sci.electronics.repair - 11 new messages in 4 topics - digest

sci.electronics.repair
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Today's topics:

* pretty girls hot videos&photos - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/bccdb535f86049e0?hl=en
* my love for you - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/c3eff2f203c3e1bf?hl=en
* 100v--> 10V Trans. on 120V - 3 messages, 3 authors
http://groups.google.com/group/sci.electronics.repair/t/c8528fdeff78820d?hl=en
* PSU voltage instability - 6 messages, 3 authors
http://groups.google.com/group/sci.electronics.repair/t/640c794886b1e24f?hl=en

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TOPIC: pretty girls hot videos&photos
http://groups.google.com/group/sci.electronics.repair/t/bccdb535f86049e0?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, Dec 4 2010 9:25 pm
From: SRAVANTHI LOVE

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

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TOPIC: my love for you
http://groups.google.com/group/sci.electronics.repair/t/c3eff2f203c3e1bf?hl=en
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== 1 of 1 ==
Date: Sat, Dec 4 2010 9:36 pm
From: sri priya

http://123maza.com/35/dream444/

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TOPIC: 100v--> 10V Trans. on 120V
http://groups.google.com/group/sci.electronics.repair/t/c8528fdeff78820d?hl=en
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== 1 of 3 ==
Date: Sat, Dec 4 2010 10:17 pm
From: David Nebenzahl

On 12/4/2010 8:56 PM Brenda Ann spake thus:

> "David Nebenzahl" wrote in message
> news:4cfb0fae$0$2419$822641b3@news.adtechcomputers.com...
>
>> I'm most intrigued, though, by that "100 V" rating. Is that written on
>> the outside? Because that's a nonstandard voltage, at least for the
>> parts of the world I'm familiar with. Where are you? What's the line
>> voltage where you live?
>>
>> Maybe it's just a "nominal" rating, like the 90-140 V or so that some
>> power supplies will handle. In any case, the advice that others have
>> given here, basically "don't sweat it, the device's regulation will take
>> care of things" is good.
>
> 100V is a standard voltage in Japan. What's really interesting about Japan
> is that they not only use 100/220V power, but also 50 AND 60 Hz line
> frequencies.

Butbutbut ... shouldn't that be 100/200 V? Usually the higher voltage is
double the lower one (two equal legs of the lower voltage). Here in
North American it's actually 120 & 240, at least nominally.

--
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/

== 2 of 3 ==
Date: Sat, Dec 4 2010 10:44 pm
From: "Geoffrey S. Mendelson"

David Nebenzahl wrote:
> Butbutbut ... shouldn't that be 100/200 V? Usually the higher voltage is
> double the lower one (two equal legs of the lower voltage). Here in
> North American it's actually 120 & 240, at least nominally.

Sorry I tuned in late, 100V is the standard line voltage in Japan.

I can't say what will happen to the device but it is an unregulated supply
it will put out 12 volts instead of 10, and get hot.

If that will damage the supply, or the device is hard to guess.

What I suggest to people who move here (Israel) from the US is to take the
supply to a good electronics store and they will sell you a replacememnt
that has the correct voltage, current supply and connector.

If that is not possible, and you can't get a local electronics person to
fit a proper supply (for example if the connector is unusual), then you
may want to go to a transformer manufacturer and make up a 120->100 volt
transformer. My guess is that a small one will cost $50-$75.

Here they are stock items (230-100) because due to the different power factor
(50Hz vs 60Hz line frequencyt) large motorized 120 volt appliances last longer
on 100v than 120.

Geoff.

--
Geoffrey S. Mendelson N3OWJ/4X1GM
Those who cannot remember the past are condemned to misquote it.

== 3 of 3 ==
Date: Sat, Dec 4 2010 10:52 pm
From: "Phil Allison"

"Geoffrey S. Mendelson" ..
>
> Sorry I tuned in late, 100V is the standard line voltage in Japan.
>
> I can't say what will happen to the device but it is an unregulated supply
> it will put out 12 volts instead of 10, and get hot.

** Read the whole thread - imbecile.

Because Japan uses 50 Hz, the tranny will not run any hotter at 120 volts
at 60 Hz.

> If that will damage the supply, or the device is hard to guess.

** Guessing is always easy - imbecile.

> What I suggest to people who move here (Israel) from the US is to take the
> supply to a good electronics store and they will sell you a replacememnt
> that has the correct voltage, current supply and connector.

** Japan uses the same AC sockets as the USA.

There is simply no issue.

.... Phil

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

== 1 of 6 ==
Date: Sat, Dec 4 2010 10:57 pm
From: "Phil Allison"

"Jeff Liebermann"

>
>>I tested it with a CD ROM drive
>>attached and noticed that the 12V rail gives me a lower voltage when
>>the CD tray is moving (11.79V against the usual 11.87V).
>>Could this be due to bad capacitors?
>
> 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 !!!

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.

The LINEARITY of most DMMs is of a very high order - 1 part in 1000 is
typical.

.... Phil

== 2 of 6 ==
Date: Sat, Dec 4 2010 11:18 pm
From: Jeff Liebermann

On Sun, 05 Dec 2010 04:28:25 GMT, nontelo@dico.no (Slater) wrote:

>Jeff Liebermann <jeffl@cruzio.com> wrote:
>
>>Right. All ATX power supplies are identical. Maker and model please?
>
>Maker: Whatsup
>Model: ATX-400W P4

Sorry. I've never heard of that brand. The part number is rather
generic but matches an iCute power supply, another brand with which
I'm not familiar.

>My concern is not how off the voltage is, it's the instability: is it
>normal? The voltage changes depending on the load. The PSU inside my
>PC doesnt do this.

The drop is fairly normal for a power supply going from no load to
about 1/2A load at 12v. A drop of 80mv is about what I would expect
across the Molex connectors. With a CDROM motor load, that's
R = E / I^2 = 0.08V / 0.5^2 = 0.32 ohms
internal resistance. That's within what I guess would be normal. Also
note that only the 5V and 3.3V lines are actually regulated. The 12V
line is not.

I'm not sure why your "other brand" of ATX supply does not show a
similar drop. It might be where you're measuring it with your
unspecified model DVM (my guess is Radio Shack or worse).

In any case, what you're testing is not very realistic. If you want
to test a power supply, use a real load, or a resistor dummy load that
simulates full rated load. If there's anything wrong with the power
supply, you'll either see it with your unspecified model test
equipment, or it will blow up the power supply. I've seen power
supplies rated at 300 watts, that will shut down or die at 200 watts
(or less).

If you think you have cheap junk or defective capacitors, they will
show a drop in output voltage somewhat before full load. That not
because the regulation fails. It's because they no longer act as a
filter and you'll start to see switching ripple on the output leads.
Insufficient filtering will do much the same thing. Attach an
oscilloscope to the output leads and you should see the noise level
increase dramatically with bad caps.

>>Some power supplies are junk.

>Perhaps mine is in that league!

I've never heard of a Whatsup power supply. Neither has Google. That
should offer a clue.

Grab a flashlight and look inside. If you see a crowded pile of
electrolytic filter capacitors near the output section, it's probably
a good design. If you see fairly small and few filter capacitors,
it's probably (cheap) junk.

Good:
<http://commons.wikimedia.org/wiki/File:ATX_power_supply_interior.jpg>
Plenty of output filtering.

Junk:
<http://i01.i.aliimg.com/photo/v0/364432581/computer_power_supply_ATX_12V_2_2.jpg>
Note the lack of enough output filter caps.

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

== 3 of 6 ==
Date: Sat, Dec 4 2010 11:20 pm
From: David Nebenzahl

On 12/4/2010 10:57 PM Phil Allison spake thus:

> "Jeff Liebermann"
>
>> [O.P. wrote:]
>>
>>> I tested it with a CD ROM drive attached and noticed that the 12V
>>> rail gives me a lower voltage when the CD tray is moving (11.79V
>>> against the usual 11.87V). Could this be due to bad capacitors?
>>
>> 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 !!!
>
> 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.
>
> The LINEARITY of most DMMs is of a very high order - 1 part in 1000 is
> typical.

Wellll ...

Isn't the correct answer here "don't worry about it"?

I mean, the O.P. is reporting a voltage drop of 80 mV. Compared to a
reference of 12 volts (nominal), that's ... lessee ... 0.67%. Much less
than any *rated* regulated variation of any computer power supply, right?

--
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/

== 4 of 6 ==
Date: Sat, Dec 4 2010 11:51 pm
From: Jeff Liebermann

On Sun, 5 Dec 2010 17:57:44 +1100, "Phil Allison" <phil_a@tpg.com.au>
wrote:

>"Jeff Liebermann"
>>
>>>I tested it with a CD ROM drive
>>>attached and noticed that the 12V rail gives me a lower voltage when
>>>the CD tray is moving (11.79V against the usual 11.87V).
>>>Could this be due to bad capacitors?
>>
>> 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.

Ummmm... ok. I'm impressed with your ability to read between the
lines, especially when there's nothing there to read.

>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.

The accuracy of the DVM's ability to measure 12.000000000 VDC is
dependent on the calibration. While he could measure the relative
voltage drop (80 mv) with considerable accuracy (as you noted), he
could not determine whether the output voltage is within the specified
5% ATX tolerance (11.4 to 12.6VDC) unless the meter were calibrated to
a tolerance much better than 5%. 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).

>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. At full scale, on the 20 VDC scale:
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). That's worst case and rather improbable for
the rather small 80 mv measurement difference.

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

== 5 of 6 ==
Date: Sun, Dec 5 2010 12:17 am
From: "Phil Allison"

"David Nebenzahl"
Phil Allison spake thus:
>
>> "Jeff Liebermann"
>>
>>> [O.P. wrote:]
>>>
>>>> I tested it with a CD ROM drive attached and noticed that the 12V
>>>> rail gives me a lower voltage when the CD tray is moving (11.79V
>>>> against the usual 11.87V). Could this be due to bad capacitors?
>>>
>>> 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 !!!
>>
>> 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.
>>
>> The LINEARITY of most DMMs is of a very high order - 1 part in 1000
>> is typical.
>
> Wellll ...
>
> Isn't the correct answer here "don't worry about it"?

** NO !!

The pig arrogant arsehole made a false point.

.... Phil

== 6 of 6 ==
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

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