Driver to drive?

[Rick C]

On Friday, February 7, 2020 at 1:49:07 AM UTC-5, DecadentLinux...@decadence..org wrote:

Rick C <gnuarm.deletethisbit@gmail.com> wrote in
news:45c6c4d5-81e3-4756-bd71-cff8fd38bded@googlegroups.com:

On Sunday, February 2, 2020 at 4:03:16 PM UTC-5,
DecadentLinux...@decadence.org wrote:
Klaus Kragelund <klauskvik@hotmail.com> wrote in
news:484e78ef-6290-493c-bbd0-7c6bfe76e4a0@googlegroups.com:

On Sunday, February 2, 2020 at 3:37:03 PM UTC+1,
upsid...@downunder.com wrote:
On Sat, 1 Feb 2020 09:03:47 -0800 (PST), Klaus Kragelund
klauskvik@hotmail.com> wrote:

Hi

I am working on something for my own business

So need to do testing at below 0 degrees C

What would be a cheapskate way to do it?

Just a household freezer?

Product is just 20x20x20

There are some issues with electronics in cold temperatures.

One problem with any processor based (or sequentially logic)
system is starting the clock oscillator at extreme low
temperatures. This can be quite unreliable. Once the clock is
running, the electronics will generate some internal heat
warming the components in the box to higher temperatures.
Thus, even i some components are initially out of specs it
will be within specs after a while.

When doing cold testing, let the device cool to the lowest
temperature obtainable with equipment power turned off. Once
the lowest temperature has been achieved, turn equipment power
on and verify that the clock starts. Once running, make sure
the box outside temperature remains in your case at -20 C
despite the 5 W heating,

We have big, super expensive chambers at work, where we always
do that LOL and UOL (Lower Operating Limit and Upper Operating
Limit), which has the purpose you mention to find when it
really fails. We would normally have the LOL at -50 and UOL at
150. But for my own business if I can do a minus 20 test and
150 then I feel pretty safe

When doing indoor cool chamber tests, the initial air contains
some absolute humidity. While the chamber cools down, the
relative humidity RH increases, finally reaching 100 %, after
which condensation or frost will accumulate. Do not put the
equipment directly on the bottom of the chamber, since there
might be some condensation water on the bottom. The
condensation or frost may cause problems with uncoated PCBs.


Yes. Also, don't open the chamber when at -40, tried that,
won't do it again (heavy condensation)

Cheers

Klaus


Place the UUT in a Fluorinert bath.

I wanted to do an entire motherbaord that way and go down below
and
clock up above what the OC boys do. Some of the videos are
amusing watching some dude pouring LN2 over a CPU.

My solution <sic> would work, and for long term too, not "I
OC'd my
PC to 10GHz" (for 1 minute long enough to run the benchmark). It
is funny watching them make claims. My PC in a fish tank method
would work down to -70°C with FC-72 Fluorinert. And run... all
day.

Maybe, maybe not. I recall an outfit that was working on cooling
military electronics. They used something like Fluorinert but
instead of immersion which actually provides thermal barriers from
limited conductivity of the fluid, they sprayed it on using
patented nozzles to obtain optimum droplet size and used the heat
of vaporization to cool. While that would not cool to -70°C, it
removes more heat than immersion would until your device heated up
to at least 10°C but actually higher due to the thermal
conduction issues of the liquid.


Fluorinert does not vaporize and the immersion unit would have the
fluorinert always flowing over the parts.

Yes, that's the point. It does a much better job of cooling if it does evaporate. In the system I was talking about, they tried to make sure there was no or very little surface layer of liquid. If there was, the cooling effect would be dramatically reduced due to the higher thermal resistance.

And oh fluorinert has very
good thermal conductivity.

"very good" is a judgemental term with no quantitative value. The point is it is not as good as it needs to be to equal what can be achieved with a spray and vaporization rather than immersion.

It would work well in seal, conduction
cooled designs as well, where no movement happens or is needed. They
work far better than a friggin thermal pad or even a directly
attached air flow heat sink.

Don't care. I'm talking about systems that require much better cooling than either of those. One of the things they talked about was using a synthetic diamond substrate to mount components to provide a thermal path for cooling in a very high density package.

There are more technologies in mil-spec gear Horatio than are dreamt of in your philosophy.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

Bill Sloman <bill.sloman@ieee.org> wrote in news:285c10e9-ef32-4d0b-
8ff4-422a248d6636@googlegroups.com:

Of course it vaporises if you get it hot enough.

Not in a useable way. Its latent heat is plenty to use in a single
phase.

 

Rick C <gnuarm.deletethisbit@gmail.com> wrote in
news:f8d04178-6975-4f07-8f46-b9786de7d8dd@googlegroups.com:

There are more technologies in mil-spec gear Horatio than are
dreamt of in your philosophy.

My philosophy?

Hey, whore of the ratio... you know nothing of my experiences,
much less my fucking dreams.

Fluorinert goes down pretty cold, and regardless of your banter, it
can do a lot of cooling.

If your sources are generating that much waste heat, perhaps a
designer should get shitcanned.

And no cooling system will save it from early failure and then you
looking for places to point your finger as to where the failure was
caused. Could not possibly have been the design itself.

 

Bill Sloman <bill.sloman@ieee.org> wrote in
news:285c10e9-ef32-4d0b-8ff4-422a248d6636@googlegroups.com:

They'd work even better in a heat-pipe set-up, but water is mostly
good enough there.

Fluorinert is NOT a good candidate for the ingredients of a heat
pipe.

 

[Phil Allison]

Bill Sloman wrote:

------------------

Just like you then, Bill.

I've got a much longer fuse.

** Yep - I believe it takes quite a while for an idea to get from a dinosaurs arse right up to to it's tiny brain.




...... Phil

 

[Phil Allison]

Bill Sloman wrote:

------------------

Any time somebody gets killed by a bush-fire there's loads of publicity.

** Along with shark and crocodile attacks, they send the rabid Aussie media into a full on frenzy.

Steve Irwin's run in with a sting ray fair blew the roof off every media outlet on the planet.

Deaths by car accident, misadventure and even murder hardly rate a mention unless you happen to be a celeb.

IIRC, bush fires kill an average of 4 persons per year here.



..... Phil

 

[Phil Allison]

Whoey Louie wrote:

They left out the most relevant part. Mohammed, the young Ethiopia airline co-pilot, with just 200 hours, correctly identified the runaway trim problem and followed the exact procedure that Boeing put out after the first crash, to deal with MCAS running amok. It did not work, he could not move the trim wheel. So much for pilot training.

** As I understand, the pilot pulled the circuit breaker on the motor that drove the tail plane jack in order to take control away from the on board computer. This was in part of the training he received in a MAX simulator.

However, aerodynamic forces were so great in the steep dive the MAX was then in that the trim wheel was useless without the usual power assist.

Seems the simulator did not actually simulate the force needed on the wheel without power assist.

Wonder if some engineer will now add that feature ?



..... Phil

 

[Phil Allison]

boB wrote:

----------

Yes, those fires down there are terrible !

I hope they contain them soon. I mean, I like warm wether and all but
it's getting rediculous now.

Good point that he might be fighting fires

** The gents that do that job live in rural ( therefor fire prone) areas and are mostly much younger and rather fitter than myself.

They all refuse to accept any payment, the motivation behind which is an interesting topic for another forum.



...... Phil

 

[Phil Allison]

booB wrote:

------------

Haven't seen him on the aus.electronics group either.

I haven't seen much of a web presence of him except for maybe one or
two audio articles.

I was hoping he could at least answer some of his riddles where he
wanted us to try and figure things out.

** All but the very last was thoroughly answered and explpained.

Now that one as well.

The shame is, not one of the self promoting bullshitters that haunt this electronics sewer figured out a single one of them .

No further proof could*possibly* be needed that ALL the resident gurus are nothing but piss and wind.

So there is no confusion, I nominate:

Win, Larkin, Hobbs and Slowman for starters.

Make a big joke of them having EE degrees from various fake, commercial operations that dole them out.


...... Phil

 

[Phil Allison]

Phil Hobbs wrote:

----------------

Winfield Hill wrote:


Sorry, Win, you just don't have Phil A's talent.

** Wow - Phil H finally says something that is true.

Wonders will never cease...


..... Phil

 

[Phil Allison]

amdx wrote:

-------------

Phil Allison hasn't posted for 30 days.

** Well, time is now up.

I kind of miss having someone around that lacks all social grace,
as long as I don't really have to pay any attention to them.

** I lack all social grace ?

For peeing on trolls like you ?

How funny.


...... Phil

 

[Bill Sloman]

On Friday, February 7, 2020 at 9:17:50 PM UTC+11, Phil Allison wrote:

Bill Sloman wrote:

------------------

Any time somebody gets killed by a bush-fire there's loads of publicity..

** Along with shark and crocodile attacks, they send the rabid Aussie media into a full on frenzy.

Steve Irwin's run in with a sting ray fair blew the roof off every media outlet on the planet.

Deaths by car accident, misadventure and even murder hardly rate a mention unless you happen to be a celeb.

Four kids got killed at once by a drunken driver a couple of days ago, and that was worth quite a few column inches.

> IIRC, bush fires kill an average of 4 persons per year here.

This hasn't been an average year. This bush-fire season has seen 34 deaths so far. It's pelting with rain here at the moment, but there still some forty fires burning further away from the coast, and there are another couple of months to go before the bush-fire season would normally be expected to end.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Friday, February 7, 2020 at 9:09:42 PM UTC+11, Phil Allison wrote:

Bill Sloman wrote:

------------------

Just like you then, Bill.

I've got a much longer fuse.

** Yep - I believe it takes quite a while for an idea to get from a dinosaurs arse right up to to it's tiny brain.

There aren't any dinosaurs around any more. The ones Phil was probably thinking about had a bigger mass of nerves in their pelvis than in their heads.

It can be argued that birds are dinosaurs, but they are remarkably quick thinking, if nearly as superficial as Phil.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Friday, February 7, 2020 at 9:02:58 PM UTC+11, Phil Allison wrote:

boB wrote:

----------


Yes, those fires down there are terrible !

I hope they contain them soon. I mean, I like warm wether and all but
it's getting rediculous now.

Good point that he might be fighting fires

** The gents that do that job live in rural ( therefor fire prone) areas and are mostly much younger and rather fitter than myself.

Not all of them. Tony Abbott - an ex-prime minster and now an ex-MP - has been seen fighting fires, at least by press photographers.

> They all refuse to accept any payment, the motivation behind which is an interesting topic for another forum.

Quite a few people who do accept payment are also involved. A couple of American aviators got killed when their water-bomber crashed, and they were not working for their local community for nothing.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Friday, February 7, 2020 at 8:11:24 PM UTC+11, DecadentLinux...@decadence.org wrote:

Bill Sloman <bill.sloman@ieee.org> wrote in
news:285c10e9-ef32-4d0b-8ff4-422a248d6636@googlegroups.com:


They'd work even better in a heat-pipe set-up, but water is mostly
good enough there.


Fluorinert is NOT a good candidate for the ingredients of a heat
pipe.

Depends which Fluorinert. There are several. For a heat pipe it makes sense to use a single component liquid

https://en.wikipedia.org/wiki/Fluorinert

https://en.wikipedia.org/wiki/Perfluorohexane

The latent heat of vaporisation is lower than for water, which isn't an advantage, but it freezes and boils at rather lower temperatures.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Friday, February 7, 2020 at 8:58:27 PM UTC+11, Phil Allison wrote:

booB wrote:

------------




Haven't seen him on the aus.electronics group either.

I haven't seen much of a web presence of him except for maybe one or
two audio articles.

I was hoping he could at least answer some of his riddles where he
wanted us to try and figure things out.


** All but the very last was thoroughly answered and explained.

Now that one as well.

The shame is, not one of the self promoting bullshitters that haunt this electronics sewer figured out a single one of them .

No further proof could*possibly* be needed that ALL the resident gurus are nothing but piss and wind.

When it comes to obscure faults in audio equipment, this is probably true. Phil wouldn't do much good with phased array ultrasound machines or scanning electron microscopes, but he's unaware of his deficiencies in those areas.

So there is no confusion, I nominate:

Win, Larkin, Hobbs and Sloman for starters.

Make a big joke of them having EE degrees from various fake, commercial operations that dole them out.

I've never claimed to have any kind of EE degree. I've got a B.Sc, and M.Sc and Ph.D. but all in chemistry.

Phil's not good at paying attention.

Win had more sense than I did - he gave up on a Ph.D. in Chemical Physics and moved onto a Masters in Electronics, at MIT which isn't usually described as a fake commercial organisation.

John Larkin got his degree from Tulane (which doesn't reflect any credit on Tulane) and even that has been around for long enough to suggest that it isn't fake or commercial. Good might be a stretch.

So Phil ends up looking more confused than anybody else.

Not for the first time.

--
Bill Sloman, Sydney

 

[dcaster@krl.org]

Liquid CO2 would be a first. It might even get you a Nobel Prize.



--
Bill Sloman, Sydney

_I thought the CO2 tanks that I have contained liquid CO2.

Dan

 

[Phil Hobbs]

On 2020-02-07 04:49, Phil Allison wrote:

Phil Hobbs wrote:

----------------
Winfield Hill wrote:


Sorry, Win, you just don't have Phil A's talent.


** Wow - Phil H finally says something that is true.

Wonders will never cease...


..... Phil

Welcome back, Phil. The group just wasn't the same without our mascot.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

On Fri, 7 Feb 2020 06:23:09 -0800 (PST), "dcaster@krl.org"
<dcaster@krl.org> wrote:

Liquid CO2 would be a first. It might even get you a Nobel Prize.



--
Bill Sloman, Sydney

_I thought the CO2 tanks that I have contained liquid CO2.

The CO2 triple point of CO2 is at 5 atm and -57 C.

You need at least 50 atm to have liquid CO2 at room temperatures.

 

[amdx]

On 2/7/2020 3:47 AM, Phil Allison wrote:

amdx wrote:

-------------

Phil Allison hasn't posted for 30 days.


** Well, time is now up.


I kind of miss having someone around that lacks all social grace,
as long as I don't really have to pay any attention to them.


** I lack all social grace ?

For peeing on trolls like you ?

How funny.


..... Phil

From what I'm reading, we have a new kinder and gentler Phil.
Let's just enjoy his knowledge while this condition exists.

btw Phil, I wonder if your question had been posted before you ever saw
that circuit operating, do you think you would have known what it was doing?

Mikek