why is isolation of gate and base drives required

Discussion in 'General Electronics Chat' started by diya khan, Nov 1, 2011.

  1. diya khan

    Thread Starter New Member

    Nov 29, 2010
    18
    0
    i tried going through various books yo understand why is isolation of gate and base drives required, but no book seemed to make me understand=/

    can someone please explain me the reason.

    one more thing i wanted to clear, the gate driver circuit means the control circuit right for the switching devices?
    and the base driver circuit is the power circuit?
     
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
    2,936
    488
    Your question is not clear. Can you elaborate? Maybe with a picture/diagram?
     
  3. diya khan

    Thread Starter New Member

    Nov 29, 2010
    18
    0
    ok forget about the second part of the question.If you could just help me with the 1st part of my question:

    why is isolation of gate and base drives required?
    this is how its mentioned in the book...it says isolation can be done using 2methods, either using pulse transformer or optocouplers.

    but before going into the methods, i need to know what does the question actually mean=/
     
  4. crutschow

    Expert

    Mar 14, 2008
    12,973
    3,219
    If the transistor can not share a common ground with the drive signal (such as if the transistor is connected to the mains power) then it must be isolated by some means such as optical or magnetic coupling.

    If the transistor can share a common ground with the drive signal than no isolation is needed.
     
    diya khan likes this.
  5. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    It is also more easy to protect the main control unit from noise. Say you want to control a motor that generate a lot of interfrence. If the controller unit is galvanic isolated from the motor and the controlling FET. Electrical noise from the motor is more likely not to interfer with controlling unit. It could also be safety. If you FET control a high voltage unit. Any electrical fault on high voltage side will not go into the low voltage part of the system. If the two system are galvanic isolated
     
Loading...