Striving to Supply Reliable Power Sources
With the increased demand on mobile and rugged embedded computing systems, power challenges exist with almost every installation. While these challenges may focus on a system’s power supply unit (PSU) simply as its energy source, managing reliable, efficient power for an embedded system goes well beyond just the PSU. An integrated PSU plays a key role in a system’s operation, but today’s dense electronics systems demand more efficiency and creativity in supplying that power.
With space limitations, harsh conditions and increasing component density, system designers are looking for more efficient ways to harness and distribute energy across these compact, high density systems. In addition, the growing use of small form factors means embedded systems can now be used in both mobile and remote applications, where power sources may not be readily available. Systems need methods of sustaining a reliable and independent power source to ensure continued operations. Because of this, alternate power sources that adhere to the critical SWaP (size, weight and power) optimization factors need to be evaluated in every design application.
Why SWaP is so important
SWaP optimization plays a key role in a system’s PSU because consistent, reliable power must be able to be supplied in rugged or mobile applications where limited, or no alternate power source is available. Instead of adding a larger unit or incorporating multiple PSUs in a single system, new design methods are being applied that enable a compact footprint to be maintained.
Some alternative power methods focus on converting energy generated by an alternate source into new forms of power that can meet the demands of these highly integrated, dense computing structures—even if they are mobile, rugged, compact, etc. Others are helping condition and balance load requirements to stabilize a steady stream of power within the system itself.
In order to meet SWaP requirements as well as growing power needs, system designers are using these methods to enable power from one area of an application to be repurposed and supplied to another part of the application. That power is also being conditioned and balanced through embedded power conversion units to ensure the supply is stable and steady, yet another way to creatively optimize power within an embedded system.
Common Power Challenges
There are a variety of typical scenarios users come across when trying to power their embedded systems. Understanding these challenges, and knowing how to address them in system design, will provide a more solid baseline to incorporating more advanced power management solutions:
Fluctuation – Power can fluctuate in remote locations. The power supply needs to accommodate a system running at full load. Sometimes there may only be standby or lower power requirements. The challenge is, how can power needs be balanced to avoid over- as well as under-voltage?
Reliability – Reliable power means user safety. This is especially true in military, defense, medical and transportation applications. The loss of power means the potential loss of life. A common concern when thinking about power reliability is, what safeguards should be put in place to ensure the power supply remains steady?
Low Maintenance – When installing embedded systems in remote locations low maintenance is key. Having to do repairs for things like calibration or wear-and-tear really isn’t an option, so it’s important to think about the elements a PSU should include, so that it operates continuously with limited user intervention.
Efficient operation – No matter the application, power conversion units need to improve the operation of what is installed. It is always important to think about how a system can do more with less.
Specific power requirements
Depending upon an application’s requirements, unique areas of focus related to each set of circumstances should be taken into consideration. This can include normative requirements, environmental requirements, application-specific requirements, safety requirements or service-related requirements.
In a military environment, for example, a PSU located within a mobile critical command station can simultaneously charge a battery pack and switch to battery power in case of AC power loss. In a wayside railway environment, a high-efficiency, compact DC-DC converter with a supply voltage of 800 VDC enables the use of thinner, less expensive copper cables over longer distances.
With the increased demand on systems today, power challenges exist in almost every installation. No matter the industry, developments in power conversion technologies have made it much easier to solve these specific power problems, especially those found in military communications, railway systems and home healthcare equipment. To learn more about optimizing power conversion in high-reliability rugged embedded systems, download the White Paper: Optimizing Power Conversion in High-Reliability Rugged Embedded Systems.
