capacitor calaulation

Discussion in 'The Projects Forum' started by sangpo, Aug 18, 2013.

  1. sangpo

    Thread Starter Member

    Aug 17, 2013
    Hi all, I have started my electronic project on making battery eleimitor using stept down tarnsfermer.(stepdown to 12 volt AC. (variying from 3,6,9 12 VoutDC) Full bridge rectification was done. I want to use capacitor for smoothing the DC volt before connecting the input volt to ML317 regulator.

    So what is formula to calculate the value of smoothing capacitor. Please help me to teach how find out correct value of capacitor.

    Thank u

  2. MrChips


    Oct 2, 2009
    It depends on the load and how much ripple you can tolerate.
    1000μF @ 25V is a good starting point.
  3. WBahn


    Mar 31, 2012
    In response to the other thread you started in which you stated

    the answers are two: The smaller capacitance will result in greater ripple, which may or may not make it unacceptable. The smaller working voltage may result in the capacitor failing, possible by exploding or catching fire.

    P.S. - Why did you feel the need to start another thread to ask such a closely related question? You needn't fear;MrChips hasn't bitten anyone's head off for questioning his recommendations in quite some time. As noted by Bertus, the answer is tightly coupled to the application.
  4. wayneh


    Sep 9, 2010
    If you need to replace the 1000µF 25V rated capacitor and all you have are the 250µF 12V rated capacitors, there might be a way to do that. Once we hear what you're doing, we can advise.