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Where to Identify Diodes?

Discussion in 'Electronic Basics' started by phaeton, Mar 11, 2005.

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  1. phaeton

    phaeton Guest

    Hello again!

    I am forever indebted to sci.electronics.basics ;)

    Do you know of any website where I might be able to ID a few sets of
    diodes i've gotten in an assortment from futurlec?

    I've tried searching futurlec's site, just googling the part names, and
    also some searches at, but i don't have any hits on
    anything. They're in little baggies, and someone in Thailand or
    Australia wrote the part numbers on them with a Bluntie (which is the
    result of a well-used Sharpie).

    If i make the assumption that everyone in the English-speaking world
    (except the U.S.) slashes their Zs to differentiate them from 2s, the
    part numbers are all "2D400MW", with the only difference between the
    little baggies being the rated voltages (8.1v, 6.2v, 5.1v, 11v.. etc)

    They're tiny, and they're glass, so there aren't any markings on the
    diodes themselves. I've never seen diodes this small and they're kinda
    fascinating. I always thought glass casings was common to Ge diodes but
    that was just an assumption, not an established fact....

    Any input or pointers would be very appreciated...


  2. I made the opposite assumption, removed the MW suffix, and searched for
    ZD400 diode, and found this pdf file

    See page 29

    It lists zd400 as a zener diode, and it seems to fit your description of
    different voltages.

    You can test if they really are zener diodes by sending a current of say
    20mA through them and measure the voltage over the diode.

    In this document they are listed as 1/2 Watt zener diodes, but don't
    trust that wattage number too much, your diodes may be a later or
    different version.

    The suffix I removed, MW, can mean another wattage/package.
    But you can test run a few to find out how much power they actually can
    handle before burning up.
  3. Oooops, just realized I made a mistake. ZD400 in this file is a location,
    not a component number.

    Well, you can use my other advice about testing them anyway, and I think
    you will find that they are zener diodes, with a certain voltage and
    wattage which you can easily measure, and that's all the data you need to
    use them.
  4. Agreed, 'ZD400MW' plainly means 'Zener diode, 400 mW'.
  5. Finally, somebody who can read. Why didn't I think of that.

    The person who marked his bags of diodes simply marked them with what
    they are, it is not a component number code. Thanks.
  6. phaeton

    phaeton Guest

    Boy, don't i feel like a dolt...

    Thanks Terry...

  7. Fred Abse

    Fred Abse Guest

    Brits don't
    Aussies don't
    Canucks (English speaking ones) don't

    In fact, I can't think of an English speaking country that I've had
    anything to do with that does.
  8. phaeton

    phaeton Guest

    Hey, thanks for that link. I went up a couple of levels on the URL and
    wouldn't you know there's all kinds of interesting stuff there ;)

    I appreciate everyone's responses...

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