How to connect LED Directly to 220V

Discussion in 'General Electronics Chat' started by RRITESH KAKKAR, Jul 27, 2015.

  1. RRITESH KAKKAR

    Thread Starter Senior Member

    Jun 29, 2010
    2,831
    89
    I need calculation of connecting LED Directly to 220V long string!
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    Use a wallwart to lower the voltage and then calculate the resistor for the led from the outputr voltage of the wallwart.

    Bertus

    PS The ToS does not allow leds to be connected directly to the mains
     
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    Specs of LED? Forward voltage/current rating
     
  4. pwdixon

    Member

    Oct 11, 2012
    488
    56
    If you were to try this directly the inline resistor would need to be very high power capacity to dump the waste power and it would be very inefficient. And that's apart from the obvious danger of mains wiring itself.
     
  5. RRITESH KAKKAR

    Thread Starter Senior Member

    Jun 29, 2010
    2,831
    89
    The LED will be 1.9 to 3.5 V RED blue white 20mA 5mm
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    You say "the" LED then call out 3 colors and a wide Vf range?
    Are you just using 1 or 2 or 3 LEDs?
    Please post a schematic of how you intend to connect the LEDs?
    Are they in a series string? Or 3 in parallel or what?

    You must provide this information or we cannot tell you how to size the resistor.
     
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,801
    1,105
    I'm surprised this thread hasn't been locked!
     
    RodneyB and PackratKing like this.
  8. pwdixon

    Member

    Oct 11, 2012
    488
    56
    so am i, usually these things are caught pretty quickly. I only posted to see how far this would go.
     
  9. ScottWang

    Moderator

    Aug 23, 2012
    4,855
    767
    Sometimes we will try to guide to the right direction as safety method, if the TS insist to do that then the thread will be closed.
     
    RodneyB likes this.
  10. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    Did you see the first reply?
    I mentioned a wallwart over there for isolation.
    A phone charger might also work.(5 Volts USB).

    Bertus
     
Loading...