how to maintain constant voltage mode across mosfet /igbt ?

Discussion in 'Power Electronics' started by kittoo, Aug 1, 2016.

  1. kittoo

    Thread Starter New Member

    Jul 11, 2016
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    Hence the mosfet circuit will be operated at active region for constant current mode,then what about the constant voltage mode for battery charger applications?
     
  2. #12

    Expert

    Nov 30, 2010
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    The first thing I thin is, The goal of a battery charger is to provide a constant voltage across the battery, not the mosfet. Without a circuit diagram, I can't understand what you are asking.
     
  3. kittoo

    Thread Starter New Member

    Jul 11, 2016
    25
    1
    Thanks for reply,
    I don't have any circuit diagram,just asking whether mosfet or igbt will provide a constant voltge.
     
  4. #12

    Expert

    Nov 30, 2010
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    Not all by their self. A circuit can provide constant voltage, a shunt regulator can provide constant voltage, but a mosfet or an IGBT can not do this all alone.
     
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  5. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,689
    901
    If by active region, you mean the highlighted region shown here for a typical mosfet:
    upload_2016-8-1_7-16-16.png

    Note that in that region, the mosfet behaves like an Ohmic device. As current increases, the voltage drop across the Drain-Source increases and visa versa. Therefore, by itself, it will not provide constant voltage anymore than a resistor would.

    John
     
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