External Plug-In Adapters

An external plug-in adapter is an AC-to-DC power supply that converts an alternating current (AC) source to a direct current (DC) supply.  The most basic AC-to-DC power supply consists of a transformer, rectifier diodes and a capacitor.  This very simple unregulated supply does not usually have adequate performance or functionality for most applications, but modules that implement more sophisticated converters such as switching regulators and hot swap controllers are available.  One of the most common metrics used to characterize the performance of AC-to-DC power supplies is output ripple, which quantifies how much the output voltage varies over time.  External plug-in adapters come with various types of connectors for different applications.