Your Customized Converter even at Low Quantities

High-speed reduction or an emergency stop of a train cannot be made by simply blocking all the wheels. This would not only increase the braking distance but also cause the wheels to slide on the rail tracks, grinding off material and eventually resulting in unbalanced wheels, in addition to damage to both the rail and the wheels. Similar cars, modern trains have anti-lock braking systems (ABS) to address all these concerns. However, while the vehicle ABS is supported by 24V, the challenge in rail applications is to universally support an electronic ABS using input voltages ranging from 16V up to 160V, while ensuring that the design cannot be easily copied by a competitor. Interested in how this was solved?

Railway brakes need an ABS to control each wheel and avoid wheel-block and damaging slide on the rail tracks. The ABS also allows for rapid speed reduction of the train during an emergency stop page. The braking force for each wheel is independently controlled by ABS units using data from different sensors. Each wagon has additional central brake-control units. These control units used to be space-limited and therefore, the unique, quarter-brick form factor was utilized to optimize the geometry. The independently controlled ABS units have their own power subsystem, which can utilize a lower-cost, half-brick solution compared to the upstream solution in the central control unit.

In the past, the customers used discrete custom designs to supply the braking systems and ABS units from the typical 110V grid supply in trains. Due to its success in the national train market, the customers wanted to offer the same system for metro applications with their typical 24V grids. This would have necessitated a complete redesigning of the two discrete power solutions with very high costs for design and approvals, in addition to extremely long design cycles.

Therefore, the customers were looking for an easy way to deploy preapproved solutions that would be able to handle 24V and 110V input sources from the same product family. Simultaneously, they did not want to lose the advantage of using custom products for key components within the system as this made copying the design increasingly difficult. The few manufacturers of DC/DC converters that offered customized versions normally requested large orders to support any modifications. This made it extremely difficult in the train market, which has been driven by smaller projects and therefore, exhibited low minimum order quantities (MOQs).

This is where RECOM offered one of its key competitive advantages: Low-volume, private-label, footprint-compatible converters, semi-customized from our standard product families, covered the full 24 – 110V input range and creating the required, local 24V, 12V, and 5V voltage rails for the braking system.

These products are already railway-certified, hence, RECOM was able to extend the existing certifications to the private-label parts. Furthermore, the standard datasheets contained pre-tested, railway-grade EMI filter solutions, and therefore, the design of the power solution took a fraction of the time needed for a new discrete design. Even better, RECOM was able to modify the pin lengths of the converters, which made the mechanical design of customer’s PCB easier and opened the door for similar, semi-customized modifications for solutions.

As a manufacturer offering the highest flexibility, RECOM was able to get these products approved with a customized label and offered this semi-customized part even for low order quantities.