Most electrical engineers believe they have a good understanding of power supplies because they are relatively simple, single-function DC devices designed to output controlled voltages. However, there is much more to power supplies than this description would suggest. Although a power supply’s specifications describe its performance adequately for most applications, specifying every possible aspect of its performance (or any instrument’s, for that matter) would be far too costly in terms of both money and time.
Although a review of a power supply’s specifications should always be a part of the selection process, other characteristics should also be taken into consideration. From a user’s perspective, what’s important is understanding a supply’s power envelope to ensure it will be able to deliver power at the voltage and current parameters needed for a specific application.