Opposing single phase help!

[LEXX]

Hello, I need some help with opposing single phase windings, this (badly drawn) picture is my proposed plan, I know, 3 phase is more efficient but it is an experiment.  also, how do you change pic sizes?  Sorry for how big this one is by the way.



By my way of thinking this should work quite well, but that rarely means too much.  Thanks for any help,

LEXX

[Victor]

  You are showing the coils over the north and south poles wound in the same direction this will not work, also there is no need to wind alternate poles seperatly.

 If you wind all the north poles cw and the south poles ccw they can just be in one series string. Note that all of the coils can be physically wound in the same direction and just connected so that they are effectively in opposite directions.

 In your drawing if you broke the left side connection  from red to black and connected the center red  and center black then used the left side red and the right side black to the bridge you would be ok.

Victor

[LEXX]

"Note that all of the coils can be physically wound in the same direction and just connected so that they are effectively in opposite directions."

At the end of my run of black i connect to the end of the red run, this should be the exact same thing shouldn't it?

"In your drawing if you broke the left side connection  from red to black and connected the center red  and center black then used the left side red and the right side black to the bridge you would be ok."

What would you gain by doing this?  Wouldn't that simply even out your voltage?

Thanks,

LEXX

[Flux]

Lexx

Let's try to explain it another way, I know you are dealing with ac, but if we think of an instant in time when the voltage is not zero we can consider it as dc.

Let's assume that the coils are all wound the same way as you have shown, and also assume that the coils under the N poles produce a voltage that is + on the start and  - on the finish.

The coils under the S poles will have opposite polarity, i.e. the starts will be -  and finish +. Like batteries the + of one must join the - of the next for the volts to add.

It is usual to reverse the connection to coils under alternate poles to get this, but you can also add all the coils under N poles by joining start to finish and add all the coils under S poles in the same way.  You will now have the equivalent of 2 strings of batteries of the same voltage. You now need to add them together with + going to -.

That is why Victor is telling you to swop the ends of your red coils in relation to the black ones.

The starts of your red coils are of opposite polarity to the starts of the blacks, so at that point you need to change the sequence and join start to start.

I hope that by thinking of the polarities of the coils under N & S poles you can see it better.

Flux

[tecker]

   I take it your not getting a high enough voltage form your coil winding to give usable voltage from the unit as it is . That's the way it is . As it's drawn you have to seperate phases to use Rectifiy seperatly and retest.

[LEXX]

"The starts of your red coils are of opposite polarity to the starts of the blacks, so at that point you need to change the sequence and join start to start."

Hey Flux, please take another look, that is exactly what I did.  I kniow I'm pretty new at this so please bear with me.

Thanks,

LEXX

[Flux]

Lexx

I apologise, you are quite right, I read victors comment and didn't look at your drawing close enough.

As shown it should be ok, teach me to look properly next time.

Flux

[Ungrounded Lightning Rod]

That will just cut his voltage in half.  (A little more, since the diode drop will eat a higher percentage of the lower voltage.)

[Victor]

 Lexx

   You are correct Mea Culpa

 Victor

[Victor]

Lexx

 It is still not nessasary to encircle the stator twice, this only increases the resistance

Victor

[tecker]

  He hasn't said what's

 in or out the two phases are his only option if I interpret the drawing correctly you can hang three or four full wave rectifiers on each leg and the

 voltage drop will be negligible .  Just tie the Y in and phase it  ( riight hand rule for max output )

[LEXX]

Why would this increase resistance?  There would be the same amount of wire either way.  Also, when wiring for three phase why does everyone (most people on this server) use a 12/9 setup, is this more efficient than 16/12 because of extra coils (should be the same amount of wire if not less) or extra magnets therefore less watts per dollar?

Thanks,

LEXX

[LEXX]

What is the right hand rule?

Thanks,

LEXX

[tecker]

  Here's alink for ya

   http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/rthnd.gif

[LEXX]

Thanks tecker, how does this help??  If a person is using AC with only two leads, it should just attach to the B rectifier?

Confused,

LEXX

[Flux]

It doesn't increase the resistance, if you find it easier to do it that way, that's fine.

As for the other question about 3 phase, it depends on the number of magnets you want to use and the power you need.

The 12/9 arrangement works out nice for the common size magnets to fit a disc about 11 or 12" dia. This for convenience can be a brake disc.  The output suits an 8ft prop.

If you need more output, say for a 12ft prop, to keep efficiency up, you need more magnet material. As the speed is lower on bigger machines it makes more sense to increase the diameter and use more of the same magnets, hence 16/12  or 20/16.

Also to answer another point, your drawing is for a single phase machine, you only need one rectifier. It can not be connected 2 phase with the coil and magnet layout you have.

[tecker]

Take a look at this post .The illistration by ED might help more than my explaination

  When one phase is positive the other is negitive so you have two seperate phases . The Y is already connected .Connect each phase to the  two full wave rectifiers instead of three . Let me know if this gives the power you need.

http://www.fieldlines.com/story/2004/5/31/22477/2482

[tecker]

 

   You really will be a single phase connection but you have a y connection in your drawing and so I think this is what your after . As for the righthand rule this comes in two play with tha position of the magnets and the rotation of the rotor with the direction the coils are wound  it looks like they are clockwise .If you are using a dual rotor design it should not matter.