Re: automotive alternators, three phase, RSG

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "bob golding by way of Terry Fritz <twftesla-at-uswest-dot-net>" <yubba-at-clara-dot-net>

Hi Jim,
    This sounds like a great idea. I did have a similar idea with using my
rotary inverter a
couple of years ago (was it that long ago) I haven''t got round to it yet
mainly because I have
only just got round to building a rotary gap. This idea will be cheaper as
I don't really want to
fry my inverter. I will get on to it after the dc supply, the twin big
coil, the mot 3 phase
supply..... Arhgg I feel a shortage of counting beans coming on.
cheers
bob golding

Tesla list wrote:

> Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<jimlux-at-earthlink-dot-net>
>
> It occurs to me that an interesting experiment (I'm a great one for ideas
> for experiments, but I rarely actually get a change to try them) would be
> to rig up a big motor (gas, electric, hamster wheel, it matters not)
> driving a 3 phase alternator (as from a car, with the diodes removed) and a
> rotary spark gap on the same shaft.  By definition, the phasing of the
> spark gap will be locked to the electrical phase.  You can change the break
> rate by changing the speed of the prime mover (crack the whip on the
> squirrels) and you can change the output power by changing the field
> current on the alternator.
>
> You could probably drive 3 NSTs with the alternator (or maybe GMHEI Coils),
> then feed each one through a set of gaps, all feeding a common primary
> capacitor/inductor, at high break rates.  Maybe even 3 static gaps might
> work, if properly set. Or, for a real weird setup, how about 3 primaries on
> the same secondary?
>
> The NST won't put out much current (the frequency will be higher than 60 Hz
> from the car alternator so the leakage inductance impedance will be higher
> in proportion... I think they run several hundred Hz.. Anybody know how
> many poles the typical alternator has?
>
> This has the nifty advantage of having no electrical connection to the
> power lines, so back conducted EMI isn't an issue (for that matter, you
> could run an insulating shaft through the wall of a faraday cage and have
> your three phase TC totally isolated).
>
> Before you all leap on me, I know that Tesla built systems just like this,
> and they were also used in commercial radio in the days of spark.
>
> The interesting thing here is that it uses cheap parts: Alternators cost $5
> at the "pick your part" junk yard, and dead alternators are even cheaper. A
> dead alternator is usually dead because one of the diodes (or the internal
> regulator) has failed, and you would remove those anyway.