Re: Treadmill Motor / Generator in Air ( PART 2 ) (3.00 / 0) (#16) by CmeBREW (smke833f@hotmail.com) on Mon Apr 2nd, 2007 at 08:23:58 PM MST (User Info)

Thought I could mention one more thing about controlling this small windmill in very high winds before this post goes away. We have had several VERY windy days so far this spring. (40-50mph+) What I do now is, I hook one of those little 12vdc car heaters (200watts) directly (NOT thru the batts) to this windmill in these high winds and it controls it very well-- after the batteries are full.  You have to run a separate wire to the little fan in it though, or the voltage drop (down to around 6-7 volts) at the heater will blow out the transistor in the brushless fan. (which I unfortunetly did) I had to temporarily rig another little 12vdc fan (2watt) on the top. Later, I will make a better set-up with more heating elements. I'm going to do many 'on-off' switching type experiments, to try and get more heat. Its pretty cool - I actually get some decent little heat coming out of that little $15 200watt heater in high winds.  I just got my xantrex C-60 controller - so this little heater will be the dump load for it  now. I can't wait to hook it up, since its been a pain in the neck always watching the battery volts and turning on my TV in the middle of a windy night! When the 12vdc heater is hooked to the generator directly the blades turn only about 120rpm in about a 20mph wind. (under 20mph they stop) They turn only about 300rpm in a 30mph wind. But at about 35mph-40 they really take off and spin up fast to about 800-1000rpm (guessing) and then heat comes out of the heater until the high gust goes back down below 30mph. But it is still noticably controlled. It don't spin too much out of control like before. Thought I would just mention these recent facts. I can finally sleep at night. Also, one more thing about this Down-wind type generator I made. It has a very difficult time making a complete 180 degree turn in the lower winds. This has happened several times now- where I had to go on my roof and turn it 180 degrees around. Sometimes, the wind blows all day from the main direction, but at night there is NO wind, and the next day the wind starts up in exactly the opposite direction. My Yaw axis (pole inside the bigger pole) is not as easy to turn as I would like. 4 blades would certainly help it in the low wind turns, Or a 6 foot rotor would have alot more leverage with a bigger, better generator. Of course, after the rotor is turning it easily stays with the direction of the wind. Also, it seems to me that furling a downwind generator is extremely difficult other than the more difficult variable pitch blades. You can make it furl up or sideways - but it would take a spring and damping air cylinder which I'm not going to even mess with.(sounds like a headache to me) Rather,  I'm going for the variable pitch blades on my next bigger alternator.(6') Later friends! [ Parent ]

Treadmill Motor / Generator in Air ( PART 2 ) | 16 comments (16 topical, 0 editorial)

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