Guest
Mikko OH2HVJ <mikko.syrjalahti@nospam.fi> wrote in
news:m2wo96qhxr.fsf@mspro.home:
Damned Russkies!
news:m2wo96qhxr.fsf@mspro.home:
Damned Russkies!
K
Klaus Kragelund
Guest
Maximum power dissipation is about 5W
K
Klaus Kragelund
Guest
I will be running hot, meaning powered and will have various probes attached to monitor important nodes
Cheers
Klaus
Cheers
Klaus
Guest
Klaus Kragelund <klauskvik@hotmail.com> wrote in
news:2d4adeb5-177d-460a-be7f-38d668909298@googlegroups.com:
Then you need a 3 or 4 inch hole saw to open a hole in the chamber
which you then fill with a foam plug. That allows the wiring to be
passed through without compromising the chamber temp stability. It
does not need to be 4", but that size allows one to pass one's hand
through as well.
As to the running hot thing, I would place the UUT in unpowered and
let it settle to the cold temp for at least ten minutes, then do your
live tests and hot running observations. Maybe more than ten minutes
to settle in. If you also had an oven, you could do full bore
thermal shock tests too. Super cold board into super hot
environment, and back again.
Back in the thru hole solder days, that would expose bad solder
joints, etc. Not so much any more.
news:2d4adeb5-177d-460a-be7f-38d668909298@googlegroups.com:
Then you need a 3 or 4 inch hole saw to open a hole in the chamber
which you then fill with a foam plug. That allows the wiring to be
passed through without compromising the chamber temp stability. It
does not need to be 4", but that size allows one to pass one's hand
through as well.
As to the running hot thing, I would place the UUT in unpowered and
let it settle to the cold temp for at least ten minutes, then do your
live tests and hot running observations. Maybe more than ten minutes
to settle in. If you also had an oven, you could do full bore
thermal shock tests too. Super cold board into super hot
environment, and back again.
Back in the thru hole solder days, that would expose bad solder
joints, etc. Not so much any more.
K
Klaus Kragelund
Guest
Something like this could cool down to 1 degree, better than nothing:
https://m.aliexpress.com/item/32958448606.html?pid=808_0000_0101&spm=a2g0n.search-amp.list.32958448606&aff_trace_key=75e8164c2a4c4320999b0d65e21f7935-1575312227144-09681-DziQooLW&aff_platform=msite&m_page_id=4818amp-rq8xrQQRHiczzhJR2ALTDg1580584094112&browser_id=ef656a37e3894078b8369b7dc0b92968&is_c=N
https://m.aliexpress.com/item/32958448606.html?pid=808_0000_0101&spm=a2g0n.search-amp.list.32958448606&aff_trace_key=75e8164c2a4c4320999b0d65e21f7935-1575312227144-09681-DziQooLW&aff_platform=msite&m_page_id=4818amp-rq8xrQQRHiczzhJR2ALTDg1580584094112&browser_id=ef656a37e3894078b8369b7dc0b92968&is_c=N
K
Klaus Kragelund
Guest
Down to minus 20 for just 150 USD
https://m.aliexpress.com/item/32992265403.html?pid=808_0000_0101&spm=a2g0n.search-amp.list.32992265403&aff_trace_key=75e8164c2a4c4320999b0d65e21f7935-1575312227144-09681-DziQooLW&aff_platform=msite&m_page_id=1351amp-rq8xrQQRHiczzhJR2ALTDg1580584292463&browser_id=ef656a37e3894078b8369b7dc0b92968&is_c=N
https://m.aliexpress.com/item/32992265403.html?pid=808_0000_0101&spm=a2g0n.search-amp.list.32992265403&aff_trace_key=75e8164c2a4c4320999b0d65e21f7935-1575312227144-09681-DziQooLW&aff_platform=msite&m_page_id=1351amp-rq8xrQQRHiczzhJR2ALTDg1580584292463&browser_id=ef656a37e3894078b8369b7dc0b92968&is_c=N
Guest
On Sat, 1 Feb 2020 11:32:39 -0600, John S <Sophi.2@invalid.org> wrote:
I got a cheap Peltier heater/refrigerator from Amazon, just the size
for a few beers. It only has two temps, but effectively sweeps if you
switch. Handy for temp testing small boards or saving/curing epoxy or
keeping cokes cold for engineering Rum and Coke requirements.
--
John Larkin Highland Technology, Inc
The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
I got a cheap Peltier heater/refrigerator from Amazon, just the size
for a few beers. It only has two temps, but effectively sweeps if you
switch. Handy for temp testing small boards or saving/curing epoxy or
keeping cokes cold for engineering Rum and Coke requirements.
--
John Larkin Highland Technology, Inc
The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
G
Gerhard Hoffmann
Guest
Am 01.02.20 um 19:30 schrieb Mikko OH2HVJ:
I have used mine to recover data from an IBM Deathstar(R) SCSI disk.
Mine goes to -36° if need be.
> pouring almost syrup-like vodka from the freezer!
I have seen pics of a ham from OH who concentrated alcohol in the
deep freezer from wine by fractional freezing. I have tested the
procedure, but didn't dare to try that oily red liquid.
+9° lowest in this night from Feb. 1st to 2nd, and +14°C tomorrow.
I have not seen any snow this "winter". OK, a hint that melted
immediately when it hit the ground, and the phenomenon lasted 3 minutes.
73, Gerhard, DK4XP
I have used mine to recover data from an IBM Deathstar(R) SCSI disk.
Mine goes to -36° if need be.
> pouring almost syrup-like vodka from the freezer!
I have seen pics of a ham from OH who concentrated alcohol in the
deep freezer from wine by fractional freezing. I have tested the
procedure
, but didn't dare to try that oily red liquid.+9° lowest in this night from Feb. 1st to 2nd, and +14°C tomorrow.
I have not seen any snow this "winter". OK, a hint that melted
immediately when it hit the ground, and the phenomenon lasted 3 minutes.
73, Gerhard, DK4XP
R
Rick C
Guest
On Saturday, February 1, 2020 at 12:04:28 PM UTC-5, Klaus Kragelund wrote:
> I need minus 20 minimum
Never mind
--
Rick C.
+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209
> I need minus 20 minimum
Never mind
--
Rick C.
+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209
W
whit3rd
Guest
On Saturday, February 1, 2020 at 9:03:51 AM UTC-8, Klaus Kragelund wrote:
You can assemble a box of styrofoam boards, and put
a little liquid nitrogen in, to get a good range of low temperatures.
A chest freezer will HOLD a low temperature, and probably is
resell-able after the project is done.
Or, you can find a local outfit that has environment chambers, and
pay 'em to do the test (that gets you some extras, like humidity control).
Most costly, you can become such a local outfit...
You can assemble a box of styrofoam boards, and put
a little liquid nitrogen in, to get a good range of low temperatures.
A chest freezer will HOLD a low temperature, and probably is
resell-able after the project is done.
Or, you can find a local outfit that has environment chambers, and
pay 'em to do the test (that gets you some extras, like humidity control).
Most costly, you can become such a local outfit...
R
Rick C
Guest
On Saturday, February 1, 2020 at 12:03:51 PM UTC-5, Klaus Kragelund wrote:
20x20x20 what? cm, mm, inches, feet, furlongs?
Around here, this time of year you might do your testing outside at night with a temperature controlled heater. Maybe not this week. It's supposed to be unseasonably warm this coming week above 45°F through Thursday. What's your climate like?
--
Rick C.
- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
20x20x20 what? cm, mm, inches, feet, furlongs?
Around here, this time of year you might do your testing outside at night with a temperature controlled heater. Maybe not this week. It's supposed to be unseasonably warm this coming week above 45°F through Thursday. What's your climate like?
--
Rick C.
- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
R
Rick C
Guest
On Saturday, February 1, 2020 at 12:04:28 PM UTC-5, Klaus Kragelund wrote:
> I need minus 20 minimum
That's -4°F which my freezer will reach. Will your equipment be putting out any heat? That would make a big difference. If the tests are short including a lot of thermally dense material can act like a buffer. But if it needs to run continuously I expect you will need a pretty high capacity compressor in a small box?
--
Rick C.
-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209
> I need minus 20 minimum
That's -4°F which my freezer will reach. Will your equipment be putting out any heat? That would make a big difference. If the tests are short including a lot of thermally dense material can act like a buffer. But if it needs to run continuously I expect you will need a pretty high capacity compressor in a small box?
--
Rick C.
-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209
K
Klaus Kragelund
Guest
This guy reaches -7, with a concept that has room for improvement
https://m.youtube.com/watch?v=clZsykBt4YA
https://m.youtube.com/watch?v=clZsykBt4YA
J
Jasen Betts
Guest
On 2020-02-01, Klaus Kragelund <klauskvik@hotmail.com> wrote:
millimetres? salt and ice.
--
Jasen.
millimetres? salt and ice.
--
Jasen.
J
Jasen Betts
Guest
On 2020-02-01, Klaus Kragelund <klauskvik@hotmail.com> wrote:
> I need minus 20 minimum
that's somewhat unclear, I'm assuming you mean that you need to go
colder.
A freezer should be capable, the standard set-point is -18C, but
that's controlled by the thermostat, you could adjust that or shim the
sensor with a nearby resistor.
--
Jasen.
> I need minus 20 minimum
that's somewhat unclear, I'm assuming you mean that you need to go
colder.
A freezer should be capable, the standard set-point is -18C, but
that's controlled by the thermostat, you could adjust that or shim the
sensor with a nearby resistor.
--
Jasen.
M
Martin Riddle
Guest
On Sat, 1 Feb 2020 09:03:47 -0800 (PST), Klaus Kragelund
<klauskvik@hotmail.com> wrote:
I'd recomend a CO2 cold plate or a small Tenny chamber.
Freezers in a fridge just barely go below Zero, while a standalone
freezer may do better. But a real environmental chamber will
compensate for the added heat of the gadget and the cold plate can get
to below zero rather quickly. I've used both and wouldn't bother
messing around with something else unless the DUT is big, then it's a
double compressor large HVAC system.
Cheers
<klauskvik@hotmail.com> wrote:
I'd recomend a CO2 cold plate or a small Tenny chamber.
Freezers in a fridge just barely go below Zero, while a standalone
freezer may do better. But a real environmental chamber will
compensate for the added heat of the gadget and the cold plate can get
to below zero rather quickly. I've used both and wouldn't bother
messing around with something else unless the DUT is big, then it's a
double compressor large HVAC system.
Cheers
Guest
On Sat, 1 Feb 2020 22:44:50 -0000 (UTC), Jasen Betts
<jasen@xnet.co.nz> wrote:
Freezers typically have a "freeze" button for quickly freezing new
items to at least -25 C and then maintain it at -18 C,
For testing larger objects, the big outdoor freezer can be used. In
Finland there are test tracks (near 70N) that car and tyre
manufacturers use for winter testing. This winter here has been weeks
with neatly -40 C and more than a meter of snow this early this
winter, On the South Coast (at 60N) the temperature as been +5 C and
no snow, so you can find suitable temperatures for the tests between
60N and 70N latitude.
<jasen@xnet.co.nz> wrote:
Freezers typically have a "freeze" button for quickly freezing new
items to at least -25 C and then maintain it at -18 C,
For testing larger objects, the big outdoor freezer can be used. In
Finland there are test tracks (near 70N) that car and tyre
manufacturers use for winter testing. This winter here has been weeks
with neatly -40 C and more than a meter of snow this early this
winter, On the South Coast (at 60N) the temperature as been +5 C and
no snow, so you can find suitable temperatures for the tests between
60N and 70N latitude.
K
Klaus Kragelund
Guest
My product is 20x20x20 cm
I live in Denmark and the last couple of years we have had extremely mild winters, averaged 5.4 degrees in January, a all time record
https://www.dr.dk/nyheder/viden/klima/varmeste-januar-nogensinde-er-det-klimaforandringernes-skyld
So I need a chamber that works a room temperature
Cheers
Klaus
I live in Denmark and the last couple of years we have had extremely mild winters, averaged 5.4 degrees in January, a all time record
https://www.dr.dk/nyheder/viden/klima/varmeste-januar-nogensinde-er-det-klimaforandringernes-skyld
So I need a chamber that works a room temperature
Cheers
Klaus
M
Martin Brown
Guest
On 01/02/2020 17:04, Klaus Kragelund wrote:
> I need minus 20 minimum
The sort of freezer intended to keep dry ice in would probably do that
easily and the volume of the smallest ones is about right too.
--
Regards,
Martin Brown
> I need minus 20 minimum
The sort of freezer intended to keep dry ice in would probably do that
easily and the volume of the smallest ones is about right too.
--
Regards,
Martin Brown
Guest
On Sat, 1 Feb 2020 09:03:47 -0800 (PST), Klaus Kragelund
<klauskvik@hotmail.com> wrote:
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,
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.
This is not much of an issue when doing outdoor tests in the cold, in
which the absolute humidity is already quite low.
<klauskvik@hotmail.com> wrote:
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,
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.
This is not much of an issue when doing outdoor tests in the cold, in
which the absolute humidity is already quite low.