OT: UK to move back to imperial units?

[Dimiter_Popoff]

On 7/29/2019 16:01, Cursitor Doom wrote:

On Mon, 29 Jul 2019 13:54:52 +0300, Dimiter_Popoff wrote:

How do they manage to recruit you trolls all of you being cast using the
same form I'll never know.

AFAICS, you're the troll on here. A couple of days ago you were claiming
to be an honest broker but that facade didn't last long, did it? You're
obviously one of the many clowns that inhabit my killfile and you've
crawled out under a new nym just to vent your spleen; you didn't fool me
for a single minute. You're probably Bill Sloman and ICTFP.
"Dimiter_Popoff" indeed LOL!

Yeah yeah, more standard troll babble. You have already seen my website,
you know who I am and what I do. Oops, the logs say it was looked at
from St. Petersburg 1-2 days ago, after my first post here for a long
time. The location of the russian troll farms, sure you have nothing
to do with them, I know, I know.

Like I said, they cast you all using the same form. Not so hard to
understand why really, who would enlist as a russian propaganda troll
if they were able to do something useful.

And don't try too hard to convince people here who I am, most of them
have known me for many years. Many years before they assigned you to
troll this group.

Dimiter

======================================================
Dimiter Popoff, TGI http://www.tgi-sci.com
======================================================
http://www.flickr.com/photos/didi_tgi/

 

[Phil Hobbs]

On 7/29/19 12:48 PM, John Larkin wrote:

On Mon, 29 Jul 2019 12:13:25 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/29/19 11:41 AM, John Larkin wrote:
On Mon, 29 Jul 2019 10:12:19 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/27/19 9:21 PM, John Larkin wrote:
On Sat, 27 Jul 2019 12:36:27 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:


UK to move back to imperial units?
https://www.theguardian.com/politics/2019/jul/26/the-comma-touch-jacob-rees-mogg-sends-language-rules-to-staff

Now all we need is Pi = 3 (or 4)


2pi = 6 is usually close enough.

It's a game in our place to do math in our heads, standing at the
whiteboard.

Ours too.


Does that RC time constant affect the loop? Think for three or four
seconds and decide.

Newbies and visitors are impressed.

I would find it very difficult to design things if I didn't have a
pretty accurate feel for the magnitudes of different effects, e.g. the
parallel capacitance of a resistor.

Cheers

Phil Hobbs

The mental math is analog, like a slide rule, not actual arithmetic.
There are tricks, like crudely approximating a few constants and
reciprocals and logs, that get within 25% or so of the right answer.
That's close enough to decide whether it's worth grabbing a calculator
or running Spice.

I do a bit of both. Memorizing a few facts helps too, e.g. for thermal
vias, PTH copper is about 40-um thick and small vias (10 mil) are mostly
copper.

We have debated here about whether to pave a copper pour with a lot of
small vias or a fewer number of big ones.

You get more copper per square by using the smallest vias that get the
full metal thickness down in the middle. With a 40-micron copper
thickness, a 10-mil finished hole (250 um) has an unfinished diameter of
250+80 um, i.e.

pi/4*(330 um)**2 = 0.086 mm**2

and the finished hole's area is

pi/4*(250 um)**2 = 0.049 mm**2

so the hole area is 1 - 0.049/0.086 = 42% copper. Plated copper's
alpha is about 380 W/m/K, and FR-4's is about 0.25 W/m/K. So assuming
perfect heat spreaders on both sides, a 1.6 mm board with a rectangular
array of these holes spaced by a distance d will have a thermal
conductance per square metre of

1/theta(d) = (0.049E-6*380/d**2 + 0.25)/0.0016.

For holes on 1.5 mm pitch, this is 5300 W/K/m**2. For a square
centimetre of thermal pad, we get 1E-4 square metres, so

theta = 1/0.53 ~ 2 K/W, not bad, and that's only a 6 x 6 array of holes.

Cheers

Phil Hobbs





You can get 0.2 W/K

I do a lot of "photon budgets", which are basically feasibility
calculations mostly based on first principles and material properties.
It's a lot easier to know how your design is doing when you know how
good it could potentially be, so you know how close you are.

I've been working like a maniac the last couple of years, but once I get
my third edition submitted, I'm hoping to string a bunch of photon
budgets together into another book. It's a very useful skill that
should be more widely distributed.


Like the old GR "lightning empiricism" game.

Yup. Wasn't that Philbrick? ISTR stealing the idea from a Pease column.

Cheers

Phil Hobbs

Right, it was Philbrick. There's a section in one of Jim Williams'
books about that.

There used to be technology in Massachusetts!

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Allison]

Cursitor Doom wrote:

Dimiter_Popoff wrote:

And don't try too hard to convince people here who I am, most of them
have known me for many years. Many years before they assigned you to
troll this group.


Balderdash. I've been reading and posting to this group regularly since
the mid 1990s under various guises and I don't remember you *at all*
during all that time - despite having a *very* good memory for such
things. If you're not Bill Sloman then you're Phil Alison; I'd put money
on it.

** Very funny.

Neither Bill or I have ever used a "handle" or "sock puppet" and are not using them now.

I don't need to hide behind a stupid mask like you do nor think it one tiny bit fair to attack a poster while remaining anonymous.

Only cowards do that.

Why don't you change your handle to " Complete Dickhead "

It has the same initials and is way more descriptive.



.... Phil

 

[Cursitor Doom]

On Mon, 29 Jul 2019 12:14:25 -0400, Phil Hobbs wrote:

> He's just being a Panteltje. We're used to it round here.

Thanks for clearing that up, Phil. I was beginning to wonder.



--
This message may be freely reproduced without limit or charge only via
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protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

[Cursitor Doom]

On Mon, 29 Jul 2019 22:45:12 +0300, Dimiter_Popoff wrote:

And don't try too hard to convince people here who I am, most of them
have known me for many years. Many years before they assigned you to
troll this group.

Balderdash. I've been reading and posting to this group regularly since
the mid 1990s under various guises and I don't remember you *at all*
during all that time - despite having a *very* good memory for such
things. If you're not Bill Sloman then you're Phil Alison; I'd put money
on it.



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

 

[Chris]

On 07/29/19 23:59, Cursitor Doom wrote:

On Mon, 29 Jul 2019 12:14:25 -0400, Phil Hobbs wrote:

He's just being a Panteltje. We're used to it round here.

Thanks for clearing that up, Phil. I was beginning to wonder.

Reece Mogg is old school english, but I don't have a problem
with that. If he wants so specify rules in his own office,
then fair enough, though the left wing msm will present it in
the most prejudicial way possible, as usual...

Chris

 

[Tom Gardner]

On 30/07/19 00:11, Chris wrote:

On 07/29/19 23:59, Cursitor Doom wrote:
On Mon, 29 Jul 2019 12:14:25 -0400, Phil Hobbs wrote:

He's just being a Panteltje. We're used to it round here.

Thanks for clearing that up, Phil. I was beginning to wonder.


Reece Mogg is old school english, but I don't have a problem
with that. If he wants so specify rules in his own office,

The problem arises when he imposes it on the whole country
(which, as a lawmaker, he has done), or makes the UK look
stupid (which he does with his "metric is bad" stuff).

Presumably he wants to measure capacitance in Jars.

then fair enough, though the left wing msm will present it in
the most prejudicial way possible, as usual...

Ah. A fanatic that sees something and automatically
presumes a conspiracy.

 

[John Larkin]

On Mon, 29 Jul 2019 18:33:27 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/29/19 12:48 PM, John Larkin wrote:
On Mon, 29 Jul 2019 12:13:25 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/29/19 11:41 AM, John Larkin wrote:
On Mon, 29 Jul 2019 10:12:19 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/27/19 9:21 PM, John Larkin wrote:
On Sat, 27 Jul 2019 12:36:27 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:


UK to move back to imperial units?
https://www.theguardian.com/politics/2019/jul/26/the-comma-touch-jacob-rees-mogg-sends-language-rules-to-staff

Now all we need is Pi = 3 (or 4)


2pi = 6 is usually close enough.

It's a game in our place to do math in our heads, standing at the
whiteboard.

Ours too.


Does that RC time constant affect the loop? Think for three or four
seconds and decide.

Newbies and visitors are impressed.

I would find it very difficult to design things if I didn't have a
pretty accurate feel for the magnitudes of different effects, e.g. the
parallel capacitance of a resistor.

Cheers

Phil Hobbs

The mental math is analog, like a slide rule, not actual arithmetic.
There are tricks, like crudely approximating a few constants and
reciprocals and logs, that get within 25% or so of the right answer.
That's close enough to decide whether it's worth grabbing a calculator
or running Spice.

I do a bit of both. Memorizing a few facts helps too, e.g. for thermal
vias, PTH copper is about 40-um thick and small vias (10 mil) are mostly
copper.

We have debated here about whether to pave a copper pour with a lot of
small vias or a fewer number of big ones.

You get more copper per square by using the smallest vias that get the
full metal thickness down in the middle. With a 40-micron copper
thickness, a 10-mil finished hole (250 um) has an unfinished diameter of
250+80 um, i.e.

pi/4*(330 um)**2 = 0.086 mm**2

and the finished hole's area is

pi/4*(250 um)**2 = 0.049 mm**2

so the hole area is 1 - 0.049/0.086 = 42% copper. Plated copper's
alpha is about 380 W/m/K, and FR-4's is about 0.25 W/m/K. So assuming
perfect heat spreaders on both sides, a 1.6 mm board with a rectangular
array of these holes spaced by a distance d will have a thermal
conductance per square metre of

1/theta(d) = (0.049E-6*380/d**2 + 0.25)/0.0016.

For holes on 1.5 mm pitch, this is 5300 W/K/m**2. For a square
centimetre of thermal pad, we get 1E-4 square metres, so

theta = 1/0.53 ~ 2 K/W, not bad, and that's only a 6 x 6 array of holes.

Cheers

Phil Hobbs





You can get 0.2 W/K




I do a lot of "photon budgets", which are basically feasibility
calculations mostly based on first principles and material properties.
It's a lot easier to know how your design is doing when you know how
good it could potentially be, so you know how close you are.

I've been working like a maniac the last couple of years, but once I get
my third edition submitted, I'm hoping to string a bunch of photon
budgets together into another book. It's a very useful skill that
should be more widely distributed.


Like the old GR "lightning empiricism" game.

Yup. Wasn't that Philbrick? ISTR stealing the idea from a Pease column.

Cheers

Phil Hobbs

Right, it was Philbrick. There's a section in one of Jim Williams'
books about that.

There used to be technology in Massachusetts!

My production people don't like vias in pads, so a dpak or SOT89 or
whatever needs to have a solid pad, then a region of solder-masked
topside copper, then copper with a lot of vias. That will work for my
dpak resistor, and I'd be happy to get somewhere near, say, 6 to 8 k/w
overall.

That scheme doesn't work well for power pad parts that have leads all
around. They just have to deal with vias in the pads.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

That scheme doesn't work well for power pad parts that have leads all
around. They just have to deal with vias in the pads.

Empty vias in pads can suck up solder and leave voids, it's true. But there are lots of ways round that.

For one thing, large featureless pads typically get too much paste, which can cause open circuits in neighbouring leads of the same part. There's a happy medium someplace.

Cheers

Phil Hobbs

 

[Martin Brown]

On 29/07/2019 15:12, Phil Hobbs wrote:

On 7/27/19 9:21 PM, John Larkin wrote:
On Sat, 27 Jul 2019 12:36:27 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:


UK to move back to imperial units?
https://www.theguardian.com/politics/2019/jul/26/the-comma-touch-jacob-rees-mogg-sends-language-rules-to-staff


Now all we need is Pi = 3 (or 4)


2pi = 6 is usually close enough.

It's a game in our place to do math in our heads, standing at the
whiteboard.

Ours too.


Does that RC time constant affect the loop? Think for three or four
seconds and decide.

Newbies and visitors are impressed.

I would find it very difficult to design things if I didn't have a
pretty accurate feel for the magnitudes of different effects, e.g. the
parallel capacitance of a resistor.

I agree.

That is one thing that has been lost in the modern era of graphing
calculators and spreadsheets everywhere.

People have lost the ability to sanity check their calculations to the
nearest order of magnitude (as you always had to do when using a SR).

--
Regards,
Martin Brown

 

[Phil Allison]

Martin Brown wrote:

That is one thing that has been lost in the modern era of graphing
calculators and spreadsheets everywhere.

People have lost the ability to sanity check their calculations to the
nearest order of magnitude (as you always had to do when using a SR).

** SR = slide rule - right ?

I still have mine from Sydney University Engineering days.

It's a Castell "Electro" in good working order and resides in it's original case from the very early 70s.

Honestly, I have almost totally forgotten how to use the darn thing.

Who remembers the old joke common in large computer installations where a similar rule was enclosed in a glass case on the wall ?



..... Phil

 

[Jeroen Belleman]

Martin Brown wrote:

On 29/07/2019 15:12, Phil Hobbs wrote:
On 7/27/19 9:21 PM, John Larkin wrote:
On Sat, 27 Jul 2019 12:36:27 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:


UK to move back to imperial units?
https://www.theguardian.com/politics/2019/jul/26/the-comma-touch-jacob-rees-mogg-sends-language-rules-to-staff



Now all we need is Pi = 3 (or 4)


2pi = 6 is usually close enough.

It's a game in our place to do math in our heads, standing at
the whiteboard.

Ours too.


Does that RC time constant affect the loop? Think for three or
four seconds and decide.

Newbies and visitors are impressed.

I would find it very difficult to design things if I didn't have
a pretty accurate feel for the magnitudes of different effects,
e.g. the parallel capacitance of a resistor.

I agree.

That is one thing that has been lost in the modern era of graphing
calculators and spreadsheets everywhere.

People have lost the ability to sanity check their calculations to
the nearest order of magnitude (as you always had to do when using
a SR).

I don't think that is true. Sanity checking is something that
you acquire with experience. Young people will get there, little
by little. And then *they* start complaining that the *next*
generation has "lost" that ability. It has always been thus.

Jeroen Belleman

 

[Phil Allison]

Jeroen Belleman wrote:

Martin Brown wrote:

People have lost the ability to sanity check their calculations to
the nearest order of magnitude (as you always had to do when using
a SR).


I don't think that is true. Sanity checking is something that
you acquire with experience. Young people will get there, little
by little. And then *they* start complaining that the *next*
generation has "lost" that ability. It has always been thus.

** Sanity checking a SR result mainly depends on the ability to do mental arithmetic.

However, knowing what the right answer should look like IS mostly due to experience - but many calculator or computer simulation errors are so big accepting them is like believing the moon is actually made of green cheese.



...... Phil

 

[Martin Brown]

On 30/07/2019 00:11, Chris wrote:

On 07/29/19 23:59, Cursitor Doom wrote:
On Mon, 29 Jul 2019 12:14:25 -0400, Phil Hobbs wrote:

He's just being a Panteltje. We're used to it round here.

Thanks for clearing that up, Phil. I was beginning to wonder.

Reece Mogg is old school english, but I don't have a problem
with that. If he wants so specify rules in his own office,
then fair enough, though the left wing msm will present it in
the most prejudicial way possible, as usual...

He is pretty much the epitome of a nineteenth century rich landed gentry
from an old money family. He might yet even make a decent Leader of the
House (it is difficult to see how he could be any worse than Leadsom).

I wonder if he knows the difference between the commonly used:

I would be obliged if you could <do something for me>

and the original correct grammatical form:

I should be obliged if you would <do something for me>

When I was at school English grammar was only taught to people studying
foreign languages and nothing beyond basic subject, object and verb in
English class. I understand it has been dumbed down even further now.

Most of what I know about English grammar is from Latin classes.

--
Regards,
Martin Brown

PS spoiler alert answer a few lines below









The first form is actually a subtle insult implying that you do not
believe them to be capable of doing the action you request. This
grammatical quirk is for some strange reason still taught to overseas
students studying English as a foreign language but not in UK schools.
It is completely lost on most native English speakers today.

 

[Martin Brown]

On 30/07/2019 10:10, Jeroen Belleman wrote:

Martin Brown wrote:
On 29/07/2019 15:12, Phil Hobbs wrote:
On 7/27/19 9:21 PM, John Larkin wrote:
On Sat, 27 Jul 2019 12:36:27 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:


UK to move back to imperial units?
https://www.theguardian.com/politics/2019/jul/26/the-comma-touch-jacob-rees-mogg-sends-language-rules-to-staff




Now all we need is Pi = 3 (or 4)


2pi = 6 is usually close enough.

It's a game in our place to do math in our heads, standing at
the whiteboard.

Ours too.


Does that RC time constant affect the loop? Think for three or
four seconds and decide.

Newbies and visitors are impressed.

I would find it very difficult to design things if I didn't have
a pretty accurate feel for the magnitudes of different effects,
e.g. the parallel capacitance of a resistor.

I agree.

That is one thing that has been lost in the modern era of graphing
 calculators and spreadsheets everywhere.

People have lost the ability to sanity check their calculations to
the nearest order of magnitude (as you always had to do when using
a SR).


I don't think that is true. Sanity checking is something that
you acquire with experience.  Young people will get there, little
by little. And then *they* start complaining that the *next*
generation has "lost" that ability. It has always been thus.

I'll agree that the previous generation always complains about the next
generation's inability to do things we consider simple. But when you
were using a slide rule you pretty much had to carry the exponent in
your head. Today's calculator users trust whatever number it spits out.

I fairly often used mental arithmetic where I could but marked it SR.
It saved a heck of a lot of time compared to using log tables.

--
Regards,
Martin Brown

 

[George Herold]

On Monday, July 29, 2019 at 6:33:34 PM UTC-4, Phil Hobbs wrote:

On 7/29/19 12:48 PM, John Larkin wrote:
On Mon, 29 Jul 2019 12:13:25 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/29/19 11:41 AM, John Larkin wrote:
On Mon, 29 Jul 2019 10:12:19 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/27/19 9:21 PM, John Larkin wrote:
On Sat, 27 Jul 2019 12:36:27 GMT, Jan Panteltje
pNaOnStPeAlMtje@yahoo.com> wrote:


UK to move back to imperial units?
https://www.theguardian.com/politics/2019/jul/26/the-comma-touch-jacob-rees-mogg-sends-language-rules-to-staff

Now all we need is Pi = 3 (or 4)


2pi = 6 is usually close enough.

It's a game in our place to do math in our heads, standing at the
whiteboard.

Ours too.


Does that RC time constant affect the loop? Think for three or four
seconds and decide.

Newbies and visitors are impressed.

I would find it very difficult to design things if I didn't have a
pretty accurate feel for the magnitudes of different effects, e.g. the
parallel capacitance of a resistor.

Cheers

Phil Hobbs

The mental math is analog, like a slide rule, not actual arithmetic.
There are tricks, like crudely approximating a few constants and
reciprocals and logs, that get within 25% or so of the right answer.
That's close enough to decide whether it's worth grabbing a calculator
or running Spice.

I do a bit of both. Memorizing a few facts helps too, e.g. for thermal
vias, PTH copper is about 40-um thick and small vias (10 mil) are mostly
copper.

We have debated here about whether to pave a copper pour with a lot of
small vias or a fewer number of big ones.

You get more copper per square by using the smallest vias that get the
full metal thickness down in the middle. With a 40-micron copper
thickness, a 10-mil finished hole (250 um) has an unfinished diameter of
250+80 um, i.e.

pi/4*(330 um)**2 = 0.086 mm**2

and the finished hole's area is

pi/4*(250 um)**2 = 0.049 mm**2

so the hole area is 1 - 0.049/0.086 = 42% copper. Plated copper's
alpha is about 380 W/m/K, and FR-4's is about 0.25 W/m/K. So assuming
perfect heat spreaders on both sides, a 1.6 mm board with a rectangular
array of these holes spaced by a distance d will have a thermal
conductance per square metre of

1/theta(d) = (0.049E-6*380/d**2 + 0.25)/0.0016.

For holes on 1.5 mm pitch, this is 5300 W/K/m**2. For a square
centimetre of thermal pad, we get 1E-4 square metres, so

theta = 1/0.53 ~ 2 K/W, not bad, and that's only a 6 x 6 array of holes.

Cheers

Phil Hobbs

I think James Arthur did/ had some calculation like this.
Some questions; Does plating fill the hole to the same thickness as the
copper on the surface? (I thought less)
If you make a bigger hole will it fill with solder and thus be better?

George H.

You can get 0.2 W/K




I do a lot of "photon budgets", which are basically feasibility
calculations mostly based on first principles and material properties.
It's a lot easier to know how your design is doing when you know how
good it could potentially be, so you know how close you are.

I've been working like a maniac the last couple of years, but once I get
my third edition submitted, I'm hoping to string a bunch of photon
budgets together into another book. It's a very useful skill that
should be more widely distributed.


Like the old GR "lightning empiricism" game.

Yup. Wasn't that Philbrick? ISTR stealing the idea from a Pease column.

Cheers

Phil Hobbs

Right, it was Philbrick. There's a section in one of Jim Williams'
books about that.

There used to be technology in Massachusetts!




--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Bill Sloman]

On Tuesday, July 30, 2019 at 8:37:41 PM UTC+10, Martin Brown wrote:

On 30/07/2019 00:11, Chris wrote:
On 07/29/19 23:59, Cursitor Doom wrote:
On Mon, 29 Jul 2019 12:14:25 -0400, Phil Hobbs wrote:

He's just being a Panteltje. We're used to it round here.

Thanks for clearing that up, Phil. I was beginning to wonder.

Reece Mogg is old school English, but I don't have a problem
with that. If he wants so specify rules in his own office,
then fair enough, though the left wing msm will present it in
the most prejudicial way possible, as usual...

Of course part of his office has moved to Ireland, so it can keep on servicing European customers after Brexit'

https://www.ft.com/content/38987fe2-6f19-11e8-92d3-6c13e5c92914

Like Boris Johnson he wants to eat his cake and keep it too. Old school English, in the perfidious Albion sense.

He is pretty much the epitome of a nineteenth century rich landed gentry
from an old money family. He might yet even make a decent Leader of the
House (it is difficult to see how he could be any worse than Leadsom).

Probably not. He's a bit too conscious of his social superiority to pay enough attention to his intellectual superiors.

I wonder if he knows the difference between the commonly used:

I would be obliged if you could <do something for me

and the original correct grammatical form:

I should be obliged if you would <do something for me

When I was at school English grammar was only taught to people studying
foreign languages and nothing beyond basic subject, object and verb in
English class. I understand it has been dumbed down even further now.

Most of what I know about English grammar is from Latin classes.

The first form is actually a subtle insult implying that you do not
believe them to be capable of doing the action you request. This
grammatical quirk is for some strange reason still taught to overseas
students studying English as a foreign language but not in UK schools.
It is completely lost on most native English speakers today.

I don't see the subtle insult.

"I would be obliged" does imply the possibility that they won't do what's being asked for, but there no implication that you think that they can't do it - it merely acknowledges that it might not happen. It's a prediction of your reaction if the service were rendered.

"I should be obliged" is equally open-ended, but carries the further implication that you think that you'd have to be obliged if the service were carried out. It's not only a prediction of your reaction, but an admission that that ought to be your reaction.

What they might have meant a hundred years ago is a more complicated question.

Frequently used forms of words become idioms, and acquire additional information content in the process.

https://www.smart-words.org/quotes-sayings/idioms-meaning.html

There are papers on the subject.

--
Bill Sloman, Sydney

 

[Jan Panteltje]

On a sunny day (Tue, 30 Jul 2019 07:56:05 -0700 (PDT)) it happened
dagmargoodboat@yahoo.com wrote in
<723c5c5e-3d84-4ea1-acba-2e2b57011ab0@googlegroups.com>:

I can't say. I never watch television.
John Larkin Highland Technology, Inc


That's why it's important we ban books -- they've got no commercials,
plant no tracking cookies, and take too much time away from television.

Exactly, books kill trees so cause glowballworming, are heavy, no online updates,
fire hazard, take too much space, no live experiment movies, sensitive to fungus,
not waterproof, lower data per dollar than google and bing, usually only a one person POV,
and once you have read one all it is good for is fix a wobbling table or something.

I bought an ebook reader some time ago, it has an e-ink display.
is water proof, has WiFi and a bad browser, has some books on it
started reading those ..yuck, no, interfaced it to my navigation system
was all about that display, that is OK:
http://panteltje.com/pub/xgpspc_to_aqua2_IXIMG_0105.JPG
slow refresh... Very good readable in intense sunlight,
you could probably put the work of the great writers here on it,
and save trees.
No color.
I does not do teefee, way to slow.
Solution?
I think not.
Back to the laptop or pad.

 

On Sunday, July 28, 2019 at 6:09:34 PM UTC-4, dp wrote:

On 7/28/2019 23:43, Tom Gardner wrote:
On 28/07/19 17:01, Dimiter_Popoff wrote:
On 7/28/2019 17:16, Cursitor Doom wrote:
On Sun, 28 Jul 2019 15:24:19 +0300, Dimiter_Popoff wrote:

If anything, you trolls are both voicy and persistent, I'll give you
that.

So says someone who's obviously got no counter argument.






Yeah yeah, like I said in another post on another topic I know all
the repertoire of you russian troll crowd. Asking for agruments
against retarded nonsense you post is quite stadard.

Tell us what you do for a living. Then tell us *when* you do it.

He should also tell us which country he lives in, because
he has stated it isn't part of the UK, viz...

He will tell neither. His behaviour is standard for a russian troll,
he'll keep on babbling as long as he gets paid for his babble.
Pathetic way to earn a living.

Cursitor Doom has been posting entertaining heterodoxy and
electronics-related postings here for decades. He is not a
Russian troll. He's a hobbyist.

Cheers,
James Arthur

~~~~~~~~~~
"Correction: An item in last month's 'Entertainment' section
incorrectly identified Yoko Ono as a cannibalistic, grave-robbing
gold digger greedily feeding on the shattered dreams of a
generation. Miss Ono is a multimedia artist." (MAD Magazine, c. 1980)

 

On Monday, July 29, 2019 at 10:56:13 PM UTC-4, John Larkin wrote:

On Mon, 29 Jul 2019 18:33:27 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 7/29/19 12:48 PM, John Larkin wrote:
On Mon, 29 Jul 2019 12:13:25 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

I do a bit of both. Memorizing a few facts helps too, e.g. for thermal
vias, PTH copper is about 40-um thick and small vias (10 mil) are mostly
copper.

We have debated here about whether to pave a copper pour with a lot of
small vias or a fewer number of big ones.

You get more copper per square by using the smallest vias that get the
full metal thickness down in the middle. With a 40-micron copper
thickness, a 10-mil finished hole (250 um) has an unfinished diameter of
250+80 um, i.e.

pi/4*(330 um)**2 = 0.086 mm**2

and the finished hole's area is

pi/4*(250 um)**2 = 0.049 mm**2

so the hole area is 1 - 0.049/0.086 = 42% copper. Plated copper's
alpha is about 380 W/m/K, and FR-4's is about 0.25 W/m/K. So assuming
perfect heat spreaders on both sides, a 1.6 mm board with a rectangular
array of these holes spaced by a distance d will have a thermal
conductance per square metre of

1/theta(d) = (0.049E-6*380/d**2 + 0.25)/0.0016.

For holes on 1.5 mm pitch, this is 5300 W/K/m**2. For a square
centimetre of thermal pad, we get 1E-4 square metres, so

theta = 1/0.53 ~ 2 K/W, not bad, and that's only a 6 x 6 array of holes.

Cheers

Phil Hobbs


You can get 0.2 W/K




My production people don't like vias in pads, so a dpak or SOT89 or
whatever needs to have a solid pad, then a region of solder-masked
topside copper, then copper with a lot of vias. That will work for my
dpak resistor, and I'd be happy to get somewhere near, say, 6 to 8 k/w
overall.

That scheme doesn't work well for power pad parts that have leads all
around. They just have to deal with vias in the pads.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

I'm glad to discover you guys bringing this gem up here (rudely
hijacking an OT thread).

I too came to Phil's calculation that a dense smattering of small vias
laid down the most copper, but got John's lament from assembly houses
that the vias gobble the solder paste. "Don't do that," they said.

Maybe a sensible tack would be using small vias to maximize copper,
then estimating the aggregate void, and then estimating the paste
application adjustment from that, such that the voids are filled and
there's enough solder film left to bond the part.

Pass that info on to manufacturing, and Bob's your Brexit. I mean
uncle.

Grins,
James Arthur