Switching power supply, output ripple

[staze]

All,

In my quest to diagnose issues with my Roomba, I noticed that there's a pretty significant ripple on the output of the switching power supply/charger when loaded down to 1.25A output. Opening the thing up, I noticed there's CapXon caps in there (ugh).

I would assume the output cap is responsible for smoothing that ripple out, but I'm unsure if upping the capacity of that cap, or just putting a lower ESR cap in there, would do much to fix the ripple. Any thoughts? Is there somewhere else I should look?

Kinda crappy (cappy?) that Roomba's cost as much as they do, yet they cheap out on the power supply.

[T3sl4co1l]

What problems are you having?

Ripple probably isn't a big deal if the problem is charging the battery, though I suppose there's a chance the charge controller might not be happy with it, or something.

You can certainly try high quality capacitors, but do mind the control loop is probably designed to accommodate the high ESR; it may oscillate (squeal or hiss, perhaps at frequencies you can't hear) if you substitute something literally "too good".

Mechanics, and how much engineering they can commit to optimizing the producibility of it, dominates the cost I'm sure.

Tim