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12 volt switching power supply modification to 14.5 volts before blocking diode add

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    12 volt switching power supply modification to 14.5 volts before blocking diode add

    I saw this switching power supply on eBay and wanted to see if could be modified to run 14.5 volts before the blocking diode was add and this switching power supply seems to have no issues doing this

    I did recap the switching power supply except the the main filtering capacitors and I managed to break the selector switch for the voltage setting but just jumped it

    One note I used 25 volt capacitors on the output side of this power supply because they used 16 volt capacitors and because I am running the voltage up a little bit higher 12 volts to 14.5 volts there would have been very little head room for the voltage on the output capacitors

    One other note the ground rail that is also metal housing ground runs in between the hot side and the cold side of this switching power supply board

    One other note the ESR values of capacitors less than 100uf were any where from a little bit high to in some cases doubled or tripled in value compared to a new capacitor

    This switching power supply had some wire connectors that were wired wrong the “+” had black wires hooked to it and “-“ had red wires hooked to it I will use them in another project

    I have one question would this switching power supply put out 30 amps of current it has a cooling fan and the temperature sensor is in the choke coil

    I would post the link to where to buy one but the seller only has one left and I trying to buy the last one
    Attached Files
    Last edited by sam_sam_sam; 04-11-2021, 11:46 AM.
    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

    #2
    Re: 12 volt switching power supply modification to 14.5 volts before blocking diode a

    look very closely at the main smoothing caps and meter them.
    diode-gone-wild had a 600w psu of similar design that had salvaged and re-sleeved high voltage caps in it.
    they where even dented and they filled the dents with wax before re-sleeving!!!

    Comment


      #3
      Re: 12 volt switching power supply modification to 14.5 volts before blocking diode a

      I was going to replace them anyway because I do not recognize the manufacturer of them but I have to order them because I do have any on hand

      The question is should I go up in UF value for these two capacitors or use the value that is already in there
      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


        #4
        Re: 12 volt switching power supply modification to 14.5 volts before blocking diode a

        Originally posted by stj View Post
        look very closely at the main smoothing caps and meter them.
        diode-gone-wild had a 600w psu of similar design that had salvaged and re-sleeved high voltage caps in it.
        they where even dented and they filled the dents with wax before re-sleeving!!!
        I did not find the exact one that you have mentioned above but did find a couple of them about issues with them

        I saw a video of his that is very similar to one that I have an there is an issue with the transformer winding wires not being copper but being aluminum wire which according to him is the wrong type of wire to use so I have decided to limit it current to 15 amps for short periods of time
        Last edited by sam_sam_sam; 04-11-2021, 03:45 PM.
        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


          #5
          Re: 12 volt switching power supply modification to 14.5 volts before blocking diode a

          i cant see the cap values,
          but i suppose 330uf would be a good minimum.
          it's what old pc supplies got away with.

          Comment

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