what is the application of capacitor with 0.01 in this led chaser

Discussion in 'General Electronics Chat' started by placide, Sep 13, 2012.

  1. placide

    Thread Starter New Member

    Oct 1, 2011
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    Last edited by a moderator: Sep 13, 2012
  2. bertus

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    Hello,

    There seem to be two images in your post, but they are blocked.

    Can you UPLOAD the images to this forum.
    Attachments and Images

    Bertus
     
  3. placide

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    Oct 1, 2011
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    you can now check the link.
     
  4. placide

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    Oct 1, 2011
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  5. bertus

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    Hello,

    The capacitor on pin 5 of the NE555 is there to have noise on the reference reduced.
    There is a voltage divider inside the NE555 and pin 5 is made available outside.

    The 1K resistor in the cathodes of the LEDS is to regulate the current through the leds.

    Bertus
     
  6. placide

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    Oct 1, 2011
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    the capacitor i meant is not that one on pin 5
     
  7. bertus

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  8. SgtWookie

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    The other 0.01uF cap that is connected to pin 8 of the 555 should actually be two separate caps; one 0.1uF ceramic or metal poly film, and one 1uF or greater aluminum electrolytic. Have a look at National Semiconductor's datasheet on the LM555 timer; you'll find that recommendation within it.

    The CD4017B should have its' own 0.1uF bypass cap connected across its' Vdd/Vss pins.
     
  9. placide

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    Oct 1, 2011
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    decoupling wow, what does it decouples
     
  10. MrChips

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  11. bertus

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    Hello,

    @MrChips:

    Did you see the link I posted in post #7?

    Bertus
     
  12. MrChips

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    Oct 2, 2009
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    Sorry Bertus, no, I have been busy all day and did not check your post.
     
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