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Small DC Stepdown Board, Never gets hot ?

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  • Small DC Stepdown Board, Never gets hot ?

    Small DC to DC voltage dropping board like this : http://qqtrading.com.my/dc-dc-step-d...buck-converter

    I am using one to drop the voltage for my pedal board battery pack (using 10 x 1.44vdc fully recharged NiMh = 14.4vdc) to a more reasonable 9.5vdc or so.

    Here's the thing I am surprised at, even with 8 Boss pedals active and being used, this tiny board barely get's warm, only a couple degrees above ambient temp.

    Is it just that I am used to blistering hot Tube circuits ? How does this work without getting that hot ? It's adjustable in a wide range of voltage, and I like that.

    Can one be made to drop a high tube amp B+ in the same fashion, or is that going too far with this fundamental design ?

    Thanks for any responses !
    Last edited by HaroldBrooks; 07-19-2019, 10:10 PM.
    " Things change, not always for the better. " - Leo_Gnardo

  • #2
    I have used that module to transfer 12Vdc to 6.3Vdc for heater powering. That type of buck converter has been used for decades because it can be made to transfer power very efficiently. I guess the most common use nowadays is to convert 5v or 12v down to microprocessor and other lower voltage circuitry in pretty much every computer and mobile phone made.

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    • #3
      Same model (without mythical LM2596HV) that almost took my eye out when I fed it 52VDC. Previous one lasted ~2yrs supplying a couple hundred mA.
      Great when they work!

      Buddy at work 3D printed a tiny case for mine using online files, even lines up the V adj. screw
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      might keep the shrapnel down...

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      • #4
        Originally posted by tedmich View Post
        Same model (without mythical LM2596HV) that almost took my eye out when I fed it 52VDC. Previous one lasted ~2yrs supplying a couple hundred mA.
        Great when they work!

        Buddy at work 3D printed a tiny case for mine using online files, even lines up the V adj. screw
        [ATTACH=CONFIG]54390[/ATTACH]
        [ATTACH=CONFIG]54389[/ATTACH]

        might keep the shrapnel down...
        Yeah, I kinda felt like I was lucky to be in the safe zone for voltage, and doubted the potential for such a wide claimed range from 3vdc to 40vdc, but I am starting with a modest 14.4vdc and because it's a battery less chance (I think ?) of a surge to kill a cap and wreak havoc.

        I just saw a video discussing switching step down convertors, and I think that's how mine operates, with the ubiquitous LM2596. It seems to be working well so far, and I will definatly put it in a box by early next week to sew things up neatly.

        Would be nice to have the same chip in a high voltage variant, but not sure that exists. Very efficient... But I'm just being lazy as a multi-switched row of zener diodes would work to lower B+ voltage in a ratcheted fashion, and I already have a board with those diodes soldered in.

        Just seemed like an efficient and continuous method for dropping DC voltages, and I am amazed how cheap these things are !
        " Things change, not always for the better. " - Leo_Gnardo

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        • #5
          Originally posted by HaroldBrooks View Post
          Can one be made to drop a high tube amp B+ in the same fashion, or is that going too far with this fundamental design ?
          There's R.G. Keen's phase angle circuit if you want a high efficiency B+ dropper.

          Phase Shift Voltage Reducer.pdf

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          • #6
            Originally posted by Dave H View Post
            There's R.G. Keen's phase angle circuit if you want a high efficiency B+ dropper.

            [ATTACH]54393[/ATTACH]
            Fantastic ! Thank You !
            " Things change, not always for the better. " - Leo_Gnardo

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