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Power supply question

Lgrant1350Lgrant1350 Posts: 7
edited 2005-08-10 06:12 in General Discussion
Hi folks,
I'm adding a power supply to a project box. It is 110v input and has taps for 12v down to 3v dc I think it is.
Should those taps have some sort of load on them when it is turned on ? If so does each tap need one or just one of them?
I remember reading that a computer power supply shouldn't be turned on unless it was plugged into the mother board. I guess the same would apply to all power supply's ?
Thanks, Larry

Comments

  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-08-07 17:26
    Hi Larry, unfortunatly there isn't a single answer that works for all power supplies. I've seen supplies which require loads on all taps, ones which don't require any loads, and ones that require a load on a single tap. It all depends on the type of conversion used to create the voltages, and there are quite a few types out there. I am not knowledgable enough to know what is required for a specific type of converter, I rely on spec sheets to give guidance to what is required. So try to find a spec sheet for your particular supply, ask the manufacturer for one if you can't locate it.

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  • Lgrant1350Lgrant1350 Posts: 7
    edited 2005-08-07 19:22
    Ok, Thanks a lot Paul.

    Larry
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-08-07 21:28
    Larry,

    ·· Just out of curiosity, do you know if it's a Linear Regulated or Switching Supply?· Switching supplies generally need the load on the output.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • Lgrant1350Lgrant1350 Posts: 7
    edited 2005-08-08 01:15
    Chris,

    It is a switching supply. That means that the output is constant regardless of the load within the limitations of the power supply doesn't it ?

    Does it need a load on all the outputs or would just one be enough?

    Like an led and it's resistor for an indicator light.

    Thanks, Larry
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-08-08 01:36
    Larry,

    ·· As Paul stated, there is no standard for this.· On PC Power Supplies, which are also switching supplies, a significantly higher load is needed than an LED/Resistor for them to be stable.· Modern supplies have a load system built in.· Anyway, you may have to simply run some tests, cheking the voltages on the outputs.· Not sure if I'd use the Stamp Module in these tests though...· =)


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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com


    Post Edited (Chris Savage (Parallax)) : 8/10/2005 4:59:23 PM GMT
  • Lgrant1350Lgrant1350 Posts: 7
    edited 2005-08-10 06:12
    Ok, that's what I'll do.

    Thanks Chris

    Larry
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