Any recommendations?
Gordon

On Jan 4, 8:14*pm, Gordon wrote:
* *Any recommendations?
* Gordon

Hi, include me in the interested readers. Of most importance, relable
brands, minimum water speed to produce N amps. Im wondering if I could
just throw one over boad while at anchor with a running tide? Tides
run at 1~4 knots here and would be great to get some juice.... that is
when im not holding on during those 93 mph gusts.... Been haveing a
few storms over hear last couple days.
Bob

Gordon wrote:
Any recommendations?
Gordon

Some of the older wind generators used to have a towed sea generator as an
alternative attachment.

I haven't a clue as to their effectiveness.

Dennis.

On Fri, 04 Jan 2008 20:14:09 -0800, Gordon wrote:

Any recommendations?
Gordon

Think about it this way. If the generator is 100% efficient, then to
generate 746 watts, one horsepower must be provided. Imagine a dinghy
with a one hp engine pulling your boat backwards and you get a sense
of practicality. In practice, two or three hp is probably closer to
what the effect might be.

So there is plainly an upper limit to the amount of power a towed
generator can realistically provide to a small sailboat.

Chuck
S/V Sans Serif

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On Sat, 05 Jan 2008 08:04:38 -0500, wrote:

On Fri, 04 Jan 2008 20:14:09 -0800, Gordon wrote:

Any recommendations?
Gordon

Think about it this way. If the generator is 100% efficient, then to
generate 746 watts, one horsepower must be provided. Imagine a dinghy
with a one hp engine pulling your boat backwards and you get a sense
of practicality. In practice, two or three hp is probably closer to
what the effect might be.

So there is plainly an upper limit to the amount of power a towed
generator can realistically provide to a small sailboat.

Chuck
S/V Sans Serif

Nice post! It speaks to the 'something for nothing' hope that springs
eternal in all of us. :-)
Brian Whatcott Altus OK

wrote in message
...
On Fri, 04 Jan 2008 20:14:09 -0800, Gordon wrote:

Any recommendations?
Gordon

Think about it this way. If the generator is 100% efficient, then to
generate 746 watts, one horsepower must be provided. Imagine a dinghy
with a one hp engine pulling your boat backwards and you get a sense
of practicality. In practice, two or three hp is probably closer to
what the effect might be.

So there is plainly an upper limit to the amount of power a towed
generator can realistically provide to a small sailboat.

Chuck
S/V Sans Serif

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News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption
=----

In the late seventy Yves Gélinas "Jean-du-Sud around the World" used a towed
generator.
The electrical power produced was mainly used to communicate on his short
wave radio.
Every day he radioed his position. Then all of a sudden no more
communication were transmitted by him.
Later it was learned that the impeller on his towed generator had been
chewed to pieces.
When he returned home I talked to him and he stated that the sharks made a
meal of the generator impeller.
He also mentioned that the life expectancy of an impeller is in relation
with which region of the globe you are sailing.

In article , wrote:
In the late seventy Yves Gélinas "Jean-du-Sud around the World" used a towed
generator.
The electrical power produced was mainly used to communicate on his short
wave radio.
Every day he radioed his position. Then all of a sudden no more
communication were transmitted by him.
Later it was learned that the impeller on his towed generator had been
chewed to pieces.
When he returned home I talked to him and he stated that the sharks made a
meal of the generator impeller.
He also mentioned that the life expectancy of an impeller is in relation
with which region of the globe you are sailing.

Unless the impeller is perfectly balanced there'll be some 'wobble' and
therefore vibration. I wonder if this is similar to the 'creature in
destress' vibrations that sharks pick up? ... maybe someone could patent
this as a lure for shark fishermen!

Justin.

--
Justin C, by the sea.

Towed generators are practical for working sailboats. It is free
energy and they have usable output.

BUT.

1. Most sail boats spend over 95% of their time at a dock or at
anchor. The towed generator is useless then.
2. If you are motoring it is an extremely expensive and inefficient
way of generating power. Put an extra alternator on your engine and
gain a 500% increase in efficiency and a fraction of the installation
and maintenance cost.

wrote in message
...
On Fri, 04 Jan 2008 20:14:09 -0800, Gordon wrote:

Any recommendations?
Gordon

Think about it this way. If the generator is 100% efficient, then to
generate 746 watts, one horsepower must be provided. Imagine a dinghy
with a one hp engine pulling your boat backwards and you get a sense
of practicality. In practice, two or three hp is probably closer to
what the effect might be.

So there is plainly an upper limit to the amount of power a towed
generator can realistically provide to a small sailboat.

Small sailboat? So, probably a 12 volt battery..
746 watts is 62 amps at 12 volts-far too much for your battery.
Certainly there is an upper limit to the power you can get, but there should
be no problem in getting quite enough to power up anything you have aboard a
small sailboat.

"Edgar" wrote in
:

Small sailboat? So, probably a 12 volt battery..
746 watts is 62 amps at 12 volts-far too much for your battery.
Certainly there is an upper limit to the power you can get, but there
should be no problem in getting quite enough to power up anything you
have aboard a small sailboat.





Lionheart, my friend Geoffrey's Amel Sharki 41 has a Perkins 4-108 with
freewheeling hydraulic transmission and a shaft alternator that produces
about 25A of 12V power at 7 knots, about as fast as she'll go. It still
produces 15A at 6 knots, but drops off rapidly below 5 knots as the load
stalls it. There's a large wheel on the shaft about 6" behind the
transmission turning about a 3" wheel on the specially-designed-to-turn-
slowly alternator, which I think Motorola made. It's not self-exciting
and requires 12V, switched by a key in the control panel where the
ammeter shows you how we're doing. This key is on a welded ring with the
engine key and locks itself into the panel until you turn it off. This
prevents even the stupidest amoung us from running the shaft alternator
when the engine is running, which the instructions say will destroy it.

The key to all this is that transmission that allows the shaft to
freewheel without destroying the transmission.

Larry
--
Next time some broker tells you what a great investment he's selling,
ask him about Rhodium, a shiny metal used in Catalytic Converters.
Jan 1st 2004 2005 2006 2007 2008
Rhodium $452 $1341 $3006 $5339 $6775 PER OUNCE!
How much longer can we pay for new cars at this rate?
Feb '97 it was $182/oz