William Sommerwerck wrote:

polygonum wrote

William Sommerwerck wrote:

One might argue that all the transistors are created simultaneously in a
single processing sequence, and that the chip is, technically, a single
component.

One might argue that is the case for the 100-component circuit referred to
in the EE Times article.

One //might not// argue that. The LED lamp is made of discrete components that
are manufactured separately, and individually soldered in place.

The original article makes the very crude leap from one filament with a
claimed 0.0001% probability of failure (shouldn't that approach 100%
after a thousand hours?), to 60 electronic components yet assumes they
each have the same 0.0001% probability of failure, multiplying them up
to give a 60x higher failure rate for the LED vs the incandescent.

Subject to my eyesight, in the circuit chosen there appear to be 1
integrated circuit, 8 diodes, 8 transistors, 11 capacitors, 26
resistors, 2 chokes, 1 fuse.

Each of these classes of component have different probabilities of
failure, and in "cheap" PSU circuits it tends to be the capacitors with
the highest, for a given circuit a bit of analysis will probably reveal
three or four "pinch" components that are likely to be responsible for
90% of all the failures.

Searching for other LED lamp schematics, was that one chosen because it
was considered a well designed circuit, or because it has a conveniently
high component count?

Andy Burns wrote:

The original article makes the very crude leap from one filament with a
claimed 0.0001% probability of failure

Grrrr! 0.01% in both cases

The Natural Philosopher wrote:
On 03/01/15 22:33, Adam Aglionby wrote:
On Saturday, January 3, 2015 9:11:17 PM UTC, Tim Watts wrote:
On 03/01/15 10:13, Tim Watts wrote:
On the subject - what *is* the best way to drive LEDs?

Seems to me that whilst convenient and in line with my earlier comments
on standardisation, putting little 230V PSUs in every lamp that get hot
and blow up is not the best way forward.

Does a 12V supply offer any advantages in terms of minimising on board
electronics? 12V SELV is at least standard.

24V is better , double voltage half the current and copper, but thats
laways the issue , low voltage dosen`t equal low current.


If an LED has a Vf (forward voltage drop) of x volts, is it considered
good form to put 12/x LEDs in series across the supply with no other
limiting circuitry?

Vf isn`t really fixed, it varies from batch to batch, fractionally but
enough.

Thing is a iny increase in Vf can have an expotentially large increase
in current, not so much of a pronlem at a nominal 20mA more of an
issue at 350mA


Or is there a really simple 2 pin current regulator on a chip
available?

2 pin will get very hot..

not of its a capacitor or an inductor.
frankly a choke and a full wave bridge and a smoothing cap is all you
need. Shove the LEDS in series.

Same as a fluorescent in principle, less the starter ********.
Fluorescent tube is just like an HV LED in general electrical
characteristics, once 'lit'.

Not very 'dimmable' mind you.




Old style 0.2" 20mA LEDs weren't that bothered, but I'm not au fait
with
high power Crees and the like.


for big LEDs constant current drive has lot to reccomend it over
constant voltage and resistors, little 20mA LEDs are fair game for all
sort sof things.

Anyone?




The thing about Vf is that has a negative temperature component in the
region of 2mV/C. So if you assume that there is a 50C operating
temperature variation, this changes Vf by 5%. This will produce massive
If variations if not fed from a fixed current supply. Any increase in If
increases running temperature, so you have perfect thermal runaway
conditions. LEDS do not like high temperatures, I can't remember all the
details now but the efficiency drops and the thermal losses increase,
hence the short life if you over run them.

On 04/01/15 10:10, Capitol wrote:
The Natural Philosopher wrote:
On 03/01/15 22:33, Adam Aglionby wrote:
On Saturday, January 3, 2015 9:11:17 PM UTC, Tim Watts wrote:
On 03/01/15 10:13, Tim Watts wrote:
On the subject - what *is* the best way to drive LEDs?

Seems to me that whilst convenient and in line with my earlier
comments
on standardisation, putting little 230V PSUs in every lamp that get
hot
and blow up is not the best way forward.

Does a 12V supply offer any advantages in terms of minimising on board
electronics? 12V SELV is at least standard.

24V is better , double voltage half the current and copper, but thats
laways the issue , low voltage dosen`t equal low current.


If an LED has a Vf (forward voltage drop) of x volts, is it considered
good form to put 12/x LEDs in series across the supply with no other
limiting circuitry?

Vf isn`t really fixed, it varies from batch to batch, fractionally but
enough.

Thing is a iny increase in Vf can have an expotentially large increase
in current, not so much of a pronlem at a nominal 20mA more of an
issue at 350mA


Or is there a really simple 2 pin current regulator on a chip
available?

2 pin will get very hot..

not of its a capacitor or an inductor.
frankly a choke and a full wave bridge and a smoothing cap is all you
need. Shove the LEDS in series.

Same as a fluorescent in principle, less the starter ********.
Fluorescent tube is just like an HV LED in general electrical
characteristics, once 'lit'.

Not very 'dimmable' mind you.




Old style 0.2" 20mA LEDs weren't that bothered, but I'm not au fait
with
high power Crees and the like.


for big LEDs constant current drive has lot to reccomend it over
constant voltage and resistors, little 20mA LEDs are fair game for all
sort sof things.

Anyone?




The thing about Vf is that has a negative temperature component in
the region of 2mV/C. So if you assume that there is a 50C operating
temperature variation, this changes Vf by 5%. This will produce massive
If variations if not fed from a fixed current supply. Any increase in If
increases running temperature, so you have perfect thermal runaway
conditions. LEDS do not like high temperatures, I can't remember all the
details now but the efficiency drops and the thermal losses increase,
hence the short life if you over run them.

that's why I suggested a series choke or cap: inherent current limit


--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll

On Saturday, January 3, 2015 11:09:35 PM UTC, Tim Watts wrote:

SNIPPED

I know of the constant current drive thing

Advantage of compensating for cable V drop is the advantage used at whackier voltages and currents in airfield lighting but advantage can be used with LEDs, ran high power LEDs of many meters of CAT5 before.

- but it's not terribly
generalisable (ie you just can't add extra lamps at will - perhaps a few
more of the same lamp type but not a mixture).

Its a question of same lamp Current rather than Voltage, the large COB arrays are an example, can find them in variety of voltages and currents for same nominal Wattage, depending on how LEDs in the array are combined in series and paralel.

That's why I was wondering what might be done to minimise on-lamp
electronics which still being able to use a standard supply upstream.

Been through this before with LV lighting, low voltage means copper sizes can become ridiculous, own feeling is external drivers, much like per lamp LV trafos, is a way forward.

On 03/01/2015 17:14, Huge wrote:
This is completely impossible to determine. There are far too many paths
through a modern microprocessor to test them all. Hence the Intel maths
debacle of a few years ago.

I heard that the DEC Alpha team ran their floating point tests on it,
and the error was detected in a few minutes.

Still, we know what happened to Alpha

Andy

On 03/01/2015 21:50, Bob Eager wrote:
On Sat, 03 Jan 2015 18:23:51 +0000, Adrian wrote:

On Sat, 03 Jan 2015 10:19:37 -0800, Jeff Liebermann wrote:

Please put carrets around URL's so that the Usenet server doesn't
reformat it by wrapping the lines.

Please spell carats correctly and cease the apostrophe abuse so that we
don't have to wrap your lines...

ITYM 'carets'!

"Carats" ties up better with "diamond brackets" :P

Andy

35 years old? That thing must have been belt driven.

The oldest ones I saw were 1990-ish and from panasonic, with a huge
magnetic ballast. It was large, stupid and didn't fit in most fixtures. I
can't recall what the life was, but it was put together well with lots of
glass and silicone goop. There's no way in hell it was cheaper than a box
of incandescent bulbs, especially when you factor in the part where
electricity itself isn't really that expensive in the US.



When we owned a day nursery, it was located in a Victorian school building
that we bought. It was back in the early 80s. When we bought the place, it
had all old pendant fixtures in the rooms - probably something like 12 in
each room, so you can imagine what the electricity bill would have been
like. I replaced them all with some CFLs called "Dulux EL Globes". I would
guess that each was about 4 - 5" diameter and was completely translucent.
They took a while to warm up to full brightness, but the light output from
them was excellent, and of a very pleasant colour. They ran 5 days a week
from 7:30 in the morning until gone 6pm, and the failure rate was very very
low. They weren't cheap, mind ...

Arfa

"Rod Speed" wrote in message
...


"Arfa Daily" wrote in message
...


"Rod Speed" wrote in message
...


"Arfa Daily" wrote in message
...
EE Times article that came to me by email today

http://www.electronics-eetimes.com/e...s_id=222923405

Mindlessly superficial.

Much like you then ...

You never could bull**** your way out of a wet paper bag.


BWAHAHAHA !

All that 'good' stuff you've just written, then you spot my (one line)
comment - 2 days late I might add - and you revert exactly to type, as we
have all come to know and expect of you. Good old Rod, never one to let us
down old boy, are you ? :-) I suppose the paper bag is wet because I
live on a soggy little island, right ?

Arfa

"Arfa Daily" wrote in message
...


"Rod Speed" wrote in message
...


"Arfa Daily" wrote in message
...


"Rod Speed" wrote in message
...


"Arfa Daily" wrote in message
...
EE Times article that came to me by email today

http://www.electronics-eetimes.com/e...s_id=222923405

Mindlessly superficial.

Much like you then ...

You never could bull**** your way out of a wet paper bag.


BWAHAHAHA !

All that 'good' stuff you've just written, then you spot my (one line)
comment - 2 days late I might add - and you revert exactly to type, as we
have all come to know and expect of you. Good old Rod, never one to let us
down old boy, are you ? :-) I suppose the paper bag is wet because I
live on a soggy little island, right ?

LOL
I can't decide who is the biggest prick between Wodders and the silly
PHucker.
It's very close.

That also begs the question "Why did Arfa Daily post the article"? My
best guess(tm) here is that he's still having problems adjusting to
LED lighting and needs a new reason to not use LED lighting. Am I at
least close?

Not really ...

I don't like CFL lighting - that's well known. I am still reserving judgment
on LED lighting. My local supermarket recently had a major refit, and all of
their ceiling fluorescent fittings were replaced with linear LED arrays, so
at first, you don't notice that anything has changed. When I did realise, I
was surprised that the quality and intensity of the light in terms of how
well it illuminated the sales floor, was every bit as good as the original
fluorescents. They also have replaced the car park floodlights with LED
arrays, and these are crap compared to the metal halide fixtures that they
replaced. My hairdresser has replaced all of the mini spots in his ceiling
fixtures with equivalent LED bulbs. They produce a good amount of light, and
the colour is not bad, but they are unpleasantly bright to look at. They are
also not a very good shape and don't fit the fixtures terribly well. I'm not
a great fan of LED street lighting either, as I think it is harsh in
comparison to say LPS, and nothing like as effective at penetrating fog, as
it is polychromatic light. It also doesn't seem as good at producing 'even'
street lighting as LPS or even HPS is, if you can get past the yellow colour
of those types.

As everyone also knows, I am not a fan of substitute lighting technologies
brought in for eco-bollox reasons. CFLs are not as good as incandescents,
and never will be in terms of light quality, low temperature performance,
and start-up time. LEDs are better in all of those areas, but still have a
long way to go before I would consider them to be a replacement technology
for domestic incandescent bulbs, rather than the substitute which they
currently are. The 'eco' credentials for this lighting, as spouted by the
politicians and commentators, is always far too simplistic, and designed to
convince the great unwashed that they must be better because they consume so
much less energy. No account is taken of the energy budgets to make these
things in the first place, or to dispose of them (properly) when they fail.
The supermarket sales floor lights are a good example of what can be
achieved with commercial LED lighting. Where you are not trying to reproduce
sunlight - such as with airport runway and taxiway lighting - then they are,
without doubt, the best and most reliable technology for the job. There are
may LED traffic signals in the area where I live, and they seem to work
extremely well, so another area where LEDs are appropriate and good at the
job.

All of the above, we have discussed on these two groups over the years, as
the technology has changed and evolved. I merely thought that this article,
by someone who seems to be in a position to make valid comments on the
subject, had an interesting alternative view of the common wisdom that is
generally pushed. Simply that, Jeff. Hence the reason that I titled the post
"Interesting..." ...

"Rod Speed" wrote in message
...
William Sommerwerck wrote
Rod Speed wrote

Much more likely he doesn't actually have a ****ing clue about the
basics.

Are you any relation to Joshua Speed?

No idea, I've never done the genealogy that comprehensively.
I do know that I am not related to quite a few other Speeds in my country
even tho it is a rather uncommon name.
Arfa is an intelligent and knowledgeable person.

He clearly isn't on that particular question.

What particular question ?


He didn't even notice that cars are MUCH
more reliable than they used to be even tho they have vastly more
components
than they used to have. In spades with computer cpus and memory alone.

You are unbelievable. How did you manage to extrapolate that mindless crap
from my original post ?

Sheesh ! **** ...

Arfa

"Phil Hobbs" wrote in message
...
On 1/3/2015 1:54 PM, Jeff Liebermann wrote:
On Sat, 3 Jan 2015 07:10:25 -0800, "William Sommerwerck"
wrote:

"Jeff Liebermann" wrote in message
...

The reason for the designed in failures is the need for manufactories
to continue selling replacements. If they actually made a device that
lasts forever, they will sell a few years worth, and then go out of
business because there will be no replacement sales. Reliability is
bad for (consumer) business.

What about lighting for new buildings?

It's strictly a question of selling price.

Joe Sixpack is not going to tolerate $8 "60 watt" lamps in his house.
He wants cheap, at any cost, even if it blows up every few years. I've
noticed that most of the homes that I see that have all LED lighting,
also have a hybrid car, grid tied solar systems, and other energy
conservation devices. They tend to be affluent but not very good at
calculating the alleged savings or comparing with alternatives. When
I do this for them, some don't want to hear the bad news. They'll pay
any price, to save a few pennies. Seriously expensive LED lighting is
not a problem for this market.

However, the rest are tightwads or just plain cheap. They look at the
store shelf and see $1 CCFL lamps next to $10 LED lights. My guess is
they'll buy the $1 lamp and wait for the price of LED's to drop. I
saw this happen at the local hardware store. The flooring manager
said that when he puts the two types of lights next to each other, the
sales of CCFL lamps go up and LED's drop. When he separates them,
putting the LED's in a garish impulse buy display near the cash
register, CCFL sales drop, and LED's go up. The bottom line is that
Joe Sixpack wants cheap lights, and the only way the industry is going
to supply those is to cut corners, which show up as increased infant
mortality and lifetime failures.

However, high reliability lighting (towers, airports, buildings, etc)
are in a different class from Joe Sixpack. You don't find those
lights at the hardware store or supermarket. They're industrial
specialty items, with high quality LED's, and high prices to match.
Reputation is a big thing in such markets, so anything designed to
fail prematurely is not going to last very long.

From my perspective, the cost savings outweigh the "premature" failures.

That totally depends on how you rate lifetime. I get about 2 years on
most of my commodity CCFL lights. I haven't blown out enough lights
to produce useful statistics, but mostly I break them from impact
damage, or something in the electronics burns out, usually with a puff
of smog and a noxious smell. A capacitor would be my guess from the
smell.

However, these are not the best CCFL lights. Why would this company
advertise that their CCFL lamps have 2.5 to 6.6 times the lifetime of
ordinary CCFL lamps?
http://www.ccfllamps.com/_en/02_technology/01_detail.php?fid=3
Is it because their lamps are better, or because the ordinary CCFL
lamps have been cost reduced to produce a shorter lifetime? Dunno,
but I suspect the latter.

LED's are probably similar. You can get those that last forever, and
those that are cost reduced to blow up just after the warranty
expires. If you do the math, my guess is the price/performance ratio
is about the same.

That also begs the question "Why did Arfa Daily post the article"?
My best guess(tm) here is that he's still having problems adjusting
to LED lighting and needs a new reason to not use LED lighting.

Like most people, Arfa doesn't like high-K lighting. I switched to 5000K
CFLs,
and though it took a couple of weeks to adjust, I much prefer light that
more-closely resembles daylight, and is subjectively brighter.

It's been a while, but I recall that he could not adjust to LED
lighting. He's not the only one. The neighboring architects office
has two people that claim eyestrain from the replacement LED lighting.
Their section of the office uses ordinary fluorescent tubes and
incandescent desk lamps. (I once suggested kerosene lamps with
predictable results).

I've done some testing on myself to see what works best. 6000K
daylight LED lighting seems best for doing fine detail work.
2700-3000K is much easier on my eyes for reading, but I have trouble
focusing on detail and fine print. I use both where appropriate.


I have a bunch of Luxo desk lamps that have a 100 W incandescent
surrounded by a 22W circular fluorescent. They're by far the easiest
thing on the eyes that I've ever used.

Cheers

Phil Hobbs


Go Phil, go ! :-)

Arfa



--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

"Henry Mydlarz" wrote in message
...
"Arfa Daily" wrote in message ...

EE Times article that came to me by email today

http://www.electronics-eetimes.com/e...s_id=222923405

Arfa

A few months ago I bought at Aldi about eight LED bulbs to use on my 240V
lighting (Australia). Three of them failed within about a month, one of
them does light up occasionally. Unfortunately I could not find the
receipt for them.

Henry


Hmmm. From your aspect, point made then, I would guess ??

Arfa

Some gutless ****wit desperately cowering behind
Arfa Daily wrote just the
puerile **** that always pours from the back of it when its
got done like a ****ing dinner, as it always is by everyone.

Arfa Daily wrote
Rod Speed wrote
William Sommerwerck wrote
Rod Speed wrote

Much more likely he doesn't actually
have a ****ing clue about the basics.

Arfa is an intelligent and knowledgeable person.

He clearly isn't on that particular question.

What particular question ?

The stupid claim that article he posted made about the
purported problem with a lot more components in a LED light
instead of the single one with the incandescent it replaced.

He didn't even notice that cars are MUCH more reliable than
they used to be even tho they have vastly more components than
they used to have. In spades with computer cpus and memory alone.

You are unbelievable.

We'll see...

How did you manage to extrapolate that
mindless crap from my original post ?

The article you mindlessly posted clearly claimed that
when there are lots more components in the LED light
than in the incandescent light it replaced, that that was
absolutely certain to guarantee that it would have a shorter
life than the incandescent it replaced. Pigs arse it does.

reams of your puerile **** any 2 year old could
leave for dead flushed where it belongs

On 1/4/2015 6:02 PM, Arfa Daily wrote:

I don't like CFL lighting - that's well known. I am still reserving
judgment on LED lighting.

I wonder what we'd be saying about incandescents if they were replacing
LED lights we'd been using for a century?
I can understand if you're a photographer.
For the rest of us, it's no big deal. Things change.

On 1/4/2015 7:37 PM, Jeff Liebermann wrote:

100 watt incandescent bulb on a desk lamp? Doesn't that get rather
warm and possibly hot enough to shorten the life of the bulb?

By how much?
What's the added surface temperature?
Add that to the filament temperature.
What's the percentage increase in filament temperature?

More likely, it shortens the life of the phenolic socket and switch.

On 01/05/2015 03:06 AM, Huge wrote:
On 2015-01-05, mike wrote:
On 1/4/2015 6:02 PM, Arfa Daily wrote:

I don't like CFL lighting - that's well known. I am still reserving
judgment on LED lighting.

I wonder what we'd be saying about incandescents if they were replacing
LED lights we'd been using for a century?
I can understand if you're a photographer.
For the rest of us, it's no big deal.

Please don't include me in "the rest of us". I too think CFL lighting is
very poor, and have switched back to incandescents in a few places (I
imagine we're about 30% CFL, 30% halogen and 30% GLS (incandescent)) now.

Things change.

Not always for the better, or for the right reasons.


I can't afford to waste money on nostalgia. LEDs rule!

On Mon, 05 Jan 2015 02:42:16 -0800, mike wrote:

On 1/4/2015 7:37 PM, Jeff Liebermann wrote:

100 watt incandescent bulb on a desk lamp? Doesn't that get rather
warm and possibly hot enough to shorten the life of the bulb?

By how much?
What's the added surface temperature?
Add that to the filament temperature.
What's the percentage increase in filament temperature?

Dunno and I don't have an easy way to measure filament temperature.
What I do know is that if I insert an overpowered incandescent light
bulb in my marginally ventillated Ledu desk lamp, it will burn out
fairly soon. The fixture has a sticker on the lampshade inscribed
with:
Caution: To reduce the risk of fire, use 75 watt
type A lamp or smaller.
There's no indication of exactly what will catch fire.

More likely, it shortens the life of the phenolic socket and switch.

The socket is mostly ceramic, although the insulator might be
phenolic. I can't see the switch. The wiring is covered with heat
protecting sleeving. The insulation might deteriorate from long term
overheating but looks like it will survive nicely with normal use.

My guess(tm) is that the 75 watts is mostly from the UL testing, which
certifies that the appliance will not start a fire or electrocute the
owner. UL testing does not test for appliance lifetime or even
survival. I'm not familiar with how UL tests such things, but I
suspect it's something simple like burying the light in newspaper. I
couldn't find any data on incandescent bulb lifespan versus operating
temperature.

--
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 03/01/2015 14:16, The Natural Philosopher wrote:

snip

The deeper analysis asks the question 'what fails, and why?'

In general a chip once made, wont degrade catastrophically. Its
thermally stable, and any manufacturing faults show up on test or early on.

Yes, RAM and other chops do age, but there is a wide tolerance before
they go so far out of spec they are useless.

By far the greatest killer is heat: heat accelerates ageing., death
occurs in microseconds at 180C, decades at 30C

Many ordinary consumer electronic components - often rated at 85C - will
and do last well over a thousand hours at 180C, even parts with millions
of transistors.

The trick is knowing which ones.

Cheers
--
Syd

On 01/05/2015 3:06 AM, Huge wrote:
On 2015-01-05, mike wrote:
On 1/4/2015 6:02 PM, Arfa Daily wrote:

I don't like CFL lighting - that's well known. I am still reserving
judgment on LED lighting.

I wonder what we'd be saying about incandescents if they were replacing
LED lights we'd been using for a century?
I can understand if you're a photographer.
For the rest of us, it's no big deal.

Please don't include me in "the rest of us". I too think CFL lighting is
very poor, and have switched back to incandescents in a few places (I
imagine we're about 30% CFL, 30% halogen and 30% GLS (incandescent)) now.

10% sunlight?

John ;-#)#


--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

On 1/2/2015 8:56 AM, Arfa Daily wrote:
EE Times article that came to me by email today

http://www.electronics-eetimes.com/e...s_id=222923405


Arfa
Well, i can totally see that. Part of the reason is NOT the LED's
themselves, but the CAP's. If there is a modern multinational cartel
these days, its NOT oil but the manufacturer of small capacitors. They
build these dam things to fail in a few years anymore. Between the
elevated temps they operate at and lack of quality guts, capacitors are
the weak link. And that includes LED lights because they use them in the
power supplys.

Last year, i bought a bargain CFL lamp for $1 at the dollar store.
Worked for maybe a hour them ZBOOOM! TOOK it apart and sure enough,
capacitor guts all over.

It seems most modern LCD tv's have a life of two or three years then
they go haywire. I was all ready to get a new Sharp LED set before the
first of the year on sale and was about the push go, then figured
i better do some research first. Pages and pages of it failed soon
and the manufacturer would not help. I'm sure capacitors are one
of the major reasons for that also.

i just saw some 40W LED bulbs at a ACE US hardware store for $5.99 on
sale. almost got one, but held off for now. Its hard to beat the
simplicity of a incandescent lamp.

bob

On 05/01/15 20:15, bob wrote:

It seems most modern LCD tv's have a life of two or three years then
they go haywire. I was all ready to get a new Sharp LED set before the
first of the year on sale and was about the push go, then figured
i better do some research first. Pages and pages of it failed soon
and the manufacturer would not help. I'm sure capacitors are one
of the major reasons for that also.

I have 3 Samsung screens:

42" TV, circa 2005, running as well now as the day it was new;

20" (ish) computer monitor, 2006 ish, still good, maybe the backlight is
a tad dimmer than it used to be;

20" ish TV, circa 2008, still perfect, using it now.

So Samsung seems reliable.

i just saw some 40W LED bulbs at a ACE US hardware store for $5.99 on
sale. almost got one, but held off for now. Its hard to beat the
simplicity of a incandescent lamp.

bob

Rod Speed udtrykte præcist:
Huge wrote
William Sommerwerck wrote

His basic premise makes sense -- more components = lower reliability --
but the fact is that one can easily find electronic devices 50 and 60
years old that have never been serviced that continue to work. Members of
this group probably own them.

This is a category error.

No.

Yes, we all have 'n' year old electronic devices, because we have thrown
away the ones that have failed.

And yet cars are in fact MUCH more reliable now even tho they have a lot more
components than they used to have.

My Yaris ran on 3 cylinders. First I changed spark plugs, because that
what usually worked on old cars. But even with a gap of 1.5mm, the
spark was fine.
So I hooked up the OBD-2 reader: Engine misfire cylinder 1.
I exchanged two "spark plug caps" which is really the ignition coil and
some electronics, one unit per cylinder.
Now "Engine misfire cylinder 3"
So a "new" used unit from a junk yard gotthe car running again.
The car only had run 460000km, not sure when, if ever, the spark plugs
had been changed.

So new cars are MUCH more reliable.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

Leif Neland wrote
Rod Speed wrote
Huge wrote
William Sommerwerck wrote

His basic premise makes sense -- more components = lower
reliability -- but the fact is that one can easily find electronic
devices 50 and 60 years old that have never been serviced that
continue to work. Members of this group probably own them.

This is a category error.

No.

Yes, we all have 'n' year old electronic devices, because
we have thrown away the ones that have failed.

And yet cars are in fact MUCH more reliable now even tho
they have a lot more components than they used to have.

My Yaris ran on 3 cylinders. First I changed spark
plugs, because that what usually worked on old cars.
But even with a gap of 1.5mm, the spark was fine.

Because of all those other components that old cars didn't have.

I haven't even bothered to change mine after 10 years.

So I hooked up the OBD-2 reader: Engine misfire cylinder 1.
I exchanged two "spark plug caps" which is really the
ignition coil and some electronics, one unit per cylinder.

Very unusual way to do things.

Now "Engine misfire cylinder 3"
So a "new" used unit from a junk yard gotthe car
running again. The car only had run 460000km, not
sure when, if ever, the spark plugs had been changed.

So new cars are MUCH more reliable.

Yep. Because they have vastly more components.

"Rod Speed" wrote in message
...
Some gutless ****wit desperately cowering behind
Arfa Daily wrote just the
puerile **** that always pours from the back of it when its got done like
a ****ing dinner, as it always is by everyone.

Everybody who matters knows exactly who I am. You are just not one who
*does* matter Rod. The email address is valid. I'm sure if you were clever
enough to be able to look it up, you could get me right down to a street
address. As for me writing puerile ****, the words pot, kettle and black
come to mind. Most of what you write is *total* **** that no one wants to
hear, and frequently tell you so. But you are so full of yourself and your
opinionated crap, that it all goes over your head. Much like certain other
of your countrymen, as soon as anyone dares to call you out on your mindless
pontifications, you just revert to type, and start screaming bucket-mouthed
abuse. Why don't you just do everyone a big favour, and **** off for another
six months like you often do. And where are you when you do disappear ? In
jail, with any luck ...

Arfa

- or Geoff, if you prefer

"Huge" wrote in message
...
On 2015-01-05, mike wrote:
On 1/4/2015 6:02 PM, Arfa Daily wrote:

I don't like CFL lighting - that's well known. I am still reserving
judgment on LED lighting.

I wonder what we'd be saying about incandescents if they were replacing
LED lights we'd been using for a century?
I can understand if you're a photographer.
For the rest of us, it's no big deal.

Please don't include me in "the rest of us". I too think CFL lighting is
very poor, and have switched back to incandescents in a few places (I
imagine we're about 30% CFL, 30% halogen and 30% GLS (incandescent)) now.

Things change.

Not always for the better, or for the right reasons.

+1 on each of your points

Arfa



--
Today is Setting Orange, the 5th day of Chaos in the YOLD 3181
Celebrate Mungday
I don't have an attitude problem. If you have a problem with my attitude,
that's your problem.

On 1/4/2015 10:37 PM, Jeff Liebermann wrote:
On Sat, 03 Jan 2015 14:21:23 -0500, Phil Hobbs
wrote:

I have a bunch of Luxo desk lamps that have a 100 W incandescent
surrounded by a 22W circular fluorescent. They're by far the easiest
thing on the eyes that I've ever used.
Cheers
Phil Hobbs

100 watt incandescent bulb on a desk lamp? Doesn't that get rather
warm and possibly hot enough to shorten the life of the bulb?

Not in the 20 or so years I've been using them. Of course, they were
made onshore, which helps.


I also use two lights, but differently. One is an area flood light,
usually on the ceiling. The other is a desk lamp with a flood light
to light up whatever I'm working on. If the work is large, two flood
lights.

This is what I've been using for close work:
http://www.11junk.com/jeffl/pics/drivel/slides/luxo-flood.html
(Oops. I just noticed it's a Ledu, not a Luxo.)

Brr. Ledu is a crappy knockoff of Luxo. I got one by mistake, and it
rapidly went into the trash. Trust me, the $200 a real Luxo costs is a
bargain in the long run.

"Equivalent watts" is a crock. A real 100W bulb puts out about 1690
lumens, so my desk lamps are probably well north of 2500.

Highly recommended, if you have a couple of hundred 100W incandescents
stashed in a cupboard like mine.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

"Rod Speed" wrote in message
...
Arfa Daily wrote
Rod Speed wrote
William Sommerwerck wrote
Rod Speed wrote

Much more likely he doesn't actually have a ****ing clue about the
basics.

Arfa is an intelligent and knowledgeable person.

He clearly isn't on that particular question.

What particular question ?

The stupid claim that article he posted made about the
purported problem with a lot more components in a LED light instead of the
single one with the incandescent it replaced.
He didn't even notice that cars are MUCH more reliable than they used to
be even tho they have vastly more components than they used to have. In
spades with computer cpus and memory alone.

You are unbelievable.

We'll see...

How did you manage to extrapolate that mindless crap from my original
post ?

The article you mindlessly posted clearly claimed that when there are lots
more components in the LED light than in the incandescent light it
replaced, that that was absolutely certain to guarantee that it would have
a shorter life than the incandescent it replaced. Pigs arse it does.
reams of your puerile **** any 2 year old could leave for dead flushed
where it belongs



Oh you stupid stupid man. Do you even understand what the word "interesting"
means ? No, of course you don't, because you aren't ...

I didn't post any article. I posted a *link* to an article written by
someone else. I never said I agreed with it. I never said that I disagreed
with it. I never made any comment about the reliability of cars, or indeed
any system with greater or fewer components in it. The trouble with you is
that you like the sound of your own voice too much. You latch onto just
about every post that's made, and start spouting your half-arsed opinions
about stuff that you often clearly understand nothing at all about. You also
get completely wrong ideas in your empty head about what other people have
said, or attribute things that *have* been said, to the wrong poster.

Again, **** ...

Arfa

On 1/5/2015 5:42 AM, mike wrote:
On 1/4/2015 7:37 PM, Jeff Liebermann wrote:

100 watt incandescent bulb on a desk lamp? Doesn't that get rather
warm and possibly hot enough to shorten the life of the bulb?

By how much?
What's the added surface temperature?
Add that to the filament temperature.
What's the percentage increase in filament temperature?

More likely, it shortens the life of the phenolic socket and switch.


Phenolic socket? Dear me, you need to get a better class of lamp.
The Luxos are all ceramic and metal, with glass fibre sleeves on the
wiring and two layers of air-spaced metal shield between the bulbs and
the switches.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

Some gutless ****wit desperately cowering behind
Arfa Daily wrote just the
puerile **** that always pours from the back of it when its
got done like a ****ing dinner, as it always is by everyone.

Arfa Daily wrote
Rod Speed wrote
Arfa Daily wrote
Rod Speed wrote
William Sommerwerck wrote
Rod Speed wrote

Much more likely he doesn't actually have a ****ing clue about the
basics.

Arfa is an intelligent and knowledgeable person.

He clearly isn't on that particular question.

What particular question ?

The stupid claim that article he posted made about the
purported problem with a lot more components in a LED light instead of
the single one with the incandescent it replaced.

He didn't even notice that cars are MUCH more reliable than they used
to be even tho they have vastly more components than they
used to have. In spades with computer cpus and memory alone.

You are unbelievable.

We'll see...

How did you manage to extrapolate that mindless crap from my original
post ?

The article you mindlessly posted clearly claimed that when there are
lots more components in the LED light than in the incandescent light it
replaced, that that was absolutely certain to guarantee that it would
have a shorter life than the incandescent it replaced. Pigs arse it does.

reams of your puerile **** any 2 year old could
leave for dead flushed where it belongs

On 01/05/2015 12:15 PM, bob wrote:
On 1/2/2015 8:56 AM, Arfa Daily wrote:
EE Times article that came to me by email today

http://www.electronics-eetimes.com/e...s_id=222923405



Arfa
Well, i can totally see that. Part of the reason is NOT the LED's
themselves, but the CAP's. If there is a modern multinational cartel
these days, its NOT oil but the manufacturer of small capacitors. They
build these dam things to fail in a few years anymore. Between the
elevated temps they operate at and lack of quality guts, capacitors are
the weak link. And that includes LED lights because they use them in the
power supplys.

Last year, i bought a bargain CFL lamp for $1 at the dollar store.
Worked for maybe a hour them ZBOOOM! TOOK it apart and sure enough,
capacitor guts all over.

It seems most modern LCD tv's have a life of two or three years then
they go haywire. I was all ready to get a new Sharp LED set before the
first of the year on sale and was about the push go, then figured
i better do some research first. Pages and pages of it failed soon
and the manufacturer would not help. I'm sure capacitors are one
of the major reasons for that also.

i just saw some 40W LED bulbs at a ACE US hardware store for $5.99 on
sale. almost got one, but held off for now. Its hard to beat the
simplicity of a incandescent lamp.

bob

As usual, heat is the enemy. Reading the technical specs for caps is
enlightening. They are rated usually at something like 2,000 to 5,000
hours at their rated temperature. So an 80C cap will die after something
like 2000 hrs at 80C or 4000 hours at 50C and 10000 hours at 40C (not
looking it up!), whereas a 105C cap will last 10000 hours at 85C, etc.
So, the better the grade of cap the longer it will last in warm to hot
environments. And there is the equivalent resistance and inductance to
consider as well. Some caps are much more tolerant of 50/60hz and others
are better at 20,000hz. Selecting those takes time and the cost
accountants slip in at some point...

John :-#)#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

Jeff Liebermann wrote:
On 3 Jan 2015 06:50:55 GMT, Bob Eager wrote:

On Fri, 02 Jan 2015 17:32:41 -0800, Jeff Liebermann wrote:

All this begs the question "Why did the author write the article"? Scott
That also begs the question "Why did Arfa Daily post the article"? My
This also begs the question "Why did I write this long rant when I

http://afterdeadline.blogs.nytimes.com/2008/09/25/begging-the-question-again/?_r=0

Please put carrets around URL's so that the Usenet server doesn't
reformat it by wrapping the lines.

Please post definition of "carrets" as entering it in many ways in
google fails to find answer.

If your one-line comment is about my use of "begs the question",
you're correct that mine was not the correct usage. It should have
been "raises the question" as described in:
http://begthequestion.info
My appologies. I'll instruct my proof reader to check for such
grammatical errors.

Jeff Liebermann wrote:
On 3 Jan 2015 06:50:55 GMT, Bob Eager wrote:

On Fri, 02 Jan 2015 17:32:41 -0800, Jeff Liebermann wrote:

All this begs the question "Why did the author write the article"? Scott
That also begs the question "Why did Arfa Daily post the article"? My
This also begs the question "Why did I write this long rant when I

http://afterdeadline.blogs.nytimes.com/2008/09/25/begging-the-question-again/?_r=0

Please put carrets around URL's so that the Usenet server doesn't
reformat it by wrapping the lines.

If your one-line comment is about my use of "begs the question",
you're correct that mine was not the correct usage. It should have
been "raises the question" as described in:
http://begthequestion.info
My appologies. I'll instruct my proof reader to check for such
grammatical errors.


Are those sideways less than more than symbols Carets? I thought that ^
is a carete and would such a caret before and after the URL work?

On 06/01/15 06:10, John Robertson wrote:

As usual, heat is the enemy. Reading the technical specs for caps is
enlightening. They are rated usually at something like 2,000 to 5,000
hours at their rated temperature. So an 80C cap will die after something
like 2000 hrs at 80C or 4000 hours at 50C and 10000 hours at 40C (not
looking it up!), whereas a 105C cap will last 10000 hours at 85C, etc.
So, the better the grade of cap the longer it will last in warm to hot
environments. And there is the equivalent resistance and inductance to
consider as well. Some caps are much more tolerant of 50/60hz and others
are better at 20,000hz. Selecting those takes time and the cost
accountants slip in at some point...

That's very interesting.

Based on this random driver circuit:

http://www.ecnmag.com/sites/ecnmag.c...206-web(1).jpg

and looking at RS for 680uF around 50V electrolytics:

the 105C are around 50-70 pence
125C are around 130 pence
150C are 252 pence

There seems to be 1 big cap in that circuit - I don't have time now to
cost all of the electrolytics but this looks like a case of adding maybe
3 pounds would make the difference between a short life and a very long
life.

I suspect Philips use the good components - their LED bulbs seem to last
a long time (my tests are still pending) but they cost rather more than
3 pounds over the cheaper LEDs.

On 06/01/15 06:10, John Robertson wrote:

As usual, heat is the enemy. Reading the technical specs for caps is
enlightening. They are rated usually at something like 2,000 to 5,000
hours at their rated temperature. So an 80C cap will die after something
like 2000 hrs at 80C or 4000 hours at 50C and 10000 hours at 40C (not
looking it up!), whereas a 105C cap will last 10000 hours at 85C, etc.
So, the better the grade of cap the longer it will last in warm to hot
environments. And there is the equivalent resistance and inductance to
consider as well. Some caps are much more tolerant of 50/60hz and others
are better at 20,000hz. Selecting those takes time and the cost
accountants slip in at some point...

Just out of interest, do any mains LEDs use simple reactive droppers, eg
capacitor or inductor, then bridge rectifier and smoothing capacitor?

And do 12V LEDs have driver circuits which are less stressed than their
mains equivalents? ie are 12V formats more likely to last longer?

On 06/01/15 08:07, Tim Watts wrote:
On 06/01/15 06:10, John Robertson wrote:

As usual, heat is the enemy. Reading the technical specs for caps is
enlightening. They are rated usually at something like 2,000 to 5,000
hours at their rated temperature. So an 80C cap will die after something
like 2000 hrs at 80C or 4000 hours at 50C and 10000 hours at 40C (not
looking it up!), whereas a 105C cap will last 10000 hours at 85C, etc.
So, the better the grade of cap the longer it will last in warm to hot
environments. And there is the equivalent resistance and inductance to
consider as well. Some caps are much more tolerant of 50/60hz and others
are better at 20,000hz. Selecting those takes time and the cost
accountants slip in at some point...

Just out of interest, do any mains LEDs use simple reactive droppers, eg
capacitor or inductor, then bridge rectifier and smoothing capacitor?

I suspect not at this point in time.

The problem is that an inductor is large and expensive at 50hz.

Consider 25W of LED. that represents 100mA of current, or an inductor
impedance of around 2.4k ohms 7.6 henries.

That is a fairly large beast. Too large for a light bulb - and indeed
its pretty similar to what's inside a fluorescent ballast of similar
wattage.

Ergo these days we rectify, smooth and chop and transform at much higher
freqs than 50hz to get power at different voltages or to achieve current
limiting. And that gets rid of 100hz flicker too..or should,

And it gets rid of big iron cored chokes. smaller cheaper ferrites with
less copper involved are far far cheaper.

BUT you have the switching transistors and the rectification and
smoothing components operating at high power and mains voltage - bad
reliability especially when HOT.

Actually what is needed is the electronics independent of the bulb.
Maybe built into the light fitting, as it is with fluorescent. And
independently replaceable.

And do 12V LEDs have driver circuits which are less stressed than their
mains equivalents? ie are 12V formats more likely to last longer?

Probably. switching at 12V is not such a hard task for most electronics

The problems of LED bulbs are nothing to do with LEDS and a lot to do
with miniaturisation and cost.

Personally I think that we should be looking at LED lights that are
neither ES nor bayonet, but in fact sit on the end of a piece of wire,
and are large enough and expensive enough to be considered fittings, not
consumables, and simply get wired in when the house is built.

And last at least 15 years.

E.g. you replace a ceiling rose assembly with something remote from the
'bulb' that drives the 'bulb' over a piece of wire at LV. Or you have
integrated lumieres that replace conventional ones.

And indeed in-wall power supplies for designer lighting etc.


--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll

"Tim Watts" wrote in message
...
On 06/01/15 06:10, John Robertson wrote:

As usual, heat is the enemy. Reading the technical specs for caps is
enlightening. They are rated usually at something like 2,000 to 5,000
hours at their rated temperature. So an 80C cap will die after something
like 2000 hrs at 80C or 4000 hours at 50C and 10000 hours at 40C (not
looking it up!), whereas a 105C cap will last 10000 hours at 85C, etc.
So, the better the grade of cap the longer it will last in warm to hot
environments. And there is the equivalent resistance and inductance to
consider as well. Some caps are much more tolerant of 50/60hz and others
are better at 20,000hz. Selecting those takes time and the cost
accountants slip in at some point...

Just out of interest, do any mains LEDs use simple reactive droppers, eg
capacitor or inductor, then bridge rectifier and smoothing capacitor?

And do 12V LEDs have driver circuits which are less stressed than their
mains equivalents? ie are 12V formats more likely to last longer?

Yes, you don’t need to use caps at all with some configurations of
those, most obviously with series leds.