60 W, however, a double load of up to 5 sec. is possible without restriction. The output voltage is 120 VDC, protection against overcurrent, overvoltage and over-temperature helps to protect the subsequent applications against overloads.

The 4TE converter has a continuous efficiency of over 84 % depending on the input voltage. Further characteristics of this superior converter are parallel connection with exact power distribution, redundancy operation, hot swap, surge-immune outputs and a temperature range between -40 and 85 °C.

The plug-and-play solution supports the high EMC requirements for ISDN signals in order to secure an interference-free radio communication. This required switching frequencies of the converter steps of ˃300 kHz at over 3000 VDC isolation. 

High environmental requirements as well as an MTBF value of   ˃760,000 h according to MIL-HDBK-217-F round-off the pack.


  • Input:  24.4…84 VDC
  • Output:  120 VDC
  • Power: 60 W / 120 W (5 sec.)
  • Temperature: EN 50155 – Class TX
  • Isolation I/O: 3250 VDC
  • Hold up time:  10 ms

Features: reverse polarity protection and inrush current limitation (active), parallel mode, hot swap, redundancy operation, protection against excess current, overvoltage and high temperature

Standards: EN 50155, EN 50121-3-2, EN 50121-1 and -4, EN 50125-1 and -3, EN 61373