Triac gate control

Discussion in 'Homework Help' started by Cbaz, Feb 10, 2010.

  1. Cbaz

    Thread Starter New Member

    Oct 27, 2009
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    I am currently a University student undertaking a project on dimmer circuits and I am using a triac for this operation. What are the advantages of using a micro controller to fire the gate compared to using an analogue control circuit.i.e. using a diac variable resistor and capacitor. The microcontroller circuit has an increased cost, are there applications that would justify using a microcontroller to control the gate. What type of microcontoller circuits would adequately control the gate firing angle
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    Have you looked into the issue? If so, share your tentative conclusions with us.
     
  3. Cbaz

    Thread Starter New Member

    Oct 27, 2009
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    For just a standard lamp dimmer seen in the household I cant see why an analogue circuit wouldnt suffice. Does a microcontroller have greater control over the fire angle and less power losses
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    Consider that the uC will require a separate power supply plus isolation circuitry to fire the TRIAC. Not to mention the zero crossing detector to base the timing from.
     
  5. Cbaz

    Thread Starter New Member

    Oct 27, 2009
    12
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    If the uC has a greater power consumption are their any applications where it would be advantageous to use a uC to control a triacs gate for a dimmer circuit compared to an analgoue approach. The project title given to me by my tutor was called design of a single phase A.C dimmer circuit. There was a previous project carried out on this title that used variable resistor, capacitor and diac to control the firing angle. My tutor wants me to elaborate on this previous project and suggest that I look at a uC for the gate control but I'm trying to look at justification for this circuits extra complexity. I would be grateful for your help
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    What sort of help? The extra expense of elaboration has been noted.
     
  7. thyristor

    Active Member

    Dec 27, 2009
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    0
    For simple dimming there aren't any advantages.

    BUT, suppose you wanted non-simple dimming? Suppose you wanted lights to dim automatically in response to some other input than just turning a dimmer control. Suppose you wanted lights to decrease and increase in illumination according to a certain pattern or sequence for interior design for example. Then a uC would be a very useful beast. Think outside the box and let your imagination start to run.
     
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