OK so i did one thing, how about another?

Discussion in 'General Electronics Chat' started by peck68, Mar 21, 2010.

  1. peck68

    Thread Starter Member

    Nov 27, 2009
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    I am over the moon at the minute - for ages and ages i have been searching how to fade an LED in and then fade it back out again, for the average noob like me it's obvious how to fade it out but to fade in is something of a different story ;)

    Anyway out of sheer pot luck from messing around with two 100uF caps and an LED i did it :cool: (scheme attached)

    Anyway, i want this to be able to now fade in and out continuously from a 555 timer...

    Can anybody help me here? I do know how to use a 555 by the way now :)
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    did you check the 555 PWM here on AAC. It's a good place to start
     
  3. peck68

    Thread Starter Member

    Nov 27, 2009
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    Nope but had a nice long conversation about it yesterday ;)

    http://forum.allaboutcircuits.com/showthread.php?t=35831

    ---

    But though, stop me if im wrong, that just dims the LED with a duty cycle set by a pot. It doesn't go fade in, hold, fade out, hold, [repeat]

    With the circuit i have there does, but i have to move the switch manually, so having a regular 555 will flick that switch for me - i just dont know how
     
  4. peck68

    Thread Starter Member

    Nov 27, 2009
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    OHH i think it might have been staring at me the whole time :eek:

    Would this be correct?
     
  5. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    So all you need is a really slow changing PWM.
    You can adjust the modulator timing any way you like, you might have to use 2 555 to accomplish this.
    First you need to learn more about the PWM duty cycles
     
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