30v to 120v, dc to ac? help

Discussion in 'The Projects Forum' started by DreyeIce, Nov 23, 2011.

  1. DreyeIce

    Thread Starter New Member

    Nov 23, 2011
    I bought a military generator, its from WW2, but it runs great... at the terminals, the tag says it puts out 30v, 10A and 300w,

    i was curious about putting one or two 120V ac plugs on it to run a few things while camping or upon a power outage or whatever,

    i can read and build circuits, but i have never made one, and i cant find schematics for the 30v to 120v, mixed with a dc to ac converter,

    all help is appreciated,


    it looks like this, (not my pic)
  2. crutschow


    Mar 14, 2008
    You could use an inverter such as this.
  3. SgtWookie


    Jul 17, 2007
  4. DreyeIce

    Thread Starter New Member

    Nov 23, 2011
    ok, well what about this circuit?


    i can modify it to accept a higher 30v,

    those inverters you guys posted... now that i think about it, i bought a motomaster eliminator inverter for my car, the 300w version, could that accept the 30v or could i change something so it accepts 30v? i still would like to be able to use it in the car though, i just wanted to have a few 120v for the odd use camping or something like that, its more of a fun project for me :D

    this is what i have... looks similar to some in that link,

  5. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    Home made power inverters come up more often than the sun around here.

    None of them are close to efficient, usually a square wave output, or 2 step square wave called "modified sine wave" in the more complicated varieties.

    However, none of them can hold a candle to the cost per watt of commercially made power inverters. They work, they power pretty much everything due to sinewave output, and they are low cost.

    The better quality inverters will work over a range of input voltages and still give a 120VAC output as well.

    You may be better off changing the 30VDC Dynamo to a 12VDC alternator+ Voltage Regulator and end up with more electrical power from the same shaft power as well, though it would be a shame to modify such a well kept historical item, or even use it for more than demonstration.

    I'd suggest a modern inverter type genset, they are quiet, low cost, and very powerful for their size. If you want to change the generator in the photo, I'd suggest selling it to a WWII collector and using the money to purchase a new genset, you'll probably have cash left over from the looks of it.
  6. SgtWookie


    Jul 17, 2007
    It looks like they stole that circuit from Tony van Roon's site:
    and stripped his name out of it. Unfortunately, the circuit is really no good. There is no method of output voltage regulation. The output would be a rather rough square wave; really only suitable for incandescent lamps or perhaps ceiling fans. Tony removed the schematic from the website after I had a chat with him sometime in the middle of last year.

    Without seeing the schematics, I'd have to say no. At the very least, the broadband transformer(s) in the inverter would have to be rewound, and most likely a number of capacitors replaced. It would require somewhat advanced hobbyist skills.

    That would make the conversion even more complex. It might be do-able, but without a schematic, that would be the first thing that would need to be generated - and you are the only one with that particular unit that I know of.

    "Looking similar to some of these" is really quite vague.

    I tell you what. I have a 4-door car, and it looks similar to some of these:

    Can you tell me in detail how to rebuild my transmission? :confused:

    While the above example may seem absurd, it is extremely similar to the way you have asked us to help you.