Providing a customised power supply for a ruggedised Wi-Fi access point

With the transportation industry continually evolving, there is an increasing need for Wi-Fi access points for applications such as uninterrupted train-to-trackside communications, train and carriage coupling to establish an end-to-end Ethernet and IP backbone, and passenger services such as onboard Wi-Fi, entertainment, and more.

Challenge

Our customer was a provider of Wi-Fi 5 and Wi-Fi 6 ruggedised access points for railway and light rail usage. Their project goal was to create the next generation of their product, enabling suitability for the needs of today’s market whilst also future-proofing. An upgrade of the power supply, as well as various surrounding components, was required.

The customer had a number of requirements that proved challenging throughout the project:

• The Wi-Fi access point required a higher power solution whilst maintaining excellent heat management and a small footprint
• The Wi-Fi access point required a higher bandwidth of communication, containing more components but in the same compact package, whilst maintaining existing or better levels of electromagnetic interference (EMI)
• The end price of the power supply needed to match their target price range
   

Solution

To ensure we could first recommend a solution closely matched to the customers’ requirements on power, heat management, and size, we held a technical meeting to explore the list of specifications further to enable us to provide a technical proposal. The standard product we chose to recommend for the environment was an isolated DC/DC converter from our strategic partner, Cincon.

With the customer in agreement, the project moved into the sample stage. However, with no standard product meeting the exact requirements, we worked with Cincon to modify the sizing of the components in order to draw more power, as well as adjusting the overload/overcurrent protection levels.

The modification met the required efficiency level during the customer's functional test and therefore progressed onto the customer completing the design of the Wi-Fi access point based on the power supply. During the design phase, the customer encountered a technical challenge whereby the filters within the design didn’t meet the electromagnetic compatibility (EMC) standard for the rail industry.

We escalated this issue to Cincon and arranged for all three parties to come together to collaboratively solve this technical challenge. Due to its complexity, it took some time to identify the best route forward. Cincon then undertook modification of the internal components which included several filter stages, input and output stages, PCB layout and component selection for various modules, and also some recommendations for the customer to make at system level. This ensured the Wi-Fi access point complied with the required EMC standards whilst not increasing in footprint.

With all technical and commercial requirements met, the customer committed to ordering the customised 40W (5V/8A) quarter brick, EMC level B power supply, covering one year of business. The quality and flexibility of this product went on to exceed customer expectations.

 

Benefit

As the customer didn’t have extensive in-house capabilities, choosing to work with us on this project not only enabled them to have a customised high-power solution that met the demands of the rail industry, but also provided them with an extended design house for support throughout crucial stages of their project.

Our long-standing relationship with Cincon connected the customer to an expert power supply manufacturer that could deliver a best-in-class product at a price within their target range, whilst providing flexibility and reducing their time to market.