Astable 555 timer in Tina Pro Invalid floating point

Discussion in 'Homework Help' started by TheSoundshark, Nov 24, 2010.

  1. TheSoundshark

    Thread Starter New Member

    Nov 24, 2010
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    Im new to the forum so quick Hi :)

    Ok basically i'm building a basic alarm set up as part of a project work i have everything sorted apart from a simple astable 555 timer to run a flashing led and a siren. for some reason Tina Pro the software i use keeps bringing up errors. ill add a screen shot if somebody could shed a little light on this i would be most appreciative.

    Thanks in advance
    Anthony

    http://yfrog.com/mufaildip <<<<<screenshot
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    You have DISCHARGE tied close to Vcc, try disconnecting it, or a bypass cap to ground and see what happens.
     
  3. TheSoundshark

    Thread Starter New Member

    Nov 24, 2010
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    Last edited: Nov 24, 2010
  4. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    When you use those test points (VF1), you must have a ground somewhere.

    How fast did you want those led's to flash? You have them flashing very quickly right now.
     
  5. TheSoundshark

    Thread Starter New Member

    Nov 24, 2010
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  6. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    Last edited: Nov 24, 2010
  7. TheSoundshark

    Thread Starter New Member

    Nov 24, 2010
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    im using transiants as 555 dosnt have a DC floating point and im not guessing im following diagrams from the net iv found but no luck.
     
  8. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    Do you know what parameters you set for the transients? Also set the transients to

    In the interactive transient mode, check the timing you want, and then select zero initial values. The default is calculate operating point. If you want that VF1 test point to display properly, place a ground on the negative terminal of the battery.

    I still stand by my earlier recommendation about you reading the ebook section.

    Here are the results from your latest guess. You will notice the duty cycle is large ... the off time (zero volts) is very, very short.
     
    Last edited: Nov 25, 2010
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