thyristor firing angle control using microcontroller

Discussion in 'The Projects Forum' started by jeay pakistan, Aug 19, 2010.

  1. jeay pakistan

    jeay pakistan Thread Starter New Member

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    hy huys .i m working on project "slip power recovery drive for 3p slip ring induction motor" and want to design inverter using scr can any budy guide ma to adjust firing angle using microcontroller
     
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  2. beenthere

    beenthere Retired Moderator

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    You will need an input from a zero crossing detector to synch the microprocessor with the AC line. The phase angle may be adjusted by triggering the SCR at any desired time after the AC waveform crosses zero. The period is 20 milliseconds for 50 Hz power.
     
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  3. cpleng7

    cpleng7 Active Member

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    can explain more detail in the zero crosing detector
     
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  4. DickCappels

    DickCappels Moderator

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    Here is the basic idea. If you use an appropriately rated opto-isolator, you can have your firing circuit operate near ground, isolated from the power line -much safer, particularly early in the game, when you might want to monitor waveforms. You can drive your thysistor's gate through an isolated pulse transformer. If you do this, make sure your control circuit is properly grounded for your own safety (and keep one hand in your back pocket!)


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