EE rant...

[bitrex]

On 1/1/2023 11:04 PM, John Larkin wrote:

https://www.theregister.com/2022/07/18/electrical_engineers_extinction/?td=rt-9cp

I\'ve been thinking for some time now that EE schools don\'t turn out
people who like electricity, but maker culture might.

\"And to make it your life, there has to be a lot of high-status,
high-wage, high-interest jobs to do at the end.\"

Software-startup culture is glamorous in its way, the young kids can
very quickly feel like they\'re working on something novel.

The EE jobs available tend to be at established companies, like Northrop
Grumman or Nexteer Automotive or Fisher Scientific or BAE systems etc,
you can go down the list on job sites and see what they are.

Biggest complaints you hear from EEs about working places like that is
that the jobs aren\'t particularly high status. They don\'t pay
particularly great. The \"company culture\" sucks. And worst of all the
job responsibilities tend to be rigid and the work not particularly
interesting.

 

[Jan Panteltje]

On a sunny day (Wed, 4 Jan 2023 10:43:20 -0800) it happened Joerg
<news@analogconsultants.com> wrote in <k1lvmaF2dmeU1@mid.individual.net>:

On 1/3/23 8:07 AM, John Larkin wrote:
On Tue, 03 Jan 2023 06:30:16 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:

On a sunny day (Mon, 02 Jan 2023 17:40:24 -0800) it happened John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote in
ep17rhh7of7bjadr2m685ik4108ts536fh@4ax.com>:

[...]

AC termination is nasty for DC-asymmetric data. Fine for clocks or
biphase or 8B10B sorts of things.


I did it for just about everything. Except when the bus was being
redlined in terms of what the driver chips could do and the timing was
being \"tweaked\" but IMO that\'s bad design to begin with.


Indeed, like analog video 1 Vpp
You lose your black level...
OTOH a diode after the RC will fix that for video (clamp the negative sync pulse at some fixed level).
It all depends...


Forgot the name of it but National Semiconductor made a nice clamp IC to
avoid black level droop. There were als Japanese ones but I never used
them in product designs because availability was iffy and many clients
were married to certain local distributors for reasons I\'ll never
understand. Those usually didn\'t stock the Asian black level clamp chips.

Broadcasting studios cameras clamping on the black (not bottom sync)
hundreds if not thousands of those circuits, in my time with tubes
and then transistors.
We had equipment / modules from Fernsehn GmbH in those days, Philips plumbicon color cameras.
Ampex video recorders...

Analog video was fun.

I did this project to get my digital hands on up to date, for hardware and software:
http://panteltje.com/panteltje/raspberry_pi_dvb-s_transmitter/

Now we have DVB-S2 via satellite and DVB-T2 terrestrial here..
New standard every few years, everybody had to buy a new DVB-T2 box... few years back..

Wonder what\'s next
DVB-S2 is close to the Shannon limit, but I did get surprised again today:
https://www.asus.com/content/asus-spatial-vision-technology/

 

[Jan Panteltje]

On a sunny day (Wed, 4 Jan 2023 10:43:20 -0800) it happened Joerg
<news@analogconsultants.com> wrote in <k1lvmaF2dmeU1@mid.individual.net>:

On 1/3/23 8:07 AM, John Larkin wrote:
On Tue, 03 Jan 2023 06:30:16 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:

On a sunny day (Mon, 02 Jan 2023 17:40:24 -0800) it happened John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote in
ep17rhh7of7bjadr2m685ik4108ts536fh@4ax.com>:

[...]

AC termination is nasty for DC-asymmetric data. Fine for clocks or
biphase or 8B10B sorts of things.


I did it for just about everything. Except when the bus was being
redlined in terms of what the driver chips could do and the timing was
being \"tweaked\" but IMO that\'s bad design to begin with.


Indeed, like analog video 1 Vpp
You lose your black level...
OTOH a diode after the RC will fix that for video (clamp the negative sync pulse at some fixed level).
It all depends...


Forgot the name of it but National Semiconductor made a nice clamp IC to
avoid black level droop. There were als Japanese ones but I never used
them in product designs because availability was iffy and many clients
were married to certain local distributors for reasons I\'ll never
understand. Those usually didn\'t stock the Asian black level clamp chips.

Broadcasting studios cameras clamping on the black (not bottom sync)
hundreds if not thousands of those circuits, in my time with tubes
and then transistors.
We had equipment / modules from Fernsehn GmbH in those days, Philips plumbicon color cameras.
Ampex video recorders...

Analog video was fun.

I did this project to get my digital hands on up to date, for hardware and software:
http://panteltje.com/panteltje/raspberry_pi_dvb-s_transmitter/

Now we have DVB-S2 via satellite and DVB-T2 terrestrial here..
New standard every few years, everybody had to buy a new DVB-T2 box... few years back..

Wonder what\'s next
DVB-S2 is close to the Shannon limit, but I did get surprised again today:
https://www.asus.com/content/asus-spatial-vision-technology/

 

[Jan Panteltje]

On a sunny day (Wed, 4 Jan 2023 10:43:20 -0800) it happened Joerg
<news@analogconsultants.com> wrote in <k1lvmaF2dmeU1@mid.individual.net>:

On 1/3/23 8:07 AM, John Larkin wrote:
On Tue, 03 Jan 2023 06:30:16 GMT, Jan Panteltje
pNaonStpealmtje@yahoo.com> wrote:

On a sunny day (Mon, 02 Jan 2023 17:40:24 -0800) it happened John Larkin
jlarkin@highlandSNIPMEtechnology.com> wrote in
ep17rhh7of7bjadr2m685ik4108ts536fh@4ax.com>:

[...]

AC termination is nasty for DC-asymmetric data. Fine for clocks or
biphase or 8B10B sorts of things.


I did it for just about everything. Except when the bus was being
redlined in terms of what the driver chips could do and the timing was
being \"tweaked\" but IMO that\'s bad design to begin with.


Indeed, like analog video 1 Vpp
You lose your black level...
OTOH a diode after the RC will fix that for video (clamp the negative sync pulse at some fixed level).
It all depends...


Forgot the name of it but National Semiconductor made a nice clamp IC to
avoid black level droop. There were als Japanese ones but I never used
them in product designs because availability was iffy and many clients
were married to certain local distributors for reasons I\'ll never
understand. Those usually didn\'t stock the Asian black level clamp chips.

Broadcasting studios cameras clamping on the black (not bottom sync)
hundreds if not thousands of those circuits, in my time with tubes
and then transistors.
We had equipment / modules from Fernsehn GmbH in those days, Philips plumbicon color cameras.
Ampex video recorders...

Analog video was fun.

I did this project to get my digital hands on up to date, for hardware and software:
http://panteltje.com/panteltje/raspberry_pi_dvb-s_transmitter/

Now we have DVB-S2 via satellite and DVB-T2 terrestrial here..
New standard every few years, everybody had to buy a new DVB-T2 box... few years back..

Wonder what\'s next
DVB-S2 is close to the Shannon limit, but I did get surprised again today:
https://www.asus.com/content/asus-spatial-vision-technology/

 

[Fred Bloggs]

On Sunday, January 1, 2023 at 3:52:48 PM UTC-5, Ricky wrote:

I was looking at enclosed power supplies and many have similar specs. But looking at the mechanical data the MORNSUN and CUI products are nearly indistinguishable.

Anyone know if MORNSUN and CUI are the same company or if they share the same products? Heck, I checked a third unit from Aimtec and it seems the same. Are all these guys buying from another company?

I did a little digging, and MORNSUN and CUI don\'t seem to be the same company.

MORNSUN is 100% China

CUI, recently acquired by Bel Fuse in 2019, is 100% American, manufactured in Oregon

BTW- it\'s not \"enclosed power supplies\"-

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Fred Bloggs]

On Sunday, January 1, 2023 at 3:52:48 PM UTC-5, Ricky wrote:

I was looking at enclosed power supplies and many have similar specs. But looking at the mechanical data the MORNSUN and CUI products are nearly indistinguishable.

Anyone know if MORNSUN and CUI are the same company or if they share the same products? Heck, I checked a third unit from Aimtec and it seems the same. Are all these guys buying from another company?

I did a little digging, and MORNSUN and CUI don\'t seem to be the same company.

MORNSUN is 100% China

CUI, recently acquired by Bel Fuse in 2019, is 100% American, manufactured in Oregon

BTW- it\'s not \"enclosed power supplies\"-

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Fred Bloggs]

On Sunday, January 1, 2023 at 3:52:48 PM UTC-5, Ricky wrote:

I was looking at enclosed power supplies and many have similar specs. But looking at the mechanical data the MORNSUN and CUI products are nearly indistinguishable.

Anyone know if MORNSUN and CUI are the same company or if they share the same products? Heck, I checked a third unit from Aimtec and it seems the same. Are all these guys buying from another company?

I did a little digging, and MORNSUN and CUI don\'t seem to be the same company.

MORNSUN is 100% China

CUI, recently acquired by Bel Fuse in 2019, is 100% American, manufactured in Oregon

BTW- it\'s not \"enclosed power supplies\"-

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Phil Hobbs]

Jan Panteltje wrote:

On a sunny day (Wed, 4 Jan 2023 08:39:59 -0500) it happened Phil Hops wrote

Jan Panteltje wrote:
On a sunny day (Wed, 4 Jan 2023 09:20:44 +0000) it happened Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote in <tp3gdi$1ra1$1@gioia.aioe.org>:

On 02/01/2023 19:21, Jan Panteltje wrote:
My website hosting company \"Godaddy.com\" moved to Microsoft for my email.
What a lot of crap that is!! The old pop-email no longer works,
pop-email took a second here for incoming to add to my email system that goes back to 1998.

Are you sure about that?
Is it a very recent thing (as in failed 27/12/22 by any chance?)


POP worked fine on MS Office 365/Outlook with the server settings here:

https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-8361e398-8af4-4e97-b147-6c6c4ac95353

interesting
but godddy has done more things wrong, this was the limit
1) they would re-encode my JPG pictures so it would take less space on their server
but then people could not read my circuit diagrams..

(Talk about leading with your chin!)

Were you trying to commi-nukate something?

It\'s a boxing expression. Normally a boxer takes the first punch with
his right or left fist. \"Leading with your chin\" means putting your
chin in first, i.e. just asking to be knocked out.

In this case, the far-famed illegibility of your schematics is the
\"chin\" in question. Capiche?

Cheers

Phil Hobbs
(Who obviously needs to be more explicit when teasing ESL folks.)

 

[Phil Hobbs]

Jan Panteltje wrote:

On a sunny day (Wed, 4 Jan 2023 08:39:59 -0500) it happened Phil Hops wrote

Jan Panteltje wrote:
On a sunny day (Wed, 4 Jan 2023 09:20:44 +0000) it happened Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote in <tp3gdi$1ra1$1@gioia.aioe.org>:

On 02/01/2023 19:21, Jan Panteltje wrote:
My website hosting company \"Godaddy.com\" moved to Microsoft for my email.
What a lot of crap that is!! The old pop-email no longer works,
pop-email took a second here for incoming to add to my email system that goes back to 1998.

Are you sure about that?
Is it a very recent thing (as in failed 27/12/22 by any chance?)


POP worked fine on MS Office 365/Outlook with the server settings here:

https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-8361e398-8af4-4e97-b147-6c6c4ac95353

interesting
but godddy has done more things wrong, this was the limit
1) they would re-encode my JPG pictures so it would take less space on their server
but then people could not read my circuit diagrams..

(Talk about leading with your chin!)

Were you trying to commi-nukate something?

It\'s a boxing expression. Normally a boxer takes the first punch with
his right or left fist. \"Leading with your chin\" means putting your
chin in first, i.e. just asking to be knocked out.

In this case, the far-famed illegibility of your schematics is the
\"chin\" in question. Capiche?

Cheers

Phil Hobbs
(Who obviously needs to be more explicit when teasing ESL folks.)

 

[Phil Hobbs]

Jan Panteltje wrote:

On a sunny day (Wed, 4 Jan 2023 08:39:59 -0500) it happened Phil Hops wrote

Jan Panteltje wrote:
On a sunny day (Wed, 4 Jan 2023 09:20:44 +0000) it happened Martin Brown
\'\'\'newspam\'\'\'@nonad.co.uk> wrote in <tp3gdi$1ra1$1@gioia.aioe.org>:

On 02/01/2023 19:21, Jan Panteltje wrote:
My website hosting company \"Godaddy.com\" moved to Microsoft for my email.
What a lot of crap that is!! The old pop-email no longer works,
pop-email took a second here for incoming to add to my email system that goes back to 1998.

Are you sure about that?
Is it a very recent thing (as in failed 27/12/22 by any chance?)


POP worked fine on MS Office 365/Outlook with the server settings here:

https://support.microsoft.com/en-us/office/pop-imap-and-smtp-settings-8361e398-8af4-4e97-b147-6c6c4ac95353

interesting
but godddy has done more things wrong, this was the limit
1) they would re-encode my JPG pictures so it would take less space on their server
but then people could not read my circuit diagrams..

(Talk about leading with your chin!)

Were you trying to commi-nukate something?

It\'s a boxing expression. Normally a boxer takes the first punch with
his right or left fist. \"Leading with your chin\" means putting your
chin in first, i.e. just asking to be knocked out.

In this case, the far-famed illegibility of your schematics is the
\"chin\" in question. Capiche?

Cheers

Phil Hobbs
(Who obviously needs to be more explicit when teasing ESL folks.)

 

[Joerg]

On 1/10/23 8:57 PM, Jan Panteltje wrote:

On a sunny day (Tue, 10 Jan 2023 14:57:00 -0800) it happened Joerg
news@analogconsultants.com> wrote in <k268puFi1h6U1@mid.individual.net>:


Number two: The same guy said that grounded gate circuits in RF stages
make no sense at all. Huh? I did one of those during my very first job
assignment when the ink on my degree was barely dry. And lots before as
a hobbyist.

Sure, used those in some projects.



Number three: Another professor said that we only need to learn all this
transistor-level stuff for the exam. Once we graduated this would all be
obsoleted by integrated circuits. That one took the cake. Still, it
seemed I was the only one who didn\'t believe such nonsense. However, it
provided me with the epiphany \"Ha! This is my niche!\". And that\'s what
it became. Never looked back.

This was at a European ivy league place which made it even more
disappointing.


In my school, a teacher (old one) was teaching us about transistors.
Transistors most of us were experimenting with at home..
So one guy asked;
\'Sir what exactly is a complementary pair?\'

It\'s similar to a transgender amplifier

In Germany we always used their expressions of plug and jack for
connectors. One document was in English and it mentioned a female
connector. The guy reading that passage aloud blushed a bit ...

Teacher got furious, thought it was a sex joke, and asked the guy to leave..
It took the whole class (most of use knew the answer) to convince the
teacher that that was a legitimate question.
Early sixties that was...
I think that teacher never had a transistor in his hands,, mostly lived in the tube ages.
Lucky we also had an other teacher who knew what he was doing..

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

On 1/10/23 8:57 PM, Jan Panteltje wrote:

On a sunny day (Tue, 10 Jan 2023 14:57:00 -0800) it happened Joerg
news@analogconsultants.com> wrote in <k268puFi1h6U1@mid.individual.net>:


Number two: The same guy said that grounded gate circuits in RF stages
make no sense at all. Huh? I did one of those during my very first job
assignment when the ink on my degree was barely dry. And lots before as
a hobbyist.

Sure, used those in some projects.



Number three: Another professor said that we only need to learn all this
transistor-level stuff for the exam. Once we graduated this would all be
obsoleted by integrated circuits. That one took the cake. Still, it
seemed I was the only one who didn\'t believe such nonsense. However, it
provided me with the epiphany \"Ha! This is my niche!\". And that\'s what
it became. Never looked back.

This was at a European ivy league place which made it even more
disappointing.


In my school, a teacher (old one) was teaching us about transistors.
Transistors most of us were experimenting with at home..
So one guy asked;
\'Sir what exactly is a complementary pair?\'

It\'s similar to a transgender amplifier

In Germany we always used their expressions of plug and jack for
connectors. One document was in English and it mentioned a female
connector. The guy reading that passage aloud blushed a bit ...

Teacher got furious, thought it was a sex joke, and asked the guy to leave..
It took the whole class (most of use knew the answer) to convince the
teacher that that was a legitimate question.
Early sixties that was...
I think that teacher never had a transistor in his hands,, mostly lived in the tube ages.
Lucky we also had an other teacher who knew what he was doing..

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

On 1/10/23 8:57 PM, Jan Panteltje wrote:

On a sunny day (Tue, 10 Jan 2023 14:57:00 -0800) it happened Joerg
news@analogconsultants.com> wrote in <k268puFi1h6U1@mid.individual.net>:


Number two: The same guy said that grounded gate circuits in RF stages
make no sense at all. Huh? I did one of those during my very first job
assignment when the ink on my degree was barely dry. And lots before as
a hobbyist.

Sure, used those in some projects.



Number three: Another professor said that we only need to learn all this
transistor-level stuff for the exam. Once we graduated this would all be
obsoleted by integrated circuits. That one took the cake. Still, it
seemed I was the only one who didn\'t believe such nonsense. However, it
provided me with the epiphany \"Ha! This is my niche!\". And that\'s what
it became. Never looked back.

This was at a European ivy league place which made it even more
disappointing.


In my school, a teacher (old one) was teaching us about transistors.
Transistors most of us were experimenting with at home..
So one guy asked;
\'Sir what exactly is a complementary pair?\'

It\'s similar to a transgender amplifier

In Germany we always used their expressions of plug and jack for
connectors. One document was in English and it mentioned a female
connector. The guy reading that passage aloud blushed a bit ...

Teacher got furious, thought it was a sex joke, and asked the guy to leave..
It took the whole class (most of use knew the answer) to convince the
teacher that that was a legitimate question.
Early sixties that was...
I think that teacher never had a transistor in his hands,, mostly lived in the tube ages.
Lucky we also had an other teacher who knew what he was doing..

--
Regards, Joerg

http://www.analogconsultants.com/

 

[John Larkin]

On Thu, 5 Jan 2023 13:42:02 -0000 (UTC), Dan Purgert <dan@djph.net>
wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

On 2023-01-05, Don Y wrote:
On 1/5/2023 5:07 AM, Dan Purgert wrote:
[...]
On the other hand; I already have a (weak) grasp of what a (linear?)
power-supply needs to have -- rectifier -> smoothing caps -> (I think) a
handful of transistors & resistors to get the desired voltage -> output
capacitor(s). And this (hopefully) gets me a little more understanding
of using transistors as more than just switches ... well, maybe.

Yes, but, at the end of the day, you\'re reinventing something that
a gazillion manufacturers sell in a bazillion different varieties
for less money than the postage on the parts you\'ll order to roll
your own.

Yep. And at the end of the day, when I memorized my 1-12 times tables in
grade school \"because you won\'t always have a calculator in your
pocket!\" ...

Again, this is more of a \"homework project(tm)\". Yeah, it\'s been done a
million times; yeah, I could just buy a linear regulator IC ...



If you have a \'scope, it can be a good exercise -- if only to let you
see how the \"signal\" changes as it moves through the circuit. And,
how it reacts to differing loads (e.g., see the ripple on the input
filter increase when the filter is having to supply a larger load
reflected through the regulator. What happens if you change the value
of the filter? Or, use a half-wave rectifier?)

That\'s more like where my thought process was going with this \"homework
project\". Fiddle with it, see what happens \"inside\" an LM338 (etc),
and, well, hopefully learn a thing or two. While it\'s not a scope, I
have one of those USB logic-analyzers that \"can\" do analog readings as
well, so we\'ll see how it works out.

Worst case, I have a powersupply that I\'m less concerned about blowing a
part inside, because, well, I have the schematic and the parts and ...


[I don\'t mean to discourage you. Rather, hoping you find something
to tackle that leads to an \"aha\" moment -- which tends to cause you to
crave more such moments.]

Yes, I am craving \"aha-moments\" with analog. It\'s pure wizardry seeing
a couple long wires (plus some other components) pull enough energy out
of thin air, that I can listen to a broadcast ...

Programming micros is fun enough too; but I\'m finding I\'m pulling away
from C, and into Assembly, just for the chance at those same \"aha
moments\".

[...]
That\'s why I suggested looking at the problem differently. Instead
of buying something that someone else has claimed is a \"moisture sensor\",
think about how moisture affects things and how those effects might be
detected.

Mhm, right now I\'m using the module\'s circuit (plus that blog that tore
it apart) as that jumping off point.

At the moment, I know it\'s a 555 running in astable mode, with the
\"sensor\" part being a pair of traces on the PCB acting as a capacitor.
Best I can figure at the moment (and not having understood that blog I\'m
reading... or the full implications of the 555 datasheet), those
\"capacitor-of-pcb-traces\" will potentially vary the 555\'s duty cycle,
which means the cap on the output will have more time to bleed through
its resistor... Or maybe once I get the understanding, I\'ll see that the
\"sensor\" part is actually on the output, rather than the input...


For example, *hair* stretches when wet. Can you conceive of a way to
sense this elasticity?

Could probably do something with a load cell ... soak the hair, stretch
it in the cell (but cell still reads zero), as it dries, the cell will
deflect.



Water is sensed in fuels by noting changes in conductivity.

Yeah, I have the feeling a resistive sensor would corrode in no time
flat...

[...]
So, back to this moisture sensor project. As you said, there are a
billion different \"module\" things out there, with half again as many
sloppily written \"tutorials\" for their use (bleh).

Thankfully, I was pointed to one blog (whose name escapes me at the
moment, and I can\'t find it in my browser history after a quick search,
so I must\'ve bookmarked it on the currently dead tablet...), where they
actually took a dive into the module and showed what it did, and how
(and a good bit of it sailed over my head -- but there were so many
links to references).

I found the use of chilled mirrors to sense dewpoint to be an \"aha\"
moment. Almost comical.

yay, getting out of a hot shower

Why get out? Hot showers are a key component of design.

[...]
I\'ve found that people are less interested in the more technical
devices I can show them (potential clients, friends, etc.). But,
the \"novelty\" items get lots of attention. Perhaps because they
are easier to relate to than something overly technical (folks
don\'t want to appear ignorant if they don\'t understand how something
works or its purpose). Or, maybe they just appreciate the whimsy!?

Indeed. Might as well be magic

You have been insulted by Sloman, so are officially on your way to
being an electronics design engineer.

Let me know if I can help.

Have you played with Raspberry Pi?

 

[John Larkin]

On Thu, 5 Jan 2023 13:42:02 -0000 (UTC), Dan Purgert <dan@djph.net>
wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

On 2023-01-05, Don Y wrote:
On 1/5/2023 5:07 AM, Dan Purgert wrote:
[...]
On the other hand; I already have a (weak) grasp of what a (linear?)
power-supply needs to have -- rectifier -> smoothing caps -> (I think) a
handful of transistors & resistors to get the desired voltage -> output
capacitor(s). And this (hopefully) gets me a little more understanding
of using transistors as more than just switches ... well, maybe.

Yes, but, at the end of the day, you\'re reinventing something that
a gazillion manufacturers sell in a bazillion different varieties
for less money than the postage on the parts you\'ll order to roll
your own.

Yep. And at the end of the day, when I memorized my 1-12 times tables in
grade school \"because you won\'t always have a calculator in your
pocket!\" ...

Again, this is more of a \"homework project(tm)\". Yeah, it\'s been done a
million times; yeah, I could just buy a linear regulator IC ...



If you have a \'scope, it can be a good exercise -- if only to let you
see how the \"signal\" changes as it moves through the circuit. And,
how it reacts to differing loads (e.g., see the ripple on the input
filter increase when the filter is having to supply a larger load
reflected through the regulator. What happens if you change the value
of the filter? Or, use a half-wave rectifier?)

That\'s more like where my thought process was going with this \"homework
project\". Fiddle with it, see what happens \"inside\" an LM338 (etc),
and, well, hopefully learn a thing or two. While it\'s not a scope, I
have one of those USB logic-analyzers that \"can\" do analog readings as
well, so we\'ll see how it works out.

Worst case, I have a powersupply that I\'m less concerned about blowing a
part inside, because, well, I have the schematic and the parts and ...


[I don\'t mean to discourage you. Rather, hoping you find something
to tackle that leads to an \"aha\" moment -- which tends to cause you to
crave more such moments.]

Yes, I am craving \"aha-moments\" with analog. It\'s pure wizardry seeing
a couple long wires (plus some other components) pull enough energy out
of thin air, that I can listen to a broadcast ...

Programming micros is fun enough too; but I\'m finding I\'m pulling away
from C, and into Assembly, just for the chance at those same \"aha
moments\".

[...]
That\'s why I suggested looking at the problem differently. Instead
of buying something that someone else has claimed is a \"moisture sensor\",
think about how moisture affects things and how those effects might be
detected.

Mhm, right now I\'m using the module\'s circuit (plus that blog that tore
it apart) as that jumping off point.

At the moment, I know it\'s a 555 running in astable mode, with the
\"sensor\" part being a pair of traces on the PCB acting as a capacitor.
Best I can figure at the moment (and not having understood that blog I\'m
reading... or the full implications of the 555 datasheet), those
\"capacitor-of-pcb-traces\" will potentially vary the 555\'s duty cycle,
which means the cap on the output will have more time to bleed through
its resistor... Or maybe once I get the understanding, I\'ll see that the
\"sensor\" part is actually on the output, rather than the input...


For example, *hair* stretches when wet. Can you conceive of a way to
sense this elasticity?

Could probably do something with a load cell ... soak the hair, stretch
it in the cell (but cell still reads zero), as it dries, the cell will
deflect.



Water is sensed in fuels by noting changes in conductivity.

Yeah, I have the feeling a resistive sensor would corrode in no time
flat...

[...]
So, back to this moisture sensor project. As you said, there are a
billion different \"module\" things out there, with half again as many
sloppily written \"tutorials\" for their use (bleh).

Thankfully, I was pointed to one blog (whose name escapes me at the
moment, and I can\'t find it in my browser history after a quick search,
so I must\'ve bookmarked it on the currently dead tablet...), where they
actually took a dive into the module and showed what it did, and how
(and a good bit of it sailed over my head -- but there were so many
links to references).

I found the use of chilled mirrors to sense dewpoint to be an \"aha\"
moment. Almost comical.

yay, getting out of a hot shower

Why get out? Hot showers are a key component of design.

[...]
I\'ve found that people are less interested in the more technical
devices I can show them (potential clients, friends, etc.). But,
the \"novelty\" items get lots of attention. Perhaps because they
are easier to relate to than something overly technical (folks
don\'t want to appear ignorant if they don\'t understand how something
works or its purpose). Or, maybe they just appreciate the whimsy!?

Indeed. Might as well be magic

You have been insulted by Sloman, so are officially on your way to
being an electronics design engineer.

Let me know if I can help.

Have you played with Raspberry Pi?

 

[John Larkin]

On Thu, 5 Jan 2023 13:42:02 -0000 (UTC), Dan Purgert <dan@djph.net>
wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

On 2023-01-05, Don Y wrote:
On 1/5/2023 5:07 AM, Dan Purgert wrote:
[...]
On the other hand; I already have a (weak) grasp of what a (linear?)
power-supply needs to have -- rectifier -> smoothing caps -> (I think) a
handful of transistors & resistors to get the desired voltage -> output
capacitor(s). And this (hopefully) gets me a little more understanding
of using transistors as more than just switches ... well, maybe.

Yes, but, at the end of the day, you\'re reinventing something that
a gazillion manufacturers sell in a bazillion different varieties
for less money than the postage on the parts you\'ll order to roll
your own.

Yep. And at the end of the day, when I memorized my 1-12 times tables in
grade school \"because you won\'t always have a calculator in your
pocket!\" ...

Again, this is more of a \"homework project(tm)\". Yeah, it\'s been done a
million times; yeah, I could just buy a linear regulator IC ...



If you have a \'scope, it can be a good exercise -- if only to let you
see how the \"signal\" changes as it moves through the circuit. And,
how it reacts to differing loads (e.g., see the ripple on the input
filter increase when the filter is having to supply a larger load
reflected through the regulator. What happens if you change the value
of the filter? Or, use a half-wave rectifier?)

That\'s more like where my thought process was going with this \"homework
project\". Fiddle with it, see what happens \"inside\" an LM338 (etc),
and, well, hopefully learn a thing or two. While it\'s not a scope, I
have one of those USB logic-analyzers that \"can\" do analog readings as
well, so we\'ll see how it works out.

Worst case, I have a powersupply that I\'m less concerned about blowing a
part inside, because, well, I have the schematic and the parts and ...


[I don\'t mean to discourage you. Rather, hoping you find something
to tackle that leads to an \"aha\" moment -- which tends to cause you to
crave more such moments.]

Yes, I am craving \"aha-moments\" with analog. It\'s pure wizardry seeing
a couple long wires (plus some other components) pull enough energy out
of thin air, that I can listen to a broadcast ...

Programming micros is fun enough too; but I\'m finding I\'m pulling away
from C, and into Assembly, just for the chance at those same \"aha
moments\".

[...]
That\'s why I suggested looking at the problem differently. Instead
of buying something that someone else has claimed is a \"moisture sensor\",
think about how moisture affects things and how those effects might be
detected.

Mhm, right now I\'m using the module\'s circuit (plus that blog that tore
it apart) as that jumping off point.

At the moment, I know it\'s a 555 running in astable mode, with the
\"sensor\" part being a pair of traces on the PCB acting as a capacitor.
Best I can figure at the moment (and not having understood that blog I\'m
reading... or the full implications of the 555 datasheet), those
\"capacitor-of-pcb-traces\" will potentially vary the 555\'s duty cycle,
which means the cap on the output will have more time to bleed through
its resistor... Or maybe once I get the understanding, I\'ll see that the
\"sensor\" part is actually on the output, rather than the input...


For example, *hair* stretches when wet. Can you conceive of a way to
sense this elasticity?

Could probably do something with a load cell ... soak the hair, stretch
it in the cell (but cell still reads zero), as it dries, the cell will
deflect.



Water is sensed in fuels by noting changes in conductivity.

Yeah, I have the feeling a resistive sensor would corrode in no time
flat...

[...]
So, back to this moisture sensor project. As you said, there are a
billion different \"module\" things out there, with half again as many
sloppily written \"tutorials\" for their use (bleh).

Thankfully, I was pointed to one blog (whose name escapes me at the
moment, and I can\'t find it in my browser history after a quick search,
so I must\'ve bookmarked it on the currently dead tablet...), where they
actually took a dive into the module and showed what it did, and how
(and a good bit of it sailed over my head -- but there were so many
links to references).

I found the use of chilled mirrors to sense dewpoint to be an \"aha\"
moment. Almost comical.

yay, getting out of a hot shower

Why get out? Hot showers are a key component of design.

[...]
I\'ve found that people are less interested in the more technical
devices I can show them (potential clients, friends, etc.). But,
the \"novelty\" items get lots of attention. Perhaps because they
are easier to relate to than something overly technical (folks
don\'t want to appear ignorant if they don\'t understand how something
works or its purpose). Or, maybe they just appreciate the whimsy!?

Indeed. Might as well be magic

You have been insulted by Sloman, so are officially on your way to
being an electronics design engineer.

Let me know if I can help.

Have you played with Raspberry Pi?

 

[Jan Panteltje]

On a sunny day (Wed, 4 Jan 2023 10:30:35 -0800) it happened Joerg
<news@analogconsultants.com> wrote in <k1luubF29nmU1@mid.individual.net>:

On 1/2/23 2:34 PM, Joe Gwinn wrote:
On Mon, 2 Jan 2023 12:59:00 -0800, Joerg <news@analogconsultants.com
wrote:

On 1/2/23 12:20 PM, whit3rd wrote:
On Monday, January 2, 2023 at 10:25:28 AM UTC-8, John Larkin wrote:

\"QUESTION: which upper level math courses did you find most applicable
to your major or masters courses. Are there any other free/cheap
courses that can set me up for success in Power Electronics and/or
Embedded systems?\"

I don\'t think that higher-level math courses set people up for success
in any EE field except academics.

Sensing, measuring, and filtering get a lot of utility from Fourier transform
techniques; it\'s hard to imagine success in phase-shift measurement without
using a F-transform. Absence of high-level math courses sets people
up for failure, but they won\'t ever know that.


Actually during one of my consulting projects in the mid-90\'s I reversed
that trend at a client. They had a big DSP do lots of Fourier transforms
and the auto-calibration routine for that board took forever. Tens of
seconds. I reverted all that to time-domain and it was finished after a
few hundred msec, every single time.

In the 80\'s we often did it with zero-crossers. Less math but blazingly
fast.

What was this big DSP doing? This story rings a bell.

In radar, the initial calibration involves multiple alternating
conversions between time and frequency domains, because the desired
result is a clean pulse in the time domain, achieved by adjusting
phase and amplitude settings as a function of frequency.


I am not at liberty to go into great detail but in a nutshell the DSP
was there to calibrate a multi-channel RF system via FFT with respect to
amplitude and phase. High precision was required. Theoretically it
could, of course, be done with the FFT but it took way too long and it
didn\'t always converge to the precision they needed. The sofwtare also
was, let\'s say, a bit temperamental.


Once the correct settings have been found iteratively, subsequent
calibration is by adjusting the various settings back to those golden
numbers - the file containing those golden numbers is of course called
a golden database.

Antenna pattern is first calibrated by a like process.


My time-domain routine didn\'t need any golden numbers and converged
every single time within less than half a second. We let the uC handle
that because the computational load dropped to peanuts. The big DSP
became unemployed.

The project start was the usual, everyone saying that FFT was the name
of the game and there wasn\'t any other decent way. If it didn\'t work in
time domain I\'d have to buy everyone a beer at night. If it did,
everyone had to buy me a beer. I needed a designated driver that night ...

Yes too much mamaticians work treated as God.
Same for Einstein.
In case of gravity we need a mechanism, likely a Le Sage like particle,
seems I can explain much what we observe with that, including dark-matter.
And if EM radiation is a state of - and carried by - Le Sage particles,
then uniting everything is not that hard, comes naturally.

But I am but a neural net made of grey matter...
Or all is linked by kwantuuum coupling... ;-)

We are just like the ant creeping up on a wall
not knowing what the wall is made of, what it was build for,
and who or what the architect is and intended by building it.
Lots of things to discover!

Need to work on my create life make your own dino kit.

 

[Jan Panteltje]

On a sunny day (Wed, 4 Jan 2023 10:30:35 -0800) it happened Joerg
<news@analogconsultants.com> wrote in <k1luubF29nmU1@mid.individual.net>:

On 1/2/23 2:34 PM, Joe Gwinn wrote:
On Mon, 2 Jan 2023 12:59:00 -0800, Joerg <news@analogconsultants.com
wrote:

On 1/2/23 12:20 PM, whit3rd wrote:
On Monday, January 2, 2023 at 10:25:28 AM UTC-8, John Larkin wrote:

\"QUESTION: which upper level math courses did you find most applicable
to your major or masters courses. Are there any other free/cheap
courses that can set me up for success in Power Electronics and/or
Embedded systems?\"

I don\'t think that higher-level math courses set people up for success
in any EE field except academics.

Sensing, measuring, and filtering get a lot of utility from Fourier transform
techniques; it\'s hard to imagine success in phase-shift measurement without
using a F-transform. Absence of high-level math courses sets people
up for failure, but they won\'t ever know that.


Actually during one of my consulting projects in the mid-90\'s I reversed
that trend at a client. They had a big DSP do lots of Fourier transforms
and the auto-calibration routine for that board took forever. Tens of
seconds. I reverted all that to time-domain and it was finished after a
few hundred msec, every single time.

In the 80\'s we often did it with zero-crossers. Less math but blazingly
fast.

What was this big DSP doing? This story rings a bell.

In radar, the initial calibration involves multiple alternating
conversions between time and frequency domains, because the desired
result is a clean pulse in the time domain, achieved by adjusting
phase and amplitude settings as a function of frequency.


I am not at liberty to go into great detail but in a nutshell the DSP
was there to calibrate a multi-channel RF system via FFT with respect to
amplitude and phase. High precision was required. Theoretically it
could, of course, be done with the FFT but it took way too long and it
didn\'t always converge to the precision they needed. The sofwtare also
was, let\'s say, a bit temperamental.


Once the correct settings have been found iteratively, subsequent
calibration is by adjusting the various settings back to those golden
numbers - the file containing those golden numbers is of course called
a golden database.

Antenna pattern is first calibrated by a like process.


My time-domain routine didn\'t need any golden numbers and converged
every single time within less than half a second. We let the uC handle
that because the computational load dropped to peanuts. The big DSP
became unemployed.

The project start was the usual, everyone saying that FFT was the name
of the game and there wasn\'t any other decent way. If it didn\'t work in
time domain I\'d have to buy everyone a beer at night. If it did,
everyone had to buy me a beer. I needed a designated driver that night ...

Yes too much mamaticians work treated as God.
Same for Einstein.
In case of gravity we need a mechanism, likely a Le Sage like particle,
seems I can explain much what we observe with that, including dark-matter.
And if EM radiation is a state of - and carried by - Le Sage particles,
then uniting everything is not that hard, comes naturally.

But I am but a neural net made of grey matter...
Or all is linked by kwantuuum coupling... ;-)

We are just like the ant creeping up on a wall
not knowing what the wall is made of, what it was build for,
and who or what the architect is and intended by building it.
Lots of things to discover!

Need to work on my create life make your own dino kit.

 

[Jan Panteltje]

On a sunny day (Wed, 4 Jan 2023 10:30:35 -0800) it happened Joerg
<news@analogconsultants.com> wrote in <k1luubF29nmU1@mid.individual.net>:

On 1/2/23 2:34 PM, Joe Gwinn wrote:
On Mon, 2 Jan 2023 12:59:00 -0800, Joerg <news@analogconsultants.com
wrote:

On 1/2/23 12:20 PM, whit3rd wrote:
On Monday, January 2, 2023 at 10:25:28 AM UTC-8, John Larkin wrote:

\"QUESTION: which upper level math courses did you find most applicable
to your major or masters courses. Are there any other free/cheap
courses that can set me up for success in Power Electronics and/or
Embedded systems?\"

I don\'t think that higher-level math courses set people up for success
in any EE field except academics.

Sensing, measuring, and filtering get a lot of utility from Fourier transform
techniques; it\'s hard to imagine success in phase-shift measurement without
using a F-transform. Absence of high-level math courses sets people
up for failure, but they won\'t ever know that.


Actually during one of my consulting projects in the mid-90\'s I reversed
that trend at a client. They had a big DSP do lots of Fourier transforms
and the auto-calibration routine for that board took forever. Tens of
seconds. I reverted all that to time-domain and it was finished after a
few hundred msec, every single time.

In the 80\'s we often did it with zero-crossers. Less math but blazingly
fast.

What was this big DSP doing? This story rings a bell.

In radar, the initial calibration involves multiple alternating
conversions between time and frequency domains, because the desired
result is a clean pulse in the time domain, achieved by adjusting
phase and amplitude settings as a function of frequency.


I am not at liberty to go into great detail but in a nutshell the DSP
was there to calibrate a multi-channel RF system via FFT with respect to
amplitude and phase. High precision was required. Theoretically it
could, of course, be done with the FFT but it took way too long and it
didn\'t always converge to the precision they needed. The sofwtare also
was, let\'s say, a bit temperamental.


Once the correct settings have been found iteratively, subsequent
calibration is by adjusting the various settings back to those golden
numbers - the file containing those golden numbers is of course called
a golden database.

Antenna pattern is first calibrated by a like process.


My time-domain routine didn\'t need any golden numbers and converged
every single time within less than half a second. We let the uC handle
that because the computational load dropped to peanuts. The big DSP
became unemployed.

The project start was the usual, everyone saying that FFT was the name
of the game and there wasn\'t any other decent way. If it didn\'t work in
time domain I\'d have to buy everyone a beer at night. If it did,
everyone had to buy me a beer. I needed a designated driver that night ...

Yes too much mamaticians work treated as God.
Same for Einstein.
In case of gravity we need a mechanism, likely a Le Sage like particle,
seems I can explain much what we observe with that, including dark-matter.
And if EM radiation is a state of - and carried by - Le Sage particles,
then uniting everything is not that hard, comes naturally.

But I am but a neural net made of grey matter...
Or all is linked by kwantuuum coupling... ;-)

We are just like the ant creeping up on a wall
not knowing what the wall is made of, what it was build for,
and who or what the architect is and intended by building it.
Lots of things to discover!

Need to work on my create life make your own dino kit.

 

[Phil Hobbs]

whit3rd wrote:

On Thursday, January 5, 2023 at 1:41:38 PM UTC-8, Phil Hobbs wrote:
whit3rd wrote:

[about FFT/divide/inverseFFT deconvolution]

...the FFT algorithm has no mechanism to
accept data with non-constant signficance, which is what, obviously,
happens with a divide-by-almost-zero step in the data processing.
It\'s gonna give you what the \'signal\' says, not what the \'signal\' and known
signal/noise ratio, tell you. That means using an FFT for the inverse is
excessively noise-sensitive. There\'s OTHER ways to do a Fourier inversion
that do allow the noise estimate its due influence.

The problem has nothing to do with the FFT, and everything to do with
what you\'re trying to do with it. Dividing transforms is a perfectly
rational way to deconvolve, provided you take into account the
finite-length effects and prepare the denominator correctly.

Think again; an FFT algorithm implements least-squares fitting, essentially;

Bollocks. An FFT is an information-preserving operation, unlike
least-squares fits.

> there\'s zero difference between the transform\'s inversion and the original data,

Right, i.e. it\'s not a least-squares fit, it\'s exact.

> which (zero) is obviously the minimum of sum-of-squares-of-differences.

You\'re maybe thinking of a continuous-time orthonormal-function
expansion, e.g. a Fourier or Bessel or Chebyshev series. In that case,
_truncating_ the series leads to the least-squares optimum for that
order. Least squares optima tend not to be that useful--the infamous
\"Gibbs phenomenon\" being a typical example.

But there are a lot, a lot of ways of producing a finite expansion that
don\'t have that problem, just as there are all sorts of ways of
controlling noise gain in deconvolution.

Dividing by an inverse function is precisely a weighting operation.

But, it\'s not correct if the standard deviations of the elements are not identical,
because it IS minimizing sum-of-squares of differences, rather than the
(correct) sum of (squares-of-differences/sigma-squared-of-this-element).

What makes that the One True Algorithm? Why assume that all frequencies
have to have the same SNR? That\'s not at all common in real life, and
it\'s often a win to sacrifice a significant amount of SNR for improved
resolution, data rate, or what have you. It\'s horses for courses.

And none of that has anything to do with how you perform the actual
deconvolution.

Cheers

Phil Hobbs

--
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