sci.electronics.repair - 25 new messages in 9 topics - digest

sci.electronics.repair
http://groups.google.com/group/sci.electronics.repair?hl=en

sci.electronics.repair@googlegroups.com

Today's topics:

* PSU voltage instability - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/640c794886b1e24f?hl=en
* RAC Portable Power Station, need DC adaptor spec - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/b105b15b5ad9d933?hl=en
* american beer inferier? - 12 messages, 8 authors
http://groups.google.com/group/sci.electronics.repair/t/79cf21563e25cfa2?hl=en
* Confusing PbF inspection test appearance. - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/eed229ecc0ba2b0c?hl=en
* common problem with Dell PCs - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/47ad46d2aa2d5bf7?hl=en
* low cost thermocouple DAQ that works with ubuntu linux tia sal22 - 2
messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/6df4cca829179f26?hl=en
* sharp CD loader, tape and radio power problem - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/e0db2f844f71308e?hl=en
* FULLY HOT ENTERTAINMENT - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/a5fa0edc3faeaba3?hl=en
* Question for the group... - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/9de2c59f54ee9292?hl=en

==============================================================================
TOPIC: PSU voltage instability
http://groups.google.com/group/sci.electronics.repair/t/640c794886b1e24f?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Dec 5 2010 12:28 am
From: "Phil Allison"

"Jeff Liebermann is a FUCKING CUNT"

>> If you're getting 10mv accuracy with your DVM, you must have a decent
>>> way of calibrating your instrument to that resolution. 100mv accuracy
>>> is more reasonable.
>>
>>** How pedantic and idiotic !!!
>
> Pedantic
> -adjective
> 1. ostentatious in one's learning.
> 2. overly concerned with minute details or formalisms, esp. in
> teaching.

** More fucking, idotic pedantry.

Only thing this stinking POS is any good at.

> Ummmm... ok.

** Go fuck your mother.

>>The OP is only asking about the small DROP in voltage he measured under
>>load - which NOT dependant on calibration or accuracy of the meter.
>

( Snip more pedantic, fucking SHIT )

> The question was whether the power
> supply was defective, which in my opinion is more a matter of keeping
> the output voltage within the specifications (with any load).

** More pedantic BOLLOCKS.

>>The LINEARITY of most DMMs is of a very high order - 1 part in 1000 is
>>typical.
>
> Linearity is usually +/- 1 bit or LSB. If it's a 3 1/2 digit cheapo
> DVM, with a full scale reading of 1999, it probably has 10 bit A/D
> converter.

** ROTFLMAO !!!!!

Wot a FUCKING MORON.

Regular DMMS do not use conventional A-D converters.

They use "dual slope integration " - ie an analogue technique.

The "digital" bit is the fucking display.

IMBECILE !!!!!!!!!!!

> 1 bit error = 20.0 V / 2000 = +/- 10 mv error.
> For an 80 mv difference, there's a 40 mv uncertainty due to
> non-linearity (+/-10 mv error for the no-load, and another +/-10 mv
> for the loaded readings).

** Crapology.

The same meter is used and so the only error is the +/-1 bit display
uncertainty.

GO FUCK YOURSELF you STINKING PEDANT !!

.... Phil

==============================================================================
TOPIC: RAC Portable Power Station, need DC adaptor spec
http://groups.google.com/group/sci.electronics.repair/t/b105b15b5ad9d933?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Dec 5 2010 2:49 am
From: "Dave Plowman (News)"

In article <4cfb0d79$0$2411$822641b3@news.adtechcomputers.com>,
David Nebenzahl <nobody@but.us.chickens> wrote:
> I'm surprised nobody has mentioned this yet in this thread, but aren't
> those claims for how much current these things will deliver a lot of BS?

> I first saw one of these power units a couple weeks ago, when my
> neighbor used his to get my van started after he borrowed it and the
> battery started going dead. He used it twice, successfully, to
> jump-start my half-dead battery. So they do work, apparently. But his
> was similarly marked (I think 300 amps). Is there any way that such a
> small lead-acid battery could deliver this much juice? I'm skeptical.

They vary quite a bit in price. At the cheaper end I've found they will
deliver enough current (when new) to start a car with a flat battery - but
no more than a handful of times. No lead acid battery likes having what is
efficitively (at that size) a dead short across it. And as is common with
so many of these things the battery costs more to replace than the entire
unit.

The one I have is many years old. It won't deliver enough current to start
a car, but still is ok as a self contained compressor for the tyres. And
as a convenient portable 12 volt source for testing things - it will still
supply much more current than my bench PS. And only cost 20 quid...

--
*He loves nature in spite of what it did to him.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

== 2 of 2 ==
Date: Sun, Dec 5 2010 3:38 am
From: David Nebenzahl

On 12/5/2010 2:49 AM Dave Plowman (News) spake thus:

> In article <4cfb0d79$0$2411$822641b3@news.adtechcomputers.com>, David
> Nebenzahl <nobody@but.us.chickens> wrote:
>
>> I'm surprised nobody has mentioned this yet in this thread, but
>> aren't those claims for how much current these things will deliver
>> a lot of BS?
>
>> I first saw one of these power units a couple weeks ago, when my
>> neighbor used his to get my van started after he borrowed it and the
>> battery started going dead. He used it twice, successfully, to
>> jump-start my half-dead battery. So they do work, apparently. But his
>> was similarly marked (I think 300 amps). Is there any way that such a
>> small lead-acid battery could deliver this much juice? I'm skeptical.
>
> They vary quite a bit in price. At the cheaper end I've found they will
> deliver enough current (when new) to start a car with a flat battery - but
> no more than a handful of times.

So how much current do you think they're actually capable of
delivering--say with the little battery fairly fresh and fully charged?

--
How To Access Wikileaks

These sites are still up as of 12/3/10:

http://wikileaks.de
http://wikileaks.fi
http://wikileaks.nl
http://wikileaks.eu
http://wikileaks.pl

And these IP addresses can be used:

http://213.251.145.96/
http://88.80.13.160/

==============================================================================
TOPIC: american beer inferier?
http://groups.google.com/group/sci.electronics.repair/t/79cf21563e25cfa2?hl=en
==============================================================================

== 1 of 12 ==
Date: Sun, Dec 5 2010 3:58 am
From: Christopher Helms

On Dec 4, 7:03 pm, "(PeteCresswell)" <x...@y.Invalid> wrote:
> Per Peter Lucas (SAS RET):
>
> >What do Urine and american Beer have in common?
> >They both taste the same going in and comming out!!
>
> The German side of my family refers to our beer as "Pisswasser".
>
> Bad rap as far as I'm concerned bc the most noticeable fault of
> American beers like Bud and Coors is the *lack* of taste - piss
> or otherwise.

We Americans like our beer mediocre. At the end of Prohibition there
were something like 700 commercial breweries operating in the US.
Today if you don't count the micros, there are what? Three big
nationals? Anheuser Busch, Coors and Miller and they are owned by huge
conglomerates. There are a few medium sized regional brewers like
Linenkugel and Yuengling still around, but I don't know if they're
still independent or not. We Americans don't really do beer anymore.
Or anything else, for that matter.

== 2 of 12 ==
Date: Sun, Dec 5 2010 4:22 am
From: "N_Cook"

Christopher Helms <Chrishelms132@yahoo.com> wrote in message
news:21d7ea96-b70c-4294-bcc3-eef49ec8265b@m20g2000prc.googlegroups.com...
On Dec 4, 7:03 pm, "(PeteCresswell)" <x...@y.Invalid> wrote:
> Per Peter Lucas (SAS RET):
>
> >What do Urine and american Beer have in common?
> >They both taste the same going in and comming out!!
>
> The German side of my family refers to our beer as "Pisswasser".
>
> Bad rap as far as I'm concerned bc the most noticeable fault of
> American beers like Bud and Coors is the *lack* of taste - piss
> or otherwise.

&&&&&&

The beer in the Simpsons is Duff, is that a joke for the Brits or does the
word duff in the USA have the same meaning

== 3 of 12 ==
Date: Sun, Dec 5 2010 5:05 am
From: "William Sommerwerck"

> The beer in the Simpsons is Duff, is that a joke for
> the Brits or does the word duff in the USA have the
> same meaning?

To me, "duff" refers to the posterior.

== 4 of 12 ==
Date: Sun, Dec 5 2010 5:12 am
From: "William Sommerwerck"

> What do Urine and American Beer have in common?
> They both taste the same going in and comming out!!

You'd only know that if you drank urine, right?

== 5 of 12 ==
Date: Sun, Dec 5 2010 5:25 am
From: "William Sommerwerck"

I am, by the way, a teetotaler.

The story goes that American beers were once "better". But during WWII, they
were lightened to appeal more to females, who had become a larger percentage
of the drinking population (the males being away at war). No reversal to the
original taste occurred after the war.

Coors is certainly among the worst major brands. In my light-drinking days,
I tasted Coors and decided I'd rather drink plain water.

"Sam Adams" makes strong claims for the quality and character of their
beers. One of their light beers supposedly won a first prize in a German
contest where there was no light-beer category.

There is a "Discovery" series "Brewmasters", though the title should be
"Brewmaster", as the focus is on a single brewery, Dogfish Head, which makes
all sorts of beers that would never pass the German purity standards. (What
is this about Germans and purity, anyway?)

Dogfish Head is an odd company that doesn't seem to be paying attention to
simple common sense. In one episode they discover that a filler tube on one
machines has disappeared, presumably into a bottle. Not wanting to discard
the run, which would cost them thousands of dollars, they open the cases and
check the bottles one by one.

I was startled. Most food companies have a metal detector somewhere near the
end of the line to prevent such problems. (I might give them a call.)

== 6 of 12 ==
Date: Sun, Dec 5 2010 5:45 am
From: "N_Cook"

William Sommerwerck <grizzledgeezer@comcast.net> wrote in message
news:idg2ni$ea2$1@news.eternal-september.org...
> > The beer in the Simpsons is Duff, is that a joke for
> > the Brits or does the word duff in the USA have the
> > same meaning?
>
> To me, "duff" refers to the posterior.
>
>

In Britland it mainly means inferior as well as the posterior (perhaps more
usually here as a ladies front-bottom, to be twee. Strange the related
UK/USA useage of the word fanny)

== 7 of 12 ==
Date: Sun, Dec 5 2010 5:45 am
From: "Arfa Daily"

"Bryan" <bryangsimmons@gmail.com> wrote in message
news:94eeaf77-3647-498e-931c-e10eaf72634c@u25g2000pra.googlegroups.com...
> On Dec 4, 7:49 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
>> "(PeteCresswell)" <x...@y.Invalid> wrote in message
>>
>> news:4uolf6pu0l1dn1etpopdeduj12r052det9@4ax.com...
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> > Per Peter Lucas (SAS RET):
>> >>What do Urine and american Beer have in common?
>> >>They both taste the same going in and comming out!!
>>
>> > The German side of my family refers to our beer as "Pisswasser".
>>
>> > Bad rap as far as I'm concerned bc the most noticeable fault of
>> > American beers like Bud and Coors is the *lack* of taste - piss
>> > or otherwise.
>>
>> > There are, IMHO, some enjoyable American beers. But they're
>> > smaller brands - some of which are even claimed thb brewed in
>> > accordance with the old German "Purity Law" - as in
>> >http://en.wikipedia.org/wiki/Reinheitsgebot
>> > --
>> > PeteCresswell
>>
>> I rather like to drink Michelob when I'm stateside, but do I recall
>> someone
>> telling me that's actually a Canadian beer ?
>
> No. It's as American as it gets. For commercial, watery, fairly
> tasteless beer, it's the best of the bunch. It's great for canoeing/
> kayaking because you can get it in cans.
>>
>> Arfa
>
> --Bryan

There seems to be a big difference between Michelob on tap and in bottles
from what I've seen. A few years back, when you asked for a Mich in a
restaurant, that's what you got. It was about on a par with some of the
'better' lagers here in the UK. Now, it seems that you get a Mich Ultra by
default. Is that actually the only one from them in a bottle now? I don't
get over there often enough to really know. I found the Ultra a bit of an
'acquired taste'. It certainly tastes a lot weaker than other versions that
I had previously drunk, but doesn't actually seem to be. It is a lot less
'rounded' in taste - a bit thin and 'crisp' - but never-the-less, quite a
pleasant refreshing drink with a meal. Once you've let it warm up just a bit
from the almost-frozen state that it gets delivered to your table in, that
is ... For plain old 'throwing a few beers down your throat' it's hard to
beat good old Bud. Just about strong enough to qualify, and quite a pleasant
taste. Bit gassy, but tolerable. Do you get Stella Artois over there ? Or
Kronenbourg 1662? They are nice tasty lager beers.

Arfa

== 8 of 12 ==
Date: Sun, Dec 5 2010 6:39 am
From: Bryan

On Dec 5, 7:45 am, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
> "Bryan" <bryangsimm...@gmail.com> wrote in message
>
> news:94eeaf77-3647-498e-931c-e10eaf72634c@u25g2000pra.googlegroups.com...
>
>
>
> > On Dec 4, 7:49 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
> >> "(PeteCresswell)" <x...@y.Invalid> wrote in message
>
> >>news:4uolf6pu0l1dn1etpopdeduj12r052det9@4ax.com...
>
> >> > Per Peter Lucas (SAS RET):
> >> >>What do Urine and american Beer have in common?
> >> >>They both taste the same going in and comming out!!
>
> >> > The German side of my family refers to our beer as "Pisswasser".
>
> >> > Bad rap as far as I'm concerned bc the most noticeable fault of
> >> > American beers like Bud and Coors is the *lack* of taste - piss
> >> > or otherwise.
>
> >> > There are, IMHO, some enjoyable American beers. But they're
> >> > smaller brands - some of which are even claimed thb brewed in
> >> > accordance with the old German "Purity Law" - as in
> >> >http://en.wikipedia.org/wiki/Reinheitsgebot
> >> > --
> >> > PeteCresswell
>
> >> I rather like to drink Michelob when I'm stateside, but do I recall
> >> someone
> >> telling me that's actually a Canadian beer ?
>
> > No. It's as American as it gets. For commercial, watery, fairly
> > tasteless beer, it's the best of the bunch. It's great for canoeing/
> > kayaking because you can get it in cans.
>
> >> Arfa
>
> > --Bryan
>
> There seems to be a big difference between Michelob on tap and in bottles
> from what I've seen. A few years back, when you asked for a Mich in a
> restaurant, that's what you got. It was about on a par with some of the
> 'better' lagers here in the UK. Now, it seems that you get a Mich Ultra by
> default. Is that actually the only one from them in a bottle now?

Regular Mich and Mich Light are in bottles too.

> I don't get over there often enough to really know. I found the Ultra a bit of an
> 'acquired taste'. It certainly tastes a lot weaker than other versions that
> I had previously drunk, but doesn't actually seem to be. It is a lot less
> 'rounded' in taste - a bit thin and 'crisp' - but never-the-less, quite a
> pleasant refreshing drink with a meal. Once you've let it warm up just a bit
> from the almost-frozen state that it gets delivered to your table in, that
> is ...

It should only be drunk at <35F. Mich Ultra is mostly just water,
ethanol and CO2.
You can mix one 12 oz bottle of Ultra with 4 oz of Guiness Extra Sout
to get a decent pint without a lot of carbs.

> For plain old 'throwing a few beers down your throat' it's hard to
> beat good old Bud.

I'm from St. Louis (the home of Bud), and I don't drink the stuff.

> Just about strong enough to qualify, and quite a pleasant
> taste. Bit gassy, but tolerable. Do you get Stella Artois over there ? Or
> Kronenbourg 1662? They are nice tasty lager beers.

You can have my share of the Stella. Next time you're here, order a
Sierra Nevada Pale Ale, or some other beer called American pale ale.
>
> Arfa

--Bryan

== 9 of 12 ==
Date: Sun, Dec 5 2010 7:07 am
From: "(PeteCresswell)"

Per William Sommerwerck:
> (What
>is this about Germans and purity, anyway?)
http://en.wikipedia.org/wiki/Reinheitsgebot
--
PeteCresswell

== 10 of 12 ==
Date: Sun, Dec 5 2010 7:10 am
From: Rich Webb

On Sun, 5 Dec 2010 06:39:38 -0800 (PST), Bryan <bryangsimmons@gmail.com>
wrote:

>You can have my share of the Stella. Next time you're here, order a
>Sierra Nevada Pale Ale, or some other beer called American pale ale.

Indeed, all praise to Nin-Kasi for Sierra Nevada! They also brewed this
year's annual run of Celebration ale from wet hops, a pleasant surprise.

http://beeradvocate.com/articles/304

--
Rich Webb Norfolk, VA

== 11 of 12 ==
Date: Sun, Dec 5 2010 8:28 am
From: spamtrap1888

On Dec 4, 5:49 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
> "(PeteCresswell)" <x...@y.Invalid> wrote in message
>
> news:4uolf6pu0l1dn1etpopdeduj12r052det9@4ax.com...
>
>
>
> > Per Peter Lucas (SAS RET):
> >>What do Urine and american Beer have in common?
> >>They both taste the same going in and comming out!!
>
> > The German side of my family refers to our beer as "Pisswasser".
>
> > Bad rap as far as I'm concerned bc the most noticeable fault of
> > American beers like Bud and Coors is the *lack* of taste - piss
> > or otherwise.
>
> > There are, IMHO, some enjoyable American beers. But they're
> > smaller brands - some of which are even claimed thb brewed in
> > accordance with the old German "Purity Law" - as in
> >http://en.wikipedia.org/wiki/Reinheitsgebot

>
> I rather like to drink Michelob when I'm stateside, but do I recall someone
> telling me that's actually a Canadian beer ?
>

Canadian breweries have been making American brands for year,
apparently cross-border TV ads have stimulated demand for "The Silver
Bullet" etc. Then you have the strange case of Minhas Craft Brewery:
The former Huber Brewery of Wisconsin was bought out by immigrants to
Canada, who benefit from NAFTA by brewing beers there for the Canadian
market. Minhas also makes beer for Trader Joe's -- $3 for a sixpack of
cans.

TJ's used to carry Huber products back in the day.

== 12 of 12 ==
Date: Sun, Dec 5 2010 8:29 am
From: spamtrap1888

On Dec 5, 5:45 am, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
> "Bryan" <bryangsimm...@gmail.com> wrote in message
>
> news:94eeaf77-3647-498e-931c-e10eaf72634c@u25g2000pra.googlegroups.com...
>
>
>
> > On Dec 4, 7:49 pm, "Arfa Daily" <arfa.da...@ntlworld.com> wrote:
> >> "(PeteCresswell)" <x...@y.Invalid> wrote in message
>
> >>news:4uolf6pu0l1dn1etpopdeduj12r052det9@4ax.com...
>
> >> > Per Peter Lucas (SAS RET):
> >> >>What do Urine and american Beer have in common?
> >> >>They both taste the same going in and comming out!!
>
> >> > The German side of my family refers to our beer as "Pisswasser".
>
> >> > Bad rap as far as I'm concerned bc the most noticeable fault of
> >> > American beers like Bud and Coors is the *lack* of taste - piss
> >> > or otherwise.
>
> >> > There are, IMHO, some enjoyable American beers. But they're
> >> > smaller brands - some of which are even claimed thb brewed in
> >> > accordance with the old German "Purity Law" - as in
> >> >http://en.wikipedia.org/wiki/Reinheitsgebot
> >> > --
> >> > PeteCresswell
>
> >> I rather like to drink Michelob when I'm stateside, but do I recall
> >> someone
> >> telling me that's actually a Canadian beer ?
>
> > No. It's as American as it gets. For commercial, watery, fairly
> > tasteless beer, it's the best of the bunch. It's great for canoeing/
> > kayaking because you can get it in cans.
>
> >> Arfa
>
> > --Bryan
>
> There seems to be a big difference between Michelob on tap and in bottles
> from what I've seen. A few years back, when you asked for a Mich in a
> restaurant, that's what you got. It was about on a par with some of the
> 'better' lagers here in the UK. Now, it seems that you get a Mich Ultra by
> default. Is that actually the only one from them in a bottle now? I don't
> get over there often enough to really know. I found the Ultra a bit of an
> 'acquired taste'. It certainly tastes a lot weaker than other versions that
> I had previously drunk, but doesn't actually seem to be. It is a lot less
> 'rounded' in taste - a bit thin and 'crisp' - but never-the-less, quite a
> pleasant refreshing drink with a meal. Once you've let it warm up just a bit
> from the almost-frozen state that it gets delivered to your table in, that
> is ... For plain old 'throwing a few beers down your throat' it's hard to
> beat good old Bud. Just about strong enough to qualify, and quite a pleasant
> taste. Bit gassy, but tolerable. Do you get Stella Artois over there ? Or
> Kronenbourg 1662? They are nice tasty lager beers.

I can't taste the difference between Stella and Coors.

==============================================================================
TOPIC: Confusing PbF inspection test appearance.
http://groups.google.com/group/sci.electronics.repair/t/eed229ecc0ba2b0c?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Dec 5 2010 4:20 am
From: "N_Cook"

Anyone else come across this PbF situation?
With pbf solder joints on green finish pcb
and viewing pins for solder problems under x30 microscope.
Perhaps an optical effect from the curvature of the solder blobs
being concave rather than convex. Makes
it appear as though there are green rings around the pins as though failed
solder and you can see the underlying board through a solder ring-crack.
As viewing pin end on it is all a bit iffy.
To convince yourself it is an optical effect , surround the pin ,covering
the green board
with sticky paper labels of another colour and this green ring turns to the
colour of the paper

==============================================================================
TOPIC: common problem with Dell PCs
http://groups.google.com/group/sci.electronics.repair/t/47ad46d2aa2d5bf7?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Dec 5 2010 4:23 am
From: "fynnashba@yahoo.com"

I have noticed a problem with Dell PCs but b4 I advice my boss I want
to be sure.
Almost all our Dell machines (both optiplex 240 and 270) 22 out of 28
machines are all having problem with the primary IDE. After trying to
use the secondary IDE it also could not be detected.
at startup the screen will say primary, secondary IDE not found or
something like that. For one machine the CD ROM drive was detected but
when it was unplugged and plugged later the machine could not detect
it again. Is there a way round it?
We've had this problem b4 all effort to repair them failed so they
were discarded.
I don't want to jump into conclusion as a company's name is at
stake.
Thanks.

== 2 of 2 ==
Date: Sun, Dec 5 2010 6:47 am
From: Baron

fynnashba@yahoo.com Inscribed thus:

> I have noticed a problem with Dell PCs but b4 I advice my boss I want
> to be sure.
> Almost all our Dell machines (both optiplex 240 and 270) 22 out of 28
> machines are all having problem with the primary IDE. After trying to
> use the secondary IDE it also could not be detected.
> at startup the screen will say primary, secondary IDE not found or
> something like that. For one machine the CD ROM drive was detected but
> when it was unplugged and plugged later the machine could not detect
> it again. Is there a way round it?
> We've had this problem b4 all effort to repair them failed so they
> were discarded.
> I don't want to jump into conclusion as a company's name is at
> stake.
> Thanks.

Check out "Bad Caps"...

--
Best Regards:
Baron.

==============================================================================
TOPIC: low cost thermocouple DAQ that works with ubuntu linux tia sal22
http://groups.google.com/group/sci.electronics.repair/t/6df4cca829179f26?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Dec 5 2010 4:39 am
From: I AM THAT I AM

On Sat, 04 Dec 2010 22:47:12 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>I AM THAT I AM wrote:
>> On Sat, 04 Dec 2010 14:06:43 -0500, Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> I AM THAT I AM wrote:
>>>> On Wed, 01 Dec 2010 20:24:09 -0500, Phil Hobbs
>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>>
>>>>> Bob Masta wrote:
>>>>>> On Tue, 30 Nov 2010 13:11:18 -0500, Phil Hobbs
>>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>>>>
>>>>>>> Glen Walpert wrote:
>>>>>>>> On Mon, 29 Nov 2010 16:36:56 +0000, ratullloch_delthis wrote:
>>>>>>>>
>>>>>>>>> Greetings All
>>>>>>>>>
>>>>>>>>> I'm looking for a recommendation for a low cost thermocouple DAQ that
>>>>>>>>> works with ubuntu linux. Can someone recommend one. I'm trying to
>>>>>>>>> record temperture measurements over time. tia sal22
>>>>>>>>
>>>>>>>> http://www.mccdaq.com/daq-software/Linux-Support.aspx
>>>>>>>>
>>>>>>>> Single channel thermocouple to USB with linux support $99, multiple
>>>>>>>> channels more $.
>>>>>>>
>>>>>>> Thermocouples are really really horrible temperature sensors--almost as
>>>>>>> bad as ICs. Their advantages are small size, relatively low cost, and
>>>>>>> (potentially) high speed, but their disadvantage is that it's really
>>>>>>> hard to get good measurements.
>>>>>>>
>>>>>>> One reason for this is thermal conduction down the leads (which is a big
>>>>>>> problem for most temperature sensors). There's a worse one, though:
>>>>>>> due to their very low sensitivity, thermocouples are extremely
>>>>>>> vulnerable to errors caused by offset drift in the circuitry. See
>>>>>>> Figure 20.3 on P. 803 at http://electrooptical.net/www/book/draftthermal.pdf
>>>>>>
>>>>>> Not to mention that they involve a reference junction for
>>>>>> which you must know the temperature. Unless you have an ice
>>>>>> bath handy, this involves an independent non-thermocouple
>>>>>> sensor like a thermistor, diode, or IC. So just use that
>>>>>> instead! (Unless you need really high temperatures.)
>>>>>>
>>>>>> One good thing about TCs is that they don't need typically
>>>>>> calibration... they are supposed to conform to a standard
>>>>>> for the TC type (J, K, R, S etc). You just measure the
>>>>>> output voltage, correct for the reference junction
>>>>>> temperature, and look up the temperature for that voltage.
>>>>>> Accuracy is typically +/-2 degrees C. But the voltages are
>>>>>> really small: 1 mv or less at room temperature (0.10 mV
>>>>>> for R or S types).
>>>>>>
>>>>>> I'd say, save the thermocouples for the really hot stuff.
>>>>>> For "normal" temperatures (say, freezing to boiling water
>>>>>> ranges), you can get much better precision and accuracy, not
>>>>>> to mention convenience, from an IC.
>>>>>
>>>>> If all you need is a degree or two's accuracy near room temperature,
>>>>> almost any method will work. IC temperature sensors are generally
>>>>> fairly putrid--slow, inaccurate, and noisy.
>>>>>
>>>>> Cheers
>>>>>
>>>>> Phil Hobbs
>>>>
>>>>
>>>> Resistor bolometer 2 mm sq, 2 mm behind probably a Ge window (in a
>>>> little to-39 pkg) at whatever needed distance behind a half inch diameter
>>>> plastic Fresnel lens with some nice read circuitry and LCD display with
>>>> read and hold mode, etc., and a little laser focal point spotter.
>>>>
>>>> Pretty damned good accuracy from every test I could put it through,
>>>> from new batteries, all the way down to both cells being dead... the
>>>> damned thing reads. (obviously the data cell is not completely dead at
>>>> that point)
>>>>
>>>> $20 at Harbor Freight.
>>>>
>>>> http://www.harborfreight.com/infrared-thermometer-93984.html
>>>
>>> Some of those things are pretty useful--microbolometers have come a
>>> really long way. Consistency is not the same as accuracy, though, and
>>> all sensors relying on radiation are (a) vulnerable to emissivity
>>> variations, and (2) slow, at least compared to an RTD or thermistor (or
>>> thermocouple).
>>>
>>> Temperature control lives and dies by loop bandwidth, just like every
>>> other control system. Slow sensors ==> poor control. Inaccurate
>>> sensors ==>poor control. Fast, accurate sensors plus intelligent sensor
>>> placement, insulation to reduce thermal forcing, thermal grounding of
>>> leads, .... ==>good control.
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>>
>> IR sensors are faster, and that includes a bolometer. There is zero
>> settling time, and emissivity will not be a factor, because just like
>> your sensor, this would be "placed" the same every time. Accuracy is
>> dead on, if it was calibrated right in the first place as the circuitry
>> is usually VERY linear and very accurate if any linearization corrections
>> are needed, they are usually hard wired in. I'll bet that it even has
>> ambient compensation built into a single custom MCU/do-it-all chip.
>> Things we had to engineer in with discreet components back when the
>> finished product was $500.
>>
>> Well, it was precision lab instrumentation outputs. All the Harbor
>> Freight item has is a readout.
>>
>> I'll bet that it can be relied on to plus or minus 0.3 degrees though.
>>
>> They range from about 1.5 us to about half a second in response time.
>>
>> It probably takes a typical TC junction a tenth of a second to settle
>> through with a 'bead' size of about .75 to 1 mm.
>
>
>0.3 degrees is nowhere near close enough for instruments.

I never said that it was. I am talking about the device I posted a
link to. The devices I used to make, twenty years ago were far more
accurate than that, so they have gotten even better since. That has
nothing to do with this cheap cen-tech device for consumer use.

> For
>industrial control, that would often be just fine.

Usually not.

> However, you
>massively underestimate the contribution of emissivity error.

Not at all. All the operator need to do is make the needed
compensations for his readings. Again it comes down to operator
understanding.

So IF you had said it is very easy to forget about emissivity, you
might be closer to being right. Instead you make a blanket claim that I
do not know about emissivity, which is untrue.
>
>Radiation coupling is very poor at room temperature--a vacuum gap
>between two surfaces of unit emissivity is equivalent to the thermal
>conductivity of about 5 mm of air. (I once had occasion to calculate
>that for a sensor design.) That means that the same sensor in intimate
>contact with the given surface would be at least an order of magnitude
>faster, and probably two orders.

That is silly. IR is instant. it travels at light speed. The
thermocouple has to soak up the temperature it is sensing, and it has to
settle in at that temperature. That takes time because metal does not
conduct heat through itself instantaneously. The IR device gives an
accurate reading within milliseconds of viewing the target.

IR and the air gap between it and what it reads has no such restriction
because the air AND the bolometer do NOT need to be brought up to the
test temperature.
>
>Optical pyrometry also doesn't work too well through insulation. ;)
>
Another KNOWN factor. However, my cheap device still tells me the wall
temp of my room from 12 feet away just as well as it does from an inch
away. It works fine.

== 2 of 2 ==
Date: Sun, Dec 5 2010 7:56 am
From: Jan Panteltje

On a sunny day (Sat, 04 Dec 2010 14:09:56 -0500) it happened Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote in
<zOidnYccaPqbD2fRnZ2dnUVZ_t2dnZ2d@supernews.com>:

>Jan Panteltje wrote:
>> On a sunny day (Sat, 04 Dec 2010 12:32:34 -0500) it happened Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote in
>> <1L2dncQWso2o5mfRnZ2dnUVZ_omdnZ2d@supernews.com>:
>>
>>> signal. If you rip an electret mic apart, you'll find that it is
>>> metallized on both sides, and the signal is taken between the plates.
>>>
>>> It really isn't a capacitance microphone, although its audio
>>> characteristics are somewhat similar. The plates don't move together,
>>> and there's no net field anyway, even if they did. The physics is the
>>> change in the electric polarization due to strain in the material--i.e.
>>> a poled piezoelectric.
>>
>> <Snipped PhD confusion>
>>
>> I do not think that is correct.
>> http://en.wikipedia.org/wiki/Electret_microphone
>> Scroll to the bottom, there are 3 types of electret mikes described.
>> The second one described has the electret film fitted to the backplate, where it does *NOT MOVE AT ALL*.
>> The third one has the film on the inside front cover where it does *NOT MOVE EITHER*.
>> That sort of nullifies your argument about strain, except on your mind of course.
>>
>>
>> <insert clue here>
>>
>>
>
>We're now in violent agreement, I see.

Oh no.

>I didn't mean "move in the same
>way", but "move closer together", i.e. the spacing doesn't change, so it
>can't be a capacitance mic. Clumsily put, admittedly, but the rest of
>the argument should have removed the ambiguity. Electret mics are not
>capacitance mics.

It all depends, apart from the issues of ego and losing face,
for a man it is better to admit he is wrong, simply, at times, a pussy will blow
smoke and go side-paths.
You show how much you know about piezo, but this was about electrostatics.
Apples and oranges.

Let's look a bit closer.

If you take 'capacitor mike' literally, as one MIGHT do,
then neither the capacitor mike, nor the electret mike, really uses the CAPACITANCE.
One could make a 'capacitor mike' by making a tuned circuit (LC) oscillator, and have one fixed and one moving membrane
form a capacitor, and the frequency would change under influence of the capacitance,
so under the influence of the membrane moving, so under the influence of air pressure changes, say audible sound
if it is in the air pressure changes occur in the right frequency range.
There is a square in there somewhere, so it would not be all that linear over a large movement.
Once could use a FM radio to detect this if the circuit was made to oscillate in the FM band.
Maybe the correct word here is 'parametric'.

Then there is the real 'capacitor mike' as we call it, and that is actually an 'electrostatic mike',
http://en.wikipedia.org/wiki/Microphone
where something moves RELATIVE TO (old Einstein ;-) something else, where one of the objects carries a charge.
This is the SAME in the 'capacitor mike' and the 'electret mike'.

The difference is that the capacitor mike needs an external supply for the voltage,
and the electret uses a polarised film, so needs no external supply, simpler, cheaper, better,
no hum, no filtering problems.

So for all practical purposes, and all theoretical purposes, we can compare a 'capacitor mike'
with an 'electret mike', as both use exactly the same mechanism.
Thank you for your attention and have a nice day.

PS
There are also electrostatic speakers, Quad comes to mind as a manufacturer.
Very much HiFi.
I have even listened to electrostatic headphones.

El Pante

==============================================================================
TOPIC: sharp CD loader, tape and radio power problem
http://groups.google.com/group/sci.electronics.repair/t/e0db2f844f71308e?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Dec 5 2010 4:47 am
From: "fynnashba@yahoo.com"

a friend of mine plugged his Sharp SD-GX2-s 110 volts AC into 220
volts. The small standby transformer blew, 2 other diodes also went
bad. I detected and changed the transformer and the diodes. after
switching on the power came but quickly the relay cut out with this
message on the screen (b4 going off) Er MDRO .
subsequent check shows a short zener diode the number on the board is
D903. Identifying the part number on the diode is a problem. it reads
something like 1N141.48 or 1N1418. I have cross check in a data book
but no help.
I would be v. glad if someone can help. Thanks

== 2 of 2 ==
Date: Sun, Dec 5 2010 8:34 am
From: Sjouke Burry

fynnashba@yahoo.com wrote:
> a friend of mine plugged his Sharp SD-GX2-s 110 volts AC into 220
> volts. The small standby transformer blew, 2 other diodes also went
> bad. I detected and changed the transformer and the diodes. after
> switching on the power came but quickly the relay cut out with this
> message on the screen (b4 going off) Er MDRO .
> subsequent check shows a short zener diode the number on the board is
> D903. Identifying the part number on the diode is a problem. it reads
> something like 1N141.48 or 1N1418. I have cross check in a data book
> but no help.
> I would be v. glad if someone can help. Thanks
For a test, just remove the zener.
Protection zeners often fail shorted.
As long as yo plug into the right mains voltage,
you can do without the diode during test.
If everything works, measure the voltage, and solder in a zener
of 2-4 volts higher.

==============================================================================
TOPIC: FULLY HOT ENTERTAINMENT
http://groups.google.com/group/sci.electronics.repair/t/a5fa0edc3faeaba3?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, Dec 5 2010 5:00 am
From: SAILAJA LOVES U

http://karomasti9.blogspot.com/search/label/bipasa
http://karomasti9.blogspot.com/search/label/thrisha
http://karomasti9.blogspot.com/search/label/srisha
http://karomasti9.blogspot.com/search/label/poonam

==============================================================================
TOPIC: Question for the group...
http://groups.google.com/group/sci.electronics.repair/t/9de2c59f54ee9292?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, Dec 5 2010 6:54 am
From: "Dave"

Am working on a waffle iron that doesn't register when power is applied,
suspecting the solid state relay on the control boad. Question is, who is
it that has their logo looking like an R with a backwards J up against it?
Once knew, now can't remember. Would appreiate any help. Part number is
JH3001, if that helps.

Thanks much,

Dave

== 2 of 2 ==
Date: Sun, Dec 5 2010 7:52 am
From: "Gareth Magennis"

"Dave" <db5151@hotmail.com> wrote in message
news:-8ednfAI0JghOmbRnZ2dnUVZ_sCdnZ2d@posted.internetamerica...
> Am working on a waffle iron that doesn't register when power is applied,
> suspecting the solid state relay on the control boad. Question is, who is
> it that has their logo looking like an R with a backwards J up against it?
> Once knew, now can't remember. Would appreiate any help. Part number is
> JH3001, if that helps.
>
> Thanks much,
>
> Dave
>
>

Isn't that some kind of Standards or safety logo? A bit like the CE one?

Not a manufacturer I think.

Gareth.

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