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Replacing a mosfet with the wrong mosfet!

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    Replacing a mosfet with the wrong mosfet!

    Good evening everyone!
    I have a mosfet, this mosfet:
    https://datasheetspdf.com/pdf/767782...ctors/AOD478/1
    It seems dead, now I was wondering if I could replace it with this one:
    https://datasheetspdf.com/pdf/564339...ctors/AOD452/1
    My first impression is that one has 100V Drain-Source Voltage and the other 25Vds. However I was thinking since the 100V one is rated for 11A and the other 53A perhaps my old monitor wouldn't mind too much if I'd also slap some kind of heatsink on the 53A mosfet?. At least until I get a proper replacement(not soon)
    2
    Yeah, sure go for it!
    0%
    1
    Noooooo!
    0%
    1

    #2
    Re: Replacing a mosfet with the wrong mosfet!

    It all depends on how how this circuit requirements are but you should never down grade the voltage or the current requirements
    9 PC LCD Monitor
    6 LCD Flat Screen TV
    30 Desk Top Switching Power Supply
    10 Battery Charger Switching Power Supply for Power Tool
    6 18v Lithium Battery Power Boards for Tool Battery Packs
    1 XBox 360 Switching Power Supply and M Board
    25 Servo Drives 220/460 3 Phase
    6 De-soldering Station Switching Power Supply 1 Power Supply
    1 Dell Mother Board
    15 Computer Power Supply
    1 HP Printer Supply & Control Board * lighting finished it *


    These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

    1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
    2 Hem Saw Computer Stack Board

    All of these had CAPs POOF
    All of the mosfet that are taken out by bad caps

    Comment


      #3
      Re: Replacing a mosfet with the wrong mosfet!

      1. Must never go down on voltage unless you know the circuit.
      2. Do not go down on current, heat sink might or might not make up for it.
      3. YMMV. Changing MOSFETs can affect speed which will break things.

      So without knowing your exact circuit, no, do not make this substitution.

      Comment


        #4
        Re: Replacing a mosfet with the wrong mosfet!

        Thank you very much for the quick replies!
        Based on your answers I think I'll get a proper replacement!
        Also I think I kind of answered my question in this electroboom video, explaining what happens when you put to much voltage through a capacitor
        https://www.youtube.com/watch?v=rbCXKhhzBN0&t=204s
        I am so glad I resisted the urge to just solder that bad boy and see what happens...

        Comment


          #5
          Re: Replacing a mosfet with the wrong mosfet!

          Originally posted by Willaraz View Post
          Thank you very much for the quick replies!
          Based on your answers I think I'll get a proper replacement!
          Also I think I kind of answered my question in this electroboom video, explaining what happens when you put to much voltage through a capacitor
          https://www.youtube.com/watch?v=rbCXKhhzBN0&t=204s
          I am so glad I resisted the urge to just solder that bad boy and see what happens...
          I think he absolutely funny I have watched him a few times in the past
          9 PC LCD Monitor
          6 LCD Flat Screen TV
          30 Desk Top Switching Power Supply
          10 Battery Charger Switching Power Supply for Power Tool
          6 18v Lithium Battery Power Boards for Tool Battery Packs
          1 XBox 360 Switching Power Supply and M Board
          25 Servo Drives 220/460 3 Phase
          6 De-soldering Station Switching Power Supply 1 Power Supply
          1 Dell Mother Board
          15 Computer Power Supply
          1 HP Printer Supply & Control Board * lighting finished it *


          These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

          1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
          2 Hem Saw Computer Stack Board

          All of these had CAPs POOF
          All of the mosfet that are taken out by bad caps

          Comment


            #6
            Re: Replacing a mosfet with the wrong mosfet!

            Supplemental question, just out of curiosity.
            Could I have 4 25Vds mosfets is a parallel configuration to equal one 100Vds one? or would running them in parallel reduce gate voltage preventing them from operating,
            or allow too much current through?
            If it's too complicated nvm :-)
            Thanks again!

            Comment


              #7
              Re: Replacing a mosfet with the wrong mosfet!

              No, parallel for increasing current capacity. Voltage is same.

              you could connect in series but there is one heck of a lot of problems with doing this that it's not feasible.

              Comment

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