Waveform documentation...

[Don Y]

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 room
to accommodate these annotations. And, I can\'t see how to
maintain such a document if light of potential changes to
diagnostics (which may be numerous for a given circuit).

Any folks preparing comparable documentation have suggestions?

 

[server]

On Sun, 26 Jun 2022 11:11:28 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:

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 room
to accommodate these annotations. And, I can\'t see how to
maintain such a document if light of potential changes to
diagnostics (which may be numerous for a given circuit).

Any folks preparing comparable documentation have suggestions?

We keep a separate design notes folder, that has a lot more than could
fit on a schamatic. Personally, I don\'t like to clutter a schematic
with notes. Maybe a very few strategic ones.

If I have a rail named +60V, but it is typically 57 or something, I
might add a small note so test people don\'t get upset. Maybe note a
clock frequency in discreet small text.

We do have a block diagram and a table of contents on sheet 1, and
assign a name to each sheet.

Before we release a schematic, we do a cosmetic cleanup and delete any
layout notes or such.

https://www.dropbox.com/s/sd73vlfs7bzen2o/23S901A.pdf?dl=0

 

[Don]

Don Y wrote:

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 room
to accommodate these annotations. And, I can\'t see how to
maintain such a document if light of potential changes to
diagnostics (which may be numerous for a given circuit).

Any folks preparing comparable documentation have suggestions?

Here\'s how Sams did it back in the day:

https://crcomp.net/misc/sams.pdf

Each of the black rectangles is an oscilloscope trace. The dimensional
captions on the right side of each rectangle are easier to read off the
original document. The captions say things such as 1.2 V over HORIZ.

Sams\' obvious motivation to include traces was to enable servicemen to
fix TVs as fast as possible.

kicad enables users to insert images into a schematic. kicad, in other
words, can create Sams styled schematics.

Danke,

--
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

 

[Don Y]

On 6/26/2022 12:35 PM, Don wrote:

Don Y wrote:
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 room
to accommodate these annotations. And, I can\'t see how to
maintain such a document if light of potential changes to
diagnostics (which may be numerous for a given circuit).

Any folks preparing comparable documentation have suggestions?

Here\'s how Sams did it back in the day:

https://crcomp.net/misc/sams.pdf

Each of the black rectangles is an oscilloscope trace. The dimensional
captions on the right side of each rectangle are easier to read off the
original document. The captions say things such as 1.2 V over HORIZ.

Sams\' obvious motivation to include traces was to enable servicemen to
fix TVs as fast as possible.

kicad enables users to insert images into a schematic. kicad, in other
words, can create Sams styled schematics.

But, TV\'s have dedicated functionality; you can say \"hook color bar generator
to input and these are the waveforms you will see\". There\'s nothing comparable
to hardware-software codesign, involved (where the waveform is largely
controlled by the software and, thus, can be revised without altering the
board artwork/PL).

And, TV\'s don\'t tend to have any \"sequencing\" involved in their operation
(do you show the waveforms AS channels are being changed?). By contrast,
the sorts of things I (and many others) design inherently involve time
dependencies for their proper operation (e.g., my power supplies use
a combination of hardware signalling and out-of-band control messages
to determine current limits, overload, sleep, etc.)

I don\'t see the appeal of tying the two types of information together
in one document -- it just saves (and RESTRICTS) having another document(s)
on hand during test. If you had several different test procedures that
could be invoked, you\'d have to clutter the schematic with screenshots of
the waveforms of *each* (or, here\'s a thought: move them into another
document! :> )

[I\'ve seen schematics in which snippets of every previous revision were
included in the document (in some \"unused\" whitespace). What does this
afford anyone -- save the need to pull the schematic revision applicable
to the board revision in front of you?! This sort of thing seems more
associated with one-man shops that grew up into businesses; wanting to
economize on documentation costs while small and never \"maturing\"!]

 

[Don]

Don Y wrote:

Don wrote:
Don Y wrote:
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 room
to accommodate these annotations. And, I can\'t see how to
maintain such a document if light of potential changes to
diagnostics (which may be numerous for a given circuit).

Any folks preparing comparable documentation have suggestions?

Here\'s how Sams did it back in the day:

https://crcomp.net/misc/sams.pdf

Each of the black rectangles is an oscilloscope trace. The dimensional
captions on the right side of each rectangle are easier to read off the
original document. The captions say things such as 1.2 V over HORIZ.

Sams\' obvious motivation to include traces was to enable servicemen to
fix TVs as fast as possible.

kicad enables users to insert images into a schematic. kicad, in other
words, can create Sams styled schematics.

But, TV\'s have dedicated functionality; you can say \"hook color bar generator
to input and these are the waveforms you will see\". There\'s nothing comparable
to hardware-software codesign, involved (where the waveform is largely
controlled by the software and, thus, can be revised without altering the
board artwork/PL).

And, TV\'s don\'t tend to have any \"sequencing\" involved in their operation
(do you show the waveforms AS channels are being changed?). By contrast,
the sorts of things I (and many others) design inherently involve time
dependencies for their proper operation (e.g., my power supplies use
a combination of hardware signalling and out-of-band control messages
to determine current limits, overload, sleep, etc.)

I don\'t see the appeal of tying the two types of information together
in one document -- it just saves (and RESTRICTS) having another document(s)
on hand during test. If you had several different test procedures that
could be invoked, you\'d have to clutter the schematic with screenshots of
the waveforms of *each* (or, here\'s a thought: move them into another
document! :> )

[I\'ve seen schematics in which snippets of every previous revision were
included in the document (in some \"unused\" whitespace). What does this
afford anyone -- save the need to pull the schematic revision applicable
to the board revision in front of you?! This sort of thing seems more
associated with one-man shops that grew up into businesses; wanting to
economize on documentation costs while small and never \"maturing\"!]

You find pack rats everywhere - even at too big organizations. And, as
always, people believe whatever they choose to believe and act
accordingly.

Anyhow, the old Sams schematic linked above fired up /my/ imagination.
My mind now cogitates on a circuit challenge. How to seamlessly combine
this code:

iicWrite(iiccmd); /* RS=Instruction; RW=Write; */
nSleep (40L); /* Wait 40 ns */
iicWrite(0x24); /* E; DB5=Function Set; DB4=4-bit */
nSleep (230L); /* Wait 230 ns */
iicWrite(0x20); /* !E; DB5=Function Set; DB4=4-bit */
nSleep (270L); /* Wait 270 ns */

with this timing diagram:

https://crcomp.net/iic44780/timing.png


Danke,

--
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.

 

[Martin Rid]

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.

Cheers
--


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[John Larkin]

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.

Cheers

Does 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

 

[Don Y]

On 6/27/2022 10:05 AM, Don wrote:

Don Y wrote:

[I\'ve seen schematics in which snippets of every previous revision were
included in the document (in some \"unused\" whitespace). What does this
afford anyone -- save the need to pull the schematic revision applicable
to the board revision in front of you?! This sort of thing seems more
associated with one-man shops that grew up into businesses; wanting to
economize on documentation costs while small and never \"maturing\"!]

You find pack rats everywhere - even at too big organizations. And, as
always, people believe whatever they choose to believe and act
accordingly.

Larger organizations suffer from inertial.. But, also have more opportunities
for \"smarter eyes\" to look at the way things are being done. Small firms
often use \"re$ource$\" as an excuse to convince themselves that there is no
need to change... NOW (maybe later -- yeah, sure!)

Anyhow, the old Sams schematic linked above fired up /my/ imagination.
My mind now cogitates on a circuit challenge. How to seamlessly combine
this code:

iicWrite(iiccmd); /* RS=Instruction; RW=Write; */
nSleep (40L); /* Wait 40 ns */
iicWrite(0x24); /* E; DB5=Function Set; DB4=4-bit */
nSleep (230L); /* Wait 230 ns */
iicWrite(0x20); /* !E; DB5=Function Set; DB4=4-bit */
nSleep (270L); /* Wait 270 ns */

with this timing diagram:

https://crcomp.net/iic44780/timing.png

First, I\'d express the code in more symbolic form. E.g., without
investing much time to understand the unnamed component referenced,
here (just guessing at the binding of value to symbols in diagram):

// times in ns
#define Tac (40) // setup
#define PWeh (230) // width of E high
#define Tah (270) // address hold

#define E_CYCLE (0x20) // assert E
#define BITS_4 (0x04) // 4 bit datum
#define E_CYCLE_4_BIT (E_CYCLE | BITS_4)

// send instruction opcode (\"address\")
iicWrite(iiccmd);
nSleep ((long) Tac);

iicWrite(E_CYCLE_4_BIT); // assert E for 4 bit cycle
nSleep ((long) PWeh);
iicWrite(E_CYCLE_4_BIT & ~E_CYCLE); // release E

nSleep ((long) Tah);

I would pull this into a prose document that can exploit multimedia
in its explanation of \"why\" things are done this way.

N.B. You might be interested in \"WaveDrom\"

 

[Don Y]

On 6/27/2022 11:27 AM, Martin Rid 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.

In my case, these are \"manufacturing documents\"; information that
the folks in final test (or depot repair) would consult to verify
proper operation and/or isolate faults.

But, that would inevitably have lots of \"accompanying text\" that
would be essential to put the \"drawings\" in context: \"Do *this*
and expect to see *that* on some particular circuit node\"

 

[Martin Rid]

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
--


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[Rich S]

On Wednesday, June 29, 2022 at 5:42:59 AM UTC, Don Y wrote:

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!]

Hi Don Y,
We drifted off original topic but this one
is still very relevant to me.
I would like to know, how should consumer
product -- such as those you mentioned
-- and its manufacturer -- be evaluated for their
positive aspects towards sustainability and
minimizing negative ecological impact. It is a
whole area of study unto itself.
Yes, my organization does
happen to employ these people. But the devil
is in the details -- what specifically about
product \"X\" can make the most difference?
Thanks, Rich S.

 

[server]

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.

Our gear is always returned to the factory for repairs. We can replace
any bad parts with the correct part, QC the work, then run the full
automated test and cal and archive a test report.

And we learn about failure rates and mechanisms.

 

[Ricky]

On Sunday, June 26, 2022 at 2:11:41 PM UTC-4, Don Y wrote:

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 room
to accommodate these annotations. And, I can\'t see how to
maintain such a document if light of potential changes to
diagnostics (which may be numerous for a given circuit).

Any folks preparing comparable documentation have suggestions?

I\'m preparing a debugging guide. I was thinking of making it part of the test program, to pull up all the info needed, at the time of failure, but changed my mind. Better to separate those matters and let test proceed uninterrupted.

In the end, I prepared an HTML document with the schematics showing the probe points (added to the PDF page) and PCB layout images showing the same along with tables of the voltages expected. Also included is text guiding through the process.

I can\'t imagine this being on a schematic. While basic voltages might be useful, it\'s far more useful in the sort of document I provided.

--

Rick C.

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

 

[Chris Jones]

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).

 

[Don Y]

On 7/2/2022 4:17 PM, Rich S wrote:

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

We drifted off original topic but this one
is still very relevant to me.
I would like to know, how should consumer
product -- such as those you mentioned
-- and its manufacturer -- be evaluated for their
positive aspects towards sustainability and
minimizing negative ecological impact. It is a
whole area of study unto itself.

I think it is the nature of businesses to want for consumption.
They need a constant revenue stream to survive. Building a \"forever\"
product is one way to limit your success -- once everyone has
purchased one, the market is exhausted!

So, the first line of defense is to adjust customer expectations
soas not to think they NEED a shiney new <whatever>. If you are
a business -- and a stakeholder in said business -- then you
can make an impact with policy. Do you really need to update
all of your PC seats every time MS decides it needs a fresh
injection of revenue? Or, apple? Is there something that
application X can\'t do that you really REALLY need to do?
Do you need it enough to warrant the OS (and hardware) upgrade
that it might require??

Is there some reason that 65 inch HD TV (i.e., the one that
I rescued for our living room) is no longer \"appropriate\"
for your conference room needs? If you are letting IT people
make your equipment buying decisions/recommendations, perhaps
lump IT equipment purchases into the budget *with* salaries so
they get the message that money spent on \"new toys\" comes at
a cost of \"fewer raises\"! It\'s really easy to recommend spending
someone else\'s money -- esp if it gives you additional job
security (more stuff to install/decommission/maintain!)

Yes, my organization does
happen to employ these people. But the devil
is in the details -- what specifically about
product \"X\" can make the most difference?

There are lots of first-level recycling agencies. Their
mission statements vary (ours is to divert materials
from landfills through reuse, refurbishment or repurposing;
resorting to \"recycling\" as a last resort).

Recycling is incredibly labor intensive. If you had to
pay folks to disassemble each bit of kit into:
- sheet metal
- plastics (discard)
- valuable metals (clean aluminum, copper and gold)
- circuit boards (from which metals could be reclaimed)
- memory (which can often be reused, as is)
- CPUs (for the gold on their pins)
- fans (can be refurbished)
- hardware (screws, etc. for their metal content)
- disk drives (for the metal in their housings)
etc. you find that it costs more for the labor than you can
recover from the goods!

[A consumer PC is \"worth\" about $5 if headed for the tip,
regardless of whether there\'s an i7 inside or a 386; servers
a fair bit more but largely because of the quantity and quality
of the components]

We rely on volunteer labor for this disassembly work. These
are typically developmentally disabled \"kids\" (though they
actually may be adults) under \"adult\" supervision. Their
cognitive skills and manual dexterity are often compromised.

So, it is easy for a mechanism (assembly structure) to be
too complex for them to sort out. Simple, mainstream
fasteners (phillips) of significant size and placement are
easiest. Slotted screwdrivers are often harder to position
in the fastener. And, often used as prybars -- which can slip
and find their way into the flesh of a palm!

If they have to resort to several different tools to
disassemble something, you end up with mangled tools
and frustrated workers (they were using a #0 phillips to
remove a small screw and then continued to use it in an
attempt to loosen a #2 screw! or, an 1/8\" cabinet tip
slotted screwdriver to loosen something considerably meatier!)

Things that snap or slide together without special tools are
best. All they have to do is be shown the proper motion
to separate the items. Then, told which bin to place each.
(someone has to sort through the bins after each \"shift\"
to be sure stuff didn\'t get mixed where not intended).

The downstream recyclers will get annoyed -- and significantly
lower the price per pound they will pay us -- if things aren\'t
properly sorted. A large copper heatsink with bits of mounting
bracket still attached loses its value as it has to be further
processed. Even as a nonprofit with only a couple of bodies
\"on staff\", someone still has to pay the rent, lights,
insurance, truck/forklift maintenance, etc.

And, as prices are for BATCHES of stuff, if there are too many
(no idea who makes that determination, nor how!) items that
aren\'t \"clean\", then the entire batch (which is likely a
Gaylord) is repriced at the lower rate. I.e., the value of the
*good* work is lost in a stroke of the pen due to a few bad apples!

The old 68K Macs were ideal in this sense; one screw and everything
slid/snapped apart. But, there was a lot of plastic involved so
that\'s a downside (there is NO recycle value to plastic; sheet metal
is like $0.01/pound!)

There\'s a perverse economy, here. Durable kit is likely harder
to disassemble -- and, thus, recycle -- owing to the use
of more plentiful fasteners and components. E.g., my workstations
would have been recycled as \"complete units\" (at the much lower
rate) simply because they require too much effort and \"skill\"
to \"decompose\". So, don\'t buy durable kit unless you plan on giving
it extra life! Or, rather, DO buy durable kit and PLAN on giving it
extra life!

Don\'t buy \"toy\" UPSs -- because you *won\'t* replace the batteries!
Or, you will defer that activity until the batteries are hopelessly
swollen inside the unit. A UPS is worth (recycle value) as much as
a PC -- simply because of the weight associated with the transformer!

[Pull the batteries and recycle them separately; you can expect about
$0.20/pound for a battery whereas the UPS might be worth $0.10/pound]

[[I\'ve rescued large (2200VA) UPSs NIB! Complete with the shipping
labels intact! Gotta wonder if anyone had to answer for that \"needless\"
purchase <frown> ]]

Finally, THINK about what you\'re going to do when an item has reached
the end of its useful life FOR YOU. I tell people to think about how
they are going to dispose of items BEFORE they purchase them. PCs tend to
have extendable markets -- there is always some underprivileged kid or
school district that could make use of 500 \"used\" PCs -- *if* someone
has refurbished them and reinstalled OS/apps. But, the sheer number of
such recycled items means even that \"market\" will quickly be saturated.

Then, what do you do?

We\'ve sent entire dentist offices to Guatemala, SEMs to universities in
MX, etc. They will likely extract every last bit of useful life out
of those items. Much more aggressively than their donor corporations
did!

 

[server]

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.

 

[Rich S]

On Sunday, July 3, 2022 at 2:24:26 AM UTC, Don Y wrote:

On 7/2/2022 4:17 PM, Rich S wrote:
[If you truly understood the magnitude of the throw-away problem, you\'d
approach design entirely differently!]

We drifted off original topic but this one
is still very relevant to me.
I would like to know, how should consumer
product -- such as those you mentioned
-- and its manufacturer -- be evaluated for their
positive aspects towards sustainability and
minimizing negative ecological impact. It is a
whole area of study unto itself.
I think it is the nature of businesses to want for consumption.
They need a constant revenue stream to survive. Building a \"forever\"
product is one way to limit your success -- once everyone has
purchased one, the market is exhausted!

So, the first line of defense is to adjust customer expectations
soas not to think they NEED a shiney new <whatever>. If you are
a business -- and a stakeholder in said business -- then you
can make an impact with policy. Do you really need to update
all of your PC seats every time MS decides it needs a fresh
injection of revenue? Or, apple? Is there something that
application X can\'t do that you really REALLY need to do?
Do you need it enough to warrant the OS (and hardware) upgrade
that it might require??

Is there some reason that 65 inch HD TV (i.e., the one that
I rescued for our living room) is no longer \"appropriate\"
for your conference room needs? If you are letting IT people
make your equipment buying decisions/recommendations, perhaps
lump IT equipment purchases into the budget *with* salaries so
they get the message that money spent on \"new toys\" comes at
a cost of \"fewer raises\"! It\'s really easy to recommend spending
someone else\'s money -- esp if it gives you additional job
security (more stuff to install/decommission/maintain!)
Yes, my organization does
happen to employ these people. But the devil
is in the details -- what specifically about
product \"X\" can make the most difference?
There are lots of first-level recycling agencies. Their
mission statements vary (ours is to divert materials
from landfills through reuse, refurbishment or repurposing;
resorting to \"recycling\" as a last resort).

Recycling is incredibly labor intensive. If you had to
pay folks to disassemble each bit of kit into:
- sheet metal
- plastics (discard)
- valuable metals (clean aluminum, copper and gold)
- circuit boards (from which metals could be reclaimed)
- memory (which can often be reused, as is)
- CPUs (for the gold on their pins)
- fans (can be refurbished)
- hardware (screws, etc. for their metal content)
- disk drives (for the metal in their housings)
etc. you find that it costs more for the labor than you can
recover from the goods!

[A consumer PC is \"worth\" about $5 if headed for the tip,
regardless of whether there\'s an i7 inside or a 386; servers
a fair bit more but largely because of the quantity and quality
of the components]

We rely on volunteer labor for this disassembly work. These
are typically developmentally disabled \"kids\" (though they
actually may be adults) under \"adult\" supervision. Their
cognitive skills and manual dexterity are often compromised.

So, it is easy for a mechanism (assembly structure) to be
too complex for them to sort out. Simple, mainstream
fasteners (phillips) of significant size and placement are
easiest. Slotted screwdrivers are often harder to position
in the fastener. And, often used as prybars -- which can slip
and find their way into the flesh of a palm!

If they have to resort to several different tools to
disassemble something, you end up with mangled tools
and frustrated workers (they were using a #0 phillips to
remove a small screw and then continued to use it in an
attempt to loosen a #2 screw! or, an 1/8\" cabinet tip
slotted screwdriver to loosen something considerably meatier!)

Things that snap or slide together without special tools are
best. All they have to do is be shown the proper motion
to separate the items. Then, told which bin to place each.
(someone has to sort through the bins after each \"shift\"
to be sure stuff didn\'t get mixed where not intended).

The downstream recyclers will get annoyed -- and significantly
lower the price per pound they will pay us -- if things aren\'t
properly sorted. A large copper heatsink with bits of mounting
bracket still attached loses its value as it has to be further
processed. Even as a nonprofit with only a couple of bodies
\"on staff\", someone still has to pay the rent, lights,
insurance, truck/forklift maintenance, etc.

And, as prices are for BATCHES of stuff, if there are too many
(no idea who makes that determination, nor how!) items that
aren\'t \"clean\", then the entire batch (which is likely a
Gaylord) is repriced at the lower rate. I.e., the value of the
*good* work is lost in a stroke of the pen due to a few bad apples!

The old 68K Macs were ideal in this sense; one screw and everything
slid/snapped apart. But, there was a lot of plastic involved so
that\'s a downside (there is NO recycle value to plastic; sheet metal
is like $0.01/pound!)

There\'s a perverse economy, here. Durable kit is likely harder
to disassemble -- and, thus, recycle -- owing to the use
of more plentiful fasteners and components. E.g., my workstations
would have been recycled as \"complete units\" (at the much lower
rate) simply because they require too much effort and \"skill\"
to \"decompose\". So, don\'t buy durable kit unless you plan on giving
it extra life! Or, rather, DO buy durable kit and PLAN on giving it
extra life!

Don\'t buy \"toy\" UPSs -- because you *won\'t* replace the batteries!
Or, you will defer that activity until the batteries are hopelessly
swollen inside the unit. A UPS is worth (recycle value) as much as
a PC -- simply because of the weight associated with the transformer!

[Pull the batteries and recycle them separately; you can expect about
$0.20/pound for a battery whereas the UPS might be worth $0.10/pound]

[[I\'ve rescued large (2200VA) UPSs NIB! Complete with the shipping
labels intact! Gotta wonder if anyone had to answer for that \"needless\"
purchase <frown> ]]

Finally, THINK about what you\'re going to do when an item has reached
the end of its useful life FOR YOU. I tell people to think about how
they are going to dispose of items BEFORE they purchase them. PCs tend to
have extendable markets -- there is always some underprivileged kid or
school district that could make use of 500 \"used\" PCs -- *if* someone
has refurbished them and reinstalled OS/apps. But, the sheer number of
such recycled items means even that \"market\" will quickly be saturated.

Then, what do you do?

We\'ve sent entire dentist offices to Guatemala, SEMs to universities in
MX, etc. They will likely extract every last bit of useful life out
of those items. Much more aggressively than their donor corporations
did!

Thank you Don for the elaborate details. I expected little or none,
you provided a wealth of ideas. Have you put these thoughts
and experiences into a blog? SED is not quite the right place.
I expect you have more to say ;-)
Cheers, Rich S.

 

[Don Y]

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).

 

[Martin Rid]

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 equipme
nt. >>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
--


----Android NewsGroup Reader----
https://piaohong.s3-us-west-2.amazonaws.com/usenet/index.html

 

[Joe Gwinn]

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