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Meanwell supplies. A caution

Discussion in 'Power Supplies' started by AAH, Oct 20, 2014.

  1. AAH

    AAH I love blinky lights :) Community Project Designer

    Dec 27, 2010
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    Meanwell make among the best supplies on the market with supplies ranging from good to excellent.
    What they do do however is fool people with their marking/marketing. The SP-320 range which is reasonably commonly used for blinky heads is nothing like 320W across the range of voltages. The 320 refers to the product range more so than the output power.
    Below is a snapshot from the SP-320 data sheet.
    The commonly used 5V, 12V and 24V supplies supply 275W, 300W and 312W.

    Attached Files:

  2. David_AVD

    David_AVD Bite my shiny metal ass! Community Project Designer Generous Elf

    Jun 12, 2010
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    Victoria Point (Brisbane)
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    Re: Meanwell supplies. A caution (even with other brands).

    Yes, it pays to read the data sheet. That's why I have the wattage and current as well listed when I sell them. As far as I know there are other manufacturers that use a similar numbering scheme.

    I suspect the same thing applies to the "no name" units as well. It's just that they don't have data sheets so you really don't know. I'm not sure I'd trust what's printed on those actual PSUs either. Knock-off stuff can be bought with whatever specs you want on the sticker. :)

    Something else to remember is that the output current will also vary (inversely) with the output voltage if you tweak them away from their nominal voltage. In general you'll get less current available if they are adjusted up in voltage, but you may not get proportionally more if you set them below.

    ie. A 240W 24V unit may give you 10A @ 24V (240W), 8.9A @ 27V (240W) but only 10A @ 22V (220W). This is because the circuitry has limits on the current it can handle.

    It's certainly worth checking what the allowable current draw is, the effective output power and allow for some de-rating (say 80% loading max) if at all in doubt.
  3. multicast

    multicast Senior Elf

    Jul 13, 2013
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    Yes, Using numbers as part numbers is sometimes a bad idea..

    If in dobut, just ask here, someone will offer an opinion

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