Connect with us

beefy inverter

Discussion in 'Electronic Design' started by [email protected], Apr 16, 2007.

Scroll to continue with content
  1. Guest

    Let's say, for example, I had an old vehicle that I wanted to let sit
    in the driveway and use as a backup generator (12VDC power
    available). Nice that it already has a self-contained powerplant,
    with a good emissions control system.

    Let's say also that I wanted it to provide 1 kW of power, at 110 V.

    Let's also say that I wanted to power inductive loads with it: an
    electric saw, etc.

    So, how would I go about building one of these puppies?

    I know that the cheap square wave inverters from Wal-Mart would blow
    up if I tried to run an inductive load off them.

    Any suggestions? (posts to old Masters' Theses, etc?)

  2. GregS

    GregS Guest

    I still have the one I built. used a 555, some Mosfets, the core of an old
    torroid variac, and thats about it. Not quite 1KW, maybe 600 watts.

  3. Tim Wescott

    Tim Wescott Guest

    You'd probably find yourself overloading the car's alternator, unless
    you went to the trouble to put in an auxiliary alternator in there --
    and if you're going to do that, why not go find a clapped-out gen set
    and fix it up?


    Tim Wescott
    Wescott Design Services

    Posting from Google? See

    Do you need to implement control loops in software?
    "Applied Control Theory for Embedded Systems" gives you just what it says.
    See details at
  4. Guest

  5. Guest

    The mosfets didn't fry themselves when they saw an inductive load...?

  6. Rich Grise

    Rich Grise Guest

    I used to work for a company that made inverters like that, but they
    were big and heavy and expensive.

    For what you would have to invest in any inverter, whether you build or
    buy, you'd be better off to just go ahead and get a genset and fix it
    up, or just buy a new one, for example:

    Good Luck!
  7. Guest

    "This unit can't be shipped to California and is only approved for
    sale in 47 states".

    Love that.

    The good things about using an old vehicle are: 1) built in catalytic
    converter; 2) EGR (exhaust-gas-recirculation) system to reduce NOx;
    3) built-in muffler.

    Oh well.


  8. Tim Wescott

    Tim Wescott Guest

    On the other hand you're extracting 1kW from an engine that's good for
    at least 30kW if it's wimpy, to 200kW for a big-normal pickup. So while
    all the pollution equipment may be good when it's going down the freeway
    at normal load, I question it's ability to hold the emissions down to
    what you'd get out of a new California-approved genset.


    Tim Wescott
    Wescott Design Services

    Posting from Google? See

    Do you need to implement control loops in software?
    "Applied Control Theory for Embedded Systems" gives you just what it says.
    See details at
  9. Guest

    Ah yes, you're absolutely right. I hadn't considered that.

    Likely the EGR won't activate anyway while at idle. (I'd just
    finished troubleshooting the EGR system on my car recently. What fun
    that was.)


  10. Running a car at idle for long periods (especially if you dont take it out
    for a bit of a work out occasionally) will result in glazed bores. The
    engine will go downhill quite quickly.

    Also as others have mentioned, even a small 4cyl car engine at idle will
    use more fuel and produce more pollution than a little 2 stroke genset
    running flat out.

    -- Michael
  11. Guest

    Do you have a schematic available, for those of us who are still
    learning? ;-)

    I don't currently have a.b.s.e. access (posting from work during
    breaks), but I'll try tonight to see if I can get my DSL to log into


  12. Guest

    Why on earth bother???

    Here in the DK one can buy a noname Chinese petrol powered generator in the 2.5
    kW power range for the equivalent of USD 200.

    There is no way you can beat that!
  13. Guest

    .....Needs service every 300 hours or so!!!

    The early entrepreneurs into bio-gas (methane from pig's shite) learned that
    there is a *reason* that engines rated for power plants and ships costs about
    100 times that of the corresponding car engine :)

    The average cheap Chinese genset will probably burn out in about 200 hours or
    thereabouts also. But 200 hours cleaning the boat with a pressure washer is a
    loong time.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day