sci.electronics.repair - 26 new messages in 9 topics - digest

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Today's topics:

==============================================================================
TOPIC: Another reason to hate CFLs ...
http://groups.google.com/group/sci.electronics.repair/t/87ea27a2579f0316?hl=en
==============================================================================

== 1 of 11 ==
Date: Sat, Oct 23 2010 10:59 pm
From: "Geoffrey S. Mendelson"

Arfa Daily wrote:
> As if any more reasons were needed on top of their horrible startup
> characteristics, their ugliness, their sick coloured light, and their
> inability to last for a fraction of the claimed lifetime :-(

Actually I live CFLs. They provide a cheap source of light where I need light
but don't care how bad it looks. For example outisde lighting which is mostly
there so someone sees a light on and prefers to walk somewhere else, if even
just because it messes with their night vision.

I like them for places that I have to have a light on such as my windowless
bathroom. It's cheaper to leave one on 24/7 than have it on a timer.
Especially if I have to get up to use the toilet at 3am when the timer would
have the light off.

Over the years since I first got them in the late 1990's they have gotten
more efficient and finally someone wised up and is making them "warm",
which is close to the color that I can actually see.

The latest ones are brighter per watt, about 30%. I could see that about
a month ago when I replaced a bunch of them. I replace the one in the
bathroom when it goes out (and keep a spare as it usually happens late
at night), the others about once a year, just because.

> Now the other day, the bulb in my Anglepoise bench light failed, and as it
> was the last 60 watt pearl one I had - nowhere stocking such an animal any
> more due to EU ecobollox intervention - I put in a CFL that had come free
> in a cornflake packet or some such nonsense. Once it has warmed up in the
> morning - at least one coffee drinking time needed for this - it seemed to
> work reasonably well. Until, that is, I started trying to identify the
> resistors in my old drawers to move them into the individual value drawers
> in the new location.

We still have plenty of incadescent bulbs for sale here, and they are cheap.
I expect we are the dumping ground for bulbs made in eastern Europe but
can't be sold there. I've bought plenty of them to stock up.

We use them for reading lamps so there are 5 of them still in use in
our house.

I also have a good supply of 12v halogen bulbs, but to be honest, I'm not
sure where the lamp that the fit is. :-)

Although they are long gone on the commercial market, they are still needed
for photgraphic enlargers. 3200k color temperature (about what you are used
to) and pearl or opal finish (very smooth even distribution of light).

Since they were often hung base up printing on the top would become part of
the image, so they had the wattage etc printed on the side, like a vacuum
tube (or valve as you would say).

You can find them if you search the web for suppliers of photgraphic darkroom
equipment, which has become a thriving niche market.

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

== 2 of 11 ==
Date: Sun, Oct 24 2010 1:17 am
From: "N_Cook"

Arfa Daily <arfa.daily@ntlworld.com> wrote in message
news:PYLwo.42936$vi1.18039@newsfe07.ams2...
> As if any more reasons were needed on top of their horrible startup
> characteristics, their ugliness, their sick coloured light, and their
> inability to last for a fraction of the claimed lifetime :-(
>
> Like most of us, I suspect, I have hundreds of component drawers, which
over
> the years have become mixed up and confused, so in the circumstances of
work
> being very quiet at the moment, I decided to have a major tidy up and
clear
> out of redundant components. As a first move, I decided to rationalise the
> resistors, and re-store them by individual value, rather than in groups of
> values in the same drawer.
>
> Now the other day, the bulb in my Anglepoise bench light failed, and as it
> was the last 60 watt pearl one I had - nowhere stocking such an animal any
> more due to EU ecobollox intervention - I put in a CFL that had come free
> in a cornflake packet or some such nonsense. Once it has warmed up in the
> morning - at least one coffee drinking time needed for this - it seemed to
> work reasonably well. Until, that is, I started trying to identify the
> resistors in my old drawers to move them into the individual value drawers
> in the new location.
>
> The spectrum from this lamp is so poor and discontinuous, that it is
almost
> impossible to resolve red from brown from orange, or violet from blue or
> grey. Absolutely bloody useless. If I can't find any more 60 watt pearl
> bulbs on the 'net, then I'm going to modify the lampholder to take a low
> voltage halogen downlighter bulb, and hook it to a 12v transformer.
>
> Arfa
>

You can get your own back when you scrap them
one GE 11TBXT 3/827 10Y, 240V, 105mA CFL gave these "useful" bits
10R fusible R
2 x BU102 ?? high V, TO92
2.8uF, 400V, 105 deg F with nice long leads
30 V diac BLDB3 / DB3
high temp textile sleeving
4mH inductor
ferrite ring
2x 0.5R

== 3 of 11 ==
Date: Sun, Oct 24 2010 1:34 am
From: "Geoffrey S. Mendelson"

N_Cook wrote:
> You can get your own back when you scrap them
> one GE 11TBXT 3/827 10Y, 240V, 105mA CFL gave these "useful" bits
> 10R fusible R
> 2 x BU102 ?? high V, TO92
> 2.8uF, 400V, 105 deg F with nice long leads
> 30 V diac BLDB3 / DB3
> high temp textile sleeving
> 4mH inductor
> ferrite ring
> 2x 0.5R

How do you scrap them? The ones I have (and had in the past) were all encased
in some sort of ceramic, and to me they can only be taken apart with a hammer.

Thanks,

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

== 4 of 11 ==
Date: Sun, Oct 24 2010 1:40 am
From: David Nebenzahl

On 10/24/2010 1:34 AM Geoffrey S. Mendelson spake thus:

> N_Cook wrote:
>
>> You can get your own back when you scrap them one GE 11TBXT 3/827
>> 10Y, 240V, 105mA CFL gave these "useful" bits 10R fusible R 2 x
>> BU102 ?? high V, TO92 2.8uF, 400V, 105 deg F with nice long leads
>> 30 V diac BLDB3 / DB3 high temp textile sleeving 4mH inductor
>> ferrite ring 2x 0.5R
>
> How do you scrap them? The ones I have (and had in the past) were all
> encased in some sort of ceramic, and to me they can only be taken
> apart with a hammer.

Plastic, not ceramic. Still requires a few love-taps from a hammer, but
the circuit board can be retrieved undamaged.

--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

== 5 of 11 ==
Date: Sun, Oct 24 2010 1:50 am
From: "N_Cook"

David Nebenzahl <nobody@but.us.chickens> wrote in message
news:4cc3f0d0$0$2453$822641b3@news.adtechcomputers.com...
> On 10/24/2010 1:34 AM Geoffrey S. Mendelson spake thus:
>
> > N_Cook wrote:
> >
> >> You can get your own back when you scrap them one GE 11TBXT 3/827
> >> 10Y, 240V, 105mA CFL gave these "useful" bits 10R fusible R 2 x
> >> BU102 ?? high V, TO92 2.8uF, 400V, 105 deg F with nice long leads
> >> 30 V diac BLDB3 / DB3 high temp textile sleeving 4mH inductor
> >> ferrite ring 2x 0.5R
> >
> > How do you scrap them? The ones I have (and had in the past) were all
> > encased in some sort of ceramic, and to me they can only be taken
> > apart with a hammer.
>
> Plastic, not ceramic. Still requires a few love-taps from a hammer, but
> the circuit board can be retrieved undamaged.
>
>
> --
> The fashion in killing has an insouciant, flirty style this spring,
> with the flaunting of well-defined muscle, wrapped in flags.
>
> - Comment from an article on Antiwar.com (http://antiwar.com)

The white cone part is one-time fitted via pawls to the main part. Dremmell
grind a small hole into the cone at the break, where in case of both GE or
Philips logo is , seems to coincide with a pawl. Then lever off with
screwdriver. Cut the wires to the outside connector or desolder I suppose.
These days fibre reinforced plastic or mineralised plastic, used to be
ceramic in the original ones, Googling for BU102 + TO92 gets nowhere, I
assume as diac in there then triacs

== 6 of 11 ==
Date: Sun, Oct 24 2010 2:09 am
From: "N_Cook"

Inside Philips Genie 8W CFL
10R, 1W
2 x Si 13001 triac?
105 deg C electros 1.8uF 400V and 2x 22uF lower V
1cm cube choke
ferrite ring
4.7mH choke
probably diac as well as "diodes" not checked

== 7 of 11 ==
Date: Sun, Oct 24 2010 3:54 am
From: "William Sommerwerck"

Not so. At least not so with the lamps I use, CFLs from Home Despot.

They come on instantly (and reach full brightness in about 30s); their odd
appearance is usually covered by a shade or fixture; their color balance is
good enough for color photography (and under a glass fixture is
indistinguishable from tungsten); and their-less-than-claimed lifespan is
still pretty long (about 2K hours for these lamps), especially considering
they use about 1/4 the energy of a comparable-output tungsten lamp.

Fluorescent lamps have always suffered from weak red output and a
discontinuous spectrum. The use of CFLs in "non-industrial" environments
(kitchens, shops, businesses, offices) has forced manufacturers to "do
something" about these problems.

I had tried CFLs (Philips) when they first came out, because the electric
company subsidized them. They were bulky, dim when they came on (the Home
Despots aren't), and took "forever" to reach full brightness. And they
didn't last very long.

Several years ago Home Despot handed out free CFLs. I tried one and was
sold. I no longer use tungsten lighting. (If I needed a high-intensity desk
lamp, though, I would use tungsten.) As I write this, I'm sitting in my den
of iniquity, illuminated by a 24W Home Despot CFL. It's in a beautiful IKEA
fixture (no longer made, of course), and -- other than the fact you don't
feel a blast of infrared when you stand near it -- I defy you to tell it's
tungsten without looking at the bulb.

I use them "nekkid" in the bathroom, and though /slightly/ cool, the color
is anything but "sick". I'd call it a brilliant cool white. It in no way
resembles conventional fluorescents.

As for your problems with metamerism... I don't know whether the Home Despot
CFLs would solve the problem. However, it seems unlikely that /some/ GB
retailer isn't importing the same bulbs.

PS: I stuck one of Home Despot's free lamps in the fixture outside my condo.
It has lasted at least twice as long as the "long-life" incandescents the
condo association uses.

== 8 of 11 ==
Date: Sun, Oct 24 2010 5:34 am
From: "Geoffrey S. Mendelson"

William Sommerwerck wrote:
> As for your problems with metamerism... I don't know whether the Home Despot
> CFLs would solve the problem. However, it seems unlikely that /some/ GB
> retailer isn't importing the same bulbs.

Nope. The ones sold here (and I assume in the UK) are Hyundai (Korea),
Osram (eastern Europe), and a bunch of Chinese brands that sound like
famous Japanese ones but are not.

And they are ceramic, not plastic. :-(

I do occasionaly see Philps ones (at twice the price or more than the
others) and I have lots of GE incandescent bulbs which are made in
eastern Europe.

Geoff.
--
Geoffrey S. Mendelson N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)

== 9 of 11 ==
Date: Sun, Oct 24 2010 8:11 am
From: Meat Plow

On Sun, 24 Oct 2010 02:28:14 +0100, Arfa Daily wrote:

> As if any more reasons were needed on top of their horrible startup
> characteristics, their ugliness, their sick coloured light, and their
> inability to last for a fraction of the claimed lifetime :-(
>
> Like most of us, I suspect, I have hundreds of component drawers, which
> over the years have become mixed up and confused, so in the
> circumstances of work being very quiet at the moment, I decided to have
> a major tidy up and clear out of redundant components. As a first move,
> I decided to rationalise the resistors, and re-store them by individual
> value, rather than in groups of values in the same drawer.
>
> Now the other day, the bulb in my Anglepoise bench light failed, and as
> it was the last 60 watt pearl one I had - nowhere stocking such an
> animal any more due to EU ecobollox intervention - I put in a CFL that
> had come free in a cornflake packet or some such nonsense. Once it has
> warmed up in the morning - at least one coffee drinking time needed for
> this - it seemed to work reasonably well. Until, that is, I started
> trying to identify the resistors in my old drawers to move them into the
> individual value drawers in the new location.
>
> The spectrum from this lamp is so poor and discontinuous, that it is
> almost impossible to resolve red from brown from orange, or violet from
> blue or grey. Absolutely bloody useless. If I can't find any more 60
> watt pearl bulbs on the 'net, then I'm going to modify the lampholder to
> take a low voltage halogen downlighter bulb, and hook it to a 12v
> transformer.
>
> Arfa

I like the 6500k CFLs for security lighting and my bench light. I'm very
surprised at the longevity of the outdoor 23 watters. They have been in
use dusk to dawn in all kinds of weather, all mounted inverted and in
some sort of shroud one actually totally enclosed in a globe. Only one
has failed after two years and I expected it to fail, the globe enclosed
CFL. None of these 4 outdoor lamps are rated for inverted use either. I
did some reading on inverting a CFL and the base temperature increases
dramatically when the lamp is inverted. So I would expect cheap
electrolytics to dry up in no time.

--
Live Fast, Die Young and Leave a Pretty Corpse

== 10 of 11 ==
Date: Sun, Oct 24 2010 8:32 am
From: "Arfa Daily"

"David Nebenzahl" <nobody@but.us.chickens> wrote in message
news:4cc390a0$0$2453$822641b3@news.adtechcomputers.com...
> On 10/23/2010 6:28 PM Arfa Daily spake thus:
>
>> The spectrum from this lamp is so poor and discontinuous, that it is
>> almost impossible to resolve red from brown from orange, or violet from
>> blue or grey. Absolutely bloody useless. If I can't find any more 60 watt
>> pearl bulbs on the 'net, then I'm going to modify the lampholder to take
>> a low voltage halogen downlighter bulb, and hook it to a 12v transformer.
>
> Hate to say it, Arfa, but you sound like a Croat ranting about how much he
> hates automobiles, having driven nothing but Yugos all his life.
>
> CFLs used to be like that, sure. The ones I use (here in the Untied
> Snakes) are much better in all the parameters you mentioned: instant on,
> no appreciable warm-up time, pleasing color spectrum, long life.
>
> (Well, their packages still leave something to be desired in some
> applications, but other than that they're good.)
>
>
> --

Over the years since this technology was vaunted as the 'replacement' for
incandescent light, I have bought many examples from different
manufacturers. Whilst there has been some improvement in their performance
in that time, they remain, IMHO, a 'substitute' technology, rather than a
'replacement' one. They do not start up in the few mS that it takes an
incandescent to come on, no matter how good and up to date they are in that
respect. Neither do they reach full output for some considerable time after
they are powered. Most seem to be rated to produce 80% of their maximum
light output after 15 seconds. The remaining 20% takes a lot longer than
that. Both shortcomings are exacerbated by low ambient temperature. The
power ratings and light output are typically specced for an ambient
temperature of 25 deg C. Whilst some parts of the world may achieve this
most of the time, we don't here in the UK, and UK homes are certainly not
heated to that level from autumn through spring. Apart from that, they don't
sit properly in many decorative light fittings, and change the colour
aesthetics of some lampshades - notably for instance, in a rather nice
Tiffany style table lamp that I have. When I tried one in that, the
beautiful ruby red panels changed to a muddy colour, and the whole shade
took on a muted look, with much of the colour vibrancy that is a trademark
of this type of shade, gone. I went back to an incandescent in it. I was
able to use a clear one, as the bulb is not visible.

As another example of dubious output spectrum and CRI, I recently bought an
expensive example to go in a new light fitting in my hallway, which I had
just decorated. It was sold as a 'warm white' for household interior
lighting uses, and with a claimed equivalent light output of a 100 watt
incandescent. I chose a type that had a pearl 'globe' around the CFL spiral,
as the lampshade it was going in, was formed from glass crystal beads,
making the bulb completely visible, and part of the overall visual design.
An 'open' spiral or loop CFL design would have looked dreadful.

However, when it was fitted, the light from it was barely adequate, despite
the fact that previously, the hallway had been lit perfectly well with a 60
watt pearl incandescent bulb, and was now decorated in lighter colours than
it was before. Further, the colour spectrum was so poor that the background
of the wallpaper - actually a 'calico' colour - appeared to be a 'sick' pale
green, completely different in shade to the calico emulsion paint used
elsewhere in the hall, and which is indistinguishable from the wallpaper
background under natural daylight, or incandescent light.

My daughter, who is an artist and understands a lot about colour, saw the
new decoration for the first time after it had been completed and this new
bulb fitted, at night, and she was horrified at the effect, asking how on
earth we could have picked such horrible and mismatched colours. She knows
nothing of the technicalities and shortcomings of CFLs, and was just
reacting to something she was seeing from the artistic perspective.

My wife and I were so disappointed with her comments, that I immediately
removed the dreadful thing, and replaced it with a 60 watt pearl bulb that I
had rescued from my mother's stash after she died recently. Unfortunately,
it was the last one she, or I, had.

Once I had done this, my daughter couldn't believe the difference she was
seeing. To her, it had been 'just a light bulb'.

So, it's not just me. I think that many people don't like them - or the many
other eco, production and disposal implications (but that's another whole
story) - but are just going along with the whole thing because they are
being left with no other choice. They have their uses for sure. In areas
that have to be continuously lit for instance, or perhaps where aesthetics
don't matter. But as a replacement for incandescent light in all
circumstances ? No sir. Not yet. Not by a long long way ... And if that
makes me a Luddite and pommy whinger (just for you Philip) then yes, guilty
as charged ...

Arfa

== 11 of 11 ==
Date: Sun, Oct 24 2010 8:57 am
From: "William Sommerwerck"

> Over the years since this technology was vaunted as the
> 'replacement' for incandescent light, I have bought many
> examples from different manufacturers.

You've obviously had bad luck. Or there aren't any good ones in your neck of
the woods.

> They do not start up in the few ms that it takes an
> incandescent to come on...

True. They come on instantly. You can see the difference -- there's a
visible lag with incandescents.

> Neither do they reach full output for some considerable time
> after they're turned on.

Mine take about 30s. And they're acceptably from the moment they're turned .
(The older Philips were really dim at turn on.)

It appears that your government is aggressively forcing a conversion to CFLs
and other low-energy lighting. Forced conversion tends to short-circuit the
normal market forces that encourage companies to produce products people
really like. Your manufacturers have no real motivation to produce CFLs with
pleasing color balance.

==============================================================================
TOPIC: is this wattage accurate?
http://groups.google.com/group/sci.electronics.repair/t/9b48e563412593f0?hl=en
==============================================================================

== 1 of 3 ==
Date: Sun, Oct 24 2010 3:38 am
From: "Brenda Ann"

"John Fields" <jfields@austininstruments.com> wrote in message
news:V-KdnbZuApXQLl7RnZ2dnUVZ_qKdnZ2d@posted.toastnet...
>
> "Brenda Ann" <newsgroups@fullspectrumradio.org> wrote in message
> news:m6idndzQfMfjq1_RnZ2dnVY3go-dnZ2d@giganews.com...
>>
>>
>> "nucleus" <rose122550@yahoo.com> wrote in message
>> news:54849318-33dc-43b5-aabe-0a2c690cff86@k22g2000yqh.googlegroups.com...
>>> for those who are energy conscious, the energy consumption of these
>>> LCD TVs appear to be not only low but reversed:
>>>
>>> Sony Bravia 40 inch KDL-40EX401 --- 170 watts
>>> Sony Bravia 52 inch KDL-52EX701 --- 142 watts
>>>
>>> i recently looked at the tags on back of these sets at Sams.
>>
>> 401: Standby mode: 0.19 W
>> Shop mode: 146 W
>> Home mode: 110 W
>>
>> 701: Standby mode: 0.16 W
>> Home mode: 142 W
>>
>> Note: the 401 model is a standard LCD/Fluorescent backlight, while the
>> 701 model is an LCD/LED backlight, which is more efficient.
>>
>>
>
> That's BS, Where do you get it from Punk?
>

1) What is supposed to be BS? The specs come directly from the Sony website.
Also, it's a fact that LED backlights use ~40% less energy than fluorescent
backlights. Our Sharp Aquos uses only 85-100 watts depending upon scene
brightness.

2) Do you kiss your mother with that mouth?

== 2 of 3 ==
Date: Sun, Oct 24 2010 5:42 am
From: PeterD

On Sun, 24 Oct 2010 19:38:45 +0900, "Brenda Ann"
<newsgroups@fullspectrumradio.org> wrote:

>
>
>"John Fields" <jfields@austininstruments.com> wrote in message
>news:V-KdnbZuApXQLl7RnZ2dnUVZ_qKdnZ2d@posted.toastnet...
>>
>> "Brenda Ann" <newsgroups@fullspectrumradio.org> wrote in message
>> news:m6idndzQfMfjq1_RnZ2dnVY3go-dnZ2d@giganews.com...
>>>
>>>
>>> "nucleus" <rose122550@yahoo.com> wrote in message
>>> news:54849318-33dc-43b5-aabe-0a2c690cff86@k22g2000yqh.googlegroups.com...
>>>> for those who are energy conscious, the energy consumption of these
>>>> LCD TVs appear to be not only low but reversed:
>>>>
>>>> Sony Bravia 40 inch KDL-40EX401 --- 170 watts
>>>> Sony Bravia 52 inch KDL-52EX701 --- 142 watts
>>>>
>>>> i recently looked at the tags on back of these sets at Sams.
>>>
>>> 401: Standby mode: 0.19 W
>>> Shop mode: 146 W
>>> Home mode: 110 W
>>>
>>> 701: Standby mode: 0.16 W
>>> Home mode: 142 W
>>>
>>> Note: the 401 model is a standard LCD/Fluorescent backlight, while the
>>> 701 model is an LCD/LED backlight, which is more efficient.
>>>
>>>
>>
>> That's BS, Where do you get it from Punk?
>>
>
>1) What is supposed to be BS? The specs come directly from the Sony website.
>Also, it's a fact that LED backlights use ~40% less energy than fluorescent
>backlights. Our Sharp Aquos uses only 85-100 watts depending upon scene
>brightness.
>
>2) Do you kiss your mother with that mouth?

That response was from a person who is stalking John, not John
himself. However, now you've shown you don't have the ability to
understand that this kind of thing happens, and insulted someone who
would (if he were really replying) have given you good advice.

Learn how to inspect headers, learn that when you are insulted by
someone like that it is often the case that some nutcase is simply
impersonating him/her to get their rocks off. You succeeded in making
the jerk who's impersonating John feel good.

And just looking at numbers without carefully examining the underlying
technology won't answer your question.

== 3 of 3 ==
Date: Sun, Oct 24 2010 6:51 am
From: "Michael A. Terrell"

Brenda Ann wrote:
>
> "John Fields" <jfields@austininstruments.com> wrote in message
> news:V-KdnbZuApXQLl7RnZ2dnUVZ_qKdnZ2d@posted.toastnet...
> >
> > "Brenda Ann" <newsgroups@fullspectrumradio.org> wrote in message
> > news:m6idndzQfMfjq1_RnZ2dnVY3go-dnZ2d@giganews.com...
> >>
> >>
> >> "nucleus" <rose122550@yahoo.com> wrote in message
> >> news:54849318-33dc-43b5-aabe-0a2c690cff86@k22g2000yqh.googlegroups.com...
> >>> for those who are energy conscious, the energy consumption of these
> >>> LCD TVs appear to be not only low but reversed:
> >>>
> >>> Sony Bravia 40 inch KDL-40EX401 --- 170 watts
> >>> Sony Bravia 52 inch KDL-52EX701 --- 142 watts
> >>>
> >>> i recently looked at the tags on back of these sets at Sams.
> >>
> >> 401: Standby mode: 0.19 W
> >> Shop mode: 146 W
> >> Home mode: 110 W
> >>
> >> 701: Standby mode: 0.16 W
> >> Home mode: 142 W
> >>
> >> Note: the 401 model is a standard LCD/Fluorescent backlight, while the
> >> 701 model is an LCD/LED backlight, which is more efficient.
> >>
> >>
> >
> > That's BS, Where do you get it from Punk?
> >
>
> 1) What is supposed to be BS? The specs come directly from the Sony website.
> Also, it's a fact that LED backlights use ~40% less energy than fluorescent
> backlights. Our Sharp Aquos uses only 85-100 watts depending upon scene
> brightness.
>
> 2) Do you kiss your mother with that mouth?

Brenda, you are being trolled, and the troll is impersonating someone
from another electronics group. The real John Fields is a little rough
around the edges, but a good guy. This group isn't like RARP. There
are a lot of trolls on the sci.electronics.* newsgroups.

--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

==============================================================================
TOPIC: OT: Is this question too challenging for a BSEE graduate?
http://groups.google.com/group/sci.electronics.repair/t/31ba2b6a402a3720?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Oct 24 2010 4:07 am
From: "William Sommerwerck"

>> The principle is this... In a stable op-amp circuit, the
>> feedback forces the inverting and non-inverting inputs
>> /to have the same voltage/. The rest is trivial arithmetic.

> That statement is so significant, and so rarely understood...

Indeed. National Semiconductor used to have an on-line course in op-amp
circuit design, and this principle -- which should be the very first words
out of the instructor's mouth -- is nowhere stated. Shame on you, Bob, shame
on you.

In case the reason isn't obvious -- an ideal op-amp has infinite gain. If
there were /any/ voltage difference between the inverting and non-inverting
inputs, the op-amp's output would slam up against the positive or negative
rail.

In practice, an op-amp has finite gain (usually between 100K and 1000K).
This means the actual voltage difference has to be something other than
zero. But it's is still so close to zero that it can be ignored for the
purposes of analysis.

By the way, I cut my op-amp teeth nearly 40 years ago on the wonderful
Philbrick brook. One of the greatest pieces of technical writing ever (I
keep a copy for inspiration), and still a classic.

== 2 of 2 ==
Date: Sun, Oct 24 2010 5:43 am
From: RadioJ

On 10/24/2010 7:07 AM, William Sommerwerck wrote:
>>> The principle is this... In a stable op-amp circuit, the
>>> feedback forces the inverting and non-inverting inputs
>>> /to have the same voltage/. The rest is trivial arithmetic.
>
>> That statement is so significant, and so rarely understood...
>
> Indeed. National Semiconductor used to have an on-line course in op-amp
> circuit design, and this principle -- which should be the very first words
> out of the instructor's mouth -- is nowhere stated. Shame on you, Bob, shame
> on you.
>
> In case the reason isn't obvious -- an ideal op-amp has infinite gain. If
> there were /any/ voltage difference between the inverting and non-inverting
> inputs, the op-amp's output would slam up against the positive or negative
> rail.
>
> In practice, an op-amp has finite gain (usually between 100K and 1000K).
> This means the actual voltage difference has to be something other than
> zero. But it's is still so close to zero that it can be ignored for the
> purposes of analysis.
>
> By the way, I cut my op-amp teeth nearly 40 years ago on the wonderful
> Philbrick brook. One of the greatest pieces of technical writing ever (I
> keep a copy for inspiration), and still a classic.
>
>

That "inputs the same thing" is good to think about when you run into
integrators and differentiators too.... for the I the output is just
having to drive against the cap none too quickly to keep the inputs from
pulling away from each other while charging it. For D, the output gets
slammed trying to kept up with the quick input change on the cap going
from the input driving through the cap. My simple-minded way of thinking
of it anyhow.

==============================================================================
TOPIC: measuring ampermeter meter internal resistance
http://groups.google.com/group/sci.electronics.repair/t/27f050235cfa3de3?hl=en
==============================================================================

== 1 of 5 ==
Date: Sun, Oct 24 2010 5:37 am
From: PeterD

On Sat, 23 Oct 2010 22:14:42 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>On Sat, 23 Oct 2010 21:31:15 -0700, "John Fields"
><jfields@austininstruments.com> wrote:
>
>>No Stupid, that's not the way to ampmeter range to higher range. Why did
>>you call yourself Superpower Punk? You don't even know how to multiple the
>>power of your electronic? You see, I am a superdumb-ass and I am very
>>capable to multiple current as well as AmpMeter by 10X.
>>JF
>
>New York Makes Internet Impersonation a Crime
><http://www.hunton.com/files/tbl_s10News/FileUpload44/15889/new_york_internet_impersonation_privacy_alert.pdf>
>
>California Bans Malicious Online Impersonation
><http://www.pcworld.com/businesscenter/article/206469/california_bans_malicious_online_impersonation.html>
>
>etc...

Sadly those who do it, rarely care about laws or crime... What's funny
is that the poster is easily traceable. He should have used an
anymonous remailer like the others do. (Then he'd be blocked by our
filters!)

== 2 of 5 ==
Date: Sun, Oct 24 2010 6:49 am
From: John Fields

On Sat, 23 Oct 2010 22:14:42 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

---
Thanks for that, and now that I have Mr. I'm-not-all-that-bright's ISP
listed on the header he forged _and_ his real-world name and address
it shouldn't be long before he'll be thinking every little sound he
hears is the NYPD knocking on his door. :-)

---
JF

== 3 of 5 ==
Date: Sun, Oct 24 2010 7:00 am
From: Fred Abse

On Sat, 23 Oct 2010 21:31:15 -0700, someone calling himself "John Fields"
wrote:

> No Stupid, that's not the way to ampmeter range to higher range. Why did
> you call yourself Superpower Punk? You don't even know how to multiple the
> power of your electronic? You see, I am a superdumb-ass and I am very
> capable to multiple current as well as AmpMeter by 10X.

What a lousy impersonation.

The John Fields that we all know (and love?) writes grammatically.

--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)

== 4 of 5 ==
Date: Sun, Oct 24 2010 8:53 am
From: "Proteus"

"Fred Abse" <excretatauris@invalid.invalid> wrote in message
news:pan.2010.10.24.09.53.04.370083@invalid.invalid...
> On Sat, 23 Oct 2010 21:31:15 -0700, someone calling himself "John Fields"
> wrote:
>
>> No Stupid, that's not the way to ampmeter range to higher range. Why did
>> you call yourself Superpower Punk? You don't even know how to multiple
>> the
>> power of your electronic? You see, I am a superdumb-ass and I am very
>> capable to multiple current as well as AmpMeter by 10X.
>
>
> What a lousy impersonation.
>
> The John Fields that we all know (and love?) writes grammatically.
>
> --
> "For a successful technology, reality must take precedence
> over public relations, for nature cannot be fooled."
> (Richard Feynman)

YOU ARE MORE FUCK-UP ASSHOLE FREAK!

I AM PROTEUS

== 5 of 5 ==
Date: Sun, Oct 24 2010 8:56 am
From: "Proteus"

"PeterD" <peter2@hipson.net> wrote in message
news:02a8c6dnoh5tof2qh63nflu60s1hgd6j7e@4ax.com...
> On Sat, 23 Oct 2010 22:14:42 -0700, Jeff Liebermann <jeffl@cruzio.com>
> wrote:
>
>>On Sat, 23 Oct 2010 21:31:15 -0700, "John Fields"
>><jfields@austininstruments.com> wrote:
>>
>>>No Stupid, that's not the way to ampmeter range to higher range. Why did
>>>you call yourself Superpower Punk? You don't even know how to multiple
>>>the
>>>power of your electronic? You see, I am a superdumb-ass and I am very
>>>capable to multiple current as well as AmpMeter by 10X.
>>>JF
>>
>>New York Makes Internet Impersonation a Crime
>><http://www.hunton.com/files/tbl_s10News/FileUpload44/15889/new_york_internet_impersonation_privacy_alert.pdf>
>>
>>California Bans Malicious Online Impersonation
>><http://www.pcworld.com/businesscenter/article/206469/california_bans_malicious_online_impersonation.html>
>>
>>etc...
>
> Sadly those who do it, rarely care about laws or crime... What's funny
> is that the poster is easily traceable. He should have used an
> anymonous remailer like the others do. (Then he'd be blocked by our
> filters!)

PETERDUMB,
YOU SKUNKS KEPT FOLLOWING EACH OTHER TO SEWER. SOON THERE WON'T BE ANY
SKUNK LEFT, DON'T YOU KNOW FREAK?

YOU ARENT FOOLING ANYONE STUPID
YOU AND JOHNNY THERE SHOULD GIVE IT A GO
YOU ARE BOTH FREAKY FAGGOTY FOOLS

I AM PROTEUS

==============================================================================
TOPIC: See Kajal Hot Sexy star Sex Videos
http://groups.google.com/group/sci.electronics.repair/t/2a7a943083aafeb8?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Oct 24 2010 5:51 am
From: sukanya

See Kajal Hot Sexy star Sex Videos At http://goalvideos.co.cc

Due to High Sex Content i Have hidden the Videos in an
image. in that website on Right side Search box below click
on image and watch Videos In All Angles.

==============================================================================
TOPIC: Google AdWords $100 $75 $50 Promotional Vouchers Codes
http://groups.google.com/group/sci.electronics.repair/t/9a2768059a7ca9bb?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Oct 24 2010 6:43 am
From: tangama

Need Google AdWords Coupons $100,$75,$50 ......

Contact me at turnier76 @ gmail.com

Only @ Cheap Rates.

==============================================================================
TOPIC: Testing SMPS Video
http://groups.google.com/group/sci.electronics.repair/t/1cc72f0926af56cc?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Oct 24 2010 8:14 am
From: "Michael Kennedy"

Here is a video of this thing clicking while warming up and cooling off.

http://www.youtube.com/watch?v=ckW8XSZ7T4A

http://www.youtube.com/watch?v=urx3JrsxFmo

I have gone through this thing with my ESR meter and havent found any bad
caps. I changed some suspect caps because of their location near hot
resistors. To make things more difficult the inside of this tv is coated
with cigarrette tar... So some caps and things look blackened but in reality
its form smoke residue..

by the way thank you everyone who has made a suggestion on this. I am very
thankful everyone here is so supportive to amatures like myself..

==============================================================================
TOPIC: Vox AD30VT small combo, 2007, PbF
http://groups.google.com/group/sci.electronics.repair/t/d5851d8e1a65198c?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Oct 24 2010 8:14 am
From: Meat Plow

On Sun, 24 Oct 2010 01:48:02 +0100, Arfa Daily wrote:

> On 23/10/2010 16:37, Meat Plow wrote:
>> On Sat, 23 Oct 2010 02:11:15 +0100, Arfa Daily wrote:
>>
>>> "N_Cook"<diverse@tcp.co.uk> wrote in message
>>> news:i9s9fu$jr$1@news.eternal-september.org...
>>>> In the end it was duff PbF solder meeting 50 yearold technology, the
>>>> pcb-type pins of the valveholder. After redoing solder could simulate
>>>> the reported previous intermittant situation of half power and no
>>>> power by hovering a variously angled hot valve over the socket pins.
>>>> The 2 cathodes are tied to -15V , beyond that quite complex, traces
>>>> to njm2082 dual FET opamp and the DG211 an. sw. etc, certainly no
>>>> proper anode Vs
>>>>
>>>>
>>>>
>>> Do you have a schematic for it ? This Vox is pretty similar
>>>
>>> http://www.blueguitar.org/new/schem/misc_amp/vox_vr30reverb.pdf
>>>
>>> and also uses a 12AX7 with an anode supply of just 15v, and it does
>>> appear to be configured as a conventional genuine amplifier stage. I
>>> seem to recall Elektor magazine doing some stuff with ECC / 12AX
>>> series twin triodes. operating with low anode voltages.
>>>
>>> Arfa
>>
>> Don't they call that a starved cathode configuration?
>>
>>
>>
> Starved anode, I think.
>
> Arfa

Hmmm makes sense but there is another mode they run these effects units
in that utilize a 12AX7 called starved cathode. Unless I'm completely
mistaken.

--
Live Fast, Die Young and Leave a Pretty Corpse

==============================================================================
TOPIC: New iPod / iPhone OS version, and problems with battery rinsing again ..
.
http://groups.google.com/group/sci.electronics.repair/t/47e7affc05f8bb0f?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Oct 24 2010 8:43 am
From: "Arfa Daily"

If you install the new iOS4 revision 1 that has just come out, you might get
the problem with your battery getting rinsed from a full charge to dead flat
empty overnight again, the same as when the first version of iOS4 came out a
few months ago. Once again, the update seems to result in "Location
Services" ("settings" > "general" > "location services" > "ON" )
being set, which results in the wifi staying active continuously, instead of
sleeping when not in use. If you don't make use of location services, just
switch the feature off. This time, at least, your "Notifications" setting
doesn't appear to get over-ridden by the update, as it did on the last
update. Again, if you don't make use of this feature, keep it switched off,
as this can also result in unexpected battery useage.

Arfa

==============================================================================

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