What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Jim Thompson wrote:
What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson



Shouldn't be hard to find a replacement.

--
Les Cargill

On Sat, 08 Dec 2012 13:45:02 -0600, Les Cargill
wrote:

Jim Thompson wrote:
What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson



Shouldn't be hard to find a replacement.

Already ordered from Amazon. But bench supply makes for instantaneous
getting system back-up ;-)

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Sat, 08 Dec 2012 12:31:49 -0700, the renowned Jim Thompson
wrote:

What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson

Caps, and switching supplies can have the startup resistor or the
semis die. Also the RoHS solder joints and Chinese assembly may not be
so great.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On Sat, 08 Dec 2012 16:09:16 -0500, Spehro Pefhany
wrote:

On Sat, 08 Dec 2012 12:31:49 -0700, the renowned Jim Thompson
wrote:

What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson

Caps, and switching supplies can have the startup resistor or the
semis die. Also the RoHS solder joints and Chinese assembly may not be
so great.


Best regards,
Spehro Pefhany

This one probably pre-dates RoHS.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Sat, 08 Dec 2012 12:31:49 -0700, Jim Thompson
wrote:

What's with wall warts? Do they have a five year warranty clock
built-in?

Yes. The conspiracy theory is that components are selected to survive
no longer than the warranty period.

I just lost the third wall wart in a month.

Check your AC voltage. It may be on the high side.

All of them 5+ years old, or more, so I guess I can't complain.
What's to wear out... capacitors?

Yes. Also sometimes a thermal fuse. Linksys makes two types of wall
warts. Your antique is almost surely just a transformer, diode
bridge, and electrolytic capacitor. To provide minimal voltage
regulation, the transformer is run just below saturation, which causes
some heating. The newer types use a switching power supply. They
draw no power without a load, are more efficient, but are more
sensitive to power line transients. They also tend to spew EMI/RFI.
As usual, they kill electrolytics:
http://802.11junk.com/jeffl/pics/repair/slides/2Wire-power-supply.html
http://802.11junk.com/jeffl/pics/repair/slides/Netgear%20DSA-12R-12.html
http://802.11junk.com/jeffl/pics/repair/slides/Motorola-2210-02-PS.html

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

Ummm... yeah, that's ancient. There are 4 different hardware
versions. From the release notes, the earliest version was Aug 2000
and the latest was last updated in Sept 2009. Yours is somewhere in
between.

I'm presently up and running on a bench supply :-}

Need some spare wall warts?
http://802.11junk.com/jeffl/pics/e-waste/slides/wall-warts.html
That's about a 3 week collection at the local recycling center.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 08 Dec 2012 22:35:19 -0800, the renowned Jeff Liebermann
wrote:



Yes. The conspiracy theory is that components are selected to survive
no longer than the warranty period.

I think it's more a design spec than a conspiracy.

Looking at a typical specs of the internal parts of a linear wall
wart- at full rated current, the winding temperature rise is 70°C. At
a 30°C average ambient, if we assume the temperature in the wall wart
interior rises only 15°C (say half rated current), and 10°C internal
cap heating from the ripple current, we'll have the cap at 55°C. With
a 105°C/2000 hour rating, we should get

Life = 2000 hours * 2^((105-55)/K) where K is 10-15

Assuming K is 15, we get a life of 20,000 hours. Plugged in all the
time (24/7) that's about 2-1/3 years.

Run it at full rated current in a high ambient and you'll be at a
small fraction of that.

There are caps that will last longer, but they're too expensive to use
in an AC adapter.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On Sun, 09 Dec 2012 05:43:40 -0500, Spehro Pefhany
wrote:

On Sat, 08 Dec 2012 22:35:19 -0800, the renowned Jeff Liebermann
wrote:
Yes. The conspiracy theory is that components are selected to survive
no longer than the warranty period.

I think it's more a design spec than a conspiracy.

My first clue of a conspiracy was about 15 years ago, when I was
fixing a Sony CRT monitor (in the days when Sony made complete
monitors). It suffered from the usual electrolytic capacitor
failures. On any other brand, I could replace one or two caps, and it
would work. However, on this Sony, I discovered that a rather large
number of caps failed an ESR test, making repair uneconomical.
Inspecting the components, I noticed that there was a wide range of
rather strange voltage ratings on the electrolytics. In the past, I
would see dozens of electrolytics in a small number of standard
values. In this Sony, I saw a rather wide assortment of values and
voltages. I didn't do any lifetime calculations, but my impression
was that the voltage ratings were calculated for some target lifetime,
and no more. The result was near simultenous failure of all the caps.

Looking at a typical specs of the internal parts of a linear wall
wart- at full rated current, the winding temperature rise is 70°C.
At a 30°C average ambient, if we assume the temperature in the wall wart
interior rises only 15°C (say half rated current), and 10°C internal
cap heating from the ripple current, we'll have the cap at 55°C. With
a 105°C/2000 hour rating, we should get

Life = 2000 hours * 2^((105-55)/K) where K is 10-15

Assuming K is 15, we get a life of 20,000 hours. Plugged in all the
time (24/7) that's about 2-1/3 years.

Run it at full rated current in a high ambient and you'll be at a
small fraction of that.

That sounds a bit on the low side. Let's see how it compares with one
of the online capacitor lifetime calculators:
http://www.illinoiscapacitor.com/tech-center/life-calculators.aspx
For the wall wart, I used:
L1 = 2000 hrs Load Life Rating
Vr - 16VDC Maximum voltage rating of capacitor
Vo - 12VDC Operating voltage of application
Tm - 105C Maximum temp rating of capacitor
TA - 30C Ambient Temp.
which results in 483,000 hrs or 55.1 years.

Sheesh, no input box for ripple current. Plugging the same numbers
into the above equation:
x = (Tm - Ta + Tr) / 10 = (105 - 30 + 10) / 10 = 8.5
L2 = L1 (Vr/Vo)*2^x
L2 = 2000hrs*(16/12)*2^8.5 = 2,666*362
L2 = 965,000 hrs = 110 years

Here's yet another formula:
http://www.low-esr.com/endurance.asp
L2 = L1 * 2^(T1-T2/10) = 2000 * 2^((105-30/10)) =
L2 = 362,000 hrs = 41.3 years

Assuming that I'm not making any of my usual math errors, there seems
to be a discrepancy between the various methods of estimating
capacitor life.

There are caps that will last longer, but they're too expensive to use
in an AC adapter.

There are extended life capacitors, with up to 10,000 hrs rated life
for commodity components. I don't have a clue on pricing. Example:
http://www.niccomp.com/help/presentations/AlumE-CapExtendedOperation0809-revA.pdf
http://www.low-esr.com/endurance.asp

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 09 Dec 2012 10:18:28 -0800, the renowned Jeff Liebermann
wrote:

On Sun, 09 Dec 2012 05:43:40 -0500, Spehro Pefhany
wrote:

On Sat, 08 Dec 2012 22:35:19 -0800, the renowned Jeff Liebermann
wrote:
Yes. The conspiracy theory is that components are selected to survive
no longer than the warranty period.

I think it's more a design spec than a conspiracy.

My first clue of a conspiracy was about 15 years ago, when I was
fixing a Sony CRT monitor (in the days when Sony made complete
monitors). It suffered from the usual electrolytic capacitor
failures. On any other brand, I could replace one or two caps, and it
would work. However, on this Sony, I discovered that a rather large
number of caps failed an ESR test, making repair uneconomical.
Inspecting the components, I noticed that there was a wide range of
rather strange voltage ratings on the electrolytics. In the past, I
would see dozens of electrolytics in a small number of standard
values. In this Sony, I saw a rather wide assortment of values and
voltages. I didn't do any lifetime calculations, but my impression
was that the voltage ratings were calculated for some target lifetime,
and no more. The result was near simultenous failure of all the caps.

Looking at a typical specs of the internal parts of a linear wall
wart- at full rated current, the winding temperature rise is 70°C.
At a 30°C average ambient, if we assume the temperature in the wall wart
interior rises only 15°C (say half rated current), and 10°C internal
cap heating from the ripple current, we'll have the cap at 55°C. With
a 105°C/2000 hour rating, we should get

Life = 2000 hours * 2^((105-55)/K) where K is 10-15

Assuming K is 15, we get a life of 20,000 hours. Plugged in all the
time (24/7) that's about 2-1/3 years.

Run it at full rated current in a high ambient and you'll be at a
small fraction of that.

That sounds a bit on the low side. Let's see how it compares with one
of the online capacitor lifetime calculators:
http://www.illinoiscapacitor.com/tech-center/life-calculators.aspx
For the wall wart, I used:
L1 = 2000 hrs Load Life Rating
Vr - 16VDC Maximum voltage rating of capacitor
Vo - 12VDC Operating voltage of application
Tm - 105C Maximum temp rating of capacitor
TA - 30C Ambient Temp.
which results in 483,000 hrs or 55.1 years.

Or 9.7 years using 55 C for the ambient.

Sheesh, no input box for ripple current. Plugging the same numbers
into the above equation:
x = (Tm - Ta + Tr) / 10 = (105 - 30 + 10) / 10 = 8.5
L2 = L1 (Vr/Vo)*2^x
L2 = 2000hrs*(16/12)*2^8.5 = 2,666*362
L2 = 965,000 hrs = 110 years

Here's yet another formula:
http://www.low-esr.com/endurance.asp
L2 = L1 * 2^(T1-T2/10) = 2000 * 2^((105-30/10)) =
L2 = 362,000 hrs = 41.3 years

I assumed 55 C temperature, so you'd get 7 years with that formula.
The transformer core and copper loses and capacitor ripple current
both heat the cap (plus a bit from the diodes and thermal fuse), and
the adapter will heat the air around it to some extent. If the ambient
is 30°C (ambient for the adapter), the cap will be warmer when the
adapter is plugged in and much warmer when it is doing something.

Some of the crappier ones even use 85°C caps. Some of them use crappy
lams so they run quite warm to the touch even without load. I'll bet
some Chinese caps are 85C marked as 105C.

The ones I spec'd I had reasonable confidence they will last 5 years
under normal use (so far, so good), but I don't think it would be
harder to consistently kill them faster than that.

Assuming that I'm not making any of my usual math errors, there seems
to be a discrepancy between the various methods of estimating
capacitor life.

Sure, they are just estimates.

There are caps that will last longer, but they're too expensive to use
in an AC adapter.

There are extended life capacitors, with up to 10,000 hrs rated life
for commodity components. I don't have a clue on pricing. Example:
http://www.niccomp.com/help/presentations/AlumE-CapExtendedOperation0809-revA.pdf
http://www.low-esr.com/endurance.asp

From the prices I've seen, it would cost ~10x as much to use the
cheapest such 10K-hour caps (maybe doubling the cost of the adapter).
They're also physically larger, pushing up the size of the case,
pushing up the size of the packaging, and allowing fewer units to fit
in a TEU, so increasing sea shipping costs.

If you can get, say, 7+ years typical life, and 99% will last more
than 5, meet all technical specs and safety requirements, as well as
meet the price point marketing wants, what would you choose?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On Sun, 09 Dec 2012 14:35:59 -0500, Spehro Pefhany
wrote:

Here's yet another formula:
http://www.low-esr.com/endurance.asp
L2 = L1 * 2^(T1-T2/10) = 2000 * 2^((105-30/10)) =
L2 = 362,000 hrs = 41.3 years

I assumed 55 C temperature, so you'd get 7 years with that formula.

Oops. I assumed that ambient meant room temperature or ambient for
the entire thermal system, not the maximum capacitor operating
temperature. It would have been helpful if the various web pages had
specified operating temperature, not ambient temperature. Using 55C
results in more realistic lifetimes. Thanks.

The transformer core and copper loses and capacitor ripple current
both heat the cap (plus a bit from the diodes and thermal fuse), and
the adapter will heat the air around it to some extent. If the ambient
is 30°C (ambient for the adapter), the cap will be warmer when the
adapter is plugged in and much warmer when it is doing something.

I've seen the cheap phenol PCB's under the diodes appear somewhat
scorched from overheating. I haven't seen that under the capacitor.

Using my IR gun type thermometer, the warmest wall wart I could find
in the house was 35C, with an (ambient) room temperature of 18C.
Obviously, the insides will be warmer, especially if the wall wart is
running into transformer core saturation. All of my switchers are the
same as ambient.

Some of the crappier ones even use 85°C caps.

Yep. The electrolyte in 85C caps boils at about 125C, while the 105C
caps boil at about 190C. Other than that, there's not much difference
between the two types. If you can keep the temperature low, 85C works
just as well as 105C. Above 100C(?), the 85C cap develop increased
leakage current, while the 105C doesn't leak.

On a previous cost cutting expedition for a former employer, I
recommended switching to 85C caps. Total parts cost savings would
have been about $0.40/radio or maybe $5,000 over the life of the
product. The reaction was predictable as I was immediately accused of
being a heretic, enemy of the state, and in league with the devil.
Walmart quality was thrown in several times. Although it was decided
that the possible gain was not worth the risk, I took the time to
replace all the 105C caps with 85C caps in the radio, attach
thermistors to all the major electrolytic capacitors, and run a 30C to
70C temp test in the env chamber. (The reason for the 30C is that we
were low on CO2 for cooling and I didn't care about low temperatures).
Since I had to do this anyway to run a preliminary test on some of the
other cost cutting measures, it was an easy test. Since there were no
ripple current, there was no self heating, so the capacitor
temperatures matched that of the oven. I ran a few basic tests and
found nothing that would suggest performance deterioration or failure.
Upon presenting my results to the committee, I was again labeled a
heretic, etc...

Some of them use crappy
lams so they run quite warm to the touch even without load. I'll bet
some Chinese caps are 85C marked as 105C.

Of course. Why counterfeit a marginal product when the better quality
product is more sellable. Extra credit for fake mil-spec markings.

The ones I spec'd I had reasonable confidence they will last 5 years
under normal use (so far, so good), but I don't think it would be
harder to consistently kill them faster than that.

Capacitor brands that work are a favorite topic in the numerous "Bad
Caps" forums. What most people seem to ignore is that all the
capacitor manufacturers offer different technologies and formulations.
Some work, some don't. If someone designs a board which requires high
quality low-ESR caps in order to keep the self heating down, and
someone later substitutes a different grade from the same
manufacturer, of course it's going to fail. It's like buying anything
solely by brand name. Every brand has its winners and losers.

There are extended life capacitors, with up to 10,000 hrs rated life
for commodity components. I don't have a clue on pricing. Example:
http://www.niccomp.com/help/presentations/AlumE-CapExtendedOperation0809-revA.pdf
http://www.low-esr.com/endurance.asp

From the prices I've seen, it would cost ~10x as much to use the
cheapest such 10K-hour caps (maybe doubling the cost of the adapter).

Ouch.

They're also physically larger, pushing up the size of the case,
pushing up the size of the packaging, and allowing fewer units to fit
in a TEU, so increasing sea shipping costs.

If you can get, say, 7+ years typical life, and 99% will last more
than 5, meet all technical specs and safety requirements, as well as
meet the price point marketing wants, what would you choose?

It's usually not my decision. However, the cycle seems to be to
initially specify the best quality parts. Contrary to what common
sense would suggest, Rev 1.0 usually works fairly well. However, just
before the product hits volume production, the cost cutting committee
arrives and substitutes the absolute cheapest parts that can be found.
When the failures and returns start piling up, an over priced
consultant discovers that none of the production units were actually
built according to the original parts list. Someone mumbles something
about depleting the current stock, so the failures and returns
continue to pile up. Better quality parts are eventually introduced
just before the product is labeled end of life.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 09 Dec 2012 13:59:13 -0800, the renowned Jeff Liebermann
wrote:


Yep. The electrolyte in 85C caps boils at about 125C, while the 105C
caps boil at about 190C. Other than that, there's not much difference
between the two types. If you can keep the temperature low, 85C works
just as well as 105C. Above 100C(?), the 85C cap develop increased
leakage current, while the 105C doesn't leak.

They'll both work okay at, say 40°C, but according to the formulas,
_all_ things being equal, 105°C caps should last about four times
longer than 85°C caps.

That's why I spec them, not because I think it will ever get to 85°C.
They don't cost that much more, are not that much bigger and have a
plethora of sources. I also like to have a generous margin on the WV
(which one of the forumulas indicates would have an effect on the
life- it tends to make the cap a bit bigger and helps dissipate power
from the ESR). In both cases, I'm not sure what the real effect on
life is, but I have had not had to revisit the choices, which is good.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Jeff Liebermann writes:


I just lost the third wall wart in a month.

Check your AC voltage. It may be on the high side.

In another country, I found an alarm wall-wart, 18V/500 mA or
so. It was a 50 Hz country and the line voltage was 125VAC+.

It had sagged; no longer a rectangle, it had become a parallelgram,
with the wall-edge now ~1" higher than the sagging outer face...


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On Sun, 09 Dec 2012 19:49:14 -0600, flipper wrote:

On Sun, 09 Dec 2012 10:18:28 -0800, Jeff Liebermann
wrote:

On Sun, 09 Dec 2012 05:43:40 -0500, Spehro Pefhany
wrote:

On Sat, 08 Dec 2012 22:35:19 -0800, the renowned Jeff Liebermann
wrote:
Yes. The conspiracy theory is that components are selected to survive
no longer than the warranty period.

I think it's more a design spec than a conspiracy.

My first clue of a conspiracy was about 15 years ago, when I was
fixing a Sony CRT monitor (in the days when Sony made complete
monitors). It suffered from the usual electrolytic capacitor
failures. On any other brand, I could replace one or two caps, and it
would work. However, on this Sony, I discovered that a rather large
number of caps failed an ESR test, making repair uneconomical.
Inspecting the components, I noticed that there was a wide range of
rather strange voltage ratings on the electrolytics. In the past, I
would see dozens of electrolytics in a small number of standard
values. In this Sony, I saw a rather wide assortment of values and
voltages. I didn't do any lifetime calculations, but my impression
was that the voltage ratings were calculated for some target lifetime,
and no more. The result was near simultenous failure of all the caps.

What you describe is 'design' and not 'conspiracy'.

One persons idea of proper design is another persons conspiracy. It's
all a matter of perspective. The gray area between the two is a very
awkward place to work. I was asked to cost reduce a product I had
designed about 3 years previously. I did my best but didn't hit the
required "target" price. So, the problem was handed to someone else,
who's idea of cost reduction consisted of removing components until
the radio ceased to operate. I had designed it to work from 10v to
16.5VDC over a wide temperature range. It was better than what was
required. When the cost cutting was done, it mostly worked at room
temperature and would only work between 12.5 and 15.0VDC. I tried to
keep my changes within FCC guidelines, but such radical changes should
have required Part 15 recertification. I kept my mouth shut. Bottom
line is they took a decent radio and turned it into a pile of junk.
When the problems appeared both on the production line and in the
field, I was recovering from surgery and missed the opportunity to
tell them the obvious. Design or conspiracy? I would call it a
conspiracy.

Look, you do not have the choice of making an eternal device because
everything fails sooner or later so you can either Que Sera Sera,
whatever will be will be, or design for a target life.

Question: If I double the useful life of an electronic product, have
I also cut sales in half?

While various organizations pride themselves in recycling eWaste
wherever possible, the same organizations are clueless as to why such
products end up as eWaste in the first place. While various EU
governments are pushing for cradle to grave "ownership" of
electronics, where the manufacturer is responsible for disposal, the
same governments seem to have little interest in extending the life of
products. While various ecologically correct groups are extolling the
virtues of keeping lead out of the environment, the same organizations
are oblivious to the effects of unleaded solder has on the life of
electronic products.

Now, given this fact,

What fact? That failure is inevitable and that we should tolerate
both the causes and the consequences? We all die eventually, but is
that an excuse to live a worthless life?

why would you expect someone to design 'section
A' for life expectancy X and 'section B' for life expectancy Y when,
if either fail, the damn thing is broke?

In the not so distant past, I designed marine radios where the
customers genuinely expected the radio to last the life of the vessel.
The company offered a genuine "lifetime" warranty on it's products.
Over the 10 years I spent at this company, I was seeing many older
radios arriving for rebuilds and repair. Discussing the situation
with management, they indicated that their customers would not buy
their higher priced products without the lifetime warranty. They
didn't want to do it, but it was a business necessity.

Enter Walmart, China manufacture, and cellular phones, all of which
institutionalized the concept that products should be temporary, a
warranty is a good substitute for quality, and that it's perfectly
acceptable to trash 450,000 cell phone PER DAY. When I was doing
radios, I was looking at a product sales life of about 5 years. Todays
computers are sold for maybe 3-6 months before the new model arrives.
I can see a product being recycled after normal wear and tear. I fail
to appreciate the same from intentionally designed obsolescence and
calculated component failure.

If X is too short you've missed the target and if Y is too long you're
wasting money.

So, fix X so that it lasts longer.

True or false?
Products with a longer life are better (for the buyer)?

Unfortunately things are not that 'precise' and failures are 'rates'
rather than a deterministic point in time. This makes things more
difficult for designers and companies but puts the lie to 'conspiracy'
theories because you simply can't design 'so it fails as soon as the
warranty expires', which isn't the purpose of a warranty to begin
with.

The purpose of the warranty has changed over the years. It was
previous a method of dealing with occasional workmanship errors and
oversights. It's now the standard method of dealing with shoddy
construction, design defects, misuse, and clueless customers. Many
products have such a short lifetime, that there's no incentive to fix
production line problems, especially when the next THREE generations
of replacement products are already somewhere in the design cycle. By
the time the complaints come back from the field, the product is
already long obsolete.

Component failures are 'higher' in the 'early hours' of operation,
I.E. infant mortality, drop to a low, and then, as EOL approaches,
increase again. Infant mortality is generally due to some form of
manufacturing defect (which means process improvements can have a big
impact) and is what a warranty is intended to cover so, in fact, after
the warranty one should generally be able to expect more 'trouble
free' life. You are 'over the hump'.

Bathtub curve.
http://en.wikipedia.org/wiki/Bathtub_curve
The difference is that we never seem to get to the old age, wear and
tear, type of failures. Instead, things literally break quite early
in the curve. Eventually, the flat bottom of the bathtub curve starts
looking like a "V", with the warranty period at the apex of the "V".
If the goal is to sell more gizmos, then that's the ideal. If the
goal is to keep the stuff out of the landfill, it's disaster.

However, since these are all probability distributions over large
sample sizes there will always be 'some example' one can point at to
supposedly 'prove' any 'theory'. There will be 'one' that seems to
last forever, the 'last one to die' (I love these things. Mine lasted
'forever'), and, if you made enough of them, 'one' that failed 2
seconds before, or past, the warranty period.

Yeah, I guess, whatever all that means. Reading between your lines,
I'll guess you're trying to rationalize the current trend in
intentional decreases in product life, durability, and usability. I
would be interested to hear how such things improve the quality of
life, the environment, and the reputation of the vendor.

If we assume that intentionally targeting the product life at slightly
over the warranty period is undesirable, that begs the question "What
can we do about it"? I have some answers, but they all reek of
government intervention and meddling. The best that I can offer is to
give the manufacturers and vendors a counter incentive to NOT make
throw away products. That will raise costs, but since the rate the
consumer buys new gizmos will be correspondingly reduced, the overall
cost to the consumers will be about the same. Creating a fashion
where used products are considered desirable might also be useful. At
this time, shinny new products are some kind of status symbol. If
that could be replace with "used is beautiful" or something similar,
there might be an incentive for manufacturers to extend the life of
their products.

[Q] Is a civilization based on throw away everything sustainable?


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

In article ,
Jeff Liebermann writes:

The purpose of the warranty has changed over the years. It was
previous a method of dealing with occasional workmanship errors and
oversights. It's now the standard method of dealing with shoddy
construction, design defects, misuse, and clueless customers. Many
products have such a short lifetime, that there's no incentive to fix
production line problems, especially when the next THREE generations
of replacement products are already somewhere in the design cycle. By
the time the complaints come back from the field, the product is
already long obsolete.

It's still possible to learn from problems in the field and feed
that into design or purchasing. For example, brand-X caps don't
last as long as brand-Y, or all brands of caps die too early - maybe
we are running them too hot.


Yeah, I guess, whatever all that means. Reading between your lines,
I'll guess you're trying to rationalize the current trend in
intentional decreases in product life, durability, and usability. I
would be interested to hear how such things improve the quality of
life, the environment, and the reputation of the vendor.

If we assume that intentionally targeting the product life at slightly
over the warranty period is undesirable, that begs the question "What
can we do about it"? I have some answers, but they all reek of
government intervention and meddling. The best that I can offer is to
give the manufacturers and vendors a counter incentive to NOT make
throw away products. That will raise costs, but since the rate the
consumer buys new gizmos will be correspondingly reduced, the overall
cost to the consumers will be about the same. Creating a fashion
where used products are considered desirable might also be useful. At
this time, shinny new products are some kind of status symbol. If
that could be replace with "used is beautiful" or something similar,
there might be an incentive for manufacturers to extend the life of
their products.

It would be interesting to get lifetime data on consumer electronics.

Does anybody like Consumer Reports collect and publish it?


--
These are my opinions. I hate spam.

On Mon, 10 Dec 2012 10:50:40 -0800, Jeff Liebermann
wrote:


Incidentally,
http://www.blippee.com/gilbert.html
"Look at Gilbert toys first...they last!"
I guess that's a dead motto.

This one only lasted a year (1951-52)

http://daily-grind.net/most-dangerou...ic-energy-lab/

On Mon, 10 Dec 2012 10:50:40 -0800, Jeff Liebermann
wrote:

However, when I have a to deal
with a committee of clueless "suits" that want cheaper no matter what
it does to their quality, and then comes back a few months later and
tries to blame the engineers for the returns and failures, I tend to
call it a conspiracy. Lacking a better name for the process, I'll
continue to call it a conspiracy.

Bad management, not conspiracy.

"Never attribute to malice that which is adequately explained by
stupidity."

In article ,
Spehro Pefhany wrote:

However, when I have a to deal
with a committee of clueless "suits" that want cheaper no matter what
it does to their quality, and then comes back a few months later and
tries to blame the engineers for the returns and failures, I tend to
call it a conspiracy. Lacking a better name for the process, I'll
continue to call it a conspiracy.

Bad management, not conspiracy.

"Never attribute to malice that which is adequately explained by
stupidity."

Agreed. "Shortsightedness" is another adjective for what's happening.

It's not quite the same thing as "stupidity", because (in cases like
this) the "suits" are specifically optimizing for a desired goal
(lower cost and higher sales, NOW), and are ignoring the longer-term
costs (returns, failures, loss of sales). In a sense, it's a very
rational behavior pattern. If you don't plan on working for the same
company for at least 5-10 years, then it can make good sense to focus
only on your own short-term position.

To some extent, this "flows downhill" from the current Wall Street
financial system, in which companies' values depend very highly on
their short-term results (e.g. quarterly). In this environment,
"long-term" thinking means "next year" if you're lucky. Since project
managers and VPs tend to receive financial incentives for achieving
short-term deliverable results, meeting tight schedules, and cutting
costs, there's a serious risk of a company "eating its seed corn".

I once had the displeasure of working for a company vice president who
gloried in this sort of short-term focus... "get the current product
out the door" was Job 1, and there really wasn't a Job 2. Bug-fixing,
work on product infrastructure, and any design and development work
which wasn't directly tied to a new feature was almost entirely
de-funded. He felt that the best way to achieve product goals was to
"hire a hundred code monkeys", throw it together, kick it out the
door, and then start over again.

Two or three years of this, and the product quality had taken a really
serious downturn, customers were unhappy, engineers were miserable,
and it was becoming very difficult to do any new development because
the existing product technology was buggy, brittle, and full of
short-term hacks.

The company developed one hell of an "engineering debt" during this
VP's reign, and it took years (and a lot of money) to recover after
the VP suddenly took a higher-status job at a competing company. I
felt more than a bit sorry for the competitor!

As we walked out of the meeting where we were informed that this
particular VP had suddenly resigned, one of my coworkers remarked "I
don't know about you, but I'm hearing an angelic choir singing right
now." I knew just how he felt!

There are a few things engineers stuck in this sort of "clueless suit"
situation can do: make your concerns known to higher management (in
writing if possible) in a professional and responsible manner, keep a
good "Pearl Harbor" file (a record of all such orders and
conversations), and keep your powder dry (look for other companies
which don't have quite such a corporate death-wish).

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On 12/10/2012 6:14 PM, flipper wrote:
On Mon, 10 Dec 2012 12:36:26 -0800, (Dave Platt)
wrote:

In ,
Spehro wrote:

However, when I have a to deal
with a committee of clueless "suits" that want cheaper no matter what
it does to their quality, and then comes back a few months later and
tries to blame the engineers for the returns and failures, I tend to
call it a conspiracy. Lacking a better name for the process, I'll
continue to call it a conspiracy.

Bad management, not conspiracy.

"Never attribute to malice that which is adequately explained by
stupidity."

Agreed. "Shortsightedness" is another adjective for what's happening.

It's not quite the same thing as "stupidity", because (in cases like
this) the "suits" are specifically optimizing for a desired goal
(lower cost and higher sales, NOW), and are ignoring the longer-term
costs (returns, failures, loss of sales).

I understand your point but "shortsighted" seems a bit mild to me.

In a sense, it's a very
rational behavior pattern. If you don't plan on working for the same
company for at least 5-10 years, then it can make good sense to focus
only on your own short-term position.

To some extent, this "flows downhill" from the current Wall Street
financial system, in which companies' values depend very highly on
their short-term results (e.g. quarterly). In this environment,
"long-term" thinking means "next year" if you're lucky.

This also looks like a 'misunderstanding' to me. Surely there are
investors who try to hopscotch the market but most are looking for
continuing performance and quarterly reports are to detect 'trends'.

Since project
managers and VPs tend to receive financial incentives for achieving
short-term deliverable results, meeting tight schedules, and cutting
costs, there's a serious risk of a company "eating its seed corn".

This part, and the following, sounds like it came straight from a
management 'incentive program' training course whose basic theme could
be described as "be careful what you incentivise because that's the
behavior you will get." The one I attended had an example VP whose
bonus package was as you describe and the results were virtually the
same as you tell below.

The point was "this is a bad thing," which illustrates that 'the
company' doesn't really want that result so, as you point out at the
beginning, it's not a 'conspiracy' but a BIG MISTAKE.


I once had the displeasure of working for a company vice president who
gloried in this sort of short-term focus... "get the current product
out the door" was Job 1, and there really wasn't a Job 2. Bug-fixing,
work on product infrastructure, and any design and development work
which wasn't directly tied to a new feature was almost entirely
de-funded. He felt that the best way to achieve product goals was to
"hire a hundred code monkeys", throw it together, kick it out the
door, and then start over again.

Two or three years of this, and the product quality had taken a really
serious downturn, customers were unhappy, engineers were miserable,
and it was becoming very difficult to do any new development because
the existing product technology was buggy, brittle, and full of
short-term hacks.

The company developed one hell of an "engineering debt" during this
VP's reign, and it took years (and a lot of money) to recover after
the VP suddenly took a higher-status job at a competing company. I
felt more than a bit sorry for the competitor!

As we walked out of the meeting where we were informed that this
particular VP had suddenly resigned, one of my coworkers remarked "I
don't know about you, but I'm hearing an angelic choir singing right
now." I knew just how he felt!

There are a few things engineers stuck in this sort of "clueless suit"
situation can do: make your concerns known to higher management (in
writing if possible) in a professional and responsible manner, keep a
good "Pearl Harbor" file (a record of all such orders and
conversations), and keep your powder dry (look for other companies
which don't have quite such a corporate death-wish).

Hear, hear. In my experience it's often the case that 'bad management'
is the result of not getting good information back.

Don't think that's true. More than once I ran the problem up
the chain all the way to the company president.
I sat him down, showed him the industry trends, how what we were doing
missed the boat and proposed a slight plan alteration that would have
put is right in the center of the market. In all cases, I was told,
"if you won't do it, we'll find someone who will."
My answer in all cases was, "yes sir!"

In the last case, keeping up the illusion until after the IPO was
the primary consideration. I had the CEO going directly to my
staff and making changes. I was never told, but I sure got the
credit for all the problems it caused.
I sold my stock the day after the IPO blackout period at $19.
Guess that didn't go over too well...two months later, I was in the
unemployment line. They hired someone else to do what they wanted.
Stock is hovering around $2. Whodathunkit?

On Mon, 10 Dec 2012 14:47:44 -0500, Spehro Pefhany
wrote:

On Mon, 10 Dec 2012 10:50:40 -0800, Jeff Liebermann
wrote:


Incidentally,
http://www.blippee.com/gilbert.html
"Look at Gilbert toys first...they last!"
I guess that's a dead motto.

This one only lasted a year (1951-52)
http://daily-grind.net/most-dangerou...ic-energy-lab/

Chuckle. At the time, there were promotions for the "friendly atom"
which included nuclear powered automobiles and airplanes. I was only
3 years old at the time, so I didn't get this toy for my birthday.

Natural uranium is 0.7 micro Curies, which is not very much. Some
basics:
http://nuclearhistory.wordpress.com/2011/02/28/radioactivity-of-uranium/
A lump of natural uranium isn't dangerous, unless you're worried about
heavy metal poisoning from the minerals usually associated with
natural uranium deposits. Of course, public paranoia eventually
proscribed all forms of radioactivity, including the Thorium in
Coleman lantern mantles etc. The thorium mantles were noticeably
brighter than the current yttrium variety.

In 2002, I had to endure a radioactive treadmill stress test to see if
my heart was functioning properly. I had my Geiger counter in my car,
but didn't have the guts to take it into the hospital with me. Part
of the procedure was to inject me with Thallium 201. After the test,
I went to the local (nearby) electronics store, fired up my Korean War
era Geiger counter, and pegged it with 20,000+ counts per minute. The
reaction was interesting. Anyone that was 50 years or older,
immediately jumped away backwards when they heard the roar of the
counter. My calculations of their exposure rate did not make them any
happier. Nobody would go anywhere near me. However, those under 50,
had never had any classes or experience with radioactivity in the
skools, and usually asked something mundane like "What's that noise"?

The effect was sufficiently interesting (to me) that I repeated my
Geiger counter demonstration at some of my customers along the route
between the hospital, my office, and my home. Unfortunately, it was
only good for about two days as the half life of Thallium 201 is only
3 days. Some of my friends and customers still refuse to forgive me
for nearly creating a panic in the homes and offices.

I was also repeatedly asked a rather odd question, which had me
mystified for a while. They asked "Why do you have a Geiger counter"?
It was much later that I realized that they were really asking was if
I was conducting dangerous radioactive experiments at home.

I've also given brief demonstrations with the Geiger counter and home
made scintillation counter in skools and at radio club meetings. The
reactions varied from extreme curiosity to running away in horror.
Most of the horror came from administrators and officials. I managed
to worry a few parents when I demonstrated that a granite countertop
and potassium salt were hot:
http://healthyliving.blog.ocregister.com/2011/04/01/7-household-items-that-contain-radiation/
This was from the salt demo:
http://802.11junk.com/jeffl/crud/salt.jpg

Gilbert had the right idea. We seem to need some education in basic
radioactivity.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jim Thompson wrote:
What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply:-}

...Jim Thompson
The "old" style = = unregulated is symple, xfmr,2 diodes, cap with
the xfmr a little under-rated (for smallest size) and gets a bit warm.
Crappy design as they all put out more voltage AT FULL LOAD thantheir
"specification".
Xfmr heat slowly cooks the cheap cap to death.

On Mon, 10 Dec 2012 22:06:54 -0800, the renowned Robert Baer
wrote:

Jim Thompson wrote:
What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply:-}

...Jim Thompson
The "old" style = = unregulated is symple, xfmr,2 diodes, cap with
the xfmr a little under-rated (for smallest size) and gets a bit warm.

Four diodes and a thermal fuse (the latter to meet safety
requirements). Getting warm has a lot to do with how low end the lams
are. Paying a few cents more buys more efficiency and meets those
standards.

Crappy design as they all put out more voltage AT FULL LOAD thantheir
"specification".

Not what I've seen. They put out the spec voltage at full load.

9V nominal adapter.. open circuit 13.48V, full load 8.96V.


Xfmr heat slowly cooks the cheap cap to death.

Yup. Put another equal size cap in the product and you can let the one
in the adapter die.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Spehro Pefhany wrote:
On Mon, 10 Dec 2012 22:06:54 -0800, the renowned Robert Baer
wrote:

Jim Thompson wrote:
What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply:-}

...Jim Thompson
The "old" style = = unregulated is symple, xfmr,2 diodes, cap with
the xfmr a little under-rated (for smallest size) and gets a bit warm.

Four diodes and a thermal fuse (the latter to meet safety
requirements). Getting warm has a lot to do with how low end the lams
are. Paying a few cents more buys more efficiency and meets those
standards.
* I have opened many unregulated wall warts,from el-cheapo to
top-of-the-line, and NEVER seen any thermal fuse, period.


Crappy design as they all put out more voltage AT FULL LOAD thantheir
"specification".

Not what I've seen. They put out the spec voltage at full load.
* I have NEVER seen an unregulated wall wart like that,ever.
And i have seen an un-countable number of them in (about) 40 years.
Now, even the el-cheapo regulated ones (eg: linear series pass) do
meet label specs.
Switchers are better yet.


9V nominal adapter.. open circuit 13.48V, full load 8.96V.


Xfmr heat slowly cooks the cheap cap to death.

Yup. Put another equal size cap in the product and you can let the one
in the adapter die.


Best regards,
Spehro Pefhany

Robert Baer wrote:

* I have opened many unregulated wall warts,from el-cheapo to
top-of-the-line, and NEVER seen any thermal fuse, period.


Did you take apart all the transformers? The thermal fuses are
usually in a slot, in the molded bobbin to get them closer to the core.

On Tue, 11 Dec 2012 19:15:00 -0800, Robert Baer
wrote:

* I have opened many unregulated wall warts,from el-cheapo to
top-of-the-line, and NEVER seen any thermal fuse, period.

Well, they're normally hidden under a layer of insulating tape on the
transformer (in series with the primary), so a casual examination
might not detect it.

If they're UL class 2 they need to limit- in some cases they've made
the winding self-fusing, in others they use a thermal fuse. I don't
think self-fusing* cuts the mustard world-wide with the safety
authorities, so I've seen mostly thermal fuses in approved linear
adapters these days.

Eg. http://www.cui.com/Product/Resource/...0050-P5-SZ.pdf
... has a 130°C thermal fuse

I can't share the spec sheets of the ones I source, but they specify
the thermal fuse rating and UL/CSA approved part numbers and
manufacturers.

Crappy design as they all put out more voltage AT FULL LOAD thantheir
"specification".

Not what I've seen. They put out the spec voltage at full load.
* I have NEVER seen an unregulated wall wart like that,ever.
And i have seen an un-countable number of them in (about) 40 years.

What are the test conditions? The ones I've bought in production
quantities do what the specs say, the test reports say, and what the
label says, under the appropriate test conditions. If they didn't meet
the specifications at incoming inspection they'd be sent back! Did you
adjust the input AC voltage to the specified voltage and put an
accurate programmable load on the output? They always read a LOT
higher with a light load, some are 50% worse than others.

Now, even the el-cheapo regulated ones (eg: linear series pass) do
meet label specs.

Where do you find those? I was looking for some and they don't seem to
be very popular these days. Twenty years ago, they were more common.
It's kind of stupid to put the regulator in that little box- easier to
get rid of the heat elsewhere and not have to worry about the voltage
drop in the cord and connector.

Switchers are better yet.

For some things.. some of the cheap crap ones are missing Y caps so
they have (unspecified) HF common mode noise on the output relative to
earth. Some of the ones that have Y caps are using unapproved and
probably unsafe caps. Many of them have a lot of ripple and are
pushing the output caps hard enough they'll likely die sooner than the
linear unregulated adapters. Cheap ones may be missing common mode
input filters so they'll conduct noise.

* with self fusing, the wire insulation melts, causing shorted turns,
which draws enough current to fuse the copper wire or to blow a
non-thermal fuse in series with the primary. Since copper melts at a
higher temperature than the tape and fish paper can withstand, it has
to be shown that it won't compromise isolation.

Cooking the caps.

Larry

In article ,
Jim Thompson
wrote:

What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson

"Lawrance A. Schneider" wrote in message
...
Cooking the caps.

Larry

In article ,
Jim Thompson
wrote:

What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson

Hi Jim, most likely top posting by newbies:-(
I don't know why, but the switching warts seem to hold up better, maybe it
is less generated heat. The transformer ones seem to quit when the thermal
fuse on the primary lets go.
Tom

On Thu, 24 Jan 2013 20:24:13 -0500, "hifi-tek"
wrote:


"Lawrance A. Schneider" wrote in message
...
Cooking the caps.

Larry

In article ,
Jim Thompson
wrote:

What's with wall warts? Do they have a five year warranty clock
built-in?

I just lost the third wall wart in a month.

All of them 5+ years old, or more, so I guess I can't complain.

What's to wear out... capacitors?

This one was for my Cisco BEFSR81 Router. I think it's actually a lot
older than 5 years.

I'm presently up and running on a bench supply :-}

...Jim Thompson

Hi Jim, most likely top posting by newbies:-(
I don't know why, but the switching warts seem to hold up better, maybe it
is less generated heat. The transformer ones seem to quit when the thermal
fuse on the primary lets go.
Tom


This was a switching one.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.