5v rail?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • yonu
    Senior Member
    • Nov 2007
    • 138
    • United States

    #1

    5v rail?

    simple question how to manufacturs get a 5v rail on a destop pc with say a 6amp rating the reason i ask is i have several dead psu and am in need of a 5v regulator that can handle 3 amps.

    Thanks,
    yonu
  • Scenic
    o.O
    • Sep 2007
    • 2642
    • Germany

    #2
    Re: 5v rail?

    Originally posted by yonu
    ... am in need of a 5v regulator that can handle 3 amps.

    Thanks,
    yonu
    get an 78H05
    5V @ 5A
    but AFAIK only available in TO3 packaging (?)

    if there's a chance that 2 amps are (barely) enough: 78S05

    had those in mind when i read your post because i recently converted a 5,25" USB casing from a dual voltage (5V/12V) PSU brick (toasted) to a single 12V unit..

    12V input simply gets regulated by an 78S05 (5V 2A) i mounted inside that aluminum casing (cooled by the (replaced and now quiet running) 40mm fan)

    that story is kinda off topic here though

    Comment

    • etnietering
      Badcaps Veteran
      • Apr 2009
      • 379
      • USA

      #3
      Re: 5v rail?

      78T05
      output 3A @ 5V
      http://search.digikey.com/scripts/Dk...e=LM78T05CT-ND
      you'll need some sort of heatsink, too

      Comment

      • yonu
        Senior Member
        • Nov 2007
        • 138
        • United States

        #4
        Re: 5v rail?

        thanks i will see if i can get either one locally I take it thought the best i will get without having to have a heatsink is 1A correct?

        Comment

        Related Topics

        Collapse

        • Nagy Daniel
          Lowest possible resistance on laptop motherboard rail - Guide Table request
          by Nagy Daniel
          Hi, I'm Daniel, and I'm new to the world of repairing motherboards.

          I would like to create a table, or more likely a guideline about the voltage rails and their possible resistance rail.

          I know that the motherboard design has a very big depend on the rail's resistance, but I would like to know what is the smallest value for a rail that can be acceptable. For example, I heard that some new gaming motherboards can have 0,5 Ohm resistance on the GPU rail, but on an older type, it could be a sign of a shorted GPU rail.

          So, I generated a table with AI so I can...
          03-04-2025, 08:24 AM
        • Victor Moreira Silva
          Acer Nitro 5 LA-L181p power LED turns on by 5 secs (Short on PCH rail?)
          by Victor Moreira Silva
          Hello everyone,

          I'm trying to repair my old Acer Nitro 5 (AN517-54-55T5). I've already bought a new laptop, so this is more of a learning project. For the experience, with no high expectations of success.

          Well, my decice specs are the following:

          Model: Acer Nitro 5 AN517-54-55T5
          CPU: Intel Core i5-11400H
          GPU: NVIDIA GeForce GTX 1650
          Motherboard: GH51G LA-L181P Rev:1c

          The symptom:
          When pressing the power button, the power LED lights up for about 5 seconds and then turns off. Initially, the issue was intermittent: sometimes...
          05-26-2025, 10:49 AM
        • lefetylorant
          Lenovo Thinkcentre tiny M90Q gen 1 - no 12V rail
          by lefetylorant
          Hello Everyone,

          Long story short, I got this unit for very cheap.
          I've started to experiment with it's BIOS, as I did before successfully with an M900. However my very bad quality SOIC clip broken while dumping of the biosof and it must have damaged something on the panel, because it does not turn on, and does exactly nothing when powered. The maximum voltage that could have affected something is the 3.3 or 5v from the IC clip, because the unit was not powered while the bios dumping was in progress.

          I've performed some measurements:
          - 20V rail perfectly...
          09-14-2023, 05:05 AM
        • mkdj
          Acer TravelMate P214 - N19Q7 main power rail shorted to ground
          by mkdj
          Dear all,

          I have taken out the motherboard of a Acer TravelMate P214. There is a short to ground on the main power rail (19V). I don't have the schematics or boardview for this board (DAZ8IMB1AA0 REVA). But I have found 4 MOSFETS close to the main power rail : 2 N-Channel and 2 P-Channel.

          I have checked resistance across each of the 4 MOSFETS. I have the following readings:
          Both N-Channel Mosfets: nothing odd

          P-Channel MOSFET number 1:
          source - drain : 117 kOhm
          source - gate: 96 Ohm
          gate - drain: 117 kOhm


          P-Channel MOSFET...
          08-20-2025, 06:08 AM
        • momaka
          KingWin ABT-650MM 650 Watt ATX PSU [PCB: SW8835REV:A]
          by momaka
          For today's thread, I have a KingWin ABT-650MM ATX PSU. Official web page with the PSU specs is still up and can be found here:
          http://www.rmac.kingwin.com/products.../abt_650MM.asp

          I just can't help it when I see a broken / for parts PSU on eBay that's listed for cheap and looks at least somewhat interesting. Well, OK, I won't lie – on the outside, this PSU looks anything but interesting. It's a plain gray box with colorful “spaghetti cables”.




          What mostly drew me into buying it is its 2x PCI-E power connectors...
          03-29-2022, 11:34 PM
        • Loading...
        • No more items.
        Working...