Challenging Project!!! VCO for Dimmer

Discussion in 'The Projects Forum' started by Nara Shikamaru, Feb 8, 2008.

  1. Nara Shikamaru

    Thread Starter Active Member

    Nov 24, 2007
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    3
    Hey Everybody!!.....now this is a Challenging project, my power electronics teacher dared me to do the following, he said it can be done......

    Design a VCO using obligatory the next things....UJT, 555, TRIAC and a Optoisolator.....to control the brightness of a 110VAC Lamp Bulb......(dimmer).....

    how would you do it using all those things???
     
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
    Yes, it can be done! But, since this is "your" Challenging project, how about telling us of your research first?

    Like:
    Do you know what each of these components can do?
    Can you make a block diagram of how they might generally function together?
    There's a wealth of information out there and your teacher gave you great keywords to start searching.

    I'm hoping the teacher's "dare" was to encourage you to learn the functions and details of the design, not just find a schematic somewhere. We love to help people new to the field, by meeting them half way.

    Keep us posted! We really do want to help. :)

    Ken
     
  3. Nara Shikamaru

    Thread Starter Active Member

    Nov 24, 2007
    92
    3
    Yes i do know how each component works but i dont know how to put them together to do that VCO......i already have a design but i could not be able to add the UJT.....the problem is that i cannot attached it cause neither the Proteus, Multisim, and Circuitmaker have the X9503 50K digitally potenciometer.....

    i have a 555 astable that feeds the X9503 and also i have a comparator with a LDR that also feeds the X9503.....so the funcioning of this is an automatic Dimmer....that if the LDR desnt have any light it will be Max light in the Lamp....and viceversa.....so the output of the X9503 goes to the Optosoilator....and that goes to the circuit with the TRIAC that triggers the 110V lamp....but i dont know were to put the UJT......

    thats why i need your help!!.....theres gotta be another way to add the UJT and to not use the digitally controlled potenciometer
     
  4. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Good.

    Could you post a schematic of what you have so far?

    Ken
     
  5. Nara Shikamaru

    Thread Starter Active Member

    Nov 24, 2007
    92
    3
    I cant post it because the Proteus, Multisim and Circuitmaker Does not have the X9503 50K digitally potenciometer.........
     
  6. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
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    Can´t you just use a regular pot?
    BTW you didn´t say the digital pot has to be there.
     
  7. Nara Shikamaru

    Thread Starter Active Member

    Nov 24, 2007
    92
    3
    the digital potenciometer is not a must!!......and of course i can use a regular POT.....the problem is that if a use a regualr pot then what do i do with the 555?....with the regular pot i dont know how to use the 555 there.....
     
  8. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
    230
    I agree with kubeek on using a standard pot...and where did the comparator show up.
    I assumed from your teacher's list that those four items were the only active components.

    555 tutorials are all over the place.

    Just give us what you have for the LDR circuit. Pencil sketches are OK if the simulator can't give it to you. It's difficult to visualize from your explanation.

    But, keep it coming. :)

    Ken
     
  9. thingmaker3

    Retired Moderator

    May 16, 2005
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  10. scubasteve_911

    Senior Member

    Dec 27, 2007
    1,202
    1
    Your teacher didn't challenge you to get others to figure out the problem. Work hard at the problem and learn. If you get stumped or want a check over of your design, come on here and let us take a gander.

    Steve
     
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