Powering electronic equipment is an area of great research in virtually all electronic systems. Designs that waste less power, run cooler and manage fluctuations of voltage and current to provide “clean” power to our devices are very important.
We hear a lot about the LPS (Linear Power Supply) and the SMPS (Switch Mode Power Supply). In GENERAL it has been shown that high quality Linear Power Supplies improve the performance of audio equipment. An LPS design can be rather simple. Improving the quality of the DC power to our devices can get expensive.
The SMPS has gotten a bad “rap” in the industry and is shunned do to issues around leakage and RF noise. In many applications the SMPS is the only way we can supply power to our devices efficiently. Small SMPS power supplies give us the portability we need for devices like phones and laptop computers.
Here is a little more info from WikiPedia: https://en.m.wikipedia.org/wiki/Power_supply