power supply selection

Discussion in 'Power Electronics' started by alimash, Oct 12, 2016.

  1. alimash

    Thread Starter Member

    Oct 12, 2016
    34
    0
    Dear friends,i want to begin some testing and measurements,also building some projects,and i need a "constant voltage,constant current power supply",my questions are:
    -do i need more than 30v max voltage
    -do i need more than 5A(10A for example)
    -how much a decent power supply cost(acceptable quality)
    -what are the most known companies involved in such things
    thank you
     
  2. tranzz4md

    Member

    Apr 10, 2015
    139
    28
    You have to tell us more. Test what? Measure what? Planets? TV sets? Goldfish? Microprocessors? Standing waves? Batteries? Tesla coils? Lederhosen?
     
  3. dl324

    Distinguished Member

    Mar 30, 2015
    3,242
    619
    Welcome to AAC!

    Unless you provide information regarding what projects you have in mind and what types of devices you plan to use, no one can give you advice.

    FWIW, I use a triple supply that can only provide 1A from each voltage for most of my projects. For a significant number, I use an experimenter with a dual supply that can only provide around 150mA.

    My triple supply can do constant current on 2 of the voltages, but I never use that feature.

    If you're just starting out, wall warts (power adapters) and fixed/variable voltage regulators may be sufficient. My first project was a power supply, then a square wave signal generator, then a digital voltmeter (this was 40 years ago).

    Regarding manufacturers, I'd go for used equipment from the likes of HP, Tektronix, etc.
     
  4. MrSoftware

    Active Member

    Oct 29, 2013
    500
    122
    Everyone's needs and budgets are different and there are tons of options. What types of things are you going to be working on? How much power do they take, and how precise do you have to be able to control it? If you're working on delicate low power electronics (micro controllers, radios such as Bluetooth, etc..) then you really don't need much power. If you're working with large motors, large amplifiers, etc.. then maybe you need more power.

    I use this one and I'm reasonably happy with it:

    https://www.rigolna.com/products/dc-power-supplies/dp800/
     
  5. BR-549

    Well-Known Member

    Sep 22, 2013
    1,987
    388
    I recommend a desktop computer power supply. The fastest, cheapest most convenient way to get a power supply for tinkering.
    There are many mods and will teach you much.
     
  6. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    784
    Many people get by with a box of leftover wall warts. Most USB PSUs and various other 5V warts are tight regulated SMPSU designs.

    Generally; any SMPSU wall warts have reasonably tight regulation. The iron cored transformer variety have a habit of putting out more voltage than stated on the label. They're still useful if you have 78xx regulators in the parts drawer - the appnotes show how to boost their power rating with an external pass transistor.

    For higher power logic projects; an old AT or ATX PSU is handy, the AT is simpler to use but no 3.3V. The ATX has to have both 3.3V & 5V loaded to work properly, but you get a handy low voltage power on/off switch.
     
  7. upand_at_them

    Active Member

    May 15, 2010
    246
    29
    I recently got an HP 6216C 0-25V power supply on eBay for $5. Was listed as "not working", but the seller didn't know how to use it. (Was listed for $25, but I offered $5.)
     
  8. MrSoftware

    Active Member

    Oct 29, 2013
    500
    122
    BR-549 likes this.
  9. alimash

    Thread Starter Member

    Oct 12, 2016
    34
    0
    thank you all for reply,
    i am all set
     
  10. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    784
    EPE magazine started a project in parts starting in the September issue for a hybrid universal PSU.

    The front end is a buck/boost topology with a wide input voltage range but optimised for a typical laptop power brick.

    The multiple outputs are handled by LDO regulators to minimise switching hash.
     
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