Default units for Capacitors

Discussion in 'The Projects Forum' started by djsfantasi, Mar 5, 2014.

  1. djsfantasi

    Thread Starter AAC Fanatic!

    Apr 11, 2010
    3,382
    1,168
    The attached circuit my son is working on, has several caps without units. I believe they are in mfd, but want to confirm. Note that micro and pico farad values are called out.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    11,915
    2,961
    The unmarked ones will be μf.
    Mfd is much bigger!;)
    Max.
     
  3. bertus

    Administrator

    Apr 5, 2008
    16,419
    2,693
    Hello,

    I think they are in μF.
    The ones that are mentioned with the μF are the electrolitic ones.

    Bertus
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    11,915
    2,961
    IOW they are are all μF except the 47pf!
    Max.
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,963
    3,763
    It's worth noting that "mfd" occasionally seen on a capacitor label actually means µF. I suppose this is not ambiguous if mF is reserved for millifarads.
     
  6. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    but milifarads has never been a standard marking for caps. always microfarads.
     
  7. MaxHeadRoom

    Expert

    Jul 18, 2013
    11,915
    2,961
    Besides my bench is not big enough! :p
    Max.
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,963
    3,763
    Right, I was just pointing out that "mfd" can be misleading if you don't know the standard.
     
  9. AnalogKid

    AAC Fanatic!

    Aug 1, 2013
    5,181
    1,475
    A little history from someone who scavanged his first caps from 1940's and 50's TVs:
    mf = mfd = uF
    mmf = mmfd = pF

    ak
     
Loading...