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Forum Index : Windmills : Question on Lenz2
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| --gt-- Newbie  Joined: 29/03/2010 Location: Posts: 4 |
So finished my LENZ2 and put it out into the breeze. Was pretty happy with how things looked until I started monitoring voltages. I have a 3KVA 48 volt inverter, so started with a smart drive wired in 2X7C, but with some pretty good wind best I could get with no load was 36volts. Obviously not getting the RPM I needed so I changed the stator to 1X14C and reduced the overall diameter of the turbine hoping to get higher RPM, yet I am still lucky to peg 50V and really need more than that to charge my battery pack. Can anybody else with a LENZ2 let me know the stator config and voltage / rpm you are achieving? Not sure if my mill is a poor performer or 48V is just too much to expect. Short Clip of Lenz2 Cheers. |
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Tinker Guru  Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
gt, your expectations of your Lenz2 may be a bit high. I have been dabbling for some time with one, found that high RPM is not a feature of this design. So, if you wish to continue with your F&P and 48V system you might have to consider a geared wind turbine. I am using a 1:6.4 planetary gearbox (out of a Shibura washer drive)and this appears to work. However, keep in mind that a Lenz2 of the size shown on Ed Lenz's article is not very powerful, don't expect too much output. Klaus |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hi --gt-- What stator do you have, a 60, 80 or 100 series? The Lenz2's do have a lot of torque, so Tinkers comments abut using a gearbox are worth considering. I've used gear boxes out of dead angle grinders in the past, they are about 4:1 ratio. Nice looking dog. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| --gt-- Newbie Joined: 29/03/2010 Location: Posts: 4 |
Thanks Guys, will have a look at a gearbox. Was hoping to avoid but I guess its that or a different inverter and I know which is more expensive. Glenn I have both an 80 and 100 series stator. I used the 80 in 2X7C,and 100 1X14C. I didnt consider they would be any different in max voltage? Is one better than the other? In another twist I have have the spine and mount for another stator on the top of the mill (in addition to the one under currently being used), I also didnt think the lenz will drive two stators, but with the decent winds we get it seems to start OK, probably better if I de-cog the stators. Maybe another consideration is to increase my voltage by configuring two stators in series(DC).Not sure if it would work. Cheers, Andrew. |
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gsw999 Newbie Joined: 22/01/2011 Location: United KingdomPosts: 19 |
Hello mate , cute dog, if I was going to build a VAWT ( I trust a Lenz is similar?) Then I would have 4 of these setup to drive one motor through a geared system, then you have a huge blade area ( which could be cheap to make ) also you would only need one alternator. Is it levitated on magnets? this wouldnt be that hard to do and might miake a big difference. i am not interested in giving my hard earned money to corrupt "leaders" to pour down the drain. |
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| itsandbits1 Regular Member  Joined: 13/08/2010 Location: CanadaPosts: 81 |
as you know if you have the specs for the build, the lenz is a low rpm vawt but has good torque up to .6 tsr under load and this is its best output rpm. I don't know what you are trying to design your unit to put out in wattage but you should try to get a wind power calculation done and then build to that sq. ? spec.for your unit. There is only so much power per sq.? at a given wind speed. and then you only get 30% of that with the lenz to put into your alt which is ? efficient. so you may only harvest 10-20 % of the available wind power. find lenz power curve here http://www.usvawt.com/cgi/windpower.cgi">wind power calculater |
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| --gt-- Newbie Joined: 29/03/2010 Location: Posts: 4 |
Thanks for the info, interesting reading. I really should do a bit more math before I start the construction, but I prefer the later :-) I am going to have a look at some voltage doubler type circuits first and see if I can get my charge voltage. After that guess my best bet is to get more scientific and actually do some planning on how to tune. Once again thanks for the info. Cheers. |
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| itsandbits1 Regular Member Joined: 13/08/2010 Location: CanadaPosts: 81 |
Yeah it's a lot of fun seeing what works and where you can mix and match, but always try to play safe and build it stronger than you think it needs. Some have used the counterrotating solution to the rpm but you need to get more power to the alt too; more square meters, I think. |
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| Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Tried the counter rotating idea, would not recommend it. The startup is problematic, gave it away as too much of a hassle. Klaus |
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| itsandbits1 Regular Member Joined: 13/08/2010 Location: CanadaPosts: 81 |
lenz in action " not mine" here is an example of the counterrotating just for fun. It looks a bit complicated to get everything working right. |
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| Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Well, thanks to rather poor camera work its inconclusive if there was *any* counter rotating going on  .
Also, seeing the mechanical details just how the alternator(s) were set up would be far more instructional than showing jittery dials. This guy needs to start filming when the thing is at standstill and then starts rotating in opposite directions before I believe its doing what you said. FYI, mine had a single alternator in between the counter rotating wing shafts, one shaft turned the stator, the other the rotor. AC was rectified on board and taken off via 2 slip rings. Klaus |
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