On 06/01/15 10:47, john james wrote:


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

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.

So one thing is clear - if I decide to deploy high power LEDs I might be
better offering a SELV supply to them and choosing fittings that can
take 12V lamps.

As it happens, I will be using LEDs in a number of relatively open
fittings (GU10s ion the end of stalks, plenty of air), 3 very low power
GU10s in downlighters (2-3W range) as night lighting in the hall.

Other candidates are some 12V G4s in the bathroom, enclosed and some
GX53s (open fitting). So on the whole I should be doing OK with LED
retro fit as the price comes down.

The Natural Philosopher wrote:

[...]
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,

The flicker will only disappear if you use a large capacitor as a
storage element; usually this is found on the HV side of the inverter.
This brings back the reliability problem: it is asking a lot of a big
capacitor to survive for many years when it is potentially exposed to
occasional mains glitches from one side and continuously exposed to the
switching current waveform on the other.

For a given energy storage capacity, capacitors are smaller, lighter and
cheaper than metal-cored chokes, but it is a lot more difficult to make
them as reliable in the long term.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On Mon, 05 Jan 2015 21:31:00 -0500, Phil Hobbs wrote:

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.

Indeed. I got a secondhand Luxo in 1974, and it finally packed up a
couple of years ago. It was of course replaced by...a Luxo. We also have
a couple of ten year old ones on our office desks at home, one right next
to me here.

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

And mine.

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £30a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

Rod Speed sendte dette med sin computer:
Leif Neland wrote

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.


Here is the product page:

http://www.thansen.dk/product.asp?pn=-831477966

Price is USD 160, I got an used one for 24USD.

Alas, now it needs a new back door, because wife didn't see I parked
the Landcruiser outside the garage :-(

Leif

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

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...

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.



The things that kill electrolytic capacitors are ripple current and
ESR. If you double the capacitor size, the life dramatically increases
as the running temperature decreases. I once had a very nice DOS program
which forecast capacitor life extremely well based predominantly on
ripple current.

I see that Ford have had to add cooling fans to their infinite life LED
headlamps. I've never yet seen a fan with an infinite life!

On 06/01/15 11:22, Adrian Tuddenham wrote:
For a given energy storage capacity, capacitors are smaller, lighter and
cheaper than metal-cored chokes, but it is a lot more difficult to make
them as reliable in the long term.

a very cogent and pertinent statement


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

In article , Arfa Daily
scribeth thus


"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


Don't know why you bother with him Arfa, just killfile the prat thats
what I did ages ago!...
--
Tony Sayer

On Tuesday, 6 January 2015 12:22:58 UTC, Capitol wrote:
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...

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.



The things that kill electrolytic capacitors are ripple current and
ESR.

I've always though it was temerature as the electrolyte dries up, and that's why caps also come in temerature ranges.

If you double the capacitor size, the life dramatically increases
as the running temperature decreases.

I don't think thre's such a simple connection.

I once had a very nice DOS program
which forecast capacitor life extremely well based predominantly on
ripple current.

But did it really work, I supsect not.


I see that Ford have had to add cooling fans to their infinite life LED
headlamps. I've never yet seen a fan with an infinite life!

Ah but the LED has infinite life, especaially if you don;t switch it on, or don't exceed the specs, which asr usualyl stated at not having iot on more than 3 hours at a time (power LEDs)

whisky-dave wrote:

I once had a very nice DOS program
which forecast capacitor life extremely well based predominantly on
ripple current.

But did it really work, I supsect not.

It did. It forecast the failure of a capacitor which had been wrongly
ripple current specified. All 250K of them! The factory decided to
ignore the change note which replaced the capacitor with a correctly
specified device. The replacements didn't fail.

Adrian Tuddenham wrote
The Natural Philosopher wrote

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,

The flicker will only disappear if you use a large capacitor as
a storage element; usually this is found on the HV side of the
inverter. This brings back the reliability problem: it is asking
a lot of a big capacitor to survive for many years

PC power supplys done like that last fine.

when it is potentially exposed to occasional
mains glitches from one side

It isnt hard to stop those getting to the cap.

and continuously exposed to the
switching current waveform on the other.

That doesn’t happen either with the big cap.

For a given energy storage capacity, capacitors are smaller,
lighter and cheaper than metal-cored chokes, but it is a lot
more difficult to make them as reliable in the long term.

Yes, but in practice its long term enough with PC power supplys.

Leif Neland wrote
Rod Speed wrote
Leif Neland wrote

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.

Here is the product page:

http://www.thansen.dk/product.asp?pn=-831477966

Price is USD 160, I got an used one for 24USD.

I have considered the Yaris but don't thing I'll ever get one
given that approach. I've got a Hyundai Getz myself but likely
won't be replacing it unless it breaks dramatically. The previous
VW Golf lasted me 35+ years and I only needed to replace that
when I was stupid enough to no do anything about a known
windscreen leak after a windscreen replacement and that
eventually rusted out the floor and I could be arsed fixing that.

Alas, now it needs a new back door, because wife didn't
see I parked the Landcruiser outside the garage :-(

Should be able to get one of those cheap too given that
most of the writeoffs would be at the other end of the car.

Rod Speed wrote:

Adrian Tuddenham wrote
[...]
For a given energy storage capacity, capacitors are smaller,
lighter and cheaper than metal-cored chokes, but it is a lot
more difficult to make them as reliable in the long term.

Yes, but in practice its long term enough with PC power supplys.

....but not when the PSUs also have to fit into the cap of a light bulb
and under-cut the price of the nearest rival.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Rod Speed forklarede den 06-01-2015:
Leif Neland wrote
Rod Speed wrote
Leif Neland wrote

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.

Here is the product page:

http://www.thansen.dk/product.asp?pn=-831477966

Price is USD 160, I got an used one for 24USD.

I have considered the Yaris but don't thing I'll ever get one given that
approach.

I find it a good approach, omitting a distributor and 5 cables which
can be attacked by moisture.
Here everything high voltage is sitting nice and dry almost inside the
engine, below a plastic cover.

I've got a Hyundai Getz myself but likely
won't be replacing it unless it breaks dramatically. The previous
VW Golf lasted me 35+ years and I only needed to replace that
when I was stupid enough to no do anything about a known
windscreen leak after a windscreen replacement and that eventually rusted out
the floor and I could be arsed fixing that.

Alas, now it needs a new back door, because wife didn't see I parked the
Landcruiser outside the garage :-(

Should be able to get one of those cheap too given that
most of the writeoffs would be at the other end of the car.

I've sent off enquries to two dealers, including a whole car with front
damage for for 1000USD.

Leif

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

On 02/01/2015 14:56, Arfa Daily wrote:
EE Times article that came to me by email today

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


Arfa

Some very interesting maths there certainly. Particularly how he comes
up with "a 25% failure rate" for LEDs.

I consider that a valid reason for disregarding anything he has to say
about the matter.

Tim Watts forklarede:

As it happens, I will be using LEDs in a number of relatively open fittings
(GU10s ion the end of stalks, plenty of air), 3 very low power GU10s in
downlighters (2-3W range) as night lighting in the hall.

Consider using red leds for guide lights at night, it makes it easier
to go to sleep again if you have to get up at night.

Leif

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

On 06/01/15 20:12, Leif Neland wrote:
Tim Watts forklarede:

As it happens, I will be using LEDs in a number of relatively open
fittings (GU10s ion the end of stalks, plenty of air), 3 very low
power GU10s in downlighters (2-3W range) as night lighting in the hall.

Consider using red leds for guide lights at night, it makes it easier to
go to sleep again if you have to get up at night.

Leif


Very good idea! You can get coloured GU10s IIRC.

This will show through the front door glass (bedrooms are downstairs) so
we might get mistaken for a knocking shop, which would add some interest
to our daily humdrum lives

On 05/01/2015 20:57, Leif Neland wrote:
The car only had run 460000km, not sure when, if ever, the spark plugs
had been changed.

That's pretty good - nearly half a million on one set of plugs.

Andy

"Adrian Tuddenham" wrote in message
valid.invalid...
Rod Speed wrote:

Adrian Tuddenham wrote
[...]
For a given energy storage capacity, capacitors are smaller,
lighter and cheaper than metal-cored chokes, but it is a lot
more difficult to make them as reliable in the long term.

Yes, but in practice its long term enough with PC power supplys.

...but not when the PSUs also have to fit into the cap of a light bulb

Sure, but that doesn’t happen with the ones with an external power supply.

and under-cut the price of the nearest rival.

Happens in spades with PC power supplys.

Leif Neland wrote
Rod Speed wrote
Leif Neland wrote
Rod Speed wrote
Leif Neland wrote

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.

Here is the product page:

http://www.thansen.dk/product.asp?pn=-831477966

Price is USD 160, I got an used one for 24USD.

I have considered the Yaris but don't thing
I'll ever get one given that approach.

I find it a good approach,

I don't.

omitting a distributor

No distributor in my Getz.

and 5 cables which can be attacked by moisture.

But much more expensive to fix than replacing a cable.

I've never had to replace a distributor, the most I
have ever had to do is replace the rotor for peanuts.

Here everything high voltage is sitting nice and dry
almost inside the engine, below a plastic cover.

I've got a Hyundai Getz myself but likely won't be replacing
it unless it breaks dramatically. The previous VW Golf lasted
me 35+ years and I only needed to replace that when I was
stupid enough to no do anything about a known windscreen
leak after a windscreen replacement and that eventually rusted
out the floor and I could be arsed fixing that.

Alas, now it needs a new back door, because wife didn't
see I parked the Landcruiser outside the garage :-(

Should be able to get one of those cheap too given that
most of the writeoffs would be at the other end of the car.

I've sent off enquries to two dealers, including
a whole car with front damage for for 1000USD.

"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.



You see ? There you go again. Nothing new to say, so hey, just say exactly
the same thing over again. Clever ? Not as such. And let's just analyze the
content, shall we ? "A gutless ****wit desperately cowering behind ..."

So, gutless ? Why would I need 'guts' to talk to a ****-headed moron like
you ? Desperately cowering ? Why in your wildest dreams would you believe
that anything you could do or say on here would make me desperate or want to
hide from you ? Using a nic ? So what ? Loads of people do. I've used it for
15 years or more. It's a bit of a laugh - too subtle for you of course, but
again, anyone who matters - that's not you - knows the story behind why I
use it. I don't 'hide' behind anything. As I said to you before, the email
address is valid, and I don't hide or change anything in the headers of
anything I post. If you are that desperate to know who I am, work it out.
But I suppose you are too thick to do that.

You are a total waste of space and bandwidth. Nobody is actually interested
in anything you have to say ...

Arfa

"tony sayer" wrote in message
...
In article , Arfa Daily
scribeth thus


"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


Don't know why you bother with him Arfa, just killfile the prat thats
what I did ages ago!...
--
Tony Sayer


Playing with him amuses me, Tony ... :-)

Arfa

"Rod Speed" wrote in message
...
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


Wahey ! And again. Nothing new to say, so just snip anything of relevance to
try and justify yourself, and then say the same thing over again. You really
are a ****in robot, aren't you ? Just do everybody a favour, and get back to
your kangaroo shagging ...

Arfa

On Tue, 06 Jan 2015 18:55:32 +1100, F Murtz
wrote:

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?

I think we've successfully demonstrated that the more trivial the
topic, the more attention it receives on Usenet.

For a personalized copy of my full confession for the capital crime of
using the wrong name, compounded by spelling it wrong, please send $1
to the address below.

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

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.

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.

"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.

LOL

"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.



And you call me a ****wit. You are just a dopey saddo who everybody laughs
at. Go get a life, arsewipe.

Plonk ...

Arfa

"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.


****, thrice over ...

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.

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.

In sci.electronics.repair Tim Watts wrote:
On 03/01/15 05:03, Cydrome Leader wrote:

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

Philips SL probably - 35 year old this year:

http://en.wikipedia.org/wiki/Compact...scent_lamp.JPG

the panasonic ones looked similar, but with glass. As you can see from the
size, there's very few places the thing would even fit.