help with finding a transformer

Discussion in 'The Projects Forum' started by frosr6, Jan 24, 2012.

  1. frosr6

    Thread Starter New Member

    Jan 10, 2012
    Im trying to find a transformer that will supply 30 amps for a bench top power supply circuit i built. I would like to produce up to 28-30 vdc at 30 amps. This is the schematic i drew up and am using[​IMG] a 100amp full bridge rectifier that i had. thanks for any help or info
    Last edited: Jan 24, 2012
  2. Wendy


    Mar 24, 2008
    For the record this is for an electrolysis circuit. The OP and I emailed each other off line and I approved a resubmission. I have serviced hydrogen generators for old bonders, you will need a water refill system (preferably filter or DI water) and a electrolysis chemical. Generally Potassium Hydroxide is used, though a wide range of chemicals will work.

    If you mix the gasses (as in Brown's Gas) be extremely cautious, it is an explosive mixture. A little research will go a long way to making it safe.

    I could be wrong, but I don't think the large caps will help either way.

    Electrolysis is a good way to make a local source of hydrogen, but if used in big quantities a tank of H2 gas is much cheaper. Electrolysis is extremely inefficient, if convenient.
  3. wayneh


    Sep 9, 2010
    Just curious, what do you mean by this? I would think you get a stoichiometric conversion of current to hydrogen, essentially 100% efficiency. No?
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010

    Sorry, I can't remember how to substitute a short word for the actual link, but I do remember it was real simple.

    The book is a free pdf download and a very good look at the ways and methods used, at the turn of the 20th century, for the manufacture of hydrogen and oxygen with electricity. This is the only time in our history when it was actually done commercially.
  5. wayneh


    Sep 9, 2010
    What a great reference. And it answered my question: Electrolysis is only 50-60% efficient using a well designed apparatus, mostly because you need to drive it with a voltage higher than the theoretical minimum.

    I'm surprised to learn that making hydrogen and oxygen by electrolysis, say by solar power, for later conversion back to electricity in a fuel cell, is no more efficient than modern batteries.
  6. bountyhunter

    Well-Known Member

    Sep 7, 2009
    Hydrogen fuel cells are just the latest scam to come up with a miracle solution to our energy problems. In a car, they run clean and produce no emissions...... but they fail to mention how much electricity it takes to produce the hydrogen and that most of our electricity is generated by coal fired power plants. So the net overall effect is a lot worse.

    As for a 30V/30A transformer? Sure, they probably can build one. I estimate it would be about the size of a bowling ball and probably weight about 30 - 40 pounds.
  7. wayneh


    Sep 9, 2010
    So true. The ill-fated Chevy Volt would be even less attractive than it is now - if that's possible - if people understood that it's basically a low-efficiency, coal-powered car.