High voltage switches

Discussion in 'The Projects Forum' started by MarkJC, Dec 5, 2010.

  1. MarkJC

    Thread Starter New Member

    Dec 5, 2010
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    I'm working on a project where I need to be able to implement a switch capable of turning ON/OFF current flow in a high voltage circuit using a very small base voltage.

    The current flow that I need to control will be between 500V-2000V (~10-15mA current) and the base voltage that I would like to control that flow with will be only 3.3V (10-20mA current).

    I've come across two components I could use as switches - an NPN transistor or a solid state relay. Problem is, most of these seem to only be for low voltage applications. And in the case of NPN, I can't find one that has acceptable emitter-base and collector-base voltage limits. Can you recommend or point me to a source for components that might work for this project?
     
  2. mik3

    Senior Member

    Feb 4, 2008
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    An IGBT shall be suitable for your application, however, it needs 15V to its gate to turn on.

    Are you going to drive it by a microcontroller?
     
  3. MarkJC

    Thread Starter New Member

    Dec 5, 2010
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    Yes, that is the plan right now. Any thoughts on a way to get around the 15V turn on voltage at the gate? Is the gate voltage limited or power limited (where the combination of current/voltage matters)? I'll be dealing with DC so I guess that rules out a transformer.
     
  4. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    I guess you have a 3.3V microcontroller.

    You need to provide a 15V DC power supply by some means. Then I advice you to use an IGBT gate driver to drive the IGBT.
     
  5. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,770
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    most definately some form of opto coupled circuit would be of use here. DC isolation
     
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