I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the
bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
john larkin <jl@glen--canyon.com> wrote:
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the
bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good
cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133 >>
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
Not a whole lot. In the near-field region, B obeys Laplace’s equation,
which means among other things that the field falls off on the length scale >of the gap, not of the whole inductor.
Cheers
Phil Hobbs
On Wed, 23 Oct 2024 18:14:57 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the
bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good
cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
Not a whole lot. In the near-field region, B obeys Laplace’s equation,
which means among other things that the field falls off on the length scale >> of the gap, not of the whole inductor.
Cheers
Phil Hobbs
You are right. A similar part is 47 uH in free air, 44.6 mounted on a multilayer board, and 42.1 squeezed between the board and a big chunk
of aluminum.
So it will work.
On Wed, 23 Oct 2024 18:14:57 -0000 (UTC), Phil Hobbs ><pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the
bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good
cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
Not a whole lot. In the near-field region, B obeys Laplace’s equation, >>which means among other things that the field falls off on the length scale >>of the gap, not of the whole inductor.
Cheers
Phil Hobbs
You are right. A similar part is 47 uH in free air, 44.6 mounted on a >multilayer board, and 42.1 squeezed between the board and a big chunk
of aluminum.
So it will work.
On 24/10/2024 5:33 am, john larkin wrote:
On Wed, 23 Oct 2024 18:14:57 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the >>>> bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good >>>> cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
Not a whole lot. In the near-field region, B obeys Laplace’s equation, >>> which means among other things that the field falls off on the length
scale
of the gap, not of the whole inductor.
Cheers
Phil Hobbs
You are right. A similar part is 47 uH in free air, 44.6 mounted on a
multilayer board, and 42.1 squeezed between the board and a big chunk
of aluminum.
So it will work.
Somebody who knew what they were doing could model it in LTSpice. The adjacent metal-work is a poorly coupled shorted turn. Model your
inductor as 47uH coil with 0.135 series resistance and 4pF of parallel capacitance, and model the metal as a coupled - perhaps 1nH single turn
- with perhaps 1% coupling and maybe a milliohm of resistance.
On 10/24/24 12:07, Bill Sloman wrote:
On 24/10/2024 5:33 am, john larkin wrote:
On Wed, 23 Oct 2024 18:14:57 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the >>>>> bottom of the multilayer board. There's a 0.2" gap between the bottom >>>>> of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good >>>>> cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder >>>>> what that will do to its electrical behavior.
Not a whole lot. In the near-field region, B obeys Laplace’s equation, >>>> which means among other things that the field falls off on the length
scale
of the gap, not of the whole inductor.
Cheers
Phil Hobbs
You are right. A similar part is 47 uH in free air, 44.6 mounted on a
multilayer board, and 42.1 squeezed between the board and a big chunk
of aluminum.
So it will work.
Somebody who knew what they were doing could model it in LTSpice. The
adjacent metal-work is a poorly coupled shorted turn. Model your
inductor as 47uH coil with 0.135 series resistance and 4pF of parallel
capacitance, and model the metal as a coupled - perhaps 1nH single turn
- with perhaps 1% coupling and maybe a milliohm of resistance.
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
On Wed, 23 Oct 2024 11:33:23 -0700, john larkin <jl@glen--canyon.com>
wrote:
On Wed, 23 Oct 2024 18:14:57 -0000 (UTC), Phil Hobbs >><pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the >>>> bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good >>>> cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
Not a whole lot. In the near-field region, B obeys Laplace’s equation, >>>which means among other things that the field falls off on the length scale >>>of the gap, not of the whole inductor.
Cheers
Phil Hobbs
You are right. A similar part is 47 uH in free air, 44.6 mounted on a >>multilayer board, and 42.1 squeezed between the board and a big chunk
of aluminum.
So it will work.
Depending on how closely packed the parts were, you might
gat adjacent parts acting as pole pieces. So space >> than
body hight.
Assuming also that your metalwork is Al and not Fe.
RL
RL
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >analogue computing to work out his designs i.e. He built prototypes and >measured them.
On 10/24/24 12:07, Bill Sloman wrote:
On 24/10/2024 5:33 am, john larkin wrote:
On Wed, 23 Oct 2024 18:14:57 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
john larkin <jl@glen--canyon.com> wrote:
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the >>>>> bottom of the multilayer board. There's a 0.2" gap between the bottom >>>>> of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good >>>>> cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder >>>>> what that will do to its electrical behavior.
Not a whole lot. In the near-field region, B obeys Laplace’s equation, >>>> which means among other things that the field falls off on the
length scale
of the gap, not of the whole inductor.
Cheers
Phil Hobbs
You are right. A similar part is 47 uH in free air, 44.6 mounted on a
multilayer board, and 42.1 squeezed between the board and a big chunk
of aluminum.
So it will work.
Somebody who knew what they were doing could model it in LTSpice. The
adjacent metal-work is a poorly coupled shorted turn. Model your
inductor as 47uH coil with 0.135 series resistance and 4pF of parallel
capacitance, and model the metal as a coupled - perhaps 1nH single
turn - with perhaps 1% coupling and maybe a milliohm of resistance.
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use analogue computing to work out his designs i.e. He built prototypes and measured them.
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >analogue computing to work out his designs i.e. He built prototypes and >measured them.
You youngsters probably don't remember a time when there wasn't Spice.
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.
On 25/10/2024 7:56 am, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Actually, it is extremely useful for people who work with real parts and
who want to know exactly what is going on. You can see stuff that is
very hard to measure on real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use analogue computing to work out his designs i.e. He built prototypes and measured them.
But he understood what he was measuring - a least most of the time.
His revolutionary ideas about capacitor microphones and the patent application he made fell down when he found out about the Philips capacitative pressure gauges which had been exploiting the same
principle for about a decade before.
This played out in the pages of Wireless World, between the first and
second parts of a two part article.
I don't think he mentioned the Philips pressure gauges,
but I've got a 1954 reference to them in my
1970 Ph.D. thesis
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >>> analogue computing to work out his designs i.e. He built prototypes and >>> measured them.
You youngsters probably don't remember a time when there wasn't Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships between resistance, capacitance, frequency and time constant (put in two and the others appear, put in three and the error% appears). It also gives dB
loss below or above the 'cutoff' frequency. Some years ago I also made
some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
Those and a pocket calculator are still the only 'computing' I use for
design work.
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:56 am, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Actually, it is extremely useful for people who work with real parts and
who want to know exactly what is going on. You can see stuff that is
very hard to measure on real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >>> analogue computing to work out his designs i.e. He built prototypes and >>> measured them.
But he understood what he was measuring - a least most of the time.
His revolutionary ideas about capacitor microphones and the patent
application he made fell down when he found out about the Philips
capacitative pressure gauges which had been exploiting the same
principle for about a decade before.
If anything, that enhances his reputation rather than diminishing it, A single inventor working on a project in his spare time compared with a laboratory-full of specialists working full-time on commercial projects
(if I remember rightly) one of which was almost certainly partly
financed by the Ford Motor Company.
This played out in the pages of Wireless World, between the first and
second parts of a two part article.
The articles were in WW Nov/Dec 1963. At the end he refers to two Dutch papers:
Philips Technical Review Vol9 Nr12 1947/48 pp357-363
Omroep-technische Mededelingen Feb15 1961
These are both describing to low-noise condenser microphones but he
points out that they don't have some of the desirable features of his
design.
I don't think he mentioned the Philips pressure gauges,>but I've got a 1954 reference to them in my
1970 Ph.D. thesis
That may have been the article on capacitive pressure gauges for car
engines in the Philips Technical Review.
Their main problem was that
the temperatures and pressures they were trying to measure gave a short diaphragm life if the diaphragm was thin enough to respond to the
required frequency range with sufficient sensitivity.
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use
analogue computing to work out his designs i.e. He built prototypes and
measured them.
You youngsters probably don't remember a time when there wasn't Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships between >resistance, capacitance, frequency and time constant (put in two and the >others appear, put in three and the error% appears). It also gives dB
loss below or above the 'cutoff' frequency. Some years ago I also made
some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
Those and a pocket calculator are still the only 'computing' I use for
design work.
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that >>>>> doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >>> analogue computing to work out his designs i.e. He built prototypes and >>> measured them.
You youngsters probably don't remember a time when there wasn't Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships between resistance, capacitance, frequency and time constant (put in two and the others appear, put in three and the error% appears). It also gives dB loss below or above the 'cutoff' frequency. Some years ago I also made some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
Those and a pocket calculator are still the only 'computing' I use for design work.
No surprise there, though I am a bit surprised that you would admit it
in public.
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >> >>> analogue computing to work out his designs i.e. He built prototypes and >> >>> measured them.
You youngsters probably don't remember a time when there wasn't Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships between
resistance, capacitance, frequency and time constant (put in two and the >> > others appear, put in three and the error% appears). It also gives dB
loss below or above the 'cutoff' frequency. Some years ago I also made
some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
Those and a pocket calculator are still the only 'computing' I use for
design work.
No surprise there, though I am a bit surprised that you would admit it
in public.
I don't understand why you use the word 'admit'. I make my own tools to
meet my particular requirements, there is nothing shameful about that.
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that >>>>>>> doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >>>>> analogue computing to work out his designs i.e. He built prototypes and >>>>> measured them.
You youngsters probably don't remember a time when there wasn't Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But >>>> it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships between
resistance, capacitance, frequency and time constant (put in two and the >>> others appear, put in three and the error% appears). It also gives dB
loss below or above the 'cutoff' frequency. Some years ago I also made
some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
Those and a pocket calculator are still the only 'computing' I use for
design work.
No surprise there, though I am a bit surprised that you would admit it
in public.
I don't understand why you use the word 'admit'. I make my own tools to
meet my particular requirements, there is nothing shameful about that.
On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid >>>>> (Liz Tuddenham) wrote:Hey!!! Who are you calling a youngster?!!! :-)
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk> >>>>>>> wrote:[...]
plugging numbers pulled out of thin air into LTSpice is better that >>>>>>>> doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use >>>>>> analogue computing to work out his designs i.e. He built prototypes and >>>>>> measured them.
You youngsters probably don't remember a time when there wasn't Spice. >>>>
I did some simulation in Basic-Plus, and it was a nuisance. My first >>>>> PC sim program was Tatum labs ECA, which required a typed netlist. But >>>>> it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships between >>>> resistance, capacitance, frequency and time constant (put in two and the >>>> others appear, put in three and the error% appears). It also gives dB >>>> loss below or above the 'cutoff' frequency. Some years ago I also made >>>> some lookup tables for combinations of 5% tolerance resistors in series >>>> and parallel.
Those and a pocket calculator are still the only 'computing' I use for >>>> design work.
No surprise there, though I am a bit surprised that you would admit it
in public.
I don't understand why you use the word 'admit'. I make my own tools to
meet my particular requirements, there is nothing shameful about that.
You have been admonished by Sloman. Confess your errors and beg
forgiveness.
Have you used LT Spice? It's easy to learn and is great fun. It makes
time for snacking and napping too.
I even use it instead of a calculator for simple stuff like voltage
dividers and RC time constants and things.
I can fiddle LC filters to at least third order. Sometimes 5th order,
until things diverge and explode.
LT Spice schematics can be screen-shot for things like block diagram
figures in manuals too.
On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that >> >>>>> doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed
to use analogue computing to work out his designs i.e. He built
prototypes and measured them.
You youngsters probably don't remember a time when there wasn't
Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist.
But it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships
between resistance, capacitance, frequency and time constant (put in
two and the others appear, put in three and the error% appears). It
also gives dB loss below or above the 'cutoff' frequency. Some years
ago I also made some lookup tables for combinations of 5% tolerance
resistors in series and parallel.
Those and a pocket calculator are still the only 'computing' I use
for design work.
No surprise there, though I am a bit surprised that you would admit it
in public.
I don't understand why you use the word 'admit'. I make my own tools to >meet my particular requirements, there is nothing shameful about that.
You have been admonished by Sloman. Confess your errors and beg
forgiveness.
Have you used LT Spice? It's easy to learn and is great fun. I(t makes
time for snacking and napping too.
john larkin <jl@glen--canyon.com> wrote:
On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid >>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk> >>>>>>>> wrote:[...]
plugging numbers pulled out of thin air into LTSpice is better that >>>>>>>>> doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed >>>>>>> to use analogue computing to work out his designs i.e. He built >>>>>>> prototypes and measured them.
You youngsters probably don't remember a time when there wasn't
Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first >>>>>> PC sim program was Tatum labs ECA, which required a typed netlist. >>>>>> But it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships
between resistance, capacitance, frequency and time constant (put in >>>>> two and the others appear, put in three and the error% appears). It >>>>> also gives dB loss below or above the 'cutoff' frequency. Some years >>>>> ago I also made some lookup tables for combinations of 5% tolerance
resistors in series and parallel.
Those and a pocket calculator are still the only 'computing' I use
for design work.
No surprise there, though I am a bit surprised that you would admit it >>>> in public.
I don't understand why you use the word 'admit'. I make my own tools to >>> meet my particular requirements, there is nothing shameful about that.
You have been admonished by Sloman. Confess your errors and beg
forgiveness.
My reply to that had anatomical connotations. :-)
Have you used LT Spice? It's easy to learn and is great fun. I(t makes
time for snacking and napping too.
I don't think they ever did a version that would run on a Mac G3 (OS
8.6), which is my main workhorse.
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid >>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk> >>>>>>>> wrote:[...]
plugging numbers pulled out of thin air into LTSpice is better that >>>>>>>>> doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed >>>>>>> to use analogue computing to work out his designs i.e. He built >>>>>>> prototypes and measured them.
You youngsters probably don't remember a time when there wasn't
Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first >>>>>> PC sim program was Tatum labs ECA, which required a typed netlist. >>>>>> But it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships
between resistance, capacitance, frequency and time constant (put in >>>>> two and the others appear, put in three and the error% appears). It >>>>> also gives dB loss below or above the 'cutoff' frequency. Some years >>>>> ago I also made some lookup tables for combinations of 5% tolerance >>>>> resistors in series and parallel.
Those and a pocket calculator are still the only 'computing' I use >>>>> for design work.
No surprise there, though I am a bit surprised that you would admit it >>>> in public.
I don't understand why you use the word 'admit'. I make my own tools to >>> meet my particular requirements, there is nothing shameful about that.
You have been admonished by Sloman. Confess your errors and beg
forgiveness.
My reply to that had anatomical connotations. :-)
Have you used LT Spice? It's easy to learn and is great fun. I(t makes
time for snacking and napping too.
I don't think they ever did a version that would run on a Mac G3 (OS
8.6), which is my main workhorse.
I’ve been running LTspice using Wine on Linux for 15 years or so, no problems. Wine runs fine on both x86 and apple silicon, I’m told.
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use
analogue computing to work out his designs i.e. He built prototypes and
measured them.
You youngsters probably don't remember a time when there wasn't Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships between >resistance, capacitance, frequency and time constant (put in two and the >others appear, put in three and the error% appears). It also gives dB
loss below or above the 'cutoff' frequency. Some years ago I also made
some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
Those and a pocket calculator are still the only 'computing' I use for
design work.
He was remarkably good, just not totally perfect.
His footnote reference to "squegging" in the 1959 class-D oscillator
paper is another minor drop-off. He can't be blamed for it, but a
super-hero might have done better.
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:You have been admonished by Sloman. Confess your errors and beg
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid >> >>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed
to use analogue computing to work out his designs i.e. He built
prototypes and measured them.
You youngsters probably don't remember a time when there wasn't
Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first >> >>>>>> PC sim program was Tatum labs ECA, which required a typed netlist.
But it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships
between resistance, capacitance, frequency and time constant (put in >> >>>>> two and the others appear, put in three and the error% appears). It >> >>>>> also gives dB loss below or above the 'cutoff' frequency. Some years >> >>>>> ago I also made some lookup tables for combinations of 5% tolerance
resistors in series and parallel.
Those and a pocket calculator are still the only 'computing' I use
for design work.
No surprise there, though I am a bit surprised that you would admit it >> >>>> in public.
I don't understand why you use the word 'admit'. I make my own tools to >> >>> meet my particular requirements, there is nothing shameful about that. >> >>
forgiveness.
My reply to that had anatomical connotations. :-)
Have you used LT Spice? It's easy to learn and is great fun. I(t makes
time for snacking and napping too.
I don't think they ever did a version that would run on a Mac G3 (OS
8.6), which is my main workhorse.
I’ve been running LTspice using Wine on Linux for 15 years or so, no
problems. Wine runs fine on both x86 and apple silicon, I’m told.
A G3 won't run Linux or any of the OSX applications.
On Sat, 26 Oct 2024 12:41:05 +0100, liz@poppyrecords.invalid.invalid[...]
(Liz Tuddenham) wrote:
A G3 won't run Linux or any of the OSX applications.
Yeah. Linux will run on anything that will run Windows on Intel.
Which modern Intel Macs will do. I have such a Mac, and run both
MacOS and Windows on it. I bet that the new Apple silicon will run
Windows in emulation as well.
john larkin <jl@glen--canyon.com> wrote:
On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid >> >> >> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>[...]
wrote:
plugging numbers pulled out of thin air into LTSpice is better that >> >> >>>>> doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed
to use analogue computing to work out his designs i.e. He built
prototypes and measured them.
You youngsters probably don't remember a time when there wasn't
Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first >> >> >> PC sim program was Tatum labs ECA, which required a typed netlist.
But it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships
between resistance, capacitance, frequency and time constant (put in
two and the others appear, put in three and the error% appears). It >> >> > also gives dB loss below or above the 'cutoff' frequency. Some years >> >> > ago I also made some lookup tables for combinations of 5% tolerance
resistors in series and parallel.
Those and a pocket calculator are still the only 'computing' I use
for design work.
No surprise there, though I am a bit surprised that you would admit it
in public.
I don't understand why you use the word 'admit'. I make my own tools to
meet my particular requirements, there is nothing shameful about that.
You have been admonished by Sloman. Confess your errors and beg
forgiveness.
My reply to that had anatomical connotations. :-)
Have you used LT Spice? It's easy to learn and is great fun. I(t makes
time for snacking and napping too.
I don't think they ever did a version that would run on a Mac G3 (OS
8.6), which is my main workhorse.
Joe Gwinn <joegwinn@comcast.net> wrote:
On Sat, 26 Oct 2024 12:41:05 +0100, liz@poppyrecords.invalid.invalid[...]
(Liz Tuddenham) wrote:
A G3 won't run Linux or any of the OSX applications.
Yeah. Linux will run on anything that will run Windows on Intel.
Which modern Intel Macs will do. I have such a Mac, and run both
MacOS and Windows on it. I bet that the new Apple silicon will run
Windows in emulation as well.
This machine is a G3 running Mac OS 8.6, it is not Intel-based and
cannot run Windows or Linux or OSX.
Joe Gwinn <joegwinn@comcast.net> wrote:
On Sat, 26 Oct 2024 12:41:05 +0100, liz@poppyrecords.invalid.invalid[...]
(Liz Tuddenham) wrote:
A G3 won't run Linux or any of the OSX applications.
Yeah. Linux will run on anything that will run Windows on Intel.
Which modern Intel Macs will do. I have such a Mac, and run both
MacOS and Windows on it. I bet that the new Apple silicon will run
Windows in emulation as well.
This machine is a G3 running Mac OS 8.6, it is not Intel-based and
cannot run Windows or Linux or OSX.
I'm designing a small PCB with essentially 5 sync buck switching
regulators. Board space is tight so I want to put the inductors on the
bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
On 23-10-2024 19:22, john larkin wrote:
I'm designing a small PCB with essentially 5 sync buck switchingThe proximity of the aluminum is probably close to the effects of having >ground plane or not below the inductor.
regulators. Board space is tight so I want to put the inductors on the
bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good
cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133 >>
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
Steve Sandler has tested this:
https://www.signalintegrityjournal.com/blogs/17-practical-emc/post/2694-dc-dc-converters-solid-return-plane-or-cutouts-under-switch-node-and-inductor
Found very little effect.
Similar test:
https://www.monolithicpower.com/en/learning/resources/when-is-it-beneficial-to-place-a-copper-layer-beneath-dc-dc-power-supplies?srsltid=AfmBOoq_cYcCoGN57iR4TXaq9n4hlYK1VWLt5m6yYGpVBdRF6RF7L7hz
On Fri, 25 Oct 2024 16:08:08 +1100, Bill Sloman <bill.sloman@ieee.org>
wrote:
<snip>
He was remarkably good, just not totally perfect.
His footnote reference to "squegging" in the 1959 class-D oscillator
paper is another minor drop-off. He can't be blamed for it, but a
super-hero might have done better.
What's wrong with 'squegging' ? It's a simple word that covers
a host of faults that all give the same approximate symptom . .
On 27/10/2024 2:20 am, legg wrote:
On Fri, 25 Oct 2024 16:08:08 +1100, Bill Sloman <bill.sloman@ieee.org>
wrote:
<snip>
He was remarkably good, just not totally perfect.
His footnote reference to "squegging" in the 1959 class-D oscillator
paper is another minor drop-off. He can't be blamed for it, but a
super-hero might have done better.
What's wrong with 'squegging' ? It's a simple word that covers
a host of faults that all give the same approximate symptom . .
With the advantage of 65 years of hindsight, it looks as if what he was >seeing was gain in bipolar transistors running in the inverted mode.
"Squegging" was mostly used for weird oscillations in resonant circuits.
Class-D oscillators built with MOSFet switches don't squeg. Class-D >oscillators built with bipolar transistors in LTSpice don't squeg either
- the Gummel-Poon transistor model doesn't model inverted mode behavior
all that well.
On Sun, 27 Oct 2024 15:01:34 +1100, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 27/10/2024 2:20 am, legg wrote:
On Fri, 25 Oct 2024 16:08:08 +1100, Bill Sloman <bill.sloman@ieee.org>
wrote:
<snip>
He was remarkably good, just not totally perfect.
His footnote reference to "squegging" in the 1959 class-D oscillator
paper is another minor drop-off. He can't be blamed for it, but a
super-hero might have done better.
What's wrong with 'squegging' ? It's a simple word that covers
a host of faults that all give the same approximate symptom . .
With the advantage of 65 years of hindsight, it looks as if what he was
seeing was gain in bipolar transistors running in the inverted mode.
"Squegging" was mostly used for weird oscillations in resonant circuits.
Class-D oscillators built with MOSFet switches don't squeg. Class-D
oscillators built with bipolar transistors in LTSpice don't squeg either
- the Gummel-Poon transistor model doesn't model inverted mode behavior
all that well.
Squegging in any oscillatory circuit, driven or otherwise,
describes widely varying amplitudes that typically approach
self-quenching and can otherwise approach unintentional
overstess in the 'wobulating' cycle.
Not what the doctor ordered, or the designer anticipated.
Only blocking oscillators do it on purpose.
On 28/10/2024 3:43 am, legg wrote:
On Sun, 27 Oct 2024 15:01:34 +1100, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 27/10/2024 2:20 am, legg wrote:
On Fri, 25 Oct 2024 16:08:08 +1100, Bill Sloman <bill.sloman@ieee.org> >>>> wrote:
<snip>
He was remarkably good, just not totally perfect.
His footnote reference to "squegging" in the 1959 class-D oscillator >>>>> paper is another minor drop-off. He can't be blamed for it, but a
super-hero might have done better.
What's wrong with 'squegging' ? It's a simple word that covers
a host of faults that all give the same approximate symptom . .
With the advantage of 65 years of hindsight, it looks as if what he was
seeing was gain in bipolar transistors running in the inverted mode.
"Squegging" was mostly used for weird oscillations in resonant circuits. >>>
Class-D oscillators built with MOSFet switches don't squeg. Class-D
oscillators built with bipolar transistors in LTSpice don't squeg either >>> - the Gummel-Poon transistor model doesn't model inverted mode behavior
all that well.
Squegging in any oscillatory circuit, driven or otherwise,
describes widely varying amplitudes that typically approach
self-quenching and can otherwise approach unintentional
overstess in the 'wobulating' cycle.
Not what the doctor ordered, or the designer anticipated.
Only blocking oscillators do it on purpose.
What Baxandall was describing was a situation where you've built a
class-D oscillator and used a feed inductor which has an appreciably
higher inductance than the inverter transformer.
If you simulate that in LTSpice, the voltage at the centre tap starts
off climbing up to about twice the steady-state peak and drops below the
rail during recovery, but this roller-coaster effect dies away. In real
life it doesn't (if you are using bipolar transistor for your switches).
My guess is that you could stop it by adding the right zener diode
between the centre tap and ground - one that didn't ever conduct when
the circuit was running smoothly, but would start conducting if the
centre tap got much above the steady state peak. This stops the
centre-tap ever getting below the rail at the bottom of the start-up
roller coaster - or at least it does in LTSpice and would keep you away
from the mode of operation where the switching transistors were
operating in the inverted mode.
Peter Baxandall invented the circuit before 1959, before Zener diodes
were widely available.
Bill Sloman <bill.sloman@ieee.org> wrote:
On 28/10/2024 3:43 am, legg wrote:
On Sun, 27 Oct 2024 15:01:34 +1100, Bill Sloman <bill.sloman@ieee.org>
wrote:
On 27/10/2024 2:20 am, legg wrote:
On Fri, 25 Oct 2024 16:08:08 +1100, Bill Sloman <bill.sloman@ieee.org> >>>>> wrote:
<snip>
He was remarkably good, just not totally perfect.
His footnote reference to "squegging" in the 1959 class-D oscillator >>>>>> paper is another minor drop-off. He can't be blamed for it, but a
super-hero might have done better.
What's wrong with 'squegging' ? It's a simple word that covers
a host of faults that all give the same approximate symptom . .
With the advantage of 65 years of hindsight, it looks as if what he was >>>> seeing was gain in bipolar transistors running in the inverted mode.
"Squegging" was mostly used for weird oscillations in resonant circuits. >>>>
Class-D oscillators built with MOSFet switches don't squeg. Class-D
oscillators built with bipolar transistors in LTSpice don't squeg either >>>> - the Gummel-Poon transistor model doesn't model inverted mode behavior >>>> all that well.
Squegging in any oscillatory circuit, driven or otherwise,
describes widely varying amplitudes that typically approach
self-quenching and can otherwise approach unintentional
overstess in the 'wobulating' cycle.
Not what the doctor ordered, or the designer anticipated.
Only blocking oscillators do it on purpose.
What Baxandall was describing was a situation where you've built a
class-D oscillator and used a feed inductor which has an appreciably
higher inductance than the inverter transformer.
If you simulate that in LTSpice, the voltage at the centre tap starts
off climbing up to about twice the steady-state peak and drops below the
rail during recovery, but this roller-coaster effect dies away. In real
life it doesn't (if you are using bipolar transistor for your switches).
My guess is that you could stop it by adding the right zener diode
between the centre tap and ground - one that didn't ever conduct when
the circuit was running smoothly, but would start conducting if the
centre tap got much above the steady state peak. This stops the
centre-tap ever getting below the rail at the bottom of the start-up
roller coaster - or at least it does in LTSpice and would keep you away
from the mode of operation where the switching transistors were
operating in the inverted mode.
Peter Baxandall invented the circuit before 1959, before Zener diodes
were widely available.
That topology is very critical around conduction overlap vs dead band and nano seconds matter.
On Sun, 27 Oct 2024 01:14:45 +0200, Klaus Vestergaard Kragelund <klauskvik@hotmail.com> wrote:
On 23-10-2024 19:22, john larkin wrote:
I'm designing a small PCB with essentially 5 sync buck switchingThe proximity of the aluminum is probably close to the effects of having
regulators. Board space is tight so I want to put the inductors on the
bottom of the multilayer board. There's a 0.2" gap between the bottom
of the board and a big aluminum flange.
Unshielded drum cores have the most energy storage per volume or
dollars. They store energy in the universe instead of in ferrite. Good
cooling too.
Something like this just fits
https://www.digikey.com/en/products/detail/bourns-inc/SRN8040TA-470M/6155133
Its mag field lines will bounce off the PCB planes and the flange,
change from the classic bar magnet pattern into a pancake . I wonder
what that will do to its electrical behavior.
ground plane or not below the inductor.
Steve Sandler has tested this:
https://www.signalintegrityjournal.com/blogs/17-practical-emc/post/2694-dc-dc-converters-solid-return-plane-or-cutouts-under-switch-node-and-inductor
Found very little effect.
Similar test:
https://www.monolithicpower.com/en/learning/resources/when-is-it-beneficial-to-place-a-copper-layer-beneath-dc-dc-power-supplies?srsltid=AfmBOoq_cYcCoGN57iR4TXaq9n4hlYK1VWLt5m6yYGpVBdRF6RF7L7hz
They seem mostly concerned with EMI, which isn't a concern for me now.
I just wanted to be sure that the inductor would work in the switching regulator, sandwiched close between a multilayer PCB and the aluminum baseplate.
My 48-to-5-volt switcher should be OK. The load current is low so I
can use a lot of microhenries if needed. If I trust my AADE LC-meter,
L drops roughly 20% when the inductor is squeezed between the
conductive things.
The four half-bridge power switchers are more concerning. I think
we'll try to make room for four giant shielded inductors on the parts
side of that section... move other things to the bottom of the board.
Our policy is for PCB layer 2 to be a solid ground plane, and we very
rarely chop holes in that.
On Sat, 26 Oct 2024 12:41:05 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
john larkin <jl@glen--canyon.com> wrote:
On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
Bill Sloman <bill.sloman@ieee.org> wrote:You have been admonished by Sloman. Confess your errors and beg
On 25/10/2024 7:37 pm, Liz Tuddenham wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid >>> >>>>>> (Liz Tuddenham) wrote:
john larkin <jl@glen--canyon.com> wrote:
On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk> >>> >>>>>>>> wrote:[...]
plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?
It is for people who don't actually work with real parts.
Peter Baxandall (of tone control and QUAD amplifier fame) claimed >>> >>>>>>> to use analogue computing to work out his designs i.e. He built >>> >>>>>>> prototypes and measured them.
You youngsters probably don't remember a time when there wasn't
Spice.
Hey!!! Who are you calling a youngster?!!! :-)
I did some simulation in Basic-Plus, and it was a nuisance. My first >>> >>>>>> PC sim program was Tatum labs ECA, which required a typed netlist. >>> >>>>>> But it was pretty cool.
I have a spreadsheet I wrote for calculating the relationships
between resistance, capacitance, frequency and time constant (put in >>> >>>>> two and the others appear, put in three and the error% appears). It >>> >>>>> also gives dB loss below or above the 'cutoff' frequency. Some years >>> >>>>> ago I also made some lookup tables for combinations of 5% tolerance >>> >>>>> resistors in series and parallel.
Those and a pocket calculator are still the only 'computing' I use >>> >>>>> for design work.
No surprise there, though I am a bit surprised that you would admit it >>> >>>> in public.
I don't understand why you use the word 'admit'. I make my own tools to
meet my particular requirements, there is nothing shameful about that. >>> >>
forgiveness.
My reply to that had anatomical connotations. :-)
Have you used LT Spice? It's easy to learn and is great fun. I(t makes >>> >> time for snacking and napping too.
I don't think they ever did a version that would run on a Mac G3 (OS
8.6), which is my main workhorse.
I’ve been running LTspice using Wine on Linux for 15 years or so, no >>> problems. Wine runs fine on both x86 and apple silicon, I’m told.
A G3 won't run Linux or any of the OSX applications.
Yeah. Linux will run on anything that will run Windows on Intel.
Which modern Intel Macs will do. I have such a Mac, and run both
MacOS and Windows on it. I bet that the new Apple silicon will run
Windows in emulation as well.
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