Wayne.B wrote in
:

The most practical alternative in my opinion
is to drive a sine wave inverter with a high current alternator. This
has a number of advantages starting with extra battery charging
capability, the use of standard/easily repaired/replaced components,
and fewer appendages on the engine. I'm doing this on my trawler to
save generator usage while underway. It is important to size the
alternator very generously since most will not develop rated current
for more than a short period of time. Also important is to use large
cables (at least #2) between the alternator and inverter, and to use
multiple belts to drive the alternator. Single belts will not hold up
very long delivering more than 70 or 80 amps.


I don't think it will be very long before some smart builder tosses
caution to the wind and simply buys the rights to use hybrid technology
from the cars. Unlike the cars, the boats have room and lifting power
for much larger capacity batteries than the little hybrid cars, say
buried into the keel for ballast, instead of topside where they
shouldn't be. Lithium Polymer batteries really require no maintenance
so the battery packs can simply be installed and left for many years,
same as in the cars with much tougher use.

Propulsion for the boat will simply be part of the boat's overall power
system, high voltage traction motors as the cars are using with
electronic controls and automatic engine start/stop as needed for
maximum efficiency. The prime mover will be a high voltage
alternator/rectifier. Saildrive traction motors will also be used as
recharging alternators while underway under sail to supplement the prime
mover, reducing runtime and fuel usage.

Being a high voltage DC system, not this old nonsense 12/24/48VDC from
the 1940's charging lead-acid beasts, the weight of many of the
components will be offset by using small, high voltage wiring in the
boat, instead of these huge battery cables, monstrous contactors and
current, current, CURRENT. 10A at 400VDC = 4000 watts of serious power,
not 138 watts like a 12V system. 10A can easily be switched by a wide
variety of solid state devices that don't even get warm and use
negligible power. High voltage switching AC power supplies running off
the high voltage bus will provide 115/230 50/60 Hz AC to power
appliances and a new range of boat electronics that will run off the AC
bus at sea and simply switch to the shore bus at the dock. 12VDC/24VDC
appliances will be soon phased out as relics of the past.

Boats will, probably, be equipped with twin engines and twin traction
motor/alternators for redundancy made from much smaller prime movers.
Because the prime mover is now running an AVERAGE load, it no longer
needs to produce a peak takeoff power. The battery supplies, just like
the cars, will provide peak power. Engines will run with more constant
loads at maximum fuel efficiency under computer control. If one engine
or traction motor system fails, the other mover simply runs both
traction systems at reduced average power until repairs are made,
automatically cross connecting in the redundant systems. At anchor,
both engines may run to operate heavy loads, dropping automatically to
one as the batteries become charged and loads drop. When batteries
become charged, the engine will be stopped by the computer until the
batteries are drained down and require charging again. How long they
are off is up to the boat owner and his loading. The computer will
handle the discharging/recharging with no input from the humans. This
will eliminate the supercharging, overcharging, undercharging, and crazy
ideas incompetent owners have tortured battery systems with since the
first 6V car battery out of the old Chevy was brought aboard for a
light.

In article ,
says...
Wayne.B wrote in
:

The most practical alternative in my opinion
is to drive a sine wave inverter with a high current alternator. This
has a number of advantages starting with extra battery charging
capability, the use of standard/easily repaired/replaced components,
and fewer appendages on the engine. I'm doing this on my trawler to
save generator usage while underway. It is important to size the
alternator very generously since most will not develop rated current
for more than a short period of time. Also important is to use large
cables (at least #2) between the alternator and inverter, and to use
multiple belts to drive the alternator. Single belts will not hold up
very long delivering more than 70 or 80 amps.


I don't think it will be very long before some smart builder tosses
caution to the wind and simply buys the rights to use hybrid technology
from the cars. Unlike the cars, the boats have room and lifting power
for much larger capacity batteries than the little hybrid cars, say
buried into the keel for ballast, instead of topside where they
shouldn't be. Lithium Polymer batteries really require no maintenance
so the battery packs can simply be installed and left for many years,
same as in the cars with much tougher use.

The battery pack in our Prius puts out 350V. I'm not sure I want
to pay for the engineering to make that reliable in the marine
environment. High voltages and salt water on a small boat---
that makes me nervous.

Propulsion for the boat will simply be part of the boat's overall power
system, high voltage traction motors as the cars are using with
electronic controls and automatic engine start/stop as needed for
maximum efficiency. The prime mover will be a high voltage
alternator/rectifier. Saildrive traction motors will also be used as
recharging alternators while underway under sail to supplement the prime
mover, reducing runtime and fuel usage.

Being a high voltage DC system, not this old nonsense 12/24/48VDC from
the 1940's charging lead-acid beasts, the weight of many of the
components will be offset by using small, high voltage wiring in the
boat, instead of these huge battery cables, monstrous contactors and
current, current, CURRENT. 10A at 400VDC = 4000 watts of serious power,
not 138 watts like a 12V system. 10A can easily be switched by a wide
variety of solid state devices that don't even get warm and use
negligible power. High voltage switching AC power supplies running off
the high voltage bus will provide 115/230 50/60 Hz AC to power
appliances and a new range of boat electronics that will run off the AC
bus at sea and simply switch to the shore bus at the dock. 12VDC/24VDC
appliances will be soon phased out as relics of the past.

Boats will, probably, be equipped with twin engines and twin traction
motor/alternators for redundancy made from much smaller prime movers.
Because the prime mover is now running an AVERAGE load, it no longer
needs to produce a peak takeoff power. The battery supplies, just like
the cars, will provide peak power. Engines will run with more constant
loads at maximum fuel efficiency under computer control. If one engine
or traction motor system fails, the other mover simply runs both
traction systems at reduced average power until repairs are made,
automatically cross connecting in the redundant systems. At anchor,
both engines may run to operate heavy loads, dropping automatically to
one as the batteries become charged and loads drop. When batteries
become charged, the engine will be stopped by the computer until the
batteries are drained down and require charging again. How long they
are off is up to the boat owner and his loading. The computer will
handle the discharging/recharging with no input from the humans. This
will eliminate the supercharging, overcharging, undercharging, and crazy
ideas incompetent owners have tortured battery systems with since the
first 6V car battery out of the old Chevy was brought aboard for a
light.

IIRC, Batteries in hybrid cards (at least the NIMH batteries in the
Prius) stay in the 70 to 90% of full charge range to prolong lifetime.
That system will need a lot of work to be useful for long runs
without engine recharge.


Mark Borgerson

On Apr 7, 8:17*pm, Bruce In Bangkok wrote:
On Mon, 6 Apr 2009 19:06:28 -0700 (PDT), "Capt.Bill"





wrote:
On Apr 6, 7:00 pm, "David Martel" wrote:
Capt. Bill,

http://www.seafrost.com/andmoney others were easy to google. You know
your boat and whether you can fit the equipment in.

Dave M.

Your right Dave. If I had been looking for engine driven aircon or
refrigeration systems they are easy to Google up.

But I'm not looking for those. I'm looking for an engine driven AC
current generating system.

There was/is at least one company that made/makes one. I just can't
recall their name or find them on the web so far.

Perhaps you'll be able to easily Google that info up.

Years ago there was someone offering a modification for a normal auto
alternator. Essentially to remove the diodes and use it as an A.C.
alternator.

Is this the type of devise that you are looking for?

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)- Hide quoted text -

- Show quoted text -

No, not really Bruce. But thanks for playing. :-)

It's driving me nuts, because I remember seeing and reading about this
thing in the past. But for the life of me I can't think of the name of
it. It ran off the main engine to give you 120v power while you were
underway. It may have been a high output DC alternator coupled with an
inverter to give you sable power at varying RPMs. Or you may have had
to run at a consistant RPM. I just can't recall the details.

On Wed, 08 Apr 2009 01:00:18 GMT, "Lew Hodgett"
wrote:


"Bruce In Bangkok" wrote:

Years ago there was someone offering a modification for a normal
auto
alternator. Essentially to remove the diodes and use it as an A.C.
alternator.

Leece-Neville alternators had the AC terminations on the rear housing
as standard.

Also offered a firewall mounted transformer to provide 120VAC from the
alternator; however, since alternator output is frequency sensitive,
had to operate the engine at a fixed RPM if you needed 60 HZ.

Didn't sell a lot of transformers, BTW.

Lew

I only remember the adverts in magazines. Never actually saw one. With
today's electronics I think it would be easier just to run an
inverter.
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

"Bruce In Bangkok" wrote:

I only remember the adverts in magazines. Never actually saw one.
With
today's electronics I think it would be easier just to run an
inverter.

Alternator output is rectified AC, not pure DC, which is NBD if you
have a storage battery connected since it absorbs the ripple as well
as functioning as a humongous capacitor.

Not sure if today's inverter can accept rectified AC or do they
require pure DC.

In any event, having a storage battery in the system makes life easy.

Lew

On Wed, 08 Apr 2009 15:05:29 GMT, "Lew Hodgett"
wrote:

Alternator output is rectified AC, not pure DC, which is NBD if you
have a storage battery connected since it absorbs the ripple as well
as functioning as a humongous capacitor.

Not sure if today's inverter can accept rectified AC or do they
require pure DC.

In any event, having a storage battery in the system makes life easy.

Normal practice is to have the alternator, inverter, starting battery
and/or house bank, all in paralell. I'm doing this on my boat with a
Xantrex 2.0 inverter/charger and it is working just fine. We are able
to get about 1.5 KW continuous from the inverter using a 250 amp
alternator, 1/0 wire for the interconnects and dual 1/2 inch belts.
The house bank is 4 golf cart batts in series-parallel.

The alternator actually creates 3 phase AC which is then rectified
into pulsating DC. Because it starts out as 3 phase the ripple is
less than you would otherwise expect.

On Wed, 8 Apr 2009 00:35:14 -0700 (PDT), "Capt.Bill" wrote:
It's driving me nuts, because I remember seeing and reading about this
thing in the past. But for the life of me I can't think of the name of
it. It ran off the main engine to give you 120v power while you were
underway. It may have been a high output DC alternator coupled with an
inverter to give you sable power at varying RPMs. Or you may have had
to run at a consistant RPM. I just can't recall the details.

Are you thinking of the Yanmar flywheel generator??
It's driven by the main engine. In fact, it bolts onto the back of the
engine between the bellhousing and the gearbox, thus becomng part of
the drive train.
Here's a link to some info, see if this rings a bell::
http://www.boatingoz.com.au/default....ws%2F13034%2F0

Rick .

On Sun, 26 Apr 2009 17:03:15 -0500, lid wrote:

On Wed, 8 Apr 2009 00:35:14 -0700 (PDT), "Capt.Bill" wrote:
It's driving me nuts, because I remember seeing and reading about this
thing in the past. But for the life of me I can't think of the name of
it. It ran off the main engine to give you 120v power while you were
underway. It may have been a high output DC alternator coupled with an
inverter to give you sable power at varying RPMs. Or you may have had
to run at a consistant RPM. I just can't recall the details.




I think that you are talking about a modification to a conventional
auto alternator that provided 110 VAC. I remember them also.

As far as I remember they just bypassed the normal diodes in the
alternator and you controlled the engine RPM to get 60 H. I also don't
remember that they were very popular.

What is it that you are trying to do?


Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

On Apr 26, 6:03*pm, wrote:
On Wed, 8 Apr 2009 00:35:14 -0700 (PDT), "Capt.Bill" wrote:
It's driving me nuts, because I remember seeing and reading about this
thing in the past. But for the life of me I can't think of the name of
it. It ran off the main engine to give you 120v power while you were
underway. It may have been a high output DC alternator coupled with an
inverter to give you sable power at varying RPMs. Or you may have had
to run at a consistant RPM. I just can't recall the details.

Are you thinking of the Yanmar flywheel generator??
It's driven by the main engine. In fact, it bolts onto the back of the
engine between the bellhousing and the gearbox, thus becomng part of
the drive train.
Here's a link to some info, see if this rings a bell::http://www.boatingoz.com.au/default....ID=News%2F1303...

Rick .

No I wasn't. But that is very interesting, thanks.

On Apr 26, 7:33*pm, Bruce in Bangkok
wrote:
On Sun, 26 Apr 2009 17:03:15 -0500, wrote:
On Wed, 8 Apr 2009 00:35:14 -0700 (PDT), "Capt.Bill" wrote:
It's driving me nuts, because I remember seeing and reading about this
thing in the past. But for the life of me I can't think of the name of
it. It ran off the main engine to give you 120v power while you were
underway. It may have been a high output DC alternator coupled with an
inverter to give you sable power at varying RPMs. Or you may have had
to run at a consistant RPM. I just can't recall the details.

I think that you are talking about a modification to a conventional
auto alternator that provided 110 VAC. I remember them also.

As far as I remember they just bypassed the normal diodes in the
alternator and you controlled the engine RPM to get 60 H. I also don't
remember that they were very popular.

What is it that you are trying to do?

Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

I was trying to help someone with a power boat who was looking for a
way to generate 120v power while underway without having to by a stand
alone generator.