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Re: [PSUBS-MAILIST] Back to surface propulsion (generators)
Yes, batteries in series increases voltage, parallel increases available current. You caught me sleeping!!
bob duncan
john m <powercap2000@yahoo.com> wrote:
Hi, I'm new to this list,
but this is at least something I know about
so I'll comment:
I noticed a couple of points made in the thread
about 12/24 etc that need correcting.
1. Adding batteries in series increases the voltage,
not the current (that would be a parallel connection).
However putting 24V across a resistance that was
designed for 12 will sure cause it to draw more
current, perhaps too much. I've done it with weak
starters on high-comp. engines in the winter.
The manufacturers went from 6V to 12V electrics
generally in the 50s because the starters would draw
much less current for a given load.
2. An alternator is generally much more efficient than
the old generators for developing power. They are 3
phase and work better than the old generators at lower
speeds.
3. A 12V alternator can (depending on its
particular
regulator config) give you any voltage you want, up to
120V. Not at 60Hz necessarily, but if you spin them
fast enough and play with the external regulator
circuit, they will give you a few hundred watts at any
voltage within reason you choose. Some now have
internal regulators, and you'd have to open them up
and screw with them.
Cheers,
John
--- Coalbunny wrote:
> Get a motor that uses brushes. Havn't messed with
> brushless motors, so
> I don't know if they work. But a motor that uses
> the regular graphite
> brushes can be electrically driven to produce
> mechanical power or
> mechanically driven to produce electricity. Kinda
> like the St. Louis
> motor of years back. Get a motor and a multimeter
> and you can figure
> out what voltage and what amperage you're gonna get
> at a given number of
> RPMs. Just takes some experimenting is all.
A
> decent one to start with
> is a fan motor for a swamp cooler. You can get a
> used motor fairly
> cheap and record the data from the experiments.
> Carl
>
>
> Ian Roxborough wrote:
> >
> > Most US military vehicles and large trucks
> (tractor/trailer type) are
> > 24 volt. Many Toyota diesel Land Cruisers are
> 24volt. From what I've heard, alternators are not
> very effiecent as electrical generators.
> >
> > Ian.
> >
> > On Mon, 13 Oct 2003 08:21:10 -0700 (PDT)
> > Bob Duncan wrote:
> >
> > > I may be a little rusy concerning DC electrical
> systems. Older automobiles in the U.S. had 6 VDC
> electrical systems.
> > > The matter of using 2 batteries in series is to
> have more current (amperage) available.
> > >
> > > bob duncan
>
> >
> > > Warren Greenway wrote:
> > > Diesel powered cars in the USA use 12V systems.
> Diesel
> > > systems are actually more compatible with lower
> > > voltages
> > > then gasoline cars.
> > >
> > > Warren.
> > >
> > > --- David Buchner wrote:
> > > >
> > > > Do diesel-powered cars have 24 volt starters,
> and
> > > > two batteries in
> > > > series... or did I make that up? Does this
> mean they
> > > > also have 24 volt
> > > > alternators? Which I could use to make a 24
> volt
> > > > dedicated
> > > > battery-charging generator?
> > > >
> > >
> > >
> > > __________________________________
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> > > Two guiding principles govern Israel Naval
> Commando doctrine:
> > >
> > > 1.Every defense system is vulnerable.
> > >
> > > 2.The enemy can deal with weapons and
> operational methods that are known; for that reason,
> naval commandos use imagination, daring and
> initiative, to create situations which cannot be
> anticipated.
> > >
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>
> --
> "Without deviation from the norm, progress is not
> possible" - F. Zappa
__________________________________
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Two guiding principles govern Israel Naval Commando doctrine:
1.Every defense system is vulnerable.
2.The enemy can deal with weapons and operational methods that are known; for that reason, naval commandos use imagination, daring and initiative, to create situations which cannot be anticipated.
Do you Yahoo!?
The New Yahoo! Shopping - with improved product search