# A Coil With Taps For Phases ??

R

#### Randy Gross

Jan 1, 1970
0
In response to my post about an anti-cogging core:

Jasen said:
as I understand it he's decribing a setup where there's a magnet
rotating inside a freomagnetic ring and in the gaps between the ring
and the magnet is wound the output coils.
it seems to me that you could use a single continous coil wound around
the core like in a way similar to a toroidial transformer but with the
ends shorted (to make it continuous) and tapped at equal spacing for
however many phases you want.

I'm trying to make clear sense of the second paragraph describing the
stator arrangement. The ring core has the coil wrapped around it in a
continuous closed loop (toroidal), and then tapped equadistantly for
individual phases.

Would these be true phases or taps to siphon off a percentage of the
total voltage induced in the coil?

If they are true phases, how is the common referenced in the closed
loop to complete the circuit for each phase?

F

#### Fred Abse

Jan 1, 1970
0
In response to my post about an anti-cogging core:

Jasen said:
rotating inside a freomagnetic ring and in the gaps between the ring and
the magnet is wound the output coils.
the core like in a way similar to a toroidial transformer but with the
ends shorted (to make it continuous) and tapped at equal spacing for
however many phases you want.

Similar to a "Gramme ring armature", sort of "Gramme ring stator"?

Should work
I'm trying to make clear sense of the second paragraph describing the
stator arrangement. The ring core has the coil wrapped around it in a
continuous closed loop (toroidal), and then tapped equadistantly for
individual phases.

Would these be true phases or taps to siphon off a percentage of the total
voltage induced in the coil?

Yes, it's just an ordinary alternator with the coils around the stator,
rather than in slots. Not as efficient, because the outside part of each
coil doesn't cut much flux, but a multiphase alternator nonetheless.
If they are true phases, how is the common referenced in the closed loop
to complete the circuit for each phase?

You don't need a common in a multiphase system. If the system is balanced,
there's no current in it. What I think you are describing would be a mesh
configuration, aka. delta or mesh if there are three phases. You could
always break each tap and rewire, if you want wye (star).

R

#### Randy Gross

Jan 1, 1970
0
Fred Abse wrote:

Yes, it's just an ordinary alternator with the coils around the
stator, rather than in slots. Not as efficient, because the outside
part of each coil doesn't cut much flux, but a multiphase alternator
nonetheless.

[email protected]

I can see why the design is obsolete and, I agree on the efficiency.
The alternator will produce less than the potential output.

rg

J

#### John Popelish

Jan 1, 1970
0
Randy said:
In response to my post about an anti-cogging core:

Jasen Betts wrote:

the core like in a way similar to a toroidial transformer but with the
ends shorted (to make it continuous) and tapped at equal spacing for
however many phases you want.

I'm trying to make clear sense of the second paragraph describing the
stator arrangement. The ring core has the coil wrapped around it in a
continuous closed loop (toroidal), and then tapped equadistantly for
individual phases.

Would these be true phases or taps to siphon off a percentage of the
total voltage induced in the coil?

If they are true phases, how is the common referenced in the closed
loop to complete the circuit for each phase?

There is one detail that I missed up to this point, when the stator is
an iron ring wound like a toroidal inductor. I think, that at each
node where you take off a connection, the coil has to change direction
of wind. Think about it and see if you can figure out why.

By the way, I intend to make a generator like this as a demo for a
high school science class. I like it, because it can be made very
skeletal so that all parts are visible. If I am wrong about the
winding direction, I will have to cut the ends and reverse wire them.

Got some nice curved neodymium magnets to energize the rotor coming
from Ebay.

R

#### Randy Gross

Jan 1, 1970
0
John said:
There is one detail that I missed up to this point, when the stator
is an iron ring wound like a toroidal inductor. I think, that at
each node where you take off a connection, the coil has to change
direction of wind. Think about it and see if you can figure out why.

Up to the point you mentioned this, I gave it no thought but you are
right, it won't alternate unless the windings are reversed.
By the way, I intend to make a generator like this as a demo for a
high school science class. I like it, because it can be made very
skeletal so that all parts are visible. If I am wrong about the
winding direction, I will have to cut the ends and reverse wire them.

I haven't seen anything more visible as a teaching aide. If you put
this unit together like I think you will, you will have a striking
conversation piece to display in your office or study for years to come.

rg
Got some nice curved neodymium magnets to energize the rotor coming
from Ebay.
[email protected]

J

#### Jasen Betts

Jan 1, 1970
0
In response to my post about an anti-cogging core:

Jasen said:
I'm trying to make clear sense of the second paragraph describing the
stator arrangement. The ring core has the coil wrapped around it in a
continuous closed loop (toroidal), and then tapped equadistantly for
individual phases.

yeah, that's what I was trying to say.
Would these be true phases or taps to siphon off a percentage of the
total voltage induced in the coil?

phases, they'd see zero-crossing as the pole passed the tap
If they are true phases, how is the common referenced in the closed
loop to complete the circuit for each phase?

It's delta-wound there is no common.

Bye.
Jasen

J

#### Jasen Betts

Jan 1, 1970
0
There is one detail that I missed up to this point, when the stator is
an iron ring wound like a toroidal inductor. I think, that at each
node where you take off a connection, the coil has to change direction
of wind. Think about it and see if you can figure out why.

I can't figure out why.

If the toroid is would such that a clockwise motion of the north pole of the
magnet produces a clockwise flow of current (or clockwise EMF) in the
windings , the clockwise movement of the south pole will cause a
counter-clockwise current direclty opposite it, leading to positive peak at
the "east pole" of the magnet and a negative peak at the "west pole"
By the way, I intend to make a generator like this as a demo for a
high school science class. I like it, because it can be made very
skeletal so that all parts are visible. If I am wrong about the
winding direction, I will have to cut the ends and reverse wire them.

try making a three phase one
Got some nice curved neodymium magnets to energize the rotor coming
from Ebay.

Bye.
Jasen

J

#### John Popelish

Jan 1, 1970
0
Jasen said:
I can't figure out why.

Then maybe I'm wrong. I picture the point that the wire attaches as
the location of the center of a salient magnetic pole on the stator.
What would normally be a single coil around an actual salient pole is
split in two and folded so that it is two coils at 90 degree to the
original coil. The fold turns each half 90 degrees, so the total
rotation, one coil, compared to the other is 180 degrees.
If the toroid is would such that a clockwise motion of the north pole of the
magnet produces a clockwise flow of current (or clockwise EMF) in the
windings , the clockwise movement of the south pole will cause a
counter-clockwise current direclty opposite it, leading to positive peak at
the "east pole" of the magnet and a negative peak at the "west pole"

try making a three phase one

Wouldn't that work my way using every other node (of 6)? I think your
way may be equivalent, except that my way produces peak voltage as the
magnet is at right angles to my taps your way produces peak voltage
when the magnet pole is at the tap. Now, excuse me while I wrap my
fingers around a ring, and play with my thumbs. I appreciate the
help, since I will soon be winding wire.

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