The first important concept to understand about unregulated DC voltage output power adapters is that they are designed and rated to produce a particular voltage at a particular maximum output load current. The output voltage of an unregulated power adapter will decrease as the current provided by the adapter output to the load increases. The power adapter selected should be matched as closely as possible to the voltage and current power requirements of the load.
The second important concept to understand about any power adapter, whether regulated or unregulated, is that the rated output current of the adapter should not be exceeded by the maximum current requirement of the load.
A third concept about unregulated power adapters which for most applications is less important, but still helpful for people to understand, is that unregulated DC output power adapters do not produce a pure and "clean" DC voltage. But if the power adapter selected is closely matched to the power requirements of the load, the purity of the DC voltage produced is more than adequate for many jobs (with few exceptions).
With the many applications and advantages discussed above considered, selecting an regulated switching power adapter for your application can be summarized as follows:
- check the power requirements and connector size specifications of the appliances or applications you wish to power.
- select a regulated switching power adapter that will power as many of your applications as possible.
Conclusion
Choosing the correct power adapter isn't difficult when the power, performance requirements, limitations, and advantages are understood. Unregulated DC output power adapters are cheap and plentiful, and available in many voltage and current output variations, though they have more limitations than regulated switching power adapters do. Unregulated DC output power adapters are better suited for dedicated applications where portability and power sensitivity are not considered a big issue. Regulated switching power adapters are the much more versatile and efficient variety. If a user can power a small number of appliances with a single regulated switching power adapter, they can be more cost effective as well.