when following everyone’s incredibly helpful advice it slipped my mind that my power supply pcb requires a 1uf electrolytic. I now have a bunch of ceramic and film ones, but Abe from AI synthesis advised me against using them, so I won’t.
for the sake of the learning experience though, what is the difference between a 1uf electrolytic cap and a 1uf ceramic cap in the case of a power supply? thanks!
I feel like I must add a bit of nuance here. First of all, current doesn’t flow through a capacitor, that’s their main property.
But indeed, most (read: unless otherwise specified) electrolytic caps are polarised, meaning their + terminal must always be kept at a higher voltage than their - terminal. Ceramic and film caps don’t have this limitation, but usually don’t go up to high capacitance values like electrolytics do.
I don’t see a reason why you couldn’t use a ceramic in this case, 1 uF is a value available for both types. If anything, a ceramic will be more reliable.
It can depend on the application and quality of parts though.
While their capacitance may be the same, ceramics and electrolytics still have different properties.
Ceramics have a lower ESR and ESL, but their effective capacitance drops under dc bias.
This means if you put a constant dc voltage on it, it will act as a smaller capacitor.
Also, the ESR and ESL make the resonant frequency very high, and voltage regulators might even oscillate under these conditions.
I don’t know what type of power supply you are using, but if the 1uF is for filtering/reservoir cap, electrolytic is probably best. Maybe even better if you put a smaller value (10-100nF or so) in parallel, if you suffer from high frequency noise