On 12/10/2014 4:51 AM, andy pugh wrote:
> On 10 December 2014 at 03:11, Dave Cole wrote:
>
>> Did you check Ebay for Acopian power supplies in the UK?
> I did, but there were none of the right spec.
>
>> 300 pounds is not cheap but amortized over 25 years it seems a lot more
>> reasonable.
> True,
On 10 December 2014 at 03:11, Dave Cole wrote:
> Did you check Ebay for Acopian power supplies in the UK?
I did, but there were none of the right spec.
> 300 pounds is not cheap but amortized over 25 years it seems a lot more
> reasonable.
True, but a transformer and a pair of rectifiers has m
On 12/9/2014 1:46 PM, andy pugh wrote:
> On 3 December 2014 at 15:46, Dave Cole wrote:
>> If you want a power supply that you can install, power up and have a
>> fair expectation of it lasting 25+ years I would go with an Acopian
>> linear power supply.
> I have had a chat with them, and it looks
On 9 December 2014 at 19:49, andy pugh wrote:
> On 9 December 2014 at 19:18, Peter C. Wallace wrote:
>
>> What about no cap? The time constant of the solenoid may be sufficient
>> to filter the 100 Hz ripple,
> It's an easy experiment.
It seems to work very well.
I am now looking at these for t
On 9 December 2014 at 19:18, Peter C. Wallace wrote:
> What about no cap? The time constant of the solenoid may be sufficient
> to filter the 100 Hz ripple, and if not, a series inductor could be added
I measured the rise-time of the solenoid current at 25mS, so that
might actually work.
It's a
On Tue, 9 Dec 2014, andy pugh wrote:
Date: Tue, 9 Dec 2014 18:46:19 +
From: andy pugh
Reply-To: "Enhanced Machine Controller (EMC)"
To: "Enhanced Machine Controller (EMC)"
Subject: Re: [Emc-users] MTBF
On 3 December 2014 at 15:46, Dave Cole wrote:
If you want
On 3 December 2014 at 15:46, Dave Cole wrote:
> If you want a power supply that you can install, power up and have a
> fair expectation of it lasting 25+ years I would go with an Acopian
> linear power supply.
I have had a chat with them, and it looks like about £300 for a PSU
for this applicatio
On Sunday 07 December 2014 23:29:15 Dave Cole did opine
And Gene did reply:
> On 12/5/2014 6:36 PM, Gene Heskett wrote:
> > On Friday 05 December 2014 11:03:36 andy pugh did opine
> >
> > And Gene did reply:
> >> On 4 December 2014 at 11:33, Gregg Eshelman
wrote:
> >>> I went back out to the cab
On 12/5/2014 6:36 PM, Gene Heskett wrote:
> On Friday 05 December 2014 11:03:36 andy pugh did opine
> And Gene did reply:
>> On 4 December 2014 at 11:33, Gregg Eshelman wrote:
>>> I went back out to the cabinets, counted slots and did a bit of
>>> multiplication. I was staring at the gutted remain
On Friday 05 December 2014 11:03:36 andy pugh did opine
And Gene did reply:
> On 4 December 2014 at 11:33, Gregg Eshelman wrote:
> > I went back out to the cabinets, counted slots and did a bit of
> > multiplication. I was staring at the gutted remains of a one terabyte
> > RAID array. The first 5
On 12/04/2014 10:12 PM, dave wrote:
>
> Ah! Nice to know that my memory is completely gone. ;-)
>
>
But, NO! What you said was quite correct. I don't know
about the capacity
of the drive, but it was a fixed-head single-platter disk
about 5" diameter.
My guess is it was a lot less than 250K byte
On 4 December 2014 at 11:33, Gregg Eshelman wrote:
> I went back out to the cabinets, counted slots and did a bit of
> multiplication. I was staring at the gutted remains of a one terabyte
> RAID array. The first 500 gigabyte hard drives had just been introduced.
> Amazing to think that for a stre
On 12/04/2014 07:29 PM, Jon Elson wrote:
> On 12/04/2014 09:55 AM, dave wrote:
>> IIRC one of the US ICBM's had something like a 250 Kb hard disk,
>> head/track; all in a rather sturdy
>> case about 5" in dia. But that was a few years ago to I can't attest to
>> the accuracy of my memory.
>>
> Yes
On 12/04/2014 09:55 AM, dave wrote:
> IIRC one of the US ICBM's had something like a 250 Kb hard disk,
> head/track; all in a rather sturdy
> case about 5" in dia. But that was a few years ago to I can't attest to
> the accuracy of my memory.
>
Yes, that would be the Minuteman computer, the Autonet
Am 04.12.2014 17:30, schrieb Viesturs Lācis:
> 2014-12-04 18:04 GMT+02:00 Jon Elson :
>> On 12/03/2014 10:52 PM, Gregg Eshelman wrote:
>>> Anyone in Europe know anyone still calling a Million a
>>> Milliard?
>> I think in German, a millionen is 10^6, and a milliarden is
>> 10^9.
>>
> In Latvian it
2014-12-04 18:04 GMT+02:00 Jon Elson :
> On 12/03/2014 10:52 PM, Gregg Eshelman wrote:
>> Anyone in Europe know anyone still calling a Million a
>> Milliard?
> I think in German, a millionen is 10^6, and a milliarden is
> 10^9.
>
In Latvian it also is million (10^6), milliard (10^9) and trillion (
On 12/04/2014 08:07 AM, Jon Elson wrote:
> On 12/04/2014 02:05 AM, Peter Blodow wrote:
>> . The device was the size of a large drawer, weighing
>> about 50 kg, and ran continously without failure (and
>> without back up system) up until we switched it all off to
>> make room for a more modern syst
On 12/04/2014 02:05 AM, Peter Blodow wrote:
> . The device was the size of a large drawer, weighing
> about 50 kg, and ran continously without failure (and
> without back up system) up until we switched it all off to
> make room for a more modern system. The disk made it more
> than 30 years wi
On 12/03/2014 10:52 PM, Gregg Eshelman wrote:
> Anyone in Europe know anyone still calling a Million a
> Milliard?
I think in German, a millionen is 10^6, and a milliarden is
10^9.
Jon
--
Download BIRT iHub F-Type - The
IIRC one of the US ICBM's had something like a 250 Kb hard disk,
head/track; all in a rather sturdy
case about 5" in dia. But that was a few years ago to I can't attest to
the accuracy of my memory.
Dave
On 12/04/2014 12:05 AM, Peter Blodow wrote:
> Am 04.12.2014 04:02, schrieb Jon Elson:
>> /sn
On 12/4/2014 1:05 AM, Peter Blodow wrote:
> At the company I was working for, I had a building management system
> installed (don't want to mention the brand, sounded like Siemens) around
> 1980. The central processor unit contained a hard disk drive with a -
> nowadays - ridiculous sounding capac
On 12/3/2014 2:03 PM, Evan Foss wrote:
> Moisture is the death of a lot of stuff. Sometimes before it is even
> assembled. A lot of parts now are packed at the factory with descant
> so that they will stay dry. Failure to dry them before soldering can
> cause the parts to break like popcorn.
One
Sorry, folks, I made a mistake: (This was because I rarely have to look
at my bank account figures)
a thousand Billions are a Billiard etc., of course.
These names for numbers are seldom used because there isn't so much
money, and other values are mostly noted in scientific notation.
Peter
Am 0
Am 04.12.2014 05:52, schrieb Gregg Eshelman:
> Then there's the American Billion 1,000,000,000
> VS the Olde English Billion 1,000,000,000,000 or what we Yanks call a
> Trillion.
>
> Anyone in Europe know anyone still calling a Million a Milliard?
>
In Germany
a thousand Millions are a Milliard (10
Am 04.12.2014 04:02, schrieb Jon Elson:
> /snip
> Yes, of course, various manufacturers test all sorts of
> stuff! But, these PUBLISHED
> MTBF numbers all seem to come from the old DESC scheme.
> When they show
> 250K hours MTBF for a hard disk drive, you KNOW they are
> using this methodology.
>
On 12/3/2014 7:31 AM, Steve Stallings wrote:
> Traco appears to be a company whose main offices
> are located in German speaking areas.
>
> Mio is used as an abbreviation for Million, especially
> in German.
>
> The document that you linked seems to use a mixture
> of . and , as the symbol for the
On 12/3/2014 5:45 AM, andy pugh wrote:
> On 3 December 2014 at 12:42, alex chiosso wrote:
>> You're right Rick . ;-)
>
> I still don't believe 1,500 x million hours.
>
> I suppose it could be a Euro-style decimal separator, and therefore
> 1.5 million hours, but that is still 171 years MTBF.
> (wh
On 12/03/2014 02:19 PM, Ron Bean wrote:
> Jon Elson writes:
>
>> One other place the military screwed up, is Tantalum
>> capacitors. These have the
>> bad characteristic that they can be VERY reliable if used
>> CONSTANTLY. That means
>> either on all the time, or used every few days. But, make
On 12/03/2014 11:39 AM, Evan Foss wrote:
> While I agree with that rant I can say that a lot of higher end stuff
> does get environmental testing. My stuff lives in a hotter than
> average environment and so I have to consider this.
>
> Also my father has worked for a few different companies that f
On Wed, Dec 3, 2014 at 2:33 PM, Marcus Bowman
wrote:
> Yeah; and as for those MTBF figures for small bearings... The last lot I used
> in my lathe fixed steady lasted for ages; except for the one which failed
> after 15 minutes ruining the job. It was small consolation to be told the
> 'tho
On Wednesday 03 December 2014 17:55:17 andy pugh did opine
And Gene did reply:
> I was pointed offlist to:
> http://www.epsma.org/pdf/MTBF%20Report_24%20June%202005.pdf
> Which contains the excellent example:
>
> "25 year old humans have an MTBF of about 800 years, (خ» about
> 0.1%/year), but not
I was pointed offlist to:
http://www.epsma.org/pdf/MTBF%20Report_24%20June%202005.pdf
Which contains the excellent example:
"25 year old humans have an MTBF of about 800 years, (λ about
0.1%/year), but not many have a comparable “service life”."
--
atp
If you can't fix it, you don't own it.
http
At some point water from the humidity in the air gets into molded
tantalum capacitors. Dipped tantalum capacitors fail because of other
mechanisms.
Moisture is the death of a lot of stuff. Sometimes before it is even
assembled. A lot of parts now are packed at the factory with descant
so that they
Jon Elson writes:
>One other place the military screwed up, is Tantalum
>capacitors. These have the
>bad characteristic that they can be VERY reliable if used
>CONSTANTLY. That means
>either on all the time, or used every few days. But, make
>something with
>tantalum caps, test it rigorously, a
On 3 Dec 2014, at 17:25, Jon Elson wrote:
> On 12/03/2014 07:40 AM, Marius Liebenberg wrote:
>> Andy
>> MTBF is obtained by testing a number of units over a period of time at
>> accelerated environmental conditions.
> MTBF CAN be evaluated this way, and it is a more truthful
> way to do it, but
On 12/3/2014 12:59 PM, andy pugh wrote:
> On 3 December 2014 at 15:46, Dave Cole wrote:
>> I believe the super reliable Acopians are the Gold Box units. But you
>> should contact them and ask them what is their most reliable power
>> supply design these days.
>>
>> http://www.acopian.com/
> In t
On 3 December 2014 at 15:46, Dave Cole wrote:
> I believe the super reliable Acopians are the Gold Box units. But you
> should contact them and ask them what is their most reliable power
> supply design these days.
>
> http://www.acopian.com/
In the UK the best source might be eBay, and those h
While I agree with that rant I can say that a lot of higher end stuff
does get environmental testing. My stuff lives in a hotter than
average environment and so I have to consider this.
Also my father has worked for a few different companies that for
defense and enterprise level hardware had to do
On 12/03/2014 07:40 AM, Marius Liebenberg wrote:
> Andy
> MTBF is obtained by testing a number of units over a period of time at
> accelerated environmental conditions.
MTBF CAN be evaluated this way, and it is a more truthful
way to do it, but it requires a LOT
of units and long testing on hi-rel
On 12/03/2014 07:38 AM, Marcus Bowman wrote:
> http://www.proz.com/kudoz/german_to_english/business_commerce_general/1072093-mio.html
> tells us it is Million hours.
>
> Interestingly, though, the term does not appear in BS EN 61709:2011 Electric
> components - Reliability - Reference conditions f
On 12/3/2014 9:27 AM, andy pugh wrote:
> On 3 December 2014 at 13:38, Marcus Bowman
> wrote:
>
>> I don't believe 1500 Million hours. It is, in any case, a calculated value
>> (not that there's anything wrong with that). If the unit contains large
>> capacitors, 1500 hours is a much more realist
So they tested a batch of parts and projected out to the point where 63
percent will have failed using some assumed distribution of failure times.
Not hard to get to 171 years using that methodology. It ignores the common
case where there is a mode of failure that causes the failures to be
cluster
Traco appears to be a company whose main offices
are located in German speaking areas.
Mio is used as an abbreviation for Million, especially
in German.
The document that you linked seems to use a mixture
of . and , as the symbol for the decimal point.
I found many references to MTBF for power
On 3 December 2014 at 13:38, Marcus Bowman
wrote:
> I don't believe 1500 Million hours. It is, in any case, a calculated value
> (not that there's anything wrong with that). If the unit contains large
> capacitors, 1500 hours is a much more realistic figure. Short; yes. But
> realistic.
63 da
I have used a lot of stuff from that company. While none of it was
this specific part I can say it was all very reliable.
On Wed, Dec 3, 2014 at 8:45 AM, Marius Liebenberg
wrote:
> Normally it is quoted in hours of service.
>
> On 2014-12-03 15:11, andy pugh wrote:
>> On 3 December 2014 at 12:55,
Normally it is quoted in hours of service.
On 2014-12-03 15:11, andy pugh wrote:
> On 3 December 2014 at 12:55, John Thornton wrote:
>> http://en.wikipedia.org/wiki/Mean_time_between_failures
> I sort-of understand MTBF, what I don't understand are the units they
> are quoting it in.
>
--
Rega
Andy
MTBF is obtained by testing a number of units over a period of time at
accelerated environmental conditions. First the infant mortality of a
product is determined and then the MTBF is deduced. Some suppliers have
an MTBF based on the number of products produced compared to the number
of re
http://www.proz.com/kudoz/german_to_english/business_commerce_general/1072093-mio.html
tells us it is Million hours.
Interestingly, though, the term does not appear in BS EN 61709:2011 Electric
components - Reliability - Reference conditions for failure rates and stress
models for conversion.
I
On 3 December 2014 at 12:55, Stuart Stevenson wrote:
> Searching for 'probability Mio' yields some interesting papers.
It does, though very few related the subject at hand. (If using the quotes)
--
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto
-
On 3 December 2014 at 12:55, John Thornton wrote:
> http://en.wikipedia.org/wiki/Mean_time_between_failures
I sort-of understand MTBF, what I don't understand are the units they
are quoting it in.
--
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto
---
Searching for 'probability Mio' yields some interesting papers.
On Wed, Dec 3, 2014 at 6:45 AM, andy pugh wrote:
> On 3 December 2014 at 12:42, alex chiosso wrote:
> > You're right Rick . ;-)
>
> I still don't believe 1,500 x million hours.
>
> I suppose it could be a Euro-style decimal separat
http://en.wikipedia.org/wiki/Mean_time_between_failures
On 12/3/2014 6:45 AM, andy pugh wrote:
> On 3 December 2014 at 12:42, alex chiosso wrote:
>> You're right Rick . ;-)
> I still don't believe 1,500 x million hours.
>
> I suppose it could be a Euro-style decimal separator, and therefore
> 1.5
On 3 December 2014 at 12:42, alex chiosso wrote:
> You're right Rick . ;-)
I still don't believe 1,500 x million hours.
I suppose it could be a Euro-style decimal separator, and therefore
1.5 million hours, but that is still 171 years MTBF.
(which would be ideal, but seems high)
--
atp
If you
You're right Rick . ;-)
On Wed, Dec 3, 2014 at 1:27 PM, Rick Lair wrote:
> It looks like " over 1500 'millions of hours' of 'Mean Time Between
> Failures' "
>
>
> Thanks
>
>
> Rick
>
>
>
> -- Original Message --
> From: "andy pugh"
> To: "Enhanced Machine Controller (EMC)"
>
> Sent: 12
On 3 December 2014 at 12:27, Rick Lair wrote:
> It looks like " over 1500 'millions of hours' of 'Mean Time Between
> Failures' "
But that would be 170,000 years, which seems unlikely too.
Even 1500 x 1000 hours (170 years) seems unlikely.
--
atp
If you can't fix it, you don't own it.
http://w
On Wed, Dec 3, 2014 at 7:20 AM, andy pugh wrote:
> Does anyone know how to interpret MTBF numbers?
>
> http://docs-europe.electrocomponents.com/webdocs/0d17/0900766b80d17a55.pdf
>
> Specifically. 1500 hours doesn't seem very long,
>
> --
> atp
> If you can't fix it, you don't own it.
> http://www
It looks like " over 1500 'millions of hours' of 'Mean Time Between
Failures' "
Thanks
Rick
-- Original Message --
From: "andy pugh"
To: "Enhanced Machine Controller (EMC)"
Sent: 12/3/2014 7:20:32 AM
Subject: [Emc-users] MTBF
>Does anyone know how to interpret MTBF numbers?
>
>h
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