DIR Return Create A Forum - Home
---------------------------------------------------------
Lynx Wind Forum
HTML https://lynxwindforumhtml.createaforum.com
---------------------------------------------------------
*****************************************************
DIR Return to: Wind Power
*****************************************************
#Post#: 2840--------------------------------------------------
Re: Diy75 Re-Build
By: nessprojects Date: May 20, 2014, 8:40 pm
---------------------------------------------------------
Think I have to eat humble pie at the moment....
Decided to do a complete check on the electrical sections of
this turbine....Bridge rectifier was good under load.....12.6v
fed directly to pma came out good and gave a reading of 1.18A
calculating to 10.68 ohms.
Gave the pma another speed check (using a drill connected
directly to shaft and a laser rpm counter) at which it starts
charge at 195rpm...so far so good. Now it went down hill from
here....at 700rpm the battery got to 15.3v at 1A hence only
15.3W (not so good). Think this is only good for 20W ???
Think you were correct about the magnets being no good and not
being beefy enough lynx....My apologies.
Think I need to either beef up the magnets (Curtin becomes a
problem) or a smaller blade/rotor and stick with a trickle
charger. ;D Hmmmm.
#Post#: 2879--------------------------------------------------
Re: Diy75 Re-Build
By: lynx wind Date: May 22, 2014, 8:22 am
---------------------------------------------------------
I am not sure I understand. The cutin at 195 rpm sounds good.
Battery going to 15.3 volts would take a lot of power not 15.3 X
1 amp. To get a battery to rise to 15.3 volts is really tough.
Maybe its a small battery but still if I put 150 watts into a 12
volt marine battery I might get to 15 volts.
Did you measure the actual amps going through the battery or was
it calculated.
My small 20" diameter turbine will go up to 1100-1200 rpm in
good winds so your 700 rpm isn't out of the question.
#Post#: 2880--------------------------------------------------
Re: Diy75 Re-Build
By: nessprojects Date: May 22, 2014, 9:20 am
---------------------------------------------------------
@Lynx
Battery was an old 43ah car battery which is not in the best of
health. (was going to stick my de-sulfator on it to see if I
could bring it back to life)
The current was measured on a multimeter with a separate
voltmeter across the battery. Readings were taken at the same
time.
another test I did was to put a voltmeter and a 21w 12v lamp
direct across the rectified side of the pma (No Battery's). I
spun the pma to 500rpm and got a reading of 6v across the lamp
at 1.12A draw.
#Post#: 3919--------------------------------------------------
Re: Diy75 Re-Build
By: nessprojects Date: July 19, 2014, 4:28 pm
---------------------------------------------------------
Update...
Well I think I know what's going on with this re-build now. Due
to the chord size of this turbine the TSR is pretty much rising
to about 1.5-1.7 instantly. Quick tests have shown this to be
the case way down to about 3 MPH winds....This also accounts for
the fact that I could not get it to run faster than about 450
RPM in 30 MPH winds.
Due to the fact that the alternator is weak this thing is just
free-wheeling essentially. I have fitted 2200uf caps in the
booster to try and load this thing as much as possible to try
things out.
I thought it was not getting out of drag mode....turns out it
was never in drag mode, it was in lift mode all the time !.
Further confirmation will be carried out and posted in the
Arduino topic once the hardware and software is complete.
#Post#: 3920--------------------------------------------------
Re: Diy75 Re-Build
By: lynx wind Date: July 19, 2014, 8:03 pm
---------------------------------------------------------
Very Interesting. Reminds me of the Miller Rotor. It's just
two blades and runs extremely fast with it's small diameter.
#Post#: 3952--------------------------------------------------
Re: Diy75 Re-Build
By: nessprojects Date: July 23, 2014, 7:55 pm
---------------------------------------------------------
Not had much in the way of winds lately but the turbine is
starting to charge at about 100 Rpm with a TSR on average of
about 1.2-1.4 using the 2200uf caps in the booster. The turbine
reaches cut in without booster at about 200-220 rpm but can only
get to a TSR of about 1.7 so it needs a good headwind to charge
by itself.
Concrete foundations have gone in today for the new tower down
the field but with the unusual 22 degrees C heat we had it made
it real hard work mixing 1/4 ton of concrete by hand, I did
enjoy a ice cold can of lager after though. ;D
#Post#: 4009--------------------------------------------------
Re: Diy75 Re-Build
By: nessprojects Date: July 29, 2014, 6:22 pm
---------------------------------------------------------
My re-build has had 6 new 1" x 2" magnets fitted.....Now she
starts charging a 12v battery at about 100rpm without any
booster and feel this could be dragging it down a little much.
This could be a good candidate now to build a buck system and
get that RPM back up.....we will see what happens.
#Post#: 4012--------------------------------------------------
Re: Diy75 Re-Build
By: nessprojects Date: July 29, 2014, 7:26 pm
---------------------------------------------------------
Well Sort off....This is the re-build so the diameter was
brought down to 24" and the blades were 22" total, The coils I
think had about 400 Turns @ 3 number. About 11 ohms total.
Blades were just 6" x 1" cut down as in a previous post.
It only had 1" diameter magnets before and used to cut in around
220 Rpm. Not sure on how good this thing is just yet but it is
just a kind of test model anyway.
I have seen about 10w today but it was suffering with a little
turbulence with a 15 mph wind.....Early days.
I might just add that the exact magnet sizes are 50mm x 25mm x
10mm.
#Post#: 4014--------------------------------------------------
Re: Diy75 Re-Build
By: Otis Date: July 29, 2014, 11:24 pm
---------------------------------------------------------
Wow. What did you used to see, watt wise, in those conditions
with your earlier magnets?
#Post#: 4015--------------------------------------------------
Re: Diy75 Re-Build
By: sut Date: July 30, 2014, 6:57 am
---------------------------------------------------------
Nice ! I had always thought that your magnets should be as thick
as your coils and the center coil hole should be as big as your
magnets to get the most out of the alt .
The other day I removed the piece of wood that sticks outside
of the 2 wings (upper and lower wing on rotor ) and made it
flush with the side to see what if anything will happen .
*****************************************************
DIR Previous Page
DIR Next Page