On Tue, 28 Jul 2009 19:05:22 GMT, (GregS)
wrote:

There are problems with everything.

Backwards. To some people, everything is a problem.

Here is what is being done tomorrow.
http://www.hydrogreenenergy.com/technology.html
greg

Thanks. I didn't know about that one. The usual problem with
submerged turbines in rivers is keeping rubbish, fish, swimmers,
critters, and debris out of the turbines. I don't see any filters,
sediment traps, diverters, grills, etc. I prefer to filet my fish
myself, not to have it done by a turbine. Mechanical feathering for
high flow flood conditions also needs to be addressed. Despite these
problems, hydro has some huge advantages. Of all the common
technologies, it's the cheapest and also the cleanest.

Now I'm feeling awfull about all the nice big DC motors I,ve thrown away.

Last year i trashed a big comp tape drive, so i know that feeling.
But one would not get me far anyway, i need quite a few.

Bart

In article ,
Arfa Daily wrote:
Read the previous response, where he says that the commutator does not
switch (windings).

OK. I see what you're getting at. There did seem to be a couple of
statements slightly at odds with one another, one of which you didn't
include. However, the two lines about his VW generator producing DC
without diodes which you did include, is a perfectly reasonable
statement, and your response to it implied (to me at least) that it is
not ... Maybe just one of those 'linguistic' things ... d;~}

You need to read the context of the posts. Mr Liebermann originally didn't
realise the commuter in a dynamo does the same job as diodes in an
alternator.

--
*Why is the man who invests all your money called a broker?

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
Read the previous response, where he says that the commutator does not
switch (windings).

OK. I see what you're getting at. There did seem to be a couple of
statements slightly at odds with one another, one of which you didn't
include. However, the two lines about his VW generator producing DC
without diodes which you did include, is a perfectly reasonable
statement, and your response to it implied (to me at least) that it is
not ... Maybe just one of those 'linguistic' things ... d;~}

You need to read the context of the posts. Mr Liebermann originally didn't
realise the commuter in a dynamo does the same job as diodes in an
alternator.

--
*Why is the man who invests all your money called a broker?

Dave Plowman London SW
To e-mail, change noise into sound.

I don't think it was Jeff who said that ... ?? Mr Nebenzahl maybe ? The
post is getting a little scruffy in construction here and there. Anyway, if
replying to specific comments, these should still be included or properly
referenced in the reply. You can't rely on people remembering things that
have been said further up the post, particularly when some responses may not
even appear to some people due to filters that they have in place for all of
the crap that finds its way onto here now. Whatever, the couple of lines
that Sjourke did see fit to copy to his response, were valid, and his
comment seemed to laugh at them as being wrong, at least to me. Anyway, I
don't wish to argue with either of you. I've got more important things to
do. If I misunderstood anybody's responses or posts, then I apologise.

Arfa

In article ,
Arfa Daily wrote:
You need to read the context of the posts. Mr Liebermann originally
didn't realise the commuter in a dynamo does the same job as diodes in
an alternator.

I don't think it was Jeff who said that ... ?? Mr Nebenzahl maybe ?

A thousand apologies to Mr Liebermann - you're right. Put it down to a
senior moment. I'm getting rather too many of those recently. ;-(

The post is getting a little scruffy in construction here and there.
Anyway, if replying to specific comments, these should still be
included or properly referenced in the reply. You can't rely on people
remembering things that have been said further up the post,
particularly when some responses may not even appear to some people due
to filters that they have in place for all of the crap that finds its
way onto here now. Whatever, the couple of lines that Sjourke did see
fit to copy to his response, were valid, and his comment seemed to
laugh at them as being wrong, at least to me. Anyway, I don't wish to
argue with either of you. I've got more important things to do. If I
misunderstood anybody's responses or posts, then I apologise.

It does get a problem when trying not to just hit reply and quote and fill
the group with unnecessary data. I think any post you have to scroll down
is too long. ;-)

--
*'ome is where you 'ang your @ *

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 29 Jul 2009 08:24:07 +0100, "Dave Plowman (News)"
wrote:

In article ,
Arfa Daily wrote:
Read the previous response, where he says that the commutator does not
switch (windings).

OK. I see what you're getting at. There did seem to be a couple of
statements slightly at odds with one another, one of which you didn't
include. However, the two lines about his VW generator producing DC
without diodes which you did include, is a perfectly reasonable
statement, and your response to it implied (to me at least) that it is
not ... Maybe just one of those 'linguistic' things ... d;~}

You need to read the context of the posts. Mr Liebermann originally didn't
realise the commuter in a dynamo does the same job as diodes in an
alternator.

That wasn't me. If it had been me, I would have:
1. Insulted the original author.
2. Complained about the lack of editing quotes, excessive brevity,
lack of information, lack of writing skills, excessive cross posting,
improper formatting, or various combinations.
3. Explained exactly how things work, even if I were wrong.
4. Supplied URL's to sites that agree with my conjecture.
5. Supplied irrelevant but interesting URL's on related subjects,
such as one does not need a commutator or diodes to generate DC:
http://en.wikipedia.org/wiki/Homopolar_generator
6. Supplied a marginally relevant and occasionally entertaining story
from my checkered past[1].
7. Supplied a contorted footnote vainly attempting to either remain
on topic, or somehow partially connect my statements with
sci.electronics.repair.

Since the original allegation does not in any way resemble my standard
style as itemized above, it obviously was not my posting.


[1] Expanding on my college wind generator project.... I went to Cal
Poly Pomona, which believes in "Learn by Doing" which I ammended into
"Learn by Destroying". My degree was in "electrical and electronic
engineering" which at the time involved several classes in motors. One
class was divided into random groups of 4 students. The instructor
then asked "Who has an old automobile generator laying around"? Like
a complete idiot, I raised my hand and our groups was instantly
sentenced to 3 months of hard labour building a wind powered generator
around it. It was suppose to be the reference or worst case design,
as everyone else was allowed to use alternators or PM motors. Ours
worked, sorta. To get enough wind, it was installed in the bed of a
pickup truck, and driven at unsafe speeds down the freeway. A traffic
ticket was avoided by promising never to do it again. That worked for
our group, but failed miserably when some of the other groups had the
same idea. Another lesson learned was that plywood propellers tend to
self destruct at about 50 mph.


"The basic assumption of the repair business is that previously it
actually worked properly. Anything else is re-design or engineering".
(Me after fighting a losing with some piece of badly designed junk).

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

In article ,
Jeff Liebermann wrote:
You need to read the context of the posts. Mr Liebermann originally
didn't realise the commuter in a dynamo does the same job as diodes in
an alternator.

That wasn't me.

Indeed - I'm sorry. I apologised in a later post.

--
*I have a degree in liberal arts -- do you want fries with that

Dave Plowman London SW
To e-mail, change noise into sound.

"Bart Bervoets" wrote in message
...

If you look on ebay you'll see many used treadmill PMDC motors
sold for this use.

Yes, so i now noticed, there are some solutions but alas a bit bulky.
I did some research already and have experimented with car alternators,
i got so far i can make one that charges at 400rpm but the wind is
too unpredictable and the field coil needs to be energized all the time
which drains your battery in dead moments, rather a pm alternator as
suggested as i don't feel much for having to build a dynamo from start,
but hey, if i have to...
But i did buy some motors on ebay as suggested, they are treadmill
motors.
Someone else suggested the use of a motor off an electrical bicycle,
benefit is that it's weatherproof.
I just thought someone here could sell me some instead
of on eekbay.
What i would like is an easy off the shelf solution, but i can see
that there isn't really one.
Thanks everybody for the input on this.

Bart


You can find them on Sam's Club website 400W for $600

he
http://www.thebackshed.com/Windmill/assemblyMini1.asp
and better i think:

http://hackedgadgets.com/2008/12/05/...ind-generator/
http://www.watchtv.net/~rburmeister/smart.html
http://www.yourgreendream.com/diy_fp_remove_from_wm.php
http://www.ecoinnovation.co.nz/p-349...and-shaft.aspx
http://www.ecoinnovation.co.nz/p-348...and-shaft.aspx

Alain


"Bart Bervoets" a écrit dans le message de news:
...
Does anyone have any large permanent magnet motors that could be used to
build a few micro wind turbines?

Bart Bervoets

On Mon, 10 Aug 2009 23:12:36 +0200, "Alain" wrote:

he
http://www.thebackshed.com/Windmill/assemblyMini1.asp
and better i think:

http://hackedgadgets.com/2008/12/05/...ind-generator/
http://www.watchtv.net/~rburmeister/smart.html
http://www.yourgreendream.com/diy_fp_remove_from_wm.php
http://www.ecoinnovation.co.nz/p-349...and-shaft.aspx
http://www.ecoinnovation.co.nz/p-348...and-shaft.aspx

Alain


"Bart Bervoets" a écrit dans le message de news:
...
Does anyone have any large permanent magnet motors that could be used to
build a few micro wind turbines?

Bart Bervoets


Never tried it, but the brushless outrunners used e.g. in model RC
planes might work, specially high KV units (hi torque, low rpm).
Basically these are 3 phase stepping motors, but with some rectifying
it could owrk. And they are getting rather cheap too.