Silicon diode resistance measurement

Discussion in 'Electronics Resources' started by marchen91979, Oct 1, 2010.

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  1. marchen91979

    Thread Starter New Member

    Sep 20, 2010
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    Please, some one help answer the following silicon diode measurement:

    The reading on the test leads to the silicon diode 500 - 800 ohms, when reversing the test leads to the measurement, the reading is 50 - 80 ohms. What is the condition of this diode. Thanks.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    What readings do you get when you measure a known good diode?
     
  3. inverter

    New Member

    Oct 13, 2010
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    If the test is meant to figure out whether the Diode is faulty or not, it seems to me that if this is measurement was done off circuit, then it looks like it is faulty.
     
  4. Bharatohri

    New Member

    Nov 10, 2014
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    When positive lead of the Meter
    Is connected with Anode of diode
    LED glows with negative lead of multimeter
     
  5. alfacliff

    Well-Known Member

    Dec 13, 2013
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    the resistance of a siode depends on the meter. older meter types showed different readings than modern digital metrs. the digital meters should show the voltage of the junction when conducting, around .5 to .7 volts for silicon and .2 to .4 for germanium. thats in the foreward direction with the black lead on gthe cathode. reversed it should be nearly open circuit. thats for out of circuit only, in circuit, anything goes, there could be anything across the diode messing up the readings.
     
  6. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    Guys, this thread is four year old!
     
  7. WBahn

    Moderator

    Mar 31, 2012
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    On average, it's actually less than two years old -- and getting younger with every new post! ;-P
     
    joeyd999 likes this.
  8. crutschow

    Expert

    Mar 14, 2008
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    It curious how new members seem to often engage in raising the dead in these forums.
     
  9. Lestraveled

    Well-Known Member

    May 19, 2014
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    Raising the dead.....it is that time of year.
     
  10. MrAl

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    Jun 17, 2014
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    Hi,
    Yes that is strange isnt it. And the post that raises the dead often is unrelated to the main topic of the thread. This one was a little related i guess.
     
  11. alfacliff

    Well-Known Member

    Dec 13, 2013
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    I have seen on this board that when a person asks a question that has been asked before, he is refered to the origional post. if a person had the decency to search for his question, why not?
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
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    ...Especially that is was never originally satisfactorily answered, as touched on in post #5, you require a meter with a Diode Test range that is capable of passing a current through the diode, the resistance range on modern meters will not do it.
    Max.
     
  13. bertus

    Administrator

    Apr 5, 2008
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