ceramics capacitors?

Discussion in 'General Electronics Chat' started by Mathematics!, Feb 22, 2009.

  1. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    ceramics capacitors what is the capacitance?

    I have radio shack part 272-801 pkg. of 100

    But the only thing on each capacitor is an underlined number.



    ...etc are these in uF, nF, pF , F or what?

    And with these ceramic disc capacitors does it matter which way I put them in?

    Their legs are both the same size. So I don't think their is a difference no plus sign or - on any sides.
  2. thingmaker3

    Retired Moderator

    May 16, 2005
  3. AlexR

    Well-Known Member

    Jan 16, 2008
    The marking 151 means that is a 150pF capacitor.
    Under this numbering scheme the first 2 digits are the value and last digit is the number of zeros to add to the end of value. It is always expressed in picofarad.
  4. Mathematics!

    Thread Starter Senior Member

    Jul 21, 2008
    What happens if I have just
    1 is that 1pF because not all of these capacitors have 3 digit numbers.

    What happens for the 1 or 2 digit numbers ? Do I take the missing digits to be zero's?
    And will their every be a 4 or 5 digit number ...?

    Thanks for your help

    Also I am just wondering in electronics what the most used sizes for a capacitor is.
    Is it like pF or nF or uF ??? And the usually range. I know they all have uses but just wondering what the majority of them and their ranges.
    Last edited: Feb 22, 2009
  5. bertus


    Apr 5, 2008
  6. SgtWookie


    Jul 17, 2007

    No. For the capacitors that you purchased, a 1 or 2 digit value is the capacitance in pF.

    Not in that assortment.

    It depends upon the application. For a DC power supply, you might use a 10,000uF capacitor after the bridge rectifier, and a 10uF plus a 0.1uF cap after the regulator. If you're building a TTL or CMOS logic circuit, you'll use 0.1uF (100nF) "bypass" capacitors across the supply pins to help keep transients under control.

    Low pF values are used in radio frequency circuits.
    High pF/low nF values can be used in timer/oscillator circuits.
    100nF caps are widely used as bypass capacitors, also used in timer/oscillator circuits.
    1uF-100uF caps are frequently used in audio applications.
    Larger caps are usually used in power supplies.