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Anyone know what this is?

Discussion in 'General Electronics Discussion' started by ARMANDO, Jul 9, 2017.

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  1. ARMANDO

    ARMANDO

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    Aug 5, 2016
    My guess is a very small diode? and the red dot indicates positive side or polarity. 20170709_135437.jpg
     
  2. kellys_eye

    kellys_eye

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    Jun 25, 2010
    A diode seems the most reasonable conclusion but a simple test will reveal the truth.
     
  3. ARMANDO

    ARMANDO

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    Aug 5, 2016
    How to test?
    I set my Fluke Multi meter to diode/continuity setting and with the red tip on the side that has a red dot with the black on the other side I get nothing. flip the leads around and I get a short beep and a reading of 1.808 ,
    1.808 what? i don't know what this value means.
    Is it a diode?
     
  4. kellys_eye

    kellys_eye

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    Jun 25, 2010
    Your Fluke may have a diode test range as you state. It will show the forward volt drop across a diode - which can be anything from 0.2V to 0.8V in the forward direction, zero in the reverse for 'standard' diodes..

    If your meter is being used correctly it is showing a forward volt drop of 1.8V - pretty high for a 'normal' diode but possible with a high voltage device (which that might be). What is the voltage rating of the capacitor adjacent to it?
     
  5. ARMANDO

    ARMANDO

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    Aug 5, 2016
    600VDC

    I think this is a high voltage device. its from a scanning electron microscope that need up to 30KV.
     
  6. kellys_eye

    kellys_eye

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    Jun 25, 2010
    Yup - the 1.8V reading may be correct then. Still a diode.
     
  7. ARMANDO

    ARMANDO

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    Aug 5, 2016
    I have a diagram that I drew and those parts are here -C1 and that suspected diode next to it. 20170709_105248.jpg
     
    levis and AnalogKid like this.
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    The mark on the diode typically indicates the cathode. That is NOT the +ve end, but if you have just a simple understanding of power supplies it is where "the positive comes out".
     
  9. dorke

    dorke

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    Jun 20, 2015
    Armando,
    Please take care,this equipment can kill you!
    I hope you know what you are doing!
     
  10. AnalogKid

    AnalogKid

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    Jun 10, 2015
    I commend your excellent schematic skills. Very refreshing.

    ak
     
  11. mayank tanwar

    mayank tanwar

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    Oct 21, 2015
    It's a kind of diode through this voltage is passed from one point to another.
     
  12. 73's de Edd

    73's de Edd

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    Aug 21, 2015
    The casing and hand applied, off color dots, reminds me exactly of units that were made by Varo, for use in their Starlight Nitescopes at that manufacturing timeframe.
    They used multiple series diode junctions internally and were very generous with underrating their breakdown specifications.
     
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