New Larger Diameter single rotor 8 foot wind genny

[Devo]

I had the remnants of this old dual rotor genny around

I decided to try a larger diameter single rotor as I had the discs & stuff around anyway.

Here is the frame reworked to bolt the stator from the inside & furling added

Here are the Blades , the tail is to short I will extend it later

The new rotor 16 1x2x1/2" neos

This ststor is wired so each inividual coil can be tapped & all 6 leads come out for the 3 phase winding , I set it up with a 3/8" air gap & wired each phase into a rectifier this gave me 5 volts at 120 rpm. Wiring it in star using the regular 2 rectifiers at the same speed gave me 4 volts at the same rpm. I am using #15 mag wire about 54 turns per coil 1 in hand. There is lots of extra space so I could go 2 in hand or to 4 or 5 phase but I will try it as is for now

I will get it all assembled & post results.

Also a while back someone (I think coldspot) asked for a picture of art's 8 foot blades here it is

Devo

[electrondady1]

whip it good devo !
i am interested in what your building.
do you recall what sort of power you were getting with the old configuration ?
i posted a question last month about the same thing , it's an idea that won't go away

http://www.fieldlines.com/story/2006/6/11/1896/64818

please post some comparative numbers if you are able.

[electrondady1]

http://www.fieldlines.com/story/2006/6/11/1896/64818

[Flux]

From your stator picture you seem to have wasted most of the winding space. You could have squeezed much more copper into those coils until the outsides touched.

[Flux]

"I set it up with a 3/8" air gap & wired each phase into a rectifier this gave me 5 volts at 120 rpm. Wiring it in star using the regular 2 rectifiers at the same speed gave me 4 volts at the same rpm. I am using #15 mag wire about 54 turns per coil 1 in hand."

What do you mean by air gap with a single rotor. If you have 3/8" between magnets and stator you will not do any good.

I presume your first connection is with a single phase rectifier for each phase ( Jerry rig), if so there is something very wrong with your star connection.

Flux

[Devo]

Flux- I did a quick test with a large air gap before assembly(3/8") & yes the first was "jerry" rigged , for star I hooked the 3 inputs together & used the three outs into 2 rectifiers.

This is just a test to see how the output is on the larger diameter as the magnets will be moving faster & assembly is much easier.

I may rewind another stator 2 in hand to get more copper/better efficency.

Devo    

[Flux]

If you used a 3/8 gap between the rotor and stator you would have little flux and what there is would be in strange places. This combined with the thin coil legs would account for the failure to get a reasonable result with star.

Your voltage waveforms will be strange to put it mildly and the two phases will not add in star.

Run it again when you can get the air gap down to a sensible figure.

Single rotor designs are not effective unless the stator is virtually touching the magnets and the stator is thinner than the magnet length.

Get everything right and you might manage to match an 8ft prop with 16 magnets but you will need to use all available winding space and get the turns about right.

Flux

[Devo]

I have it all together on the test tower , you were right Flux once the magnets got closer the output voltage between Star & each coil rectified individual evened out at low rpm. Both cut in at about 200 rpm but star puts a litlle more juice into the battery at low rpm (wish I had a way to test high rpm)

Right now it's on the tower wired in star putting between 2 & 10 amps into the battery.

I will post a picture of the completed unit later tonight.

I may do a rewind with either 2 in hand or go to more phases.When you go 3 phase you multiply 1 phase by 1.73 what do you multiply by for 4 or 5 phase?

Devo

[Flux]

You are still low in star because of the poor wire use. you are not making much use of the 1.73 that you should see.

"I may do a rewind with either 2 in hand or go to more phases.When you go 3 phase you multiply 1 phase by 1.73 what do you multiply by for 4 or 5 phase?"

4 phase is 2 phase with a second added 180 deg. Opposite coils will add to give 2.

Coils at right angles will add as 1.4 assuming you use a star point.

5 phase will again have 2 voltages, the coils at 144 deg will add as 1.9 , the ones at 72 deg will give something below 1.4.

With 4 or 5 phase it is unlikely that conduction in the rectifier will change with load but if you load enough you may get some contribution from the lower option.

With 6 phase, diametric coils give 2 and coils at 120 give 1.7 as for 3 phase .

6 phase has a characteristic that starts with the higher voltage mode but with significant load the second voltage starts to have effect. At high loads the thing effectively behaves as parallel 3 phase.  You have a lower cut in but over most of the range it is more like 3 phase. This should match the wind a little better.

Efficiency is marginally worse than 3 phase but since we throw efficiency out the window to try to match the prop it may not even be an issue. I built a machine with the option of using it 6 phase or parallel 3 phase but when I found the lower efficiency I cut the link between the 2 star points internally. I wish I had brought the link out and tried both options, I think 6 phase may be worth a try and if it didn't work out better then cutting the star link will change it back to parallel 3 phase.

Flux