Urgent:Protecting the circuit during mosfet failure

Discussion in 'The Projects Forum' started by magantiamala, Jul 2, 2012.

  1. magantiamala

    Thread Starter New Member

    May 8, 2012
    Hello , I have attached my circuit diagram above on which i am working, i need your help very urgently..In my circuit my mosfet will fail when there is some high voltage,current or temperature etc..

    When my mosfet fails the whole circuit gets damged i need some suggestions to protect my circuit even when my mosfet fails..the current flows normally in the circuit and i can replace my new mosfet by taking out the damaged mosfet.

    Could anyone provide me some ideas what would be best to protect my circuit from damaging during mosfet failure.
  2. wayneh


    Sep 9, 2010
    How about a fuse in line with the MOSFET?
  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
    It would make more sense to fix the problem that is causing the mosfet failure, wouldn't it? Could you post your circuit in another form? Many people won't open a zip file they don't know.
  4. wayneh


    Sep 9, 2010
    I believe he's testing MOSFETs and blowing them up on purpose. That means everything else needs to be rated beyond what the MOSFET can take OR at least tolerant of the MOSFET failing to a short. The latter is what fuses are for.
    shortbus likes this.
  5. praondevou

    AAC Fanatic!

    Jul 9, 2011
    I'm trying to imagine why somebody would want to do this? Confirming datasheet specs? :confused:
    shortbus likes this.
  6. Engr


    Mar 17, 2010
    I think what wayneh mentioned above is the avalanche spec of the MOSFET. The most simplest way to explain this spec is the capability of the MOSFET to absorb the stored energy transferred by the inductor. This test is most of the times called UIL Test.

    If what I mentioned is right I can say that this test is a destructive test for a MOSFET and shortbus is correct, it would make more sense to fix the problem that causes the MOSFET to fail. If UIL Test is the test that you are doing for this circuit I can give you some hints on what components to check. Just let me know if the circuit is for the UIL Test.