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LED

Discussion in 'General Electronics Chat' started by hantto, Dec 31, 2002.

  1. hantto

    hantto Member

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    What's the ABSOLUTE MAXIMUM RMS current a red LED can take?, not peak.
     
  2. bogdanfirst

    bogdanfirst New Member

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    from what i know, a normal LED can take up to 50mA, but it depends of the type....
    some red leds have a nomeinal current of 20mA, some have 2 or 0.5, so it depende on the led..but i think that for a normal 20 mA led can take up to 50mA.i'll try to find something on the net about that.
     
  3. bogdanfirst

    bogdanfirst New Member

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  4. dave

    Dave New Member

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  5. hantto

    hantto Member

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    I don't have a power supply from where i can adjust the current... and i do not have enough of different resistors to test it... :cry:
     
  6. bogdanfirst

    bogdanfirst New Member

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    u can make a simple circuit, a variable resistor and a transistor, like BC639(1 amp) and use an ampermeter to mesure the current trough the led...but any way i dont think they cand support more than 50 mA,
     
  7. kinjalgp

    kinjalgp Active Member

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    From blowing I remember once I had connected a blown LED into tha 230V AC mains socket and what I got to saw was a BIG BOOM leaving behind black somke and patches on the wall. I thought that blown LED will have no effect of 230V AC but I was wrong. The explosion was cool :lol:
     
  8. bogdanfirst

    bogdanfirst New Member

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    i tried something else with a led...
    i used an 18V ac source and conected it to a 12 V secondary of the transformer, and on the primary-220v-i had about a thousand or so.....
    i conected a led, turned on the power and BOOOOOOOOM...
    even if the led is burned the distance between the contacts is so small that a spark occurs between them so the led is blown uuup 8) , and there is also the burned crystal that becones conductor at that kind of voltage.
    i tried this also with a 12 mm transparent red led, but i put a current limiting circuit with a BF256 transistor and the led didnt blow, but there was something like a camara flash, but much greater....and it was fun because after that the led still worked, but it turned into a green led :lol: and it was a funny experience.
     
  9. hantto

    hantto Member

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    I came on to that i had the multimeter in the wrong place!! when i first measured the current. SO i tried again and my green led started to turn yellow at about 80mA. I hope you didn't put a led in anyhing that gives 250mA ;)
     

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