Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Converting AC to DC

  1. Jan 19, 2014 #1
    Hi everyone i am Julius a 400L student, this is my first post as a new member of this great forum. Please,i want to know a step by step practical guide on how to convert AC to DC , i join this forum for me to properly learn (PRACTICAL) from the masters here and it will be my pleasure if i can have at list 90 percent of help i need in this forum to succeed in my future career i am having less that 1 year to finish my program at the university waiting for your positive repose thanks.
    Last edited by a moderator: Jan 20, 2014
  2. jcsd
  3. Jan 19, 2014 #2


    User Avatar
    Gold Member

    Hello juliusabidoye,

    In the olden days, we used full wave bridge rectifiers, with a capacitor on the output, to smooth out the pulses.


    I would imagine there are other ways to do this, by now.
  4. Jan 21, 2014 #3


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    In the even older days, they used to use just a single diode (rectifier) with a reservoir capacitor, which is not always needed if all you want is 'unidirectional current' rather than a steady DC voltage. Those Selenium Rectifiers were expensive, iirc - and pretty rubbish, too.
    Did you look at Wikipedia? Here is a link.
  5. Jan 21, 2014 #4
    Converting Ac to DC is the most generic way to describe this, as Sophie points out it can be done with one Diode, from there the systems become more and more complex, each method had it's own benefits, drawbacks and pittfals - while this can be studied on paper ( internet - etc) - but IMO building each type will have the best impact.

    I would start with a small step down transformer as an ac source ( get an adviser to help and make this to be safe), and build into a small experimenters box. 120VAC to 12-0-12 Secondary. This will provide 12V or 24V AC source. ( On the AC side, you will need the plug, a fuse, and a properly rated switch), bring the 3 low voltage leads to binding posts.

    From this you can build rectifier circuits with the 1, 2, 4 Diodes, and experiment with different filtering etc. on a basic breadboard.

    Some type of basic oscilloscope will be best to see what is going on - a PC one will, do but the inputs need to be limited to ?? 0.7V? - I am not sure, but you can build a basic voltage divider probe 100/1 to keep the ratios in check. I would also advise to "build" each circuit in Spice ( LTSpice is free) - before you build the real circuit - then compare the Spice results with your real world results.

    A set up like this could support about 20-40 AC/DC conversion experiments. I have been thinking of developing this as a web-curriculum, but I would reference a suppler like radio shack for parts ( as I am based in the USA) -the Safety aspect of the AC supply is my biggest concern.
  6. Jan 21, 2014 #5
    well i want to sincerely appreciate you all that contributed to my thread i want to say i have find your information helpful thank you and God bless you.
  7. Jan 23, 2014 #6


    User Avatar
    Gold Member

  8. Jan 23, 2014 #7


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    There are quite a few of these things available and they are of various qualities and voltages. It is possible that there is a thermal cutout to avoid overheating but it would be a good idea to provide yourself with a 2A fuse (in line type, perhaps) to protect it with. Probably the cheapest way to get your 'safe' AC supply to work with.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Converting AC to DC
  1. How to convert DC to AC? (Replies: 22)

  2. Converting dc to ac (Replies: 10)

  3. DC to AC Converter (Replies: 3)