Power supplies form the heart of any electronics product from computers to appliances.
But choosing the right one for your application may be a challenge unless you know what to look for. Choosing the wrong power supply can have a negative impact on the safety, reliability, efficiency and overall performance of your system.
In this blog post, we’ll look at some of the best practices for choosing power supplies for your project.
Is there such a thing as the “best” power supply?
The best power supply is whichever one meets all the right standards for safety, power, space, power, current, voltage and budget.
Beyond that, off-the-shelf power supplies are usually broken down into these categories.
- Desktop – Desktop power supplies are a stand-alone supply that connects through cables to the AC outlet on one end, and the destination system.
- DIN-rail mount – Primarily found in industrial environments, these power supplies are attached directly to the EN and IEC DIN standard rail.
- Encapsulated – As the name suggests, these are fully enclosed with a thermally conductive material which rapidly moves the heat away from the internal converter.
- Open frame – With these supplies, the internal components are exposed, with the supply typically inserted into a system that keeps it safe. These supplies could be PC-board-mount only, or fully enclosed but with a perforated cover.
- Wall mount – Wall mount power supplies plug directly into a wall outlet, with the converted power channeled directly into the destination system.
What are the tradeoffs connected to each type of power supply?
As with anything in life, there are advantages and drawbacks to each power supply type. For example, encapsulated supplies are usually smaller and can be PC-board-mounted, but may require external components for EMI and input surge protection, as well as added heatsink, which can add to the overall cost and space requirements. After a certain point, the burden of meeting these requirements can begin to outweigh the advantages of using an encapsulated power supply.
Open-frame supplies are usually more available and less costly, but may also require airflow or conduction for cooling, unless severe derating is used. These power supplies are also not meant for wide ranges of ambient temperatures, which can cause thermal stress on power components.
Din-Rail power supplies are mounted on metal strips (din rails) and provide a compact way to expand the power components as needs demand. And since they are convection cooled, no fans are required. While they can range in voltage, most are below 100. Due to the nature of the din rail system, they are best suited to industrial control applications.
What are some pitfalls I should avoid when choosing power supplies?
First off, become familiar with the power supply options that are best suited to your project. And, try to keep from over-specification. Stick to what’s essential for your design. It will help you save on production costs.
Remember that power supplies are not perfect. Failing to recognize their limits can be disastrous, and the cost of design changes jumps dramatically as the development cycle goes on. This is because of the work that needs to happen to re-test and re-work designs -- what’s often called the “waterfall effect.”
Finally, keep in mind that smaller power supplies aren’t necessarily better. A half-brick convertor and a full-brick convertor with the same level of power and efficiency will still disperse the same heat.
If you are working on a new project, it is best to get your power supply manufacturer involved in the early stages of the project. They will be able to help you determine the best power supply solution for your application.
At MEGA Electronics, we are experienced in proving standard, modified and customized power solutions for a variety of industries. We can help you determine the right power supply for your project based on the footprint for the required power range and any additional components needed for cooling.
Our catalog of products includes wall mount, desktop, DIN rail and open frame power supplies in a range of wattages. We offer Vendor Managed Inventory and Kandan programs to support blanket orders from our North American Warehouses. And most of our AC power supply and DC power supply products meet Energy Star ratings and other nationally recognized efficiency levels.
Contact us today to learn how MEGA Electronics can help you with your next project.