How to design effective power supply thermal management
Efficient and cost-effective thermal management for power supply units (PSUs) is important when designing industrial and medical systems to ensure reliability. Designing an effective thermal management system for a PSU is a complex activity, and much depends upon whether the PSU is enclosed or open frame. If an enclosed PSU is used, the type of enclosure has an impact on airflow and thermal dissipation. While fans help, designers need to consider fan reliability as well as the back pressure caused by system fans that can significantly reduce the effectiveness of the PSU fan(s), potentially increasing PSU operating temperatures. PSUs often have lower efficiencies at low input line voltage conditions. As a result, units that are operated for extended periods under low input line conditions can result in higher thermal dissipation and the need for additional cooling. Finally,
PSUs often require derating if operated at elevated temperatures that can be experienced in industrial and medical systems. To speed the implementation of effective thermal management systems, designers can turn to PSUs specifically designed for use in industrial and medical applications that offer a range of thermal management options. This article reviews the thermal management challenges when designing industrial and medical systems and offers guidance for designing effective thermal management solutions. It then presents options when integrating PSUs into industrial and medical equipment using PSUs from Bel Power Solutions as real-world examples, and closes with some practical steps designers can follow when integrating a PSU into the overall system thermal design.
Power supply thermal management challenges PSU thermal management challenges include system airflow and the impact that system fans can have on the performance of any fans integrated into PSUs, the ambient operating temperature, the need for peak power delivery, and the impact the input voltage range can have on power dissipation. These are first-order considerations; this article does not touch on second-order thermal management considerations related to rack mount systems or special environments such as data centers. One of the first considerations is the direction of PSU airflow; normal airflow creates positive pressure exiting the system and reverse airflow creates positive pressure entering the system ( Figure 1 ).
in industrial and medical systems
By Jeff Shepard Contributed By DigiKey's North American Editors
Figure 1: In normal airflow, positive pressure exits the system (left). With reverse airflow, positive pressure enters the system (right). (Image: Bel Power Solutions)
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