From: krw on
On Sat, 16 Jan 2010 17:12:54 GMT, Jan Panteltje
<pNaonStpealmtje(a)yahoo.com> wrote:

>On a sunny day (Sat, 16 Jan 2010 12:02:26 -0500) it happened Spehro Pefhany
><speffSNIP(a)interlogDOTyou.knowwhat> wrote in
><g8s3l5lah5gm8n12mlrsnvj1eq0v6jfcef(a)4ax.com>:
>
>>On Sat, 16 Jan 2010 14:09:08 GMT, the renowned Jan Panteltje
>><pNaonStpealmtje(a)yahoo.com> wrote:
>>
>>>(Nico Coesel) wrote in <4b51bf27.575498125(a)news.planet.nl>:
>>>
>>>>Tantalums are very prone to failure.
>>>
>>>Not if you use them right
>>
>>Wot mostly consists of leaving them safely on the reel.

;-)

>Well, then they still may fail ;-)
>Just that you won't know about it.

s/know/care/

>But on the more serious side, I have never had one go kaput,

I certainly have. We have a huge fallout on 220uF 35V tantalums;
right off the reel. They're better than aluminums, though. The
aluminums didn't make it through the RoHS process. :-(

>I like them because of low ESR and small size.
>They do not dry out, some have been on for 20 years...

Some light bulbs have made it 50 years, others have cause somewhat
more problems.

>I have seen exploded ones cause damage in equipment, most likely because they were put in in reverse...
>I put one in (actually a whole series) in reverse myself one day, because the + was marked with a big --
>That came out when the first one was tested, and the resistor in series with it burned a hole in the PCB.
>That was supposed to be a fusible resistor, I have now learned that metal film resistors do not fuse very well.

That too. Even ones inserted the right direction tend to short,
taking out the series resistor. We're seeing a lot of charred
resistors next to those 220uF caps.

Many years ago, it we found that no matter what we did, 1% got
inserted backwards. ...even if the manufacturer had to put them in
the tube backwards to meet the target. ;-) The solution was a fuse
in the cap, non-polarized cases (+-+ or +--+ pinouts), or big/little
pin, though the latter still could be force fit.
From: Phil Hobbs on
On 1/15/2010 12:09 PM, John Larkin wrote:
> On Fri, 15 Jan 2010 11:21:55 -0500, WangoTango
> <Asgard24(a)mindspring.com> wrote:
>
>> In article<dwO3n.72802$IU1.46830(a)en-nntp-04.dc1.easynews.com>,
>> zapwireDASHgroups(a)yahoo.com says...
>>> "WangoTango"<Asgard24(a)mindspring.com> wrote in message
>>> news:MPG.25b96ab48fc5c5b698ae28(a)news.east.earthlink.net...
>>>> I've watched TV and not only do those guys instantly recognize
>>>> millennium old devices, they recognize millennium old ALIEN devices, and
>>>> they all invariably function.
>>>
>>> I've always been most impressed with how readily humans seem to be able to
>>> pick up on how to run, e.g., an entire alien spacecraft despite said aliens
>>> not speaking any known language, not necessarily resembling human
>>> physiologically (e.g., the wavelengths you use in displays is going to be
>>> tuned to the individual species), and of course so often coming from planets
>>> with gravities and atmospheres highly compatible with human life. :-)
>>>
>>>
>> Yeah, funny how they never 'beam' over to a 5G engineering room.
>> Or a 0G and float away.
>>
>> The problem with aliens is that they are alien.
>>
>
> The stupid TV shows just need villains to add drama. All the aliens
> that I've met were actually very nice.
>
> John
>

Speaking as a resident alien, most of the ones I know are OK in small
doses. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs at electrooptical dot net
http://electrooptical.net
From: Tim Williams on
They'll pretty well stay put. Diffusion is an exponential thing, so where
it's happening at say 800K, it's down by exp(800K/300K) = 14.4 times at room
temperature. Wait, that's not so impressive.

References.... ah, diffusion follows the Arrhenius equation, which puts it
in terms of exp(Eo/k_B*T), so the ratio between temperatures is
exp(-(Eo/k_B*T) * (1/T1 - 1/T2)). That requires knowing what the activation
energy is, though. Can't find it.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"Sylvia Else" <sylvia(a)not.at.this.address> wrote in message
news:00ff5f63$0$27810$c3e8da3(a)news.astraweb.com...
> John Larkin wrote:
>> On Fri, 15 Jan 2010 11:19:34 -0500, WangoTango
>> <Asgard24(a)mindspring.com> wrote:
>>
>>> In article <hio9k9$fsu$1(a)news.albasani.net>, pNaonStpealmtje(a)yahoo.com
>>> says...
>>>> On a sunny day (Thu, 14 Jan 2010 17:54:31 -0500) it happened WangoTango
>>>> <Asgard24(a)mindspring.com> wrote in
>>>> <MPG.25b96ab48fc5c5b698ae28(a)news.east.earthlink.net>:
>>>>
>>>>> In article <035f8778$0$1309$c3e8da3(a)news.astraweb.com>,
>>>>> adrian(a)qq.vv.net says...
>>>>>> Maybe you could ask how far in the future you have to go before your
>>>>>> 'device' becomes unrecognisable ?
>>>>> What are you talking about?
>>>>> I've watched TV and not only do those guys instantly recognize
>>>>> millennium old devices, they recognize millennium old ALIEN devices,
>>>>> and they all invariably function. I would be more interested in a
>>>>> power source that could just sit for that period of time and still be
>>>>> useable,
>>>>
>>>> Solar.
>>>>
>>> Really....do we know what a solar cell will do after 1000yrs of sitting?
>>
>> Good cells are fairly klunky monocrystalline silicon PN junctions.
>> They'd probably work fairly well after a million years if stored
>> properly.
>>
>
> This is where I wonder about difusion. Will those doping atoms stay put
> over those sorts of time scales, or would we end up with a piece of
> silicon pretty much equally doped throughout with both doping materials?
>
> Sylvia.


From: Michael A. Terrell on

Phil Hobbs wrote:
>
> On 1/15/2010 12:09 PM, John Larkin wrote:
> > On Fri, 15 Jan 2010 11:21:55 -0500, WangoTango
> > <Asgard24(a)mindspring.com> wrote:
> >
> >> In article<dwO3n.72802$IU1.46830(a)en-nntp-04.dc1.easynews.com>,
> >> zapwireDASHgroups(a)yahoo.com says...
> >>> "WangoTango"<Asgard24(a)mindspring.com> wrote in message
> >>> news:MPG.25b96ab48fc5c5b698ae28(a)news.east.earthlink.net...
> >>>> I've watched TV and not only do those guys instantly recognize
> >>>> millennium old devices, they recognize millennium old ALIEN devices, and
> >>>> they all invariably function.
> >>>
> >>> I've always been most impressed with how readily humans seem to be able to
> >>> pick up on how to run, e.g., an entire alien spacecraft despite said aliens
> >>> not speaking any known language, not necessarily resembling human
> >>> physiologically (e.g., the wavelengths you use in displays is going to be
> >>> tuned to the individual species), and of course so often coming from planets
> >>> with gravities and atmospheres highly compatible with human life. :-)
> >>>
> >>>
> >> Yeah, funny how they never 'beam' over to a 5G engineering room.
> >> Or a 0G and float away.
> >>
> >> The problem with aliens is that they are alien.
> >>
> >
> > The stupid TV shows just need villains to add drama. All the aliens
> > that I've met were actually very nice.
> >
> > John
> >
>
> Speaking as a resident alien, most of the ones I know are OK in small
> doses. ;)


How small of a dose, and is it contagious? ;-)


--
Greed is the root of all eBay.
From: JosephKK on
On Sat, 16 Jan 2010 08:05:00 -0500, "Michael A. Terrell" <mike.terrell(a)earthlink.net> wrote:

>
>JosephKK wrote:
>>
>> Indeed, consider the traps in ancient tombs.
>
>
> The original 'lint' traps? ;-)

I think they predated even 'lint' by quite a bit. ::))