few second Delay question

Discussion in 'The Projects Forum' started by RiG615, Nov 13, 2008.

  1. RiG615

    Thread Starter Active Member

    Nov 13, 2008
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    I want to know how to make a delay circuit of some sort
    I want a delay time of anywhere from 4 to 10 seconds after i click a switch

    1.5V DC > delay > motor on


    thanks
     
  2. Wendy

    Moderator

    Mar 24, 2008
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    Last edited: Nov 13, 2008
  3. RiG615

    Thread Starter Active Member

    Nov 13, 2008
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    1.5 V would be the voltage from the battery running the [small] motor, not the trigger signal
    what kind of current/ voltage can this thing handleor need(does it need 9v)?

    also what does this one add to the other one?

    im kind on new to all this stuff
     
  4. mik3

    Senior Member

    Feb 4, 2008
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    A simple method is to take a 5VDC relay (the coil voltage is 5VDC) and use a 9V battery say to activate it. Of course you will a series resistor with it to limit the current and dont destroy it. If you connect a capacitor in parallel with the relay coil you will get a delay and then the relay will be activated. In simple words, the delay will depend upon the capacitors value, the larger the capacitor the greater the delay.
     
  5. RiG615

    Thread Starter Active Member

    Nov 13, 2008
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    Instead of using the 555 timer could the formula T=CxR and use a 1000µF capacitor and a 1 k ohm resistor to create a delay of about 5 seconds?

    im confused to how this will effect the voltage and current to the [mini]motor

    -also i only need the motor on for about 3 seconds.

    thanks
     
  6. mik3

    Senior Member

    Feb 4, 2008
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    Yes you can but the time wont be actually RC, its depends on the relays pull-in voltage and the resistance of the relay coil. You can use another relay with a capacitor in series with it as to stop the motor after 3 secs.
     
  7. RiG615

    Thread Starter Active Member

    Nov 13, 2008
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    I'm working on a circuit design, but in the mean time....

    How durable are relays and capacitors? motors?
    can they be dropped, thrown ?
    can they be thrown consistently in a padded environment?
    does engulfing everything in glue help??
     
  8. RiG615

    Thread Starter Active Member

    Nov 13, 2008
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    Can a capacitor [say 1000 micro farads] hold open a relay for at least 5 seconds
    say this capacitor?
    -using a 9 volt battery to charge-
     
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