car alternator voltage regulator

Discussion in 'The Projects Forum' started by agabrielauto, Jun 16, 2009.

  1. agabrielauto

    Thread Starter New Member

    Jun 16, 2009
    Is it possible to step up from 12vdc to 96vdc a (car alternator) voltage regulator output? :confused:
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    That depends on two things - the ability of the alternator to produce that voltage (unlikely) and the ability to alter the regulator to control at that level.
  3. Externet

    AAC Fanatic!

    Nov 29, 2005
    The regulator can be modified to tell the alternator to keep raising the voltage beyond its typical 14V; but to reach 8 times that would need much, much higher rpm or 8 times the number of winding stator turns, which means rewinding the stator.

    Apply more than 12V directly into the field terminals and measure what happens. It will tell the limit capabilities of such alternator at such rpm. Do it with no car electrical equipment connected to the alternator, as whatever gets higher voltage will fry.

  4. SgtWookie


    Jul 17, 2007
    I don't know what the rectifier bridge maximum working voltage is. They are designed for low voltage and high current. I only suspect that the bridge will be reduced to smoking rubble if you manage to exceed around 50v.

    The regulator is another problem; it wasn't designed to be operated at such a high voltage. It simply supplies enough current to the "field" to keep the output somewhere around 13.8v.

    If you tried directly connecting 12v to the field, I suspect that you'll burn something up pretty quickly. The slip ring brushes are likely to go first.
  5. hwy101

    Active Member

    May 23, 2009
    I agree sarge, something is gonna blow for sure, but remember those old kits they had back in the 70's that wired to an alternator and allowed you to use power tools or a small tv, so the output was AC
    I think all it did was bypass the bridge somehow, I can't remember, it was a nightmare of wires to hook up to your vehicle.
    I only ever saw one of those units in my life.
  6. SgtWookie


    Jul 17, 2007
    I don't remember those kits.

    To get single-phase AC out, they'd have to disconnect the bridge rectifier, attach a wire to the center of the wye-wound stator windings, and power the item from just a single phase. Mighty inefficient use of the alternator.

    Senior Member

    Jul 1, 2008
    Yes, I do remember those kits. JC Whitney sold sh_t loads of them. They could power devices that didn't need to see 60Hz, like an electric drill. And yes, the alternator was capable of delivering ~120VAC. I never used one though. I think that good battery powered equipment and probably many burned up auto electric systems put them in the history folder! :)
  8. agabrielauto

    Thread Starter New Member

    Jun 16, 2009
    Thanks for your answers!!!!!!!!
    This company (, they say they can do this:"The individual output terminals of the three generators would be connected together and with our electronic controls perform as a single generator (though more efficiently since we produce much less waste heat during the generation process)."
    If I can get this high output, let's say 5,000 watts, then : Is it possible to step up from 12vdc to 96vdc the voltage regulator output?? or make it?? :confused:. (In a cheap low bugget way)
    I was investigating about a center tap transformer and other teories.
    Any help, web site, ebook, links, or anything where I can study more about this topic would be appreciated. :)
  9. SgtWookie


    Jul 17, 2007
    The largest capacity automotive alternator I know of is currently a GM alternator that puts out up to 130 Amperes. 130A x 14v = 1,820 Watts.

    You're not going to get 5,000 Watts out of an automotive alternator without melting something.