12bit Power Supply


+ Reply to Thread
Results 1 to 20 of 20
  1. #1
    Join Date
    Sep 2007
    Posts
    4

    Default 12bit Power Supply

    Hi,

    I've uploaded to YouTube my new project - 12bit Power Supply with matrix display, PS2 keyboard ( I wrote the subrutine for it as well ). Please take a look, any comments are welcome.

    Last edited by ScaleRobotics; - 29th March 2011 at 16:36. Reason: embeded video

  2. #2
    Join Date
    Feb 2006
    Location
    Gilroy, CA
    Posts
    1,530

    Default Re: 12bit Power Supply

    That looks fantastic. Too bad it's Proton Basic though. Thanks for sharing.

  3. #3
    Join Date
    Oct 2005
    Location
    Loveland CO USA
    Posts
    83

    Default Re: 12bit Power Supply

    Very clever. What LCD did you use?
    I have on my bench a Agilent N6705A that has many of he same functions. It only costs the price of a small car.

  4. #4
    Join Date
    Sep 2007
    Posts
    4

    Default Re: 12bit Power Supply

    Hi there,
    Thanks for your comment. Anyway I used 128X64 Samsung KS0108 Graphic LCD and matrix keypad which I converted to PS2, or any PS2 numeric keypad.
    Cheers

  5. #5
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,087

    Default Re: 12bit Power Supply

    Interesting project.

    Are you using PID to control the output voltage?

    Ioannis

  6. #6
    Join Date
    May 2007
    Posts
    604

    Default Re: 12bit Power Supply

    I'm guessing from the thread title that OP is using an external DAC - so PID is not needed. The MCU's I use have a built-in (dual-channel) 12-bit DAC and I have done something similar. The DAC output is scaled to 2V full scale. An op-amp (rail-to-rail) buffer with 6x gain and a simple linear output stage gives 0-12V output with 3mV resolution.
    Why pay for overpriced toys when you can have
    professional grade tools for FREE!!!

  7. #7
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,087

    Default Re: 12bit Power Supply

    If it is open loop, how is the output voltage regulated with the load?

    Feedback is required, isn't it?

    Ioannis

  8. #8
    Join Date
    May 2007
    Posts
    604

    Default Re: 12bit Power Supply

    That is the purpose of the op-amp/buffer as in the figure below - the DAC provides the Vin. The gain is changed by altering the values of the feedback resistor pair R1, R2. Gain = (R1+R2)/R2.
    Name:  TEST-6A.jpg
Views: 1678
Size:  16.1 KB
    Why pay for overpriced toys when you can have
    professional grade tools for FREE!!!

  9. #9
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,087

    Default Re: 12bit Power Supply

    OK, it is the Vref voltage of the loop that is controlled. So the PIC is not in the output voltage loop.

    OK, it has some cons, but with a high resolution DAC it will work just fine.

    In fact I ordered a couple of MAX5541, 16bit DACs to play with the idea and build a digital controled Power Supply. One for the voltage and the other for he current.

    My dream I had from childhood...

    Ioannis

  10. #10
    Join Date
    May 2007
    Posts
    604

    Default Re: 12bit Power Supply

    Using this method (MCU->Hi-Res DAC->Buffer/Amp), you can not only make the digitally controlled power supply of your childhood dreams but you can also turn it into a fully programmable unit that can generate all kinds of waveforms - very useful for test purposes. For example you can program it to generate stuff like sine, triangle, sawtooth, staircase and other custom waveforms. The trace below is a sine waveform generated by a 12-bit DAC. The timebase is 10uS/Div so the frequency is 40KHz.
    Name:  TEST-6D.jpg
Views: 1475
Size:  75.4 KB
    Why pay for overpriced toys when you can have
    professional grade tools for FREE!!!

  11. #11
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,087

    Default Re: 12bit Power Supply

    Yeap, that is the main idea.

    Not exactly to make a Power supply act like waveform generator but have it under some kind of profile control.

    E.g. for test of regulators steping the input voltage or slow starting power to load and see if it resets normaly etc.

    Ioannis

  12. #12

    Default Re: 12bit Power Supply

    can some one send me the files please

  13. #13
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    3,087

    Default Re: 12bit Power Supply

    What files?

    Ioannis

  14. #14

    Default Re: 12bit Power Supply

    schematic for this power supply

  15. #15

    Default Re: 12bit Power Supply

    there is a link in the start of video but it is a dead link :/

  16. #16
    Join Date
    Feb 2006
    Location
    Gilroy, CA
    Posts
    1,530

    Default Re: 12bit Power Supply

    I never downloaded the "code". But it seems to just be a sales pitch, from reading the posts: http://www.protonbasic.co.uk/archive...p/t-54946.html
    http://www.scalerobotics.com

  17. #17

    Default Re: 12bit Power Supply

    Quote Originally Posted by ScaleRobotics View Post
    I never downloaded the "code". But it seems to just be a sales pitch, from reading the posts: http://www.protonbasic.co.uk/archive...p/t-54946.html
    thanks for your help but i need schematic for this power supply and not the code i don't have problem with the code

  18. #18
    Join Date
    Nov 2005
    Posts
    51

    Default Re: 12bit Power Supply

    Quote Originally Posted by seifsaadaoui View Post
    thanks for your help but i need schematic for this power supply and not the code i don't have problem with the code
    If you go to that link scale posted and there is a link there where you can donwload the shcematic and PCB

    Edit sorry just looked and it's and old version, I did have the schematic but would have to dig deep for it
    Last edited by chuck; - 22nd June 2012 at 19:00.

  19. #19
    shaman's Avatar
    shaman Guest

    Default Re: 12bit Power Supply

    i am very interesting to this power supply? where I can download schematic of power supply

  20. #20
    Join Date
    Oct 2014
    Posts
    1

    Default Re: 12bit Power Supply

    That looks fantastic. Too bad it's Proton Basic though. Thanks for sharing.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts