NTC Thermistor recommendation

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  • Francesc V.
    Tempus fugit
    • Nov 2022
    • 230
    • Catalonia

    #1

    NTC Thermistor recommendation

    The NTC thermistor is blown up in a 650W SMPS (The green lentil). I can't see any reference on it.

    The assumption is that it should be a low resistance, because It's the bridge between the diode output and the input from the positive main capacitor.

    Any reference you would recommend to have some at home for this situation? Or shall I put a jumper where It was the NTC?

    Thanks in advance,
    Francesc
    Last edited by Francesc V.; 01-14-2023, 03:10 PM.
  • lotas
    Badcaps Legend
    • Jan 2016
    • 4557
    • Russia

    #2
    Re: NTC Thermistor recommendation

    I would not recommend you to put a jumper instead of a thermistor!
    It just doesn’t burn out, you rather have a short circuit in the circuit (diode bridge, mosfet, ...).
    Last edited by lotas; 01-14-2023, 04:09 PM.

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    • Francesc V.
      Tempus fugit
      • Nov 2022
      • 230
      • Catalonia

      #3
      Re: NTC Thermistor recommendation

      I know, I now.........I was in ironic mode on.

      What I don't know is which one I should use when the one to be replaced is not readable.

      Comment

      • R_J
        Badcaps Legend
        • Jun 2012
        • 9535
        • Canada

        #4
        Re: NTC Thermistor recommendation

        Make? Model? diameter of ntc, pictures? SCK-054
        Last edited by R_J; 01-14-2023, 05:32 PM.

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        • momaka
          master hoarder
          • May 2008
          • 12170
          • Bulgaria

          #5
          Re: NTC Thermistor recommendation

          Originally posted by Francesc V.
          Or shall I put a jumper where It was the NTC?
          You could put a jumper for "testing purposes"... but my recommendation then would be to do this ONLY if you have an incandescent/halogen bulb in series with the PSU's input / AC line. 200-300 Watt halogen should do well in most cases.

          Otherwise, SCK-054 or SCK-085 or SCK 2R58 could be a good start.

          That said, I have seen some PSUs not use a thermistor, and they weren't cheap no-name units either. The APFC inductor typically doesn't provide enough resistance/impedance as an NTC, but it may be enough in some cases to run the PSU without one.
          Last edited by momaka; 01-15-2023, 01:57 AM.

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          • Francesc V.
            Tempus fugit
            • Nov 2022
            • 230
            • Catalonia

            #6
            Re: NTC Thermistor recommendation

            Thank you mates..........I've purchased 3 types between 5mm and 10mm and low resistance.

            Comment

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