O
Orange
Guest
On 22 Apr 2004 12:47:10 -0700, jeffm_@email.com (JeffM) wrote:
can it do simple calculations?
S
s.d.
Guest
J
JeffM
Guest
You mean like CALC.EXE (already on you Windoze box)?
C
Chaos Master
Guest
JeffM outputs from the pin 13 of IC6:
I think Sodipodi is a great program.
Surely it can't beat professional software, but it is free.
I use Sodipodi in Windows (at home) and Slackware Linux (at work). At least I
have the "peace of mind" of not using pirated softwares.
[]s
--
_____ _ _
| ____| | \ / | Chaos MasterŽ
| | | \ / | Posting from Brazil.
| |___ | \ / | IRC: Wizard_of_Yendor / PowerNOS
|_____| | \/ | visit www.rootlinux.com.br
Just a comment from a happy Sodipodi user:
I think Sodipodi is a great program.
Surely it can't beat professional software, but it is free.
I use Sodipodi in Windows (at home) and Slackware Linux (at work). At least I
have the "peace of mind" of not using pirated softwares.
[]s
--
_____ _ _
| ____| | \ / | Chaos MasterŽ
| | | \ / | Posting from Brazil.
| |___ | \ / | IRC: Wizard_of_Yendor / PowerNOS
|_____| | \/ | visit www.rootlinux.com.br
S
Stephan Rose
Guest
On Fri, 23 Apr 2004 14:27:53 -0400, "D. Jay Newman" <jay@psu.edu>
wrote:
day....now you're stuck with a PCB package that's essentially useless
if it can't import and most importantly..export non-vendor specific
formats...
Stephan
wrote:
Not only that but....what if that vendor ceases to exist one
day....now you're stuck with a PCB package that's essentially useless
if it can't import and most importantly..export non-vendor specific
formats...
Stephan
C
Chaos Master
Guest
Orange outputs from the pin 13 of IC6:
Illustrator. For calculations you can use any spreadsheet, like Excel or the
Calc from OpenOffice.
[]s
--
Chaos MasterŽ - Posting from Brazil
MSN: wizard_of_yendor@hotmail.com
BRASNET: wizard_of_yendor
"A Elbereth Gilthoniel, silivren penna miriel o menel aglar elenath!"
No, Sodipodi is a vector image editing program like Corel Draw or Adobe
Illustrator. For calculations you can use any spreadsheet, like Excel or the
Calc from OpenOffice.
[]s
--
Chaos MasterŽ - Posting from Brazil
MSN: wizard_of_yendor@hotmail.com
BRASNET: wizard_of_yendor
"A Elbereth Gilthoniel, silivren penna miriel o menel aglar elenath!"
O
Orange
Guest
On Sat, 24 Apr 2004 14:13:03 -0300, Chaos Master <nospam@brasnet.org>
wrote:
(Algor?) that calculate for instance heat transfer and color the 3D
model depending of its temperature (red for hot, etc). Couldn't the
same thing be applied to electronics, line is red in beggining where
signal and signal-to-noise ratio is high, and then gradually becomes
blue as signal becomes lower? After amplifier it becomes red again,
etc.
That program should do some very simple vector drawings like line,
rectangle...
It would be perfect help for designing network.
wrote:
Maybe I expect too much from computer. I have seen some great programs
(Algor?) that calculate for instance heat transfer and color the 3D
model depending of its temperature (red for hot, etc). Couldn't the
same thing be applied to electronics, line is red in beggining where
signal and signal-to-noise ratio is high, and then gradually becomes
blue as signal becomes lower? After amplifier it becomes red again,
etc.
That program should do some very simple vector drawings like line,
rectangle...
It would be perfect help for designing network.
O
Orange
Guest
On Fri, 23 Apr 2004 14:18:46 +0200, "s.d."
<szymik@NOSPAM.univ-lille1.fr> wrote:
those calculations for me, but it also lacks drawing tools (its better
than excel whe working with variables). The bitmap can be imported
in MathCAD but that is not good solution.
Do you have any other ideas?
<szymik@NOSPAM.univ-lille1.fr> wrote:
I've tried Excel but its too hard to draw in it. MathCAD has done
those calculations for me, but it also lacks drawing tools (its better
than excel whe working with variables). The bitmap can be imported
in MathCAD but that is not good solution.
Do you have any other ideas?
F
Fred Bartoli
Guest
"Kevin Aylward" <kevindotaylwardEXTRACT@anasoft.co.uk> a écrit dans le
message news: oNJkc.1730$Ld.224@newsfe1-win...
So what ? Hysteresis is simply modeled at the OS level
Fred.
message news: oNJkc.1730$Ld.224@newsfe1-win...
analog wrote:
Oh..although XSpice claimed to have a hysterics core model, it is a lie.
The model acts as a Schmitt, i.e. the output values are clamped, making
it, essentially useless. But, here's a good one...
In the XSpice magnetic core code, this was called in every *iteration*
*******************
// Allocate storage for breakpoint domain & range values
H = (double *) calloc(size, sizeof(double));
if (H == '\0') {
cm_message_send(allocation_error);
return;
}
B = (double *) calloc(size, sizeof(double));
if (B == '\0') {
cm_message_send(allocation_error);
return;
}
***********
But it was worst then this
So what ? Hysteresis is simply modeled at the OS level
Fred.
W
Winfield Hill
Guest
Fred Bartoli wrote...
Thanks,
- Win
whill_at_picovolt-dot-com (use hill_at_rowland-dot-org for now)
As in, program crashed = off state?So what? Hysteresis is simply modeled at the OS level
Thanks,
- Win
whill_at_picovolt-dot-com (use hill_at_rowland-dot-org for now)
M
Mike Engelhardt
Guest
Kevin,
As the night follows the day, here comes Kevin.
saturated so fast, you can't see the curves. You can see curves
if you reduce the time step size and zoom in. There's some examples
in the help file, as there were in the original post. Here's deck
with a parallel current source and inductor. The current source
gives a unity dI/dT, so you can read out the inductance as a function
of current as the voltage on node n001:
*
L1 N001 0 Hc=16. Bs=.44 Br=.10
+ A=0.000005 Lm=0.002 Lg=0.00011 N=1000
I1 0 N001 PWL(0 0 1 1)
..tran .1
..options plotwinsize=0
..end
In the above deck, the initial magnetization curve is followed,
so you see first an increase in L as the current increases and
then later is saturates.
a inductor with a magnetic core is transversing a minor B-H
loop, the inductance changes with a discontinuity then H reverses.
This is true for any minor loop, both symmetric and asymmetric.
The corners of the football shape are as pointy as I can measure.
BTW, if you read the article, the Chan model was proposed in order
to remove discontinuities of the previous Jiles-Atherton model
used in PSpice. Yes, I did have to write an integration algorithm
for this project for LTspice that would handle the discontinuity.
But the discontinuity in inductance is physical and the correct
solution does not show spikes. See the LTspice help section
LTspice=>Circuit Elements=>L. Inductor of the current release for
more information.
Chan model was introduced for a specialty simulator, DSPICE of
Daisy Corp. locally here in Sunnyvale, CA. and has been copied
into a few other high-end SPICE programs. However, I've seen
it copied with gross errors. For example, the hard part is the
gap solution. Chan writes an equation for B(H) but when there's
a gap, you don't know H, either. Well, there's an equation for
H but that includes the permeability, which isn't known until H
is known. The math is simple enough to solve, but, with the
integration algorithm development, was the hardest part to
implement. The point of the deck I post above is that the gap
solution is correct.
For further info, there was also a discussion of LTspice's non-
linear inductors in the independent users' group on Yahoo.
--Mike
As the night follows the day, here comes Kevin.
Because your example is broken in that it goes from unsaturated to
saturated so fast, you can't see the curves. You can see curves
if you reduce the time step size and zoom in. There's some examples
in the help file, as there were in the original post. Here's deck
with a parallel current source and inductor. The current source
gives a unity dI/dT, so you can read out the inductance as a function
of current as the voltage on node n001:
*
L1 N001 0 Hc=16. Bs=.44 Br=.10
+ A=0.000005 Lm=0.002 Lg=0.00011 N=1000
I1 0 N001 PWL(0 0 1 1)
..tran .1
..options plotwinsize=0
..end
In the above deck, the initial magnetization curve is followed,
so you see first an increase in L as the current increases and
then later is saturates.
No, that certainly is not a flaw in the Chan et al model. When
a inductor with a magnetic core is transversing a minor B-H
loop, the inductance changes with a discontinuity then H reverses.
This is true for any minor loop, both symmetric and asymmetric.
The corners of the football shape are as pointy as I can measure.
BTW, if you read the article, the Chan model was proposed in order
to remove discontinuities of the previous Jiles-Atherton model
used in PSpice. Yes, I did have to write an integration algorithm
for this project for LTspice that would handle the discontinuity.
But the discontinuity in inductance is physical and the correct
solution does not show spikes. See the LTspice help section
LTspice=>Circuit Elements=>L. Inductor of the current release for
more information.
Good ferromagnetic core simulation is all but unheard of. The
Chan model was introduced for a specialty simulator, DSPICE of
Daisy Corp. locally here in Sunnyvale, CA. and has been copied
into a few other high-end SPICE programs. However, I've seen
it copied with gross errors. For example, the hard part is the
gap solution. Chan writes an equation for B(H) but when there's
a gap, you don't know H, either. Well, there's an equation for
H but that includes the permeability, which isn't known until H
is known. The math is simple enough to solve, but, with the
integration algorithm development, was the hardest part to
implement. The point of the deck I post above is that the gap
solution is correct.
For further info, there was also a discussion of LTspice's non-
linear inductors in the independent users' group on Yahoo.
--Mike
R
R.Legg
Guest
analog <analog@ieee.org> wrote in message news:<407F674C.9460B150@ieee.org>...
I(R9) in the first 12mSec of this simulation?
There seems to be a polarized irregularity as well, in the same
waveform, with asymmetrical saturation delays or volt-seconds, in
later circuit 'equilibrium'.
RL
Can you explain the anomalous behaviour illustrated in the waveform of
I(R9) in the first 12mSec of this simulation?
There seems to be a polarized irregularity as well, in the same
waveform, with asymmetrical saturation delays or volt-seconds, in
later circuit 'equilibrium'.
RL
A
analog
Guest
R.Legg wrote:
quite the right length to enter the next cycle with no net per-cycle
dc.
practically gone. The volts-seconds look balanced to me. Might I
suggest turning off waveform compression and setting the minimum step
size to 10u? -- analog
It is a start up transient due to the first partial cycle not being
quite the right length to enter the next cycle with no net per-cycle
dc.
The start up transient has decayed over many time constants and is
practically gone. The volts-seconds look balanced to me. Might I
suggest turning off waveform compression and setting the minimum step
size to 10u? -- analog
T
Terry Given
Guest
"Winfield Hill" <Winfield_member@newsguy.com> wrote in message
news:c716mq01lni@drn.newsguy.com...
Terry
news:c716mq01lni@drn.newsguy.com...
ToucheFred Bartoli wrote...
So what? Hysteresis is simply modeled at the OS level
As in, program crashed = off state?
Thanks,
- Win
whill_at_picovolt-dot-com (use hill_at_rowland-dot-org for now)
Terry
A
analog
Guest
Mike Engelhardt wrote:
Chan's modeling approach seems to be fundamentally different than
most of the other methods. Chan's approach more or less starts with
positive and negative saturation curves and that are piecewise summed
and/or offset to map out a B-H trajectory. This seems to lead to
smooth curves with a minimum of computational overhead. Most of the
other methods seem to start with an anhysteretic B-H curve and add
in hysteresis as a correction term.
The (small) problem I see with the Chan method is that the basic
curve shape is defined by the major, fully saturated loop and the
minor loops must be built up from pieces taken from the two major
boundary curves. This can lead to some non realistic seeming
behavior with erratic or aperiodic loop trajectories.
The inline asc file at the end of this post demonstrates just such a
case where the B-H trajectory violates the supposedly hard, defining
boundaries of the major loop. Also there is an unrealistically sharp
bend where this particular wayward trajectory returns to the straight
and narrow. However, these slight B-H loop idiosyncrasies probably
are immaterial to simulating more-than-realistic-enough behavior back
over in the electrical domain.
Best regards -- analog
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Version 4
SHEET 1 880 680
WIRE -208 144 -176 144
WIRE -176 144 -176 176
WIRE -176 256 -176 288
WIRE -352 288 -352 256
WIRE -288 144 -320 144
WIRE -352 144 -352 176
WIRE -320 144 -352 144
WIRE -176 144 -144 144
WIRE -112 144 -112 192
WIRE -112 240 -112 288
WIRE -64 288 -64 256
WIRE -64 176 -64 144
WIRE -64 144 -16 144
WIRE 32 144 32 192
WIRE 32 256 32 288
WIRE -16 144 32 144
WIRE -144 144 -112 144
FLAG -352 288 0
FLAG -176 288 0
FLAG -320 144 1
FLAG -144 144 2
FLAG -112 288 0
FLAG -64 288 0
FLAG 32 288 0
FLAG -16 144 3
SYMBOL ind2 -192 160 R0
WINDOW 3 -32 176 Left 0
SYMATTR Value Hc=100 Br=250m Bs=300m a=.1u lm=50m n=1 lg=0
SYMATTR InstName L1
SYMATTR Type ind
SYMBOL res -304 160 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 1
SYMBOL voltage -352 160 R0
WINDOW 3 -48 -80 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PWL(0 0 .3 4.5 .4 -1 1 20 2 -40 3 40 4 -40)
SYMATTR InstName V1
SYMBOL g -64 160 R0
SYMATTR InstName G1
SYMATTR Value 1
SYMBOL cap 16 192 R0
SYMATTR InstName C1
SYMATTR Value 1
TEXT -400 336 Left 0 !.tran 0 4 0 1m
TEXT -64 32 Center 0 ;Note: for B-H style curves plot V(3) against I(L1)
Hi Mike,
Chan's modeling approach seems to be fundamentally different than
most of the other methods. Chan's approach more or less starts with
positive and negative saturation curves and that are piecewise summed
and/or offset to map out a B-H trajectory. This seems to lead to
smooth curves with a minimum of computational overhead. Most of the
other methods seem to start with an anhysteretic B-H curve and add
in hysteresis as a correction term.
The (small) problem I see with the Chan method is that the basic
curve shape is defined by the major, fully saturated loop and the
minor loops must be built up from pieces taken from the two major
boundary curves. This can lead to some non realistic seeming
behavior with erratic or aperiodic loop trajectories.
The inline asc file at the end of this post demonstrates just such a
case where the B-H trajectory violates the supposedly hard, defining
boundaries of the major loop. Also there is an unrealistically sharp
bend where this particular wayward trajectory returns to the straight
and narrow. However, these slight B-H loop idiosyncrasies probably
are immaterial to simulating more-than-realistic-enough behavior back
over in the electrical domain.
Best regards -- analog
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Version 4
SHEET 1 880 680
WIRE -208 144 -176 144
WIRE -176 144 -176 176
WIRE -176 256 -176 288
WIRE -352 288 -352 256
WIRE -288 144 -320 144
WIRE -352 144 -352 176
WIRE -320 144 -352 144
WIRE -176 144 -144 144
WIRE -112 144 -112 192
WIRE -112 240 -112 288
WIRE -64 288 -64 256
WIRE -64 176 -64 144
WIRE -64 144 -16 144
WIRE 32 144 32 192
WIRE 32 256 32 288
WIRE -16 144 32 144
WIRE -144 144 -112 144
FLAG -352 288 0
FLAG -176 288 0
FLAG -320 144 1
FLAG -144 144 2
FLAG -112 288 0
FLAG -64 288 0
FLAG 32 288 0
FLAG -16 144 3
SYMBOL ind2 -192 160 R0
WINDOW 3 -32 176 Left 0
SYMATTR Value Hc=100 Br=250m Bs=300m a=.1u lm=50m n=1 lg=0
SYMATTR InstName L1
SYMATTR Type ind
SYMBOL res -304 160 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 0 56 VBottom 0
SYMATTR InstName R1
SYMATTR Value 1
SYMBOL voltage -352 160 R0
WINDOW 3 -48 -80 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PWL(0 0 .3 4.5 .4 -1 1 20 2 -40 3 40 4 -40)
SYMATTR InstName V1
SYMBOL g -64 160 R0
SYMATTR InstName G1
SYMATTR Value 1
SYMBOL cap 16 192 R0
SYMATTR InstName C1
SYMATTR Value 1
TEXT -400 336 Left 0 !.tran 0 4 0 1m
TEXT -64 32 Center 0 ;Note: for B-H style curves plot V(3) against I(L1)
A
analog
Guest
R.Legg wrote:
like it's spelled "maximum"). -- analog
Look harder until your synapses cross and you'll see it (it just looks
like it's spelled "maximum"). -- analog
K
Kevin Aylward
Guest
Mike Engelhardt wrote:
an expert in running LTSpice. I seem to be able to get the basic curves
to look simular now.
*smoothly* and very slowly, i.e. as in a slow sinewave, there should be
no hard switch in inductance. It should behave something like like it is
coming out of transistor saturation.
I had a look at the corrected circuit, and LTSpice seems to be handling
this ok, with no jumps. What did you do to achieve this?, as I note
below.
changes, this is sort of a different issue, anyway, if you use a sine
wave, this can't possible happen. Physical reality does not do this.
Consider a repeating minor loop finally hitting the average curve and
*continuing* on to that average curve. The slope of the average curve
should be the same as the B_+ or B_- curve at that point.
no explicit details, only general guidelines.
Its very vague. There is only one degree of freedom for the simple
symmetrical loops at the change point, as I read it. This is set, up
(Bd) to make the curve continuous at change over. That is:
B = B_- + Bd = B = B_+ - Bd
How can this automatically make the join up with the average curve have
the same slope as well? After a turn around the curve heads up to an
intersection with the average curve. This intersection dose not
intersect smoothly. This is clear because if you dont switch the curve
to let it follow the average curve, it keeps heading upwards, above what
the average says it should be. The physical proof is simply to let it
happen and look at the graph.
Mathematical proof:
Consider a turnaround point on a symetrical loop, curve going up:
consider B = B_- + Bd
Bd chosen so that B matches up the values of B at the bottom turn
around. In this case H is not offset in the paper. Now calculate the
derivative dB/dH at the top intersection of B = (B_- + B_)/2 and the
derivative of B = B_- + Bd. They don't match.
Now...this may be well be where the paper is cryptic, to say the least.
Fig. 2 of the paper does seem to show that the minor loop joins up with
the average curve smoothly, however, other than "...is a valid extension
of a minor loop..." it explains nothing else about constructing such a
curve. It does imply that H is not offset, because it is not mentioned
here, but is mentioned in the asymmetrical loop, but for a different
reason. In fact, if you look at Fig.3 for the asymmetrical case, how can
the curve that connects D to D' possibly have the same slope as the
magnetisation curve at C?
Without offsetting h, I calculate points E and F (Fig.2, case 1) (via a
quadratic) so that the curve hits D. This results in the intersection at
F not having the same slope as the average magnetisation curve at that
point.
So, whats the deal here. Is H supposed to offset as well as B?
you use a discontinuity in the input time response. The point I am
making is that if you use a smooth, very slow input, one would expect a
smooth change over from the up and down curves and average curves. That
is, dB/dH should be continuous, if the input has continuous derivatives.
True, I admit I have not made such a measurement, but excluding, QM, the
real world usually has continuous derivatives.
to time and those due to transfer characteristics.
Since V=d(flux)/dt = di/dt.d(flux)/di
If L=d(flux)/di is discontinuous, so will V be, *irrespective* of t,
(ignoring special limiting functions). So, in this sense, inductance
cannot be discontinuous.
So, I agree, the correct solution should not show a spike, because
L=d(flux)/di should be continuous, but I don't agree that L itself is
discontinuous. The flux/I graph should always have continuous
derivatives in the physical world.
How does you implementation overcome/is consistent with, the math I
posted above, since LTSpice doesn't appear to show any spikes? It would
certainly be embarrassing for me to make a simple math mistake.
See the LTspice help section
simulator as well
there was a bit more work required to add the gap in. Yeah, the mu
varies with H.
details of developing an explicit formula for u as a function of I, but
even if it is transcendental, one can write a little iterative function
to solve it.
Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.
Yeah. It looks like I didn't translate the set-up correctly. I am not
an expert in running LTSpice. I seem to be able to get the basic curves
to look simular now.
Ahmmm... well maybe its a flaw in explaining the model implementation.
Yes, if the input changes discontinuously. However, if the input changes
*smoothly* and very slowly, i.e. as in a slow sinewave, there should be
no hard switch in inductance. It should behave something like like it is
coming out of transistor saturation.
I had a look at the corrected circuit, and LTSpice seems to be handling
this ok, with no jumps. What did you do to achieve this?, as I note
below.
You missed my point. Forget the turn around point itself due to time
changes, this is sort of a different issue, anyway, if you use a sine
wave, this can't possible happen. Physical reality does not do this.
Consider a repeating minor loop finally hitting the average curve and
*continuing* on to that average curve. The slope of the average curve
should be the same as the B_+ or B_- curve at that point.
I have. Spent several days on it. Its explanation is dreadful. It gives
no explicit details, only general guidelines.
Yes I did read this, but the plots and description dont seem to tie up.
Its very vague. There is only one degree of freedom for the simple
symmetrical loops at the change point, as I read it. This is set, up
(Bd) to make the curve continuous at change over. That is:
B = B_- + Bd = B = B_+ - Bd
How can this automatically make the join up with the average curve have
the same slope as well? After a turn around the curve heads up to an
intersection with the average curve. This intersection dose not
intersect smoothly. This is clear because if you dont switch the curve
to let it follow the average curve, it keeps heading upwards, above what
the average says it should be. The physical proof is simply to let it
happen and look at the graph.
Mathematical proof:
Consider a turnaround point on a symetrical loop, curve going up:
consider B = B_- + Bd
Bd chosen so that B matches up the values of B at the bottom turn
around. In this case H is not offset in the paper. Now calculate the
derivative dB/dH at the top intersection of B = (B_- + B_)/2 and the
derivative of B = B_- + Bd. They don't match.
Now...this may be well be where the paper is cryptic, to say the least.
Fig. 2 of the paper does seem to show that the minor loop joins up with
the average curve smoothly, however, other than "...is a valid extension
of a minor loop..." it explains nothing else about constructing such a
curve. It does imply that H is not offset, because it is not mentioned
here, but is mentioned in the asymmetrical loop, but for a different
reason. In fact, if you look at Fig.3 for the asymmetrical case, how can
the curve that connects D to D' possibly have the same slope as the
magnetisation curve at C?
Without offsetting h, I calculate points E and F (Fig.2, case 1) (via a
quadratic) so that the curve hits D. This results in the intersection at
F not having the same slope as the average magnetisation curve at that
point.
So, whats the deal here. Is H supposed to offset as well as B?
Again, I agree there is a discontinuity in the *time* *derivative* if
you use a discontinuity in the input time response. The point I am
making is that if you use a smooth, very slow input, one would expect a
smooth change over from the up and down curves and average curves. That
is, dB/dH should be continuous, if the input has continuous derivatives.
True, I admit I have not made such a measurement, but excluding, QM, the
real world usually has continuous derivatives.
This is actually a bit subtle. One has to separate discontinuities due
to time and those due to transfer characteristics.
Since V=d(flux)/dt = di/dt.d(flux)/di
If L=d(flux)/di is discontinuous, so will V be, *irrespective* of t,
(ignoring special limiting functions). So, in this sense, inductance
cannot be discontinuous.
So, I agree, the correct solution should not show a spike, because
L=d(flux)/di should be continuous, but I don't agree that L itself is
discontinuous. The flux/I graph should always have continuous
derivatives in the physical world.
How does you implementation overcome/is consistent with, the math I
posted above, since LTSpice doesn't appear to show any spikes? It would
certainly be embarrassing for me to make a simple math mistake.
See the LTspice help section
No surprising with the dreadful description in the Chan paper.
Well, if I can get this glitch sorted out, it will be in a low end
simulator as well
Yes. I have had a little look at this, and came to the conclusion that
there was a bit more work required to add the gap in. Yeah, the mu
varies with H.
Not clear on what you are saying here. I haven't looked at the full
details of developing an explicit formula for u as a function of I, but
even if it is transcendental, one can write a little iterative function
to solve it.
Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.
M
Mike Engelhardt
Guest
Analog,
Chan model does make some trades in the interest of being
computationally lightweight and fully specifing B-H with just
three datasheet parameters(*) The worst issue is non-repeating
asymmetric minor loops that approach hard saturation. The current
implementation in LTspice is as proposed by Chan et al. However,
it's clear it could be "improved" upon. However, I'm not sure if
overcoming minor shortcomings is more important than deviating
from a standard that has been the basis of most of the ferromagnetic
core circuit simulation I've seen.
--Mike
(*)BTW, note that your previous issue discussed elsewhere about
initial ľ not being one of the there input parameters is handled
by selecting Br wrt Bs. It's desireable to have a low Br which
makes initial ľ closer to maximum ľ, but you can change these
with Br.
That is a really excellent analysis and interpretation. Yes, the
Chan model does make some trades in the interest of being
computationally lightweight and fully specifing B-H with just
three datasheet parameters(*) The worst issue is non-repeating
asymmetric minor loops that approach hard saturation. The current
implementation in LTspice is as proposed by Chan et al. However,
it's clear it could be "improved" upon. However, I'm not sure if
overcoming minor shortcomings is more important than deviating
from a standard that has been the basis of most of the ferromagnetic
core circuit simulation I've seen.
--Mike
(*)BTW, note that your previous issue discussed elsewhere about
initial ľ not being one of the there input parameters is handled
by selecting Br wrt Bs. It's desireable to have a low Br which
makes initial ľ closer to maximum ľ, but you can change these
with Br.
M
Mike Engelhardt
Guest
Kevin,
is quiet an abrupt effect, analogous to electrical
breakdown. If one's not aware of how abrupt it is
one can miss it as you did. That would explain why
you were also so sure core saturation was so important
to model. My advice is usually to just use linear
inductors and see if the peak current get high enough
such that differential inductance is lost. As when
one designs an IC. I don't recommend modeling
breakdown of all the transistors, just run simulations
without breakdown and check if any process has been
overvoltaged.
inductance(i.e., differential inductance) changes
discontinuously when the direction of H changes. The
upper and lower lines followed by B meet in the corner
at the same value of B, but the slope of the line,
proportional to L, changes discontinuously at this
corner upon reversal of H.
know a few people besides myself who read that article
and understood.
--Mike
It might go a bit beyond that. Magnetic core saturation
is quiet an abrupt effect, analogous to electrical
breakdown. If one's not aware of how abrupt it is
one can miss it as you did. That would explain why
you were also so sure core saturation was so important
to model. My advice is usually to just use linear
inductors and see if the peak current get high enough
such that differential inductance is lost. As when
one designs an IC. I don't recommend modeling
breakdown of all the transistors, just run simulations
without breakdown and check if any process has been
overvoltaged.
Nonsense. Look at a minor loop of a B-H curve. The
inductance(i.e., differential inductance) changes
discontinuously when the direction of H changes. The
upper and lower lines followed by B meet in the corner
at the same value of B, but the slope of the line,
proportional to L, changes discontinuously at this
corner upon reversal of H.
I could tell you, but then I'd have to hire you.
My data is that the problem lies with the reader. I
know a few people besides myself who read that article
and understood.
--Mike
K
Kevin Aylward
Guest
Mike Engelhardt wrote:
that the slopes at intersections can't match. You declare my correct
proof, false because you cant understand it, yet praise analog here for
pointing out that very same fact. Unreal dude. As I said, you need to
grow up a bit.
Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.
Yep. So here we go again Mike. I point out, and show mathematically,
that the slopes at intersections can't match. You declare my correct
proof, false because you cant understand it, yet praise analog here for
pointing out that very same fact. Unreal dude. As I said, you need to
grow up a bit.
Kevin Aylward
salesEXTRACT@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.