mutual inductance/coupling coefficient

A

Active8

Jan 1, 1970
0
hi:

i'd like to be able to get a good approximation of coupling coefficients
of coils/xfmrs. there's a link below. i was trying to find Neumann's
double line integral and the only DLI i can find is in sec 6. of that
document. not sure if it's the same thing. the doc deals with single
turn coils in the same plane with center separation D. when D=0, the
centers of the loops coincide and maybe it works, but you can't separate
the loops along the longitudinal axis. i found a program for tesla coils
that computes M and k for muti-turn coils. there's no documentaation for
the program and therefore no way to expand on it. it's supposed to be
based on Neumann's integral, but you can't enter in core permeability so
it's limited to air core coils. it's answers don't agree with the
program based on the doc below, either.

i want to approximate M for bifiliar, trifiliar, etc. xfmrs as well as
layered (one winding on top of another - they say there is no k=1) coils
and those separated or not overlapping.

is the difference between a center tapped coil and a bifiliar winding
with the non-dot end of wire 1 connected to the other wire's dot end
just a matter of coupling, all else being equal and neglecting parasitic
caps?

http://www.distinti.com/docs/ni.pdf

mike

E

Eric Y. Chang

Jan 1, 1970
0
Active8 ([email protected]) wrote:
....
: the loops along the longitudinal axis. i found a program for tesla coils
: that computes M and k for muti-turn coils. there's no documentaation for
: the program and therefore no way to expand on it. it's supposed to be
: based on Neumann's integral, but you can't enter in core permeability so
: it's limited to air core coils. it's answers don't agree with the
: program based on the doc below, either.

Hi. Most of the programs out there seem to work based on first principles
calculations or direct approximations which have been found to be good.
It is not surprising that two programs give different answers. Is your
question which program to trust, or which one to use? Have you tried
a test problem for which the answer should be easier to find (like two
concentric single wire loops). You only gave one link. There must be
two to disagree. I just saw this posted in a newsgroup: "Two engineers
will give two different answers. Solution: shoot one engineer." The
quote is attributed to Confucius, but I would expect it to be more
likely from Mencius, another Chinese philosopher. Oddly, there are
many quotes attributed to Confucius which do not really come from him,
and many quotes attributed to others which originally came from him.
Perhaps there is an element of humor involved.

A

Active8

Jan 1, 1970
0
Active8 ([email protected]) wrote:
...
: the loops along the longitudinal axis. i found a program for tesla coils
: that computes M and k for muti-turn coils. there's no documentaation for
: the program and therefore no way to expand on it. it's supposed to be
: based on Neumann's integral, but you can't enter in core permeability so
: it's limited to air core coils. it's answers don't agree with the
: program based on the doc below, either.

Hi. Most of the programs out there seem to work based on first principles
calculations or direct approximations which have been found to be good.
It is not surprising that two programs give different answers. Is your
question which program to trust, or which one to use? Have you tried
a test problem for which the answer should be easier to find (like two
concentric single wire loops). You only gave one link. There must be
two to disagree. I just saw this posted in a newsgroup: "Two engineers
will give two different answers. Solution: shoot one engineer." The
quote is attributed to Confucius, but I would expect it to be more
likely from Mencius, another Chinese philosopher. Oddly, there are
many quotes attributed to Confucius which do not really come from him,
and many quotes attributed to others which originally came from him.
Perhaps there is an element of humor involved.

the element being the person who can't remember who he's quoting, maybe?
since people confucius funny think, evelyone want funny to be, so quote
confucius try.sorry, the other program, MANDK is at

http://hot-streamer.com/TeslaCoils/Programs/MANDKV31.ZIP
http://hot-streamer.com/TeslaCoils/Programs/MANDKV31.PDF

my question? heh, heh. which one? any objections to that IEL double line
integral in the distini document? anyone know where to find the Neumann
double line integral on the net? anyone have any known good numbers i
can use to check these programs? no way for me to build and measure for
myself at this time. may be months off.

i tried two concentric loops in MANDK r=.25 inches
not sure what to call the height (length) of a one turn loop - i used
..001 - same for last turn elevation. wire size .08 - maybe that should
be the coil height.

it tells me M = .026 uH with both Ls at .03 uH -- funny, that works out
to a coupling coefficient of k = .867 and MANDK reports k = 1.0108 which
we all know is hogwash. it returned greater values of k for my other
attempts which got me wondering.

distini_m_circle gives me 2.46E-8 or .024 uH which isn't far off
compared to the Faraday result of 2.014E-8 (almost finished lunch
waiting for that to run ), i suppose, so i probably screwed up, last
time i tried. not being able to use different core permeabilities is a
limitation i'd like to overcome. i think i can work that out - the
source code is provided with the distini doc, so i can change it, but
then there's no way to campare with MANDK.

interesting doc, eh?

anyone wanting to try MANDK - put everything in the same directory and
run TB50RUN.EXE - then ignore the error msg. that worked for me. i don't
know what in the hell the distini_m_circle and faraday_m_circle errors
"not a number:" followed by todays date means.

thanks,
mike

A

Active8

Jan 1, 1970
0
Active8 ([email protected]) wrote:
...
: the loops along the longitudinal axis. i found a program for tesla coils
: that computes M and k for muti-turn coils. there's no documentaation for
: the program and therefore no way to expand on it. it's supposed to be
: based on Neumann's integral, but you can't enter in core permeability so
: it's limited to air core coils. it's answers don't agree with the
: program based on the doc below, either.

Hi. Most of the programs out there seem to work based on first principles
calculations or direct approximations which have been found to be good.
It is not surprising that two programs give different answers. Is your
question which program to trust, or which one to use? Have you tried
a test problem for which the answer should be easier to find (like two
concentric single wire loops). You only gave one link. There must be
two to disagree. I just saw this posted in a newsgroup: "Two engineers
will give two different answers. Solution: shoot one engineer." The
quote is attributed to Confucius, but I would expect it to be more
likely from Mencius, another Chinese philosopher. Oddly, there are
many quotes attributed to Confucius which do not really come from him,
and many quotes attributed to others which originally came from him.
Perhaps there is an element of humor involved.
the element being the person who can't remember who he's quoting, maybe?
since people confucius funny think, evelyone want funny to be, so quote
confucius try.sorry, the other program, MANDK is at

http://hot-streamer.com/TeslaCoils/Programs/MANDKV31.ZIP
http://hot-streamer.com/TeslaCoils/Programs/MANDKV31.PDF

my question? heh, heh. which one? any objections to that IEL double line
integral in the distini document? anyone know where to find the Neumann
double line integral on the net? anyone have any known good numbers i
can use to check these programs? no way for me to build and measure for
myself at this time. may be months off.

i tried two concentric loops in MANDK r=.25 inches
not sure what to call the height (length) of a one turn loop - i used
..001 - same for last turn elevation. wire size .08 - maybe that should
be the coil height.

it tells me M = .026 uH with both Ls at .03 uH -- funny, that works out
to a coupling coefficient of k = .867 and MANDK reports k = 1.0108 which
we all know is hogwash. it returned greater values of k for my other
attempts which got me wondering.

distini_m_circle gives me 2.46E-8 or .024 uH which isn't far off
compared to the Faraday result of 2.014E-8 (almost finished lunch
waiting for that to run ), i suppose, so i probably screwed up, last
time i tried. not being able to use different core permeabilities is a
limitation i'd like to overcome. i think i can work that out - the
source code is provided with the distini doc, so i can change it, but
then there's no way to campare with MANDK.

interesting doc, eh?

anyone wanting to try MANDK - put everything in the same directory and
run TB50RUN.EXE - then ignore the error msg. that worked for me. i don't
know what in the hell the distini_m_circle and faraday_m_circle errors
"not a number:" followed by todays date means.

thanks,
mike

A

Active8

Jan 1, 1970
0
Active8 ([email protected]) wrote:
...
: the loops along the longitudinal axis. i found a program for tesla coils
: that computes M and k for muti-turn coils. there's no documentaation for
: the program and therefore no way to expand on it. it's supposed to be
: based on Neumann's integral, but you can't enter in core permeability so
: it's limited to air core coils. it's answers don't agree with the
: program based on the doc below, either.

Hi. Most of the programs out there seem to work based on first principles
calculations or direct approximations which have been found to be good.
It is not surprising that two programs give different answers. Is your
question which program to trust, or which one to use? Have you tried
a test problem for which the answer should be easier to find (like two
concentric single wire loops). You only gave one link. There must be
two to disagree. I just saw this posted in a newsgroup: "Two engineers
will give two different answers. Solution: shoot one engineer." The
quote is attributed to Confucius, but I would expect it to be more
likely from Mencius, another Chinese philosopher. Oddly, there are
many quotes attributed to Confucius which do not really come from him,
and many quotes attributed to others which originally came from him.
Perhaps there is an element of humor involved.
sorry, the other program, MANDK is at

http://hot-streamer.com/TeslaCoils/Programs/MANDKV31.ZIP
http://hot-streamer.com/TeslaCoils/Programs/MANDKV31.PDF

my question? heh, heh. which one? any objections to that IEL double line
integral in the distini document? anyone know where to find the Neumann
double line integral on the net? anyone have any known good numbers i
can use to check these programs? no way for me to build and measure for
myself at this time. may be months off.

i tried two concentric loops in MANDK r=.25 inches
not sure what to call the height (length) of a one turn loop - i used
..001 - same for last turn elevation. wire size .08 - maybe that should
be the coil height.

it tells me M = .026 uH with both Ls at .03 uH -- funny, that works out
to a coupling coefficient of k = .867 and MANDK reports k = 1.0108 which
we all know is hogwash. it returned greater values of k for my other
attempts which got me wondering.

distini_m_circle gives me 2.46E-8 or .024 uH which isn't far off
compared to the Faraday result of 2.014E-8 (almost finished lunch
waiting for that to run ), i suppose, so i probably screwed up, last
time i tried. not being able to use different core permeabilities is a
limitation i'd like to overcome. i think i can work that out - the
source code is provided with the distini doc, so i can change it, but
then there's no way to campare with MANDK.

interesting doc, eh?

anyone wanting to try MANDK - put everything in the same directory and
run TB50RUN.EXE - then ignore the error msg. that worked for me. i don't
know what in the hell the distini_m_circle and faraday_m_circle errors
"not a number:" followed by todays date means.

thanks,
mike

R

Robert Monsen

Jan 1, 1970
0
Just to put this into perspective, the Distinti site has been judged
"Crankiest" by "Crank Dot Net".

I've got no way to form an opinion on it, however. Perhaps more learned
minds care to comment?

Regards
Bob Monsen

A

Active8

Jan 1, 1970
0
Just to put this into perspective, the Distinti site has been judged
"Crankiest" by "Crank Dot Net".

I've got no way to form an opinion on it, however. Perhaps more learned
minds care to comment?

thanks. to tell you the truth, judging by the references that "new
electromagnetism" can explain (better explain?) gravity, light
propagation, and "how does the electron know which way to go," i thought
it was another free energy hoax. don't know yet. odd thing is is that
their method of calculating M more closely matches results of another
program using the Neumann integral than does the Faraday triple
integral. more research needed.

mike

A

Active8

Jan 1, 1970
0
thanks. to tell you the truth, judging by the references that "new
electromagnetism" can explain (better explain?) gravity, light
propagation, and "how does the electron know which way to go," i thought
it was another free energy hoax. don't know yet. odd thing is is that
their method of calculating M more closely matches results of another
program using the Neumann integral than does the Faraday triple
integral. more research needed.

mike

too bad crank.net doesn't substantiate their claims. looks like they
have their fair share of idiots listed like discordians and church of
the subgenius. i didn't know church of s.g. was making any claims. i
thought it was just a brand of humor. in fact they even say that if
you're looking for a bogus religion ... CSG can save your sanity. rated
bizaar. ok. Church of Euthanasia - rated crankiest. do they really think
these guys are serious?

mike

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