Filtering AC power.

Discussion in 'General Electronics Chat' started by cjdelphi, May 26, 2010.

  1. cjdelphi

    Thread Starter New Member

    Mar 26, 2009
    Just a General question, to filter AC power, does Polarized or Non-Polarized capacitors matter? I noticed specific caps like the MKV ones, but just for literally using it for a few minutes, is there some kind of rule as to what type of capacitor to use?

    Caps pass AC current but block DC current? this is when in series though?, so does that mean when filtering AC, you have to pass in series? because surely a capacitor unless it's a none polarized will blow in parallel ?

    Maybe I need to have another lesson in 101 in Capacitors.... This came about when harvesting caps from a UPS and now i want to eventually put them to good use in other projects.
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    For AC, non polarized or bi polar caps should be used, what ever the type may be. Period
  3. Wendy


    Mar 24, 2008
    You can also put two polarized caps back to back, it will half the capacitance (assuming both caps are equal) and double the voltage. It will also double the ESR, but the end result is a non polarized cap.


    Polarized caps are a little like batteries, the chemistry only supports a charge in one direction. The above setup puts all the stress on one cap per direction. It is odd, but it works.