Mornsun has launched its new generation of railway power supplies—the 1/4 brick 100W product UWTH1DxxQB-100WR3—for railway system applications. This series features an ultra-wide input voltage range of 12:1 (14-160VDC) and simplifies peripheral design through Mornsun's new power-off retention technology. It also meets the 85℃ temperature rise requirement under full voltage and load conditions. The DIY input undervoltage adjustment function allows for flexible adjustment of the input voltage range to meet the different input voltage requirements of various railway systems. In addition to its ultra-high isolation withstand voltage design, the product meets global certification standards such as EN50155, EN62368, EN45545, AREMA, and CSA62368. This product truly realizes the concept of ultra-wide input voltage under the same peripheral conditions, avoiding the need for changes to peripheral circuitry and subsequent system recertification by the user when the input voltage is changed.
1. 14-160VDC ultra-wide voltage input, adaptable to mainstream input voltage railway systems worldwide.
The globally accepted nominal voltages for railway power supplies include 24V, 28V, 36V, 48V, 72V, 96V, and 110V. According to the EN50155 railway power supply standard, the input voltage fluctuation range is shown in the figure. It can be seen that under a nominal voltage of 24V, the minimum input voltage is 14.4V, and under a nominal voltage of 110V, the maximum input voltage can reach 154V. Our company's newly launched 14-160V ultra-wide input railway power supply is suitable for the vast majority of railway systems worldwide with varying input voltages.
To address the diverse input voltage requirements of users worldwide, the traditional approach is to categorize input voltages into three segments: 9-36VDC, 18V-75VDC, and 43-160VDC. Using different modules for different national user systems leads to challenges in material standardization and increased certification cycles, resulting in additional investment for user-end applications. The UWTH1DxxQB-100WR3, adaptable to railway systems with varying input voltages globally, avoids these problems.
2. Achieve 10ms retention after power failure; external components are simple and fixed.
Simply having an ultra-wide input voltage range is not enough to truly meet user needs; a simpler peripheral design is also required to meet stringent specifications. A prerequisite for a product to meet the needs of global users is that it requires only one unified peripheral circuit when using all input voltage ranges. Therefore, in user-side design, the ability to achieve power-down retention becomes an indispensable selection requirement.
Traditional designs place electrolytic capacitors at the product input. To achieve the concept of using a fixed set of external components, the electrolytic capacitors must have a voltage rating of ≥200VDC. When the input voltage is 24V, the energy stored in the capacitors must be able to meet the requirement of maintaining 100W of power for 10ms. This poses a significant challenge to the size of the capacitors.
Our products employ active power-loss retention technology, perfectly solving this problem. In the user's system design process, a single 470uF/100V capacitor is sufficient to meet the requirements across the entire 14-160VDC voltage range, satisfying even the most demanding system conditions.
The following diagram compares the selection of two power-down retention capacitors for two different schemes.
The UWTH1DxxQB-100WR3 product features a dedicated pin for a power-down retention external capacitor. When the system is powered on, input energy is not directly poured into the large power-down retention capacitor, effectively reducing the input capacitance. This significantly reduces the inrush current generated by the electrolytic capacitor during system power-on, further improving the reliability of the user's system. The following figure compares the inrush current of the traditional solution and our solution (tested without any suppression measures). It can be seen that our solution's inrush current is only half that of the traditional solution.
3. Programmable input undervoltage regulation
In addition to a dedicated pin for external capacitors, the UWTH1DxxQB-100WR3 also features an input undervoltage adjustment pin. By adjusting the resistance between this pin and input ground, the input undervoltage point can be easily changed, allowing users to quickly adjust it according to their system's specific needs. The correspondence between Ruvlo and undervoltage point can be found in the product's technical manual.
4. Meets the requirements for applications at altitudes up to 5000m, with ultra-high isolation and withstand voltage of 3000VAC.
The EN50155 standard for railways requires a maximum withstand voltage of 1500VAC for input to output. Our company can achieve reinforced insulation for 3000VAC for input to output, and the input/output housing meets 2500VAC requirements. During the design process, stringent safety regulations are referenced to improve the reliability of different railway systems under high-altitude application conditions.
5. More advantages and features
6. Matching filter
Adding the FC-C08D module to the front end of a DC/DC module allows the power supply product to meet the EMC requirements of the EN50155 standard. When used with Mornsun railway power modules, the maximum input voltage of the railway power supply should not exceed the maximum operating voltage of the FC-C08D.
