rant: filenames...

[Johann Klammer]

On 11/12/2021 05:47 PM, Peter wrote:

Johann Klammer <klammerj@NOSPAM.a1.net> wrote:

On 11/12/2021 03:06 PM, Johann Klammer wrote:
Altho, if it\'s slow stuff like a 400Hz sine, slowly varying, you may just have to measure the zero crossing
and guess the delay from that.


Also, 1 deg of 40kHz is around 70 nS.
I don\'t think this is relevant at all as it\'s well below your sampling period.
you could not compensate this with your 100kHz.

1 degree of *400Hz* (which is what I am generating) is 7us, which is
about 1 DAC sample period.

So despite the misunderstanding, you are still very right; there won\'t
be any realistic way to compensate for the phase shift by shifting the
table.

I could have 360 samples per cycle and then 1 sample shift would be
exactly 1 degree. Or the sample rate could be tweaked to exactly equal
the filter delay, and then I could just delay by one sample

you said your lowpass has 1 deg at 40kHz.

 

[Jan Panteltje]

On a sunny day (Mon, 15 Nov 2021 17:35:02 +0200) it happened Dimiter_Popoff
<dp@tgi-sci.com> wrote in <smtun7$6v6$1@dont-email.me>:

>The unix filenaming system is broken by design.

It is super good!


>Their file names are case dependent;

And that is a GOOD thing!
You need to learn how to search with
locate -i
As you likely know mA is not the same as MA and mOhm is not MOhm

>Dimiter Popoff

 

[Jan Panteltje]

On a sunny day (Mon, 15 Nov 2021 17:35:02 +0200) it happened Dimiter_Popoff
<dp@tgi-sci.com> wrote in <smtun7$6v6$1@dont-email.me>:

>The unix filenaming system is broken by design.

It is super good!


>Their file names are case dependent;

And that is a GOOD thing!
You need to learn how to search with
locate -i
As you likely know mA is not the same as MA and mOhm is not MOhm

>Dimiter Popoff

 

[bitrex]

On 11/18/2021 7:42 AM, bitrex wrote:

On 11/18/2021 12:28 AM, jlarkin@highlandsniptechnology.com wrote:
On Thu, 18 Nov 2021 00:00:46 -0500, bitrex <user@example.net> wrote:

On 11/17/2021 11:19 PM, jlarkin@highlandsniptechnology.com wrote:

https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D





They had to pay the burglars to snatch some out of the Smithsonian so
they could put them back on the shelf

But I really need a low cost isolation amplifier.

Looks like roughly $3 each. SiLabs has a three channel isolated ADC
that is interesting, if I can figure out the actual throughput rate.
Si8902.


I haven\'t used SiLabs isolated ADCs but I have used their isolated gate
drivers, they\'re great value parts! You can push several MHz across the
isolation barrier into a load not a problem. Only downside is a bit less
stand-off voltage than the equivalent ADI parts, and when they say
\"moisture sensitive\" they really mean it, they\'ll go bad quick if you
don\'t mount them after being exposed to non humidity-controlled
environment.

Or rather, they\'ll go bad when you try to mount them after too long in
that environment.

 

[bitrex]

On 11/18/2021 7:42 AM, bitrex wrote:

On 11/18/2021 12:28 AM, jlarkin@highlandsniptechnology.com wrote:
On Thu, 18 Nov 2021 00:00:46 -0500, bitrex <user@example.net> wrote:

On 11/17/2021 11:19 PM, jlarkin@highlandsniptechnology.com wrote:

https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D





They had to pay the burglars to snatch some out of the Smithsonian so
they could put them back on the shelf

But I really need a low cost isolation amplifier.

Looks like roughly $3 each. SiLabs has a three channel isolated ADC
that is interesting, if I can figure out the actual throughput rate.
Si8902.


I haven\'t used SiLabs isolated ADCs but I have used their isolated gate
drivers, they\'re great value parts! You can push several MHz across the
isolation barrier into a load not a problem. Only downside is a bit less
stand-off voltage than the equivalent ADI parts, and when they say
\"moisture sensitive\" they really mean it, they\'ll go bad quick if you
don\'t mount them after being exposed to non humidity-controlled
environment.

Or rather, they\'ll go bad when you try to mount them after too long in
that environment.

 

[server]

On Fri, 12 Nov 2021 15:36:26 +0000, Martin Brown
<\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 12/11/2021 14:33, jlarkin@highlandsniptechnology.com wrote:
On Fri, 12 Nov 2021 09:50:01 +0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:


I would not ask mountain rescue teams to save people who wonder up into
the mountain in flipflops using Google maps on their mobile phone to
navigate and then get lost when the battery runs out. The mountain
rescue teams are rather more forgiving but I think idiots who do that
should be charged for the full cost of their rescue.

I would limit treatment to life saving only for people who refuse to
wear seat belts and were mangled as a result of going through their
windscreen. That is another idiotic decision some make. A few mangled
survivors wondering around would do wonders for seat belt compliance.

Wow, good thing you don\'t make health-care policy. Every ER would have
an intake moralist on staff who would decide who should be rejected
and die.

Darwinism in action would be the hardest possible line. I am quite happy
to keep them alive but they can pay for their own plastic surgery to
reassemble their face if they have failed to wear a seat belt.

Do something stupid and you have to take responsibility for your actions.

US is particularly bad for this since airbag explosives are set to kill
smaller women drivers just to save the big fat lard arse who CBA to use
a seat belt. I don\'t think that is fair to women drivers YMMV. eg.

https://abcnews.go.com/US/wireStory/south-carolina-driver-killed-exploding-air-bag-inflator-77230834

Although that particular one was due to using unstable ammonium nitrate
as the propellant it was the *amount* of it that killed the driver.

Do european air bags have less propellant? Is the amount loaded on a
per-country basis?

Yes. US has a dodgy airbag policy resulting in a lot more fatalities
particularly of smaller women who have to sit closer to the steering
wheel. It is almost invariably that airbag that kills (or injures) them.

https://www.consumerreports.org/car-safety/crash-test-bias-how-male-focused-testing-puts-female-drivers-at-risk/

Somewhat more detailed analysis of the US kill smaller females airbag
policy here snappily titled \"Survey of Driver Seating Positions in
Relation to the Steering Wheel\". Being too close to it when it goes off
is a very bad thing:

https://www.jstor.org/stable/44741050

Short form version it is a bad idea to be a female driver under 5\'5\".

The same issue doesn\'t arise in Europe or Japan because seat belts are
mandatory there (and enforced).

Seat belt use is mandatory and enforced in California.

Europeans have the strangest cartoon opinions about non-europeans.



--

Father Brown\'s figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

 

[server]

On Fri, 12 Nov 2021 15:36:26 +0000, Martin Brown
<\'\'\'newspam\'\'\'@nonad.co.uk> wrote:

On 12/11/2021 14:33, jlarkin@highlandsniptechnology.com wrote:
On Fri, 12 Nov 2021 09:50:01 +0000, Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote:


I would not ask mountain rescue teams to save people who wonder up into
the mountain in flipflops using Google maps on their mobile phone to
navigate and then get lost when the battery runs out. The mountain
rescue teams are rather more forgiving but I think idiots who do that
should be charged for the full cost of their rescue.

I would limit treatment to life saving only for people who refuse to
wear seat belts and were mangled as a result of going through their
windscreen. That is another idiotic decision some make. A few mangled
survivors wondering around would do wonders for seat belt compliance.

Wow, good thing you don\'t make health-care policy. Every ER would have
an intake moralist on staff who would decide who should be rejected
and die.

Darwinism in action would be the hardest possible line. I am quite happy
to keep them alive but they can pay for their own plastic surgery to
reassemble their face if they have failed to wear a seat belt.

Do something stupid and you have to take responsibility for your actions.

US is particularly bad for this since airbag explosives are set to kill
smaller women drivers just to save the big fat lard arse who CBA to use
a seat belt. I don\'t think that is fair to women drivers YMMV. eg.

https://abcnews.go.com/US/wireStory/south-carolina-driver-killed-exploding-air-bag-inflator-77230834

Although that particular one was due to using unstable ammonium nitrate
as the propellant it was the *amount* of it that killed the driver.

Do european air bags have less propellant? Is the amount loaded on a
per-country basis?

Yes. US has a dodgy airbag policy resulting in a lot more fatalities
particularly of smaller women who have to sit closer to the steering
wheel. It is almost invariably that airbag that kills (or injures) them.

https://www.consumerreports.org/car-safety/crash-test-bias-how-male-focused-testing-puts-female-drivers-at-risk/

Somewhat more detailed analysis of the US kill smaller females airbag
policy here snappily titled \"Survey of Driver Seating Positions in
Relation to the Steering Wheel\". Being too close to it when it goes off
is a very bad thing:

https://www.jstor.org/stable/44741050

Short form version it is a bad idea to be a female driver under 5\'5\".

The same issue doesn\'t arise in Europe or Japan because seat belts are
mandatory there (and enforced).

Seat belt use is mandatory and enforced in California.

Europeans have the strangest cartoon opinions about non-europeans.



--

Father Brown\'s figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

 

[Rob]

bitrex <user@example.net> wrote:

On 11/17/2021 11:19 PM, jlarkin@highlandsniptechnology.com wrote:

https://www.mouser.com/ProductDetail/Texas-Instruments/ISO120SG?qs=rNOSrj6uCs17dA0jO5%2FyAw%3D%3D




They had to pay the burglars to snatch some out of the Smithsonian so
they could put them back on the shelf

They come in a tube of 9, and they have 8 on stock.
So probably at some time someone ordered one, they ordered a tube of 9
from TI and put the remaining 8 on stock.

 

[server]

On Fri, 12 Nov 2021 07:03:45 +0000, Peter <nospam@nospam9876.com>
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote

On Thu, 11 Nov 2021 15:12:58 -0800 (PST), Phil Allison
pallison49@gmail.com> wrote:

John Larkin wrote:
===================


Given a 12-bit DAC making a 500 Hz sine wave at 100K samples/second,
it will look perfect on a scope, with no filter.

** Not on good analog one, with a sharp trace.

I\'d expect that if the sine wave fits on the screen, you wouldn\'t see
the stairsteps.

How many spot diameters fit on one screen? Surely not 4000.

Indeed - the 12 bits is plenty. But I won\'t have 4k samples per cycle.
So there will be steps larger steps than 4k/cycle.

I can see that removing the steps is not difficult, because of the
huge \"oversampling\". They will need to be removed however, as far as
possible, for EMC reasons.

Each dac step will be tiny, so the waveform won\'t make much EMI.

These days, one doesn\'t have to do all the math; just Spice it.



--

Father Brown\'s figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

 

[server]

On Fri, 12 Nov 2021 07:03:45 +0000, Peter <nospam@nospam9876.com>
wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote

On Thu, 11 Nov 2021 15:12:58 -0800 (PST), Phil Allison
pallison49@gmail.com> wrote:

John Larkin wrote:
===================


Given a 12-bit DAC making a 500 Hz sine wave at 100K samples/second,
it will look perfect on a scope, with no filter.

** Not on good analog one, with a sharp trace.

I\'d expect that if the sine wave fits on the screen, you wouldn\'t see
the stairsteps.

How many spot diameters fit on one screen? Surely not 4000.

Indeed - the 12 bits is plenty. But I won\'t have 4k samples per cycle.
So there will be steps larger steps than 4k/cycle.

I can see that removing the steps is not difficult, because of the
huge \"oversampling\". They will need to be removed however, as far as
possible, for EMC reasons.

Each dac step will be tiny, so the waveform won\'t make much EMI.

These days, one doesn\'t have to do all the math; just Spice it.



--

Father Brown\'s figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

 

[server]

On Fri, 12 Nov 2021 16:47:49 +0000, Peter <nospam@nospam9876.com>
wrote:

Johann Klammer <klammerj@NOSPAM.a1.net> wrote:

On 11/12/2021 03:06 PM, Johann Klammer wrote:
Altho, if it\'s slow stuff like a 400Hz sine, slowly varying, you may just have to measure the zero crossing
and guess the delay from that.


Also, 1 deg of 40kHz is around 70 nS.
I don\'t think this is relevant at all as it\'s well below your sampling period.
you could not compensate this with your 100kHz.

1 degree of *400Hz* (which is what I am generating) is 7us, which is
about 1 DAC sample period.

So despite the misunderstanding, you are still very right; there won\'t
be any realistic way to compensate for the phase shift by shifting the
table.

I could have 360 samples per cycle and then 1 sample shift would be
exactly 1 degree. Or the sample rate could be tweaked to exactly equal
the filter delay, and then I could just delay by one sample

Are you rolling your own DDS in an FPGA? It would be easy to tweak the
phase to arc-seconds.



--

Father Brown\'s figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

 

[server]

Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> wrote in
news:smtvrm$17cm$1@gioia.aioe.org:

On a sunny day (Mon, 15 Nov 2021 17:35:02 +0200) it happened
Dimiter_Popoff <dp@tgi-sci.com> wrote in
smtun7$6v6$1@dont-email.me>:

The unix filenaming system is broken by design.

It is super good!


Their file names are case dependent;

And that is a GOOD thing!
You need to learn how to search with
locate -i
As you likely know mA is not the same as MA and mOhm is not MOhm

Dimiter Popoff

Just proved his meter is dim. Har har.

He\'s probably an old Novell Network/OS programmer.

 

[Jan Panteltje]

On a sunny day (Mon, 15 Nov 2021 17:35:02 +0200) it happened Dimiter_Popoff
<dp@tgi-sci.com> wrote in <smtun7$6v6$1@dont-email.me>:

>The unix filenaming system is broken by design.

It is super good!


>Their file names are case dependent;

And that is a GOOD thing!
You need to learn how to search with
locate -i
As you likely know mA is not the same as MA and mOhm is not MOhm

>Dimiter Popoff

 

[server]

On Fri, 12 Nov 2021 18:10:53 +0200, LM <sala.nimi@mail.com> wrote:

I could use a 100 pin LQFP, but when it is impossible to know what
part is available next week, I cannot.

On Thu, 11 Nov 2021 13:56:52 -0800, John Larkin
jlarkin@highland_atwork_technology.com> wrote:

On Thu, 11 Nov 2021 23:12:56 +0200, LM <sala.nimi@mail.com> wrote:

If they stay in stock, life is getting better.

Alas, not in our package. But maybe things are breaking.

We use STM32F207IGT6, LQFP176 package, in several products. The
question is whether we should gamble on them becoming available, and
design them into a new product.

They are being quoted from possibly dodgy distributors. One distrib
takes orders and payments and never delivers. Nice business model.

We\'s just buy 1000 if we could trust the source.



--

Father Brown\'s figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

 

[server]

On Fri, 12 Nov 2021 18:10:53 +0200, LM <sala.nimi@mail.com> wrote:

I could use a 100 pin LQFP, but when it is impossible to know what
part is available next week, I cannot.

On Thu, 11 Nov 2021 13:56:52 -0800, John Larkin
jlarkin@highland_atwork_technology.com> wrote:

On Thu, 11 Nov 2021 23:12:56 +0200, LM <sala.nimi@mail.com> wrote:

If they stay in stock, life is getting better.

Alas, not in our package. But maybe things are breaking.

We use STM32F207IGT6, LQFP176 package, in several products. The
question is whether we should gamble on them becoming available, and
design them into a new product.

They are being quoted from possibly dodgy distributors. One distrib
takes orders and payments and never delivers. Nice business model.

We\'s just buy 1000 if we could trust the source.



--

Father Brown\'s figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.

 

[bitrex]

On 11/11/2021 7:52 AM, Dean Hoffman wrote:

The Singing Sergeants, Lee Greenwood, and Home Free.
https://www.youtube.com/watch?v=gs0fxy8rHo8
Today marks 100 years since the dedication of the Tomb of The Unknown
Soldier.

And it was the first Veterans day in 20 years \"without a war\" THAT\'s a
\"big lie\":

<https://www.nytimes.com/2021/11/11/us/politics/biden-veterans-day.html>

<https://www.cnn.com/2021/10/22/politics/us-pakistan-afghanistan-airspace/index.html>

They just call them \"operations\" now...

 

[bitrex]

On 11/11/2021 7:52 AM, Dean Hoffman wrote:

The Singing Sergeants, Lee Greenwood, and Home Free.
https://www.youtube.com/watch?v=gs0fxy8rHo8
Today marks 100 years since the dedication of the Tomb of The Unknown
Soldier.

And it was the first Veterans day in 20 years \"without a war\" THAT\'s a
\"big lie\":

<https://www.nytimes.com/2021/11/11/us/politics/biden-veterans-day.html>

<https://www.cnn.com/2021/10/22/politics/us-pakistan-afghanistan-airspace/index.html>

They just call them \"operations\" now...

 

[John Larkin]

On Fri, 12 Nov 2021 08:09:35 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Thu, 11 Nov 2021 22:01:33 +0000) it happened Peter
nospam@nospam9876.com> wrote in <smk3rt$72m$1@dont-email.me>:

Sometimes one needs to power a circuit from one source or another.

Most LDOs, or indeed most normal regs, feed current back up to the
source. LDOs tend to use a PMOS pass transistor which has a parasitic
diode.

I am doing a design where I am using the Ricoh R1191 for this

https://eu.mouser.com/ProductDetail/Ricoh-Electronic-Devices-Company/R1191N033B-TR-FE?qs=%2Fha2pyFaduhEV6ZG3xOqbaXpStP%2FIzlm74g8
V5lGNcwdefxpMkR8XA%3D%3D

which has a series diode, so the dropout voltage is about 0.7V.

It\'s not dirt cheap but not crazy-priced either.

I am wondering why this is rare. Is it not possible to make a PMOS
device without the parasitic diode? Or have some other series element
which gets turned off when there is no input? It reminds me of an
active rectifier in switching power supplies, to avoid the Vf of the
diode(s). There is even a circuit for a bridge rectifier, although
that was commercially implemented with a complicated chip to drive the
four gates, IIRC.

One obvious solution is to use a normal LDO and have a diode in series
with the input, so long as you can be sure nothing funny will be
hapenning inside with the ground lead which could still pass negative
current.

IIRC the correct way to parallel 2 voltage regulators is have each one sense its output current
and if too high drive the current reference of the other one higher until both deliver the same current.
If you just parallel voltage controlled ones then one is likely to do all the work
due to minuscule output voltage differences.
For example one could go into current limit at 100% current and the other will then do say 10%.
Much simpler to get or design one bigger one?

You can certainly diode OR the input of a single reg, from two
sources.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[John Larkin]

On Fri, 12 Nov 2021 08:09:35 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Thu, 11 Nov 2021 22:01:33 +0000) it happened Peter
nospam@nospam9876.com> wrote in <smk3rt$72m$1@dont-email.me>:

Sometimes one needs to power a circuit from one source or another.

Most LDOs, or indeed most normal regs, feed current back up to the
source. LDOs tend to use a PMOS pass transistor which has a parasitic
diode.

I am doing a design where I am using the Ricoh R1191 for this

https://eu.mouser.com/ProductDetail/Ricoh-Electronic-Devices-Company/R1191N033B-TR-FE?qs=%2Fha2pyFaduhEV6ZG3xOqbaXpStP%2FIzlm74g8
V5lGNcwdefxpMkR8XA%3D%3D

which has a series diode, so the dropout voltage is about 0.7V.

It\'s not dirt cheap but not crazy-priced either.

I am wondering why this is rare. Is it not possible to make a PMOS
device without the parasitic diode? Or have some other series element
which gets turned off when there is no input? It reminds me of an
active rectifier in switching power supplies, to avoid the Vf of the
diode(s). There is even a circuit for a bridge rectifier, although
that was commercially implemented with a complicated chip to drive the
four gates, IIRC.

One obvious solution is to use a normal LDO and have a diode in series
with the input, so long as you can be sure nothing funny will be
hapenning inside with the ground lead which could still pass negative
current.

IIRC the correct way to parallel 2 voltage regulators is have each one sense its output current
and if too high drive the current reference of the other one higher until both deliver the same current.
If you just parallel voltage controlled ones then one is likely to do all the work
due to minuscule output voltage differences.
For example one could go into current limit at 100% current and the other will then do say 10%.
Much simpler to get or design one bigger one?

You can certainly diode OR the input of a single reg, from two
sources.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[John Larkin]

On Fri, 12 Nov 2021 08:09:35 GMT, Jan Panteltje
<pNaOnStPeAlMtje@yahoo.com> wrote:

On a sunny day (Thu, 11 Nov 2021 22:01:33 +0000) it happened Peter
nospam@nospam9876.com> wrote in <smk3rt$72m$1@dont-email.me>:

Sometimes one needs to power a circuit from one source or another.

Most LDOs, or indeed most normal regs, feed current back up to the
source. LDOs tend to use a PMOS pass transistor which has a parasitic
diode.

I am doing a design where I am using the Ricoh R1191 for this

https://eu.mouser.com/ProductDetail/Ricoh-Electronic-Devices-Company/R1191N033B-TR-FE?qs=%2Fha2pyFaduhEV6ZG3xOqbaXpStP%2FIzlm74g8
V5lGNcwdefxpMkR8XA%3D%3D

which has a series diode, so the dropout voltage is about 0.7V.

It\'s not dirt cheap but not crazy-priced either.

I am wondering why this is rare. Is it not possible to make a PMOS
device without the parasitic diode? Or have some other series element
which gets turned off when there is no input? It reminds me of an
active rectifier in switching power supplies, to avoid the Vf of the
diode(s). There is even a circuit for a bridge rectifier, although
that was commercially implemented with a complicated chip to drive the
four gates, IIRC.

One obvious solution is to use a normal LDO and have a diode in series
with the input, so long as you can be sure nothing funny will be
hapenning inside with the ground lead which could still pass negative
current.

IIRC the correct way to parallel 2 voltage regulators is have each one sense its output current
and if too high drive the current reference of the other one higher until both deliver the same current.
If you just parallel voltage controlled ones then one is likely to do all the work
due to minuscule output voltage differences.
For example one could go into current limit at 100% current and the other will then do say 10%.
Much simpler to get or design one bigger one?

You can certainly diode OR the input of a single reg, from two
sources.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon