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WHY are bench power supplies so big, bulky and heavy? Technology has advanced right?

  1. Jul 20, 2012 #1
    I am talking about those power supplies in the University lab. Also if I wish to buy any now it will still be quite big and similar to what is in the University lab.

    My question is, even after the technology has advanced, why are bench power supplies so huge and heavy? Why have they not become miniaturized with the same performance?

    Edit: miniaturized is wrong word, small will do.
     
    Last edited: Jul 20, 2012
  2. jcsd
  3. Jul 20, 2012 #2
    Re: WHY are bench power supplies so big, bulky and heavy? Technology has advanced rig

    You want a 2" by 2" multi output supply that can slip around? Also supply get smaller, but your fingers don't, neither are the output connectors. You need to have knobs on the supply to adjust the parameters and wires to plug into the supply. What is the point of making it so small?
     
  4. Jul 20, 2012 #3
    Re: WHY are bench power supplies so big, bulky and heavy? Technology has advanced rig

    I guess the word miniature has been a mistake. I would like to have Bench Power supplies with the same performance as small as the laptop power supply. :D
     
  5. Jul 20, 2012 #4
    Re: WHY are bench power supplies so big, bulky and heavy? Technology has advanced rig

    You would like a 20V, 4A power supply that cannot be adjusted or current limited, has no display, gets very hot, has less performance with transients and ripple and accuracy, and breaks within 5 years or much sooner if you do bad things to its output?
     
  6. Jul 20, 2012 #5

    berkeman

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    Re: WHY are bench power supplies so big, bulky and heavy? Technology has advanced rig

    The main reason is that you generally want lab power supplies to have very low noise on their outputs, so that means that they have to be linear power supplies, which are always going to be big and bulky because the transformers have to run off of the AC Mains frequency (50/60Hz).

    You can certainly get smaller power supplies that use switching power converters -- they can be smaller and lighter because the magnetics will be running in the 100kHz range or so. But the disadvantage is that their output rails will have noise/ripple on them from the switching action of the supply circuitry.

    One hybrid design (which I haven't seen but could certainly already exist) would use a switcher followed by a linear regulator. That would work for a fixed output voltage, and would give you a pretty small & light power supply with low output noise.
     
  7. Jul 20, 2012 #6
    Re: WHY are bench power supplies so big, bulky and heavy? Technology has advanced rig

    With all the knobs, meters, connectors, you can't make it that small. And I don't want the power supply to be drag and tumbling around. I like it nice as heavy and sit in one spot. If small is what you want, there are plenty little supply that you can buy and wire it up.
     
  8. Jul 21, 2012 #7

    Averagesupernova

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    Re: WHY are bench power supplies so big, bulky and heavy? Technology has advanced rig

    One of the smartest things I have ever seen posted here on PF. When equipment gets so small that the connecting cables just due to their stiffness moves the unit around I look around for something heavy to attach to the bottom to keep it in place.
     
  9. Jul 21, 2012 #8

    AlephZero

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    Re: WHY are bench power supplies so big, bulky and heavy? Technology has advanced rig

    Not to mention the problem that if a general purpose gizno like a power supply is small and light enough to put in somebody's pocket, it might not survive long as a lab power supply, if you get my meaning!
     
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