how to test LED/indicator light

Discussion in 'General Electronics Chat' started by sangpo, Sep 23, 2013.

  1. sangpo

    Thread Starter Member

    Aug 17, 2013
    74
    1
    Please kindly through light on my following.

    1. Is all LED same ie AC and DC?
    2. If LED for AC and DC different, then how Do I know if it is AC or DC LED?
    3. I have collected the light indicator(small bulb) from rice cooker/water boiled.
    a) what do we call this type of light bulb, LED or ????
    b) I tested for bad or good, with ohm meter, Continue mode and diode
    mode,( set in auto mode)but no showing and reading.It remains 0L. Then i
    have tested the bulb putting with AC source of 240 Volt using 120k. then

    then it is fine (glowing)
    C) How do we test this type of light indicating bulb? how do we test it using multimeter?



    Apology: With regard to my question No. 3 a) above. I remembered now that one of senior members told me it is called neon bulb in one of my prviouse post. So no need to explain on Q. 3 a))
    Thank u


    Thank you
     
    Last edited: Sep 23, 2013
  2. sangpo

    Thread Starter Member

    Aug 17, 2013
    74
    1
    Apology: With regard to my question No. 3 a) above. I remembered now that one of senior members told me it is called neon bulb in one of my prviouse post. So no need to explain on Q. 3 a))
    Thank u
     
  3. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    If it lights up, it seems to have passed the test? :)

    You can google for "neon indicator lamp specs". That should tell you it's normal operating voltage (I think it's about 90v) and the max current it can allow (important).

    With those two specs you can choose the right resistor to run that Neon lamp from 240v AC.
     
  4. abhaymv

    Active Member

    Aug 6, 2011
    104
    4
    Usually an LED should light up when you test it with a multimeter put in diode test mode with a series resistor. If you've connected the terminals properly.

    Some multimeters, however, may not work. That has happened to me before...
     
    Last edited: Sep 24, 2013
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