6.5" JR VSs Star.

[Jerry]

I tested the 6.5" dual rotor alt today. Once with the star stator once with the JR stator.

Todays testing was done at a 24 volt battery load. I had spun the star stator by hand and saw about 30 volts. From that I decided 24 volt testing would work.

I checked the wave form on the O-scope and it is indeed a very smooth sine wave.

Flux I think you had sugjested that JR (Jerry Rigged) would be a littel more eficient at cutin and it was. Then star and JR stayed prety neck and neck most of the mid point and star pulled a littel ahead at the top speed test.

However I took temperature readings and here's how the #s came out.

 1 amp JR 69.4 %, star 1 amp 71 %  

 4 amp JR 69.3 %, star 4 amp 75.1 %

 7 amp JR 74.8 %, star 7 amp 85.5 %

 10 amp JR 94.4 %, star 10 amp 105.3 %

 12 amp JR 131.3 %, star 12 amp 143.6 %.

Star was running about 10 degrees hotter and was starting to climb at the end of my test.

This was with useing round coils and round magnets.

I think most of the time either rectangle or wedge shape magnets and coils are used.

Those coil and magnet shapes produce more of some variation of a square wave.

In those casses the eficentcy and heat diferances a very pernounced between star and Jerry Rigged.

But even in this test star just runs hotter.

I think the next test alt will be the Hugh Piggot 4ft alt. I purchased the 4 ft Hugh book from our hosts but my wood blade carving guy has it now.

As I recal the magnets are the 1"X2"X1/2" and it is wound with 85 turn of 16 gage per coil. I can't remember if the coils are wound rectangle to match the magnets or wedge shape?

At any rate I will wind the with 2 in hand 19 gage. 19 gage is half the circular mills of 16 gage.

This will allow for star or Jerry Rigged within one stator. I might even get fancy and try a relay switching scheem between the 2 formates.

That would be very exciting to see the diferances between Jerry Rigged and star at a flip of a switch.

I think it will be somewhat more complex then the delta-star switch.

I may try it though, I have tuns of high amperage relays.

As you said Flux the wave form has a big influence on these tests.

It may be a while till I get the next test alt built?

                          JK TAS Jerry

[Flux]

Well done Jerry, great work.

Your results are fairly similar to what I found. I used rectangular magnets but the spacing was such that it gave a reasonable sine wave.

Your temperature tests are very interesting, that is one thing that I didn't look at.

It would be interesting to compare temperature with delta but I think you have wound your coils for parallel connection so you can't do it unless you wire coils in parallel and that is sure to cause trouble. I think your method causes less heat because the conduction angle can extend beyond 60 deg, whereas star is fixed at 60 by the rectifier operation.

Hugh's coils are rectangular.

Flux

[scottsAI]

Hello Jerry,

Nice work.

JR to Y is simple.

One double pole single throw relay/switch should do it.

One side of Coil A to both poles..

Coil B to one of second contact.

Coil C to other of second contact.

When switch is closed, is Y, open is JR.

Closed, the most neg will be battery neg, most pos will be battery pos.

Works, Open no conflicts..

I think there are 6 coils, each coil has one 180 deg opposite, they are of the same pole.

So tie together as Y in series or parallel. (or use a switch to series parallel them)

Might be best to use Two relays as two separate Y's, then easy, to switch to JR.

Have fun,

Scott.

[Jerry]

Hi Scott.

Thanks for the idea. Could you post the schematic for this?

Thanks for your hrelp.

                     ( Get rid of the Heat. )

                           JK TAS Jerry

[scottsAI]

Jerry,

Drawn as 6 coils which are two sets of Y's.

Odd coils are Y1,

Even Y2.

Off is JR, On must be Y.

The two sets of switches should be switched together.

Lets see how my first picture comes out.

Well that did not work, here is the link:

http://www.otherpower.com/images/scimages/3276/Yjr1.jpg

Have fun,

Scott.