Power Supply Design

Biggest - Smaller - Smallest capacitor value


Ringing after load has changed: unstable supply !!!
You can actually see the two different resonance frequencies in this picture.


Now with a big cap in the middle.


Better than the first time, but still no sigar.



Small - Bigger - Biggest capacitor value


Supply is stable very quickly after load change: stable supply!


So even though the same caps are used, you can get totally different results by where you place them. A big capacity does not mean the supply is always better. It is best to place a few small values correctly than to plug in a huge cap just anywhere.