Waveform documentation...

[Don Y]

On 6/28/2022 12:35 PM, Joe Gwinn wrote:

On Tue, 28 Jun 2022 07:16:13 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Tue, 28 Jun 2022 16:19:23 +1000, Chris Jones
lugnut808@spam.yahoo.com> wrote:

On 28/06/2022 13:28, jlarkin@highlandsniptechnology.com wrote:
On Mon, 27 Jun 2022 20:49:18 -0400 (EDT), Martin Rid
martin_riddle@verison.net> wrote:

John Larkin <jlarkin@highland_atwork_technology.com> Wrote in message:r
On Mon, 27 Jun 2022 14:27:07 -0400 (EDT), Martin Rid<martin_riddle@verison.net> wrote:>Don Y <blockedofcourse@foo.invalid> Wrote in message:r>> I usually build a document that describes the hardware,nominal voltages, waveforms, timing relationships, etc.Plus, captured waveforms under different operating conditions(along with those expected during specific diagnostics)I\'m getting some pushback to move these onto the schematics,directly, instead of in a supplementary document.I\'m not keen on this as it means schematics have to make roomto accommodate these annotations. And, I can\'t see how tomaintain such a document if light of potential changes todiagnostics (which may be numerous for a given circuit).Any folks preparing comparable documentation have suggestions?>>I would imagine a separate service manual would apply.>>CheersDoes anyone still do that?-- 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

Medical equipment.

Cheers

Yikes. It scares me to imagine anyone doing field repairs to medical
equipment.

It is also a bit scary to imagine being treated in a hospital during an
emergency, full of equipment that when it fails, cannot be repaired in
the field, but must instead be sent to the same overseas facility that
every other hospital in the world is trying to send their dead units to,
(especially bearing in mind that whatever emergency may well put all the
freight aircraft or their pilots out of action).

There is an argument for only procuring medical equipment with proper
service manuals, resistors big enough to have values marked on them, and
a stock of spares of any programmable devices, or spares of any boards
with massive BGAs, and no parts locked to each other by serial number.
Those countries with nationalised healthcare do have sufficient buying
power to dictate those terms if they want to, (much like the US military
to test equipment manufacturers in the past).


No surface-mount?

Our FDA is absolutely fascist about quality. They pulled a pop
inspection on one nearby outfit that made cancer-treatment gear. They
discovered some new pcb\'s on the same bench as some repair units,
which is against the rules. They shut down the facility for a year of
re-training and re-qualification, and some of the engineers quit from
boredom.

Yes. Here\'s why:

.<https://en.wikipedia.org/wiki/Therac-25>

I read the what-happened reports from the day. What a bunch of hacks,
even by the standards of that day.

Sadly, there isn\'t much that can really be done to improve things,
short of insisting on \"process\" -- and \"proof\" of adherence to same.

Some of my customers were even more zealous -- checking into the
qualifications of the engineers working on the design, wanting to
review component choices (for suitability as well as long-term
availability/second sources), insisting on placing the complete
design in escrow, etc.

I guess when it\'s YOUR ass on the line, you can never be too careful!

OTOH, you CHARGE them for these \"inconveniences\" (even though they
improve the quality of YOUR product!)

 

[John Larkin]

On Tue, 28 Jun 2022 14:19:58 -0400 (EDT), Martin Rid
<martin_riddle@verison.net> wrote:

jlarkin@highlandsniptechnology.com Wrote in message:r
On Mon, 27 Jun 2022 20:49:18 -0400 (EDT), Martin Rid<martin_riddle@verison.net> wrote:>John Larkin <jlarkin@highland_atwork_technology.com> Wrote in message:r>> On Mon, 27 Jun 2022 14:27:07 -0400 (EDT), Martin Rid<martin_riddle@verison.net> wrote:>Don Y <blockedofcourse@foo.invalid> Wrote in message:r>> I usually build a document that describes the hardware,nominal voltages, waveforms, timing relationships, etc.Plus, captured waveforms under different operating conditions(along with those expected during specific diagnostics)I\'m getting some pushback to move these onto the schematics,directly, instead of in a supplementary document.I\'m not keen on this as it means schematics have to make roomto accommodate these annotations. And, I can\'t see how tomaintain such a document if light of potential changes todiagnostics (which may be numerous for a given circuit).Any folks preparing comparable documentation have suggestions?>>I would imagine a separate service manual would
apply.>>CheersDoes anyone still do that?-- 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>>Medical equipment. >>CheersYikes. It scares me to imagine anyone doing field repairs to medicalequipment.Our gear is always returned to the factory for repairs. We can replaceany bad parts with the correct part, QC the work, then run the fullautomated test and cal and archive a test report.And we learn about failure rates and mechanisms.

Ok, how about automotive service manuals.
Feel better?

Cheers

A lot of stuff on my car can\'t be fixed by owners.

--

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

 

[Three Jeeps]

On Tuesday, June 28, 2022 at 7:52:48 PM UTC-4, John Larkin wrote:

On Tue, 28 Jun 2022 14:19:58 -0400 (EDT), Martin Rid
martin...@verison.net> wrote:

jla...@highlandsniptechnology.com Wrote in message:r
On Mon, 27 Jun 2022 20:49:18 -0400 (EDT), Martin Rid<martin...@verison..net> wrote:>John Larkin <jlarkin@highland_atwork_technology.com> Wrote in message:r>> On Mon, 27 Jun 2022 14:27:07 -0400 (EDT), Martin Rid<martin...@verison.net> wrote:>Don Y <blocked...@foo.invalid> Wrote in message:r>> I usually build a document that describes the hardware,nominal voltages, waveforms, timing relationships, etc.Plus, captured waveforms under different operating conditions(along with those expected during specific diagnostics)I\'m getting some pushback to move these onto the schematics,directly, instead of in a supplementary document.I\'m not keen on this as it means schematics have to make roomto accommodate these annotations. And, I can\'t see how tomaintain such a document if light of potential changes todiagnostics (which may be numerous for a given circuit).Any folks preparing comparable documentation have suggestions?>>I would imagine a separate service manual would
apply.>>CheersDoes anyone still do that?-- 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>>Medical equipment. >>CheersYikes. It scares me to imagine anyone doing field repairs to medicalequipment.Our gear is always returned to the factory for repairs. We can replaceany bad parts with the correct part, QC the work, then run the fullautomated test and cal and archive a test report.And we learn about failure rates and mechanisms.

Ok, how about automotive service manuals.
Feel better?

Cheers
A lot of stuff on my car can\'t be fixed by owners.
--

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

Design and mfg for repairability for most consumer products went away decades ago. Throw away society and if you believe they work, electronic recycling facilities.
Have relatives in the Boston area. Extended visits usually resulted in taking refuse to the local \'dump\'...The dump had a sizable building with tables where ppl would put their (mostly electronic) stuff for recycling. Back in the day, retrieved a Apple power station (dead supply-easily fixed), 32\" color tv ( short in HV section), Marantz 60watts am/fm receiver ( blown output transistors).
One mans ceiling is another mans floor.
J
J

 

[Don Y]

On 6/28/2022 9:21 PM, Three Jeeps wrote:

Design and mfg for repairability for most consumer products went away
decades ago.

Simple matter of labor costs. As product *price* falls, there\'s less
and less room to accommodate repair/refurbishing.

Sadly, \"consumer\" isn\'t the only market suffering from that affliction;
businesses (here) routinely replace ALL of their workstations on short
update cycles (18-36 months). Even KEYBOARDS have longer useful lives
than that (and they experience the most wear).

I see a lot of medical equipment (and DME), medicines, bicycles,
scooters, wheelchairs, phones, copiers, etc. headed to the tip.

Throw away society and if you believe they work, electronic
recycling facilities.

IME, all this does is get yesterday\'s kit into the hands of
The Less Fortunate. E.g., a group I\'m affiliated with refurbishes
hundreds of PCs each month, distributing them for low/no cost
($20) to folks who are more needy.

So, on the one hand, the item has been (temporarily) diverted
from the land fill; on the other, we\'ve effectively just created
another *user* (and, there\'s likely no one \"beneath\" him when
*he* discards the refurbished unit)

The DME is perhaps the most disheartening because you know it
represents a \"real\" need -- for someone. (yet, you often can\'t
give the stuff away because what the recipient needs more than
anything is the support that comes with a commercial sale!)

Have relatives in the Boston area. Extended visits
usually resulted in taking refuse to the local \'dump\'...The dump had a
sizable building with tables where ppl would put their (mostly electronic)
stuff for recycling. Back in the day, retrieved a Apple power station
(dead supply-easily fixed), 32\" color tv ( short in HV section), Marantz
60watts am/fm receiver ( blown output transistors). One mans ceiling is
another mans floor.

I have 30 monitors (12 in use) that I\'ve recapped or replaced blown FETs.

Two laser printers (including several NIB toner cartridges). Discarded
the color phasers, LaserJet 4M+ (w/duplexor), etc. cuz it was silly to
maintain them given how little color printing I do (I can color print at
the library -- from home! -- for $0.10/page).

Two B-size (\"Tabloid\") flat bed scanners. A 40\" wide format scanner.
A couple of sheet-fed scanners.

Half a dozen motion controllers. Box of mice and keyboards. A couple of
digitizing tablets (discarded the D-size unit as it took up too much floor
space). Discarded the pen plotters for similar reasons.

Countless bits of test equipment -- usually just needing a recal cycle
or trivial repair.

Six laptops -- each in a carrying bag. Several servers. Six identical
workstations. A dozen 1500VA sine-wave, networked UPSs. (plus several
2200-5000VA units).

Each item \"bought\" for the scrap price that the \"material recycler\"
would pay for them NOT broken down into their component parts (normally,
items are disassembled so fans can be sold to one recycler, PCBs to
another, tin/metal to a third, etc.). This because there are no
users eager to inherit an 80 pound workstation or an oversized scanner,
or a monitor with broken backlight PS, etc.

[If you truly understood the magnitude of the throw-away problem, you\'d
approach design entirely differently!]

 

[Phil Hobbs]

Joe Gwinn wrote:

On Tue, 28 Jun 2022 07:16:13 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Tue, 28 Jun 2022 16:19:23 +1000, Chris Jones
lugnut808@spam.yahoo.com> wrote:

On 28/06/2022 13:28, jlarkin@highlandsniptechnology.com wrote:
On Mon, 27 Jun 2022 20:49:18 -0400 (EDT), Martin Rid
martin_riddle@verison.net> wrote:

John Larkin <jlarkin@highland_atwork_technology.com> Wrote in message:r
On Mon, 27 Jun 2022 14:27:07 -0400 (EDT), Martin Rid<martin_riddle@verison.net> wrote:>Don Y <blockedofcourse@foo.invalid> Wrote in message:r>> I usually build a document that describes the hardware,nominal voltages, waveforms, timing relationships, etc.Plus, captured waveforms under different operating conditions(along with those expected during specific diagnostics)I\'m getting some pushback to move these onto the schematics,directly, instead of in a supplementary document.I\'m not keen on this as it means schematics have to make roomto accommodate these annotations. And, I can\'t see how tomaintain such a document if light of potential changes todiagnostics (which may be numerous for a given circuit).Any folks preparing comparable documentation have suggestions?>>I would imagine a separate service manual would apply.>>CheersDoes anyone still do that?-- 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

Medical equipment.

Cheers

Yikes. It scares me to imagine anyone doing field repairs to medical
equipment.

It is also a bit scary to imagine being treated in a hospital during an
emergency, full of equipment that when it fails, cannot be repaired in
the field, but must instead be sent to the same overseas facility that
every other hospital in the world is trying to send their dead units to,
(especially bearing in mind that whatever emergency may well put all the
freight aircraft or their pilots out of action).

There is an argument for only procuring medical equipment with proper
service manuals, resistors big enough to have values marked on them, and
a stock of spares of any programmable devices, or spares of any boards
with massive BGAs, and no parts locked to each other by serial number.
Those countries with nationalised healthcare do have sufficient buying
power to dictate those terms if they want to, (much like the US military
to test equipment manufacturers in the past).


No surface-mount?

Our FDA is absolutely fascist about quality. They pulled a pop
inspection on one nearby outfit that made cancer-treatment gear. They
discovered some new pcb\'s on the same bench as some repair units,
which is against the rules. They shut down the facility for a year of
re-training and re-qualification, and some of the engineers quit from
boredom.

Yes. Here\'s why:

.<https://en.wikipedia.org/wiki/Therac-25>

I read the what-happened reports from the day. What a bunch of hacks,
even by the standards of that day.

Joe Gwinn

Another Crown Corporation success story.

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

 

[Joe Gwinn]

On Wed, 29 Jun 2022 10:39:57 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

Joe Gwinn wrote:
On Tue, 28 Jun 2022 07:16:13 -0700, jlarkin@highlandsniptechnology.com
wrote:

On Tue, 28 Jun 2022 16:19:23 +1000, Chris Jones
lugnut808@spam.yahoo.com> wrote:

On 28/06/2022 13:28, jlarkin@highlandsniptechnology.com wrote:
On Mon, 27 Jun 2022 20:49:18 -0400 (EDT), Martin Rid
martin_riddle@verison.net> wrote:

John Larkin <jlarkin@highland_atwork_technology.com> Wrote in message:r
On Mon, 27 Jun 2022 14:27:07 -0400 (EDT), Martin Rid<martin_riddle@verison.net> wrote:>Don Y <blockedofcourse@foo.invalid> Wrote in message:r>> I usually build a document that describes the hardware,nominal voltages, waveforms, timing relationships, etc.Plus, captured waveforms under different operating conditions(along with those expected during specific diagnostics)I\'m getting some pushback to move these onto the schematics,directly, instead of in a supplementary document.I\'m not keen on this as it means schematics have to make roomto accommodate these annotations. And, I can\'t see how tomaintain such a document if light of potential changes todiagnostics (which may be numerous for a given circuit).Any folks preparing comparable documentation have suggestions?>>I would imagine a separate service manual would apply.>>CheersDoes anyone still do that?-- 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

Medical equipment.

Cheers

Yikes. It scares me to imagine anyone doing field repairs to medical
equipment.

It is also a bit scary to imagine being treated in a hospital during an
emergency, full of equipment that when it fails, cannot be repaired in
the field, but must instead be sent to the same overseas facility that
every other hospital in the world is trying to send their dead units to,
(especially bearing in mind that whatever emergency may well put all the
freight aircraft or their pilots out of action).

There is an argument for only procuring medical equipment with proper
service manuals, resistors big enough to have values marked on them, and
a stock of spares of any programmable devices, or spares of any boards
with massive BGAs, and no parts locked to each other by serial number.
Those countries with nationalised healthcare do have sufficient buying
power to dictate those terms if they want to, (much like the US military
to test equipment manufacturers in the past).


No surface-mount?

Our FDA is absolutely fascist about quality. They pulled a pop
inspection on one nearby outfit that made cancer-treatment gear. They
discovered some new pcb\'s on the same bench as some repair units,
which is against the rules. They shut down the facility for a year of
re-training and re-qualification, and some of the engineers quit from
boredom.

Yes. Here\'s why:

.<https://en.wikipedia.org/wiki/Therac-25

I read the what-happened reports from the day. What a bunch of hacks,
even by the standards of that day.

Joe Gwinn


Another Crown Corporation success story.

I had not heard of them before. I gather that they have an
interesting history, maybe too interesting.

The thing that caught my eye back then was the part where they removed
the mechanical interlock. I\'ve had bosses like that.

Joe Gwinn

 

[Allen Shieh]

在 2022年7月4日星期一 UTC+8 06:27:22，<Don Y> 写道：

On 7/3/2022 2:25 PM, Rich S wrote:
Thank you Don for the elaborate details. I expected little or none,
you provided a wealth of ideas.
I don\'t think many people actually *think* about what is required to
\"recycle\" something. It\'s as if it magically goes from a dropoff location
to \"X% recycled content\".

Sadly, electronic items are hard to truly recycle because the technology
is so quickly outdated. We can better recycle (refurbish) a peristaltic
pump than a computer -- mechanisms tend not to go obsolete as quickly.
Have you put these thoughts
and experiences into a blog? SED is not quite the right place.
I expect you have more to say ;-)
No. It is actually very depressing when you see truckloads (semi\'s)
full of stuff pull in and know you\'ll only be able to \"recover\" a
small percentage of their contents.

When I\'ve taken friends through for \"tours\", they are impressed
by the quantity of goods. Instead, they should be APPALLED!

And, you feel like an \"enabler\" -- the firm donating the items likely
thinks they are doing their part... if they truly knew how inefficient
their efforts were, you wonder if they would:
- stop trying
- try harder (including reconsidering their purchases)!

At the same time, when Ma&Pa Kettle drive in with some 20 year
old PC that they want to donate -- thinking some needy kid will
benefit from their donation... you can\'t tell them that it\'s just
so much *scrap*! :

Look around your area. I\'m sure there are some folks doing this sort
of thing (I\'ve managed to find groups in various parts of the country).
A tour can be enlightening (depressing).
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