Variable power supply

Discussion in 'Circuit Help' started by markm6164, Feb 1, 2012.

  1. markm6164

    markm6164 VIP Member

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    Anyone got a good circuit diagram so I can make a 0-30v variable power supply? I want to include digital volt and amp display. Not sure on amp output. What do you guys use?
    markm6164, Feb 1, 2012
    #1
  2. markm6164

    jackorocko VIP Member

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    How much current do you require? Do you need current limiting? Do you want a linear or switching PSU?
    jackorocko, Feb 1, 2012
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  3. markm6164

    Rleo6965 VIP Member

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    Are you going to use it for your electronic projects? You will need current limit.
    Last edited: Feb 1, 2012
    Rleo6965, Feb 1, 2012
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  4. markm6164

    markm6164 VIP Member

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    Yes just for general project use. Maybe power up the odd car Audio unit or cluster for bench testing too. What do you recommend. Thought better to build one for learning purposes than just buy one.
    markm6164, Feb 1, 2012
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  5. markm6164

    Rleo6965 VIP Member

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    If your new in electronics. Go for analog variable power supply project. It s simpler but bulky.
    Rleo6965, Feb 1, 2012
    #5
  6. markm6164

    Resqueline Moderator

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    Most (many) Lab Power Supplies are 0-30V and 0-3A. Here and here are shematic diagram examples that look like they'll work reliably.
    For testing anything higher powered than a simple car radio you'll need a dedicated 13.8V 10-50A power supply though.
    Resqueline, Feb 1, 2012
    #6
  7. markm6164

    markm6164 VIP Member

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    Thankyou.
    markm6164, Feb 1, 2012
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  8. markm6164

    monkeybanana

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    I actually just made my first power supply! Here's what I found:

    I think you could make this work for up to 30V. If you have wall adapters laying around then you can use the LM317 voltage regulator (advertised to work up to 37V):

    http://www.instructables.com/id/How-to-Build-a-Bench-Top-Power-Supply/

    I can't find the link but someone out there hooked up a digital readout display to it that only costs 10 dollars !

    looks like 30V is possible with almost the same exact circuit above:
    http://www.electronickits.com/kit/complete/powe/ck402.htm

    here is a cool kit from Jameco with negative and positive supplies with the use of a transformer if you don't have wall bricks. it's only 0-15V but you can probably use their schematic (included in link) and modify it to your purposes. Also, the video explains pretty well how it works):

    http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_20626_-1

    afrotechmods who has the greatest videos on youtube explains the voltage regulator here:
    http://www.youtube.com/watch?v=IjJWWGPjc-w

    sorry to dump all these links on you but i just went through this myself!
    Last edited: Feb 2, 2012
    monkeybanana, Feb 2, 2012
    #8
  9. markm6164

    monkeybanana

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    monkeybanana, Feb 2, 2012
    #9
  10. markm6164

    (*steve*) There is no spoon! Moderator

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    My, what a tiny heatsink he has.

    I wouldn't try to get 1.5A out of that at a low voltage...

    Check out this for an open source PSU design. This will be available in kit form almost certainly. Check out videos 1 to 6 if you're more interested in what it's designed to do, why you'd want it to do that sort of stuff, and how you make it do it.
    (*steve*), Feb 3, 2012
    #10
  11. markm6164

    monkeybanana

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    good to know. I like the videos too! i love the internet...and foreign accents...

    edit: the video is a little advanced! more studying for us beginners
    Last edited: Feb 3, 2012
    monkeybanana, Feb 3, 2012
    #11
  12. markm6164

    (*steve*) There is no spoon! Moderator

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    What accent?
    (*steve*), Feb 3, 2012
    #12
  13. markm6164

    monkeybanana

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    haha human accent
    monkeybanana, Feb 3, 2012
    #13

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