miniLenz2 with PCB stator

[windstuffnow]

  Another fun Lenz2 project.  Ok it's small and doesn't make alot of power but I'm having fun...

  This one sports a new PCB 4 layer printed stator, has the equivilant of 36 turns per coil, 4 coils per phase.   It can be wired easily in star or delta and is 1/16 of an inch thick.   Their stackable and can be wired in series or parallel for higher amps or voltage.   I've only run it using a single disc, haven't made a dual rotor out of it yet.   With a single rotor it produces 10.78 rpm per volt in star and 16.5 rpm per volt in delta.  Below is a picture of the printed board.

The miniLenz is a simple 2 sq ft machine measuring 16" tall and 18" in diameter shown below...

It does about 7 watts in a 15 mph wind charging a 12v battery at 14 volts.  It does a little better in delta.  Laid out for an 8" disc using 16 magnets.

If your interested in experimenting with one I can have them made up but their not exactly cheap.

I figured I'd share some adventures during the evolution... Fun stuff !

.

[stephent]

Nice...

neat and orderly.

You come up with some of the neatest ideas!

What do you think the trace amp limit is?

[ghurd]

Too cool!

Overlapping coils next?

Have you seen the PCB rotors in some motors, like certain brushed Kollegens?

G-

[Countryboy]

This is definately an interesting way to approach things.

Commanda did a topic not too long ago about DIY printed circuit boards.  If someone drew up a pattern with CAD, this may lower the cost of PCB's for folks since they know how to make a PCB.

[skyking01]

Excellent work Ed. Your craftsmanship is really of high quality.

Skyking01

[wayne]

Hi Ed

Very nice work like always and clever. Just wondering the current limit for the PCB stator. What would the resistance be for one phase. Sure saves time winding coils.

Good Job

Wayne

[dinges]

I doubt the making of 4-layer PCBs will ever really be DIY, but sure is a nice project. Like others, I'd be interested in hearing what the internal resistance of a coil and phase are.

Also, for outside use, I think I would coat in an extra layer of epoxy; don't think I would trust the green coating to be sufficient protection against the weater.

Where and how did you have the PCB made, and was it expensive? Do they make single PCBs, or did you need to order an entire series?

36 windings is already a lot, but, why stop at a 4 layer. Put 2 prints on top of eachother. Or 3. Or...

Might be a good way to make use of small and weak magnets, since airgap can be pretty small with these 'self supporting' coils.

[powerbuoy]

Very nicely done, excellent "out of the box" thought process ... how about using strong magnets and sandwiching (stacking) ten PCBs ... should get you 70 Watts ... right?

Powerbuoy

[windstuffnow]

  Hi All,

   The PCB Stator is actually the work of Tom at Embedtec, I just couldn't resist playing with a couple of them.  

    It's actually the first off, Hence the AFPMAS-1.  He's working on getting the resistance down.   These have a resistance of 32 ohm in star and 10.5 in delta so its a bit high for a real power maker.   It does quite well for small applications.  Their definately not cheap... either in cost or the quality of the manufacturing.

    Voltage definately isn't a problem, with the single disc it does 10.78 rpm per volt in star and 16.5 rpm per volt in delta.  Either way it will charge a 12v battery with a small turbine.  I would imagine a dual rotor unit with that small of gap would get the cut in speed in star down to around 30-40 rpm, just a blank disc on the backside would increase the output significantly.   Stacking a pair of them paralleled in delta brings the ohms down to slightly over 5 ohm, 4 of them would end up being around 2.6 ohm.   The second version should come in at a much lower resistance.  

    Lots of fun!

[vawtman]

Ed nice setup there but with direct drive how do you keep the rotors stable to maintain the gap in high winds?Always wondered about that.Thanks and nice design has always.

[windstuffnow]

 Hi Vawtman,

   The magnet disc and wing arms are all attatched to a hub that has bearings installed.  The shaft is pressed into the lower mount.  There is no movement other than rotary even in high winds.  The bearings are quite snug on the shaft.

   I mounted the stator using the center holes on the lower mount so my only concern would be the stator catching the wind and flexing or fluttering if I were to mount it outside.

   .  

[henjulfox]

Ed,

I may be way off base but...

As I understand it, the legs of the coil that pass over the magnet are what generate the electricity. The two ends only carry the power to the next leg, and add resistance.

Would it be possible to make the "wire" of the two ends wider, effectivly making them larger guage, therefore lowering the resistance of the coil?

-Henry

[ghurd]

Not only could the dead 'wire' be larger, the leg 'wire' could taper, filling some of the gap between coils.

It is 2oz? Might be worth it to go up to 3oz?

G-

[Stonebrain]

Hi ed,

If I understand well there are 4 coils on top of each other,

What is the thickness of the cupper compared to the the intermediate

layers?

If the proportion cupper/intermediade layers can be good it's certainly a good

idea for higher power too

Maybe expensif,but what if you ordered some thousenths in China?

neat idea.

Cheers,

stonebrain

 

[richhagen]

Just a comment of support, looks really neat, don't know about the current handling, but would be easy for mass production.  Rich