Help identify ceramic disc capacitor

Discussion in 'General Electronics Chat' started by walnuts, Apr 3, 2009.

  1. walnuts

    Thread Starter New Member

    Apr 3, 2009
    1
    0
    Hello,

    I have a ceramic disc capacitor from an industrial pallet scale control board that is marked with the following:

    CM
    1M
    1KW
    E

    It is orange, with 2 leads and is about 10mm diameter round and flat. Can anyone help me identify the trade number or spec so I can order replacement?

    Thanks,

    -Patrick
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Well, the 1M would be 1uF (one microfarad)
    Look again and see if it might be .1M instead.
    Look at the 1KW again, I believe you'll find it says "1KV" instead, for 1,000V rating.
     
  3. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    A 1uF ceramic disc seems rather high value for that physical size.

    Could it be 1000pF?

    Is it actually a capacitor?

    Walnuts - Is there a photo you can post?
     
  4. inventorjack

    Member

    Apr 4, 2009
    14
    0
    Actually, it's kind of hard to tell. There are two likely possibilities:

    Possibility 1: The 1M is 1 picofarad +/- 20% (1 is the first digit in picofarads, and M is an EIA Tolerance code for +/- 20%)

    Possibility 2: 1M is 1 Microfarad. In this case the E likely stands for a +/- 25% tolerance.

    Sadly, markings vary widely by manufacturer. Traditionally, ceramics are marked in picofarads if it's a full number, and microfarads if the number is prefixed by a decimal point, but even this depends on the manufacturer and when the cap was made. Your best bet is probably to see if there's an equivalent cap on the board and measure if with a multimeter.

    (Like others above, I assume the 1KW is actually 1KV.)
     
  5. Zez

    New Member

    Apr 29, 2009
    4
    0
    ...or it could be 1nF/1000V?
     
  6. Darren Holdstock

    Active Member

    Feb 10, 2009
    262
    11
    How about a photo? It might not be a ceramic cap at all - surge arrestors and big thermistors have similar packages.
     
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