Need to make Timer

Discussion in 'The Projects Forum' started by bcarriveau, Oct 27, 2008.

  1. bcarriveau

    Thread Starter Member

    Oct 27, 2008
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    Ok guys heres what i have, i Have a high idle on my pickup truck. Its activated by just applying 12v's to one wire. the thing is when i let my truck warm up i dont want it on high idle for more then 5 minutes. So i need to make a timer type deal that when i give it a signal it will supply 12volts for 0-10 minutes. I dont know anything abought electrical stuff really other then how to use a rely. Hope you can help me out i making a gadgit to compleat this.
     
  2. Rajit28

    Active Member

    Oct 21, 2008
    49
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    i recommend a 555 timer most common kind of timer available.
     
  3. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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    555? what type? how do i wire it up? how to adjust times? ect. i need a very willing person to put in plain engish to help me out. Thanks for the bit of info.
     
  4. bcarriveau

    Thread Starter Member

    Oct 27, 2008
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  5. thingmaker3

    Retired Moderator

    May 16, 2005
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  6. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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  7. Wendy

    Moderator

    Mar 24, 2008
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  8. bcarriveau

    Thread Starter Member

    Oct 27, 2008
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    wow thats some good info, still wondering if 12v would be applied it different supply's must be used? Also where can i get a test board like that? that would be very helpful.
     
  9. Wendy

    Moderator

    Mar 24, 2008
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    Most of the parts are available from Radio Shack, if you're talking about my post.
     
  10. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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    yes thank you, my mind is fried trying to figure this all out and what every thing is but im learning. thanks again.
     
  11. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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    using your model what would i have to change to make it 0-10 minutes possibly with a potentiometer to select. im more a visual learner then mathematics. sorry if its asking alot.. I just cont know what all the k m uf ect stand for, what the values are ect.
     
  12. thingmaker3

    Retired Moderator

    May 16, 2005
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    Twelve volts will work just as well as nine.
     
  13. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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    Thanks, i found a 1-10 minut model out there... http://www.kpsec.freeuk.com/docs/timer.pdf just not to happy that the capacitors can vary as much as +- 30% of their rated value.. wonder if there is a way to make sure its more stable.
     
  14. thingmaker3

    Retired Moderator

    May 16, 2005
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    The 1Mohm potentiometer will allow you to adjust for any variation in the capacitor.
     
  15. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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    ok i got every thing working with the 9v batt. but now heres the thing. when i put 12v to the circut the .1uf fried instantly, sounded like a bottle rocket going off.. i copied the kpspec build, used a 39K resistor and a 470uf cap to set the time. worked perfect till i siwtched the 9v to 12? whats the reason for this? i thought every thing would be fine.
     
  16. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
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    If your cap is an electrolytic, this symptom is consistent with reversed polarity, or with a cap working voltage rating less than the potential applied across it.
     
  17. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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    the package says high K dielectric
     
  18. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
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    because its a high K dielectricis that y it would have failed?:confused:
     
  19. Wendy

    Moderator

    Mar 24, 2008
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    What was the voltage rating of the cap? It would have been written on the side of the cap. I suspect it was in backwards myself, having done both over the years, but either could blow it up.
     
  20. bcarriveau

    Thread Starter Member

    Oct 27, 2008
    13
    0
    0.1µF 50wvdc Hi-k dielectric Disc Capacitor ?
    large one is
    470uF Electrolytic Capacitor axial leads 35wvdc maximum?
     
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