I am still pretty noob in electronics, but I am in the process of completing a homemade power supply project and I would love to hear some advises.
The supply itself is fairly straight forward - it takes 20-ish volts DC from a laptop power supply, has a bunch of switching regulators (2 fixed at 3.3V and 5.0V, 2 adjustable with voltage and current limit and another 5.0V to power an arduino nano), 4 INA219 breakouts to measure each channel voltage and current, an arduino nano to collect the data and an LCD to display voltages, currents, current limits, etc.
It all works and is cool and useful, but when I attached my homemade (arduino based) oscilloscope to its outputs I noticed there is some ripple on the 3.3V and 5V channels. It was much better with a 100uF cap, but still present, and practically gone with 1000uF cap at the output (to be precise within +-0.03V, which is the margin of error of my crappy home-made oscilloscope).
So, the question is - is there any reason not to put a 1000uF cap at the outputs of these channels?
I don't have a schematic, because the circuits was simple enough, so I didn't really need to make one before implementing it. Lets assume the question can be simplified down to just a DC power source and a step-down switching voltage regulator. I do have some power mosfets switching the channels on and off, but I don't think it changes anything significantly.
Again, the question is - is there a reason not to put a 1000uF capacitor at the output of a switching voltage regulator used as a general purpose power supply?
EDIT: Added line breaks, I couldn't figure out how to do it last night. Sorry for the mess.