BS2 gets cold and reboots...
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Posts: 46,084
I expect the short answer is going to be, get the industrial BS2. But that's
$54, and I want to check my facts first.
I have a BS2 that controls a pump, and runs it when water gets cold (to
prevent it from freezing). The circuit lives outside, in a sealed box, in
Massachusetts winters, where sub-32F is fairly common and sub-0F is
possible. I thought the power transformer would generate enough heat to keep
the BS2 happy. I was wrong. The circuit failed when it got below 30F
outside. True to spec, the BS2 acted up, and didn't get normal until it was
brought inside for ten minutes. (The way it acted up was odd: it booted when
power was applied, ran well enough to flash the initial "I'm starting up"
LED, and then rebooted itself a few seconds later, probably when it tried to
signal the relay to close. Does the BS2 get more voltage sensitive when it
gets cold?)
Anyway, my options are
1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage: easy
solution. Disadvantage: the circuit's supposed to save power by only running
a pump when needed. Running a light bulb all the time defeats the point.
Also, in the summer, the bulb might drive the temp in there over the BS2's
other temperature limit.
2) Have the light bulb only go on when it's cold - the BS2 is watching the
temp anyway. But this means redesigning the circuit, adding another relay,
larger enclosure... very big pain.
3) Industrial BS2. Good to -40F, which covers any winter I expect to see
here, but a $54 solution, which probably offsets the power savings the
circuit's supposed to be providing. Anyone know if the industrial version is
really good to -40F? What's different about the chip?
*mutter* Any better suggestions?
$54, and I want to check my facts first.
I have a BS2 that controls a pump, and runs it when water gets cold (to
prevent it from freezing). The circuit lives outside, in a sealed box, in
Massachusetts winters, where sub-32F is fairly common and sub-0F is
possible. I thought the power transformer would generate enough heat to keep
the BS2 happy. I was wrong. The circuit failed when it got below 30F
outside. True to spec, the BS2 acted up, and didn't get normal until it was
brought inside for ten minutes. (The way it acted up was odd: it booted when
power was applied, ran well enough to flash the initial "I'm starting up"
LED, and then rebooted itself a few seconds later, probably when it tried to
signal the relay to close. Does the BS2 get more voltage sensitive when it
gets cold?)
Anyway, my options are
1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage: easy
solution. Disadvantage: the circuit's supposed to save power by only running
a pump when needed. Running a light bulb all the time defeats the point.
Also, in the summer, the bulb might drive the temp in there over the BS2's
other temperature limit.
2) Have the light bulb only go on when it's cold - the BS2 is watching the
temp anyway. But this means redesigning the circuit, adding another relay,
larger enclosure... very big pain.
3) Industrial BS2. Good to -40F, which covers any winter I expect to see
here, but a $54 solution, which probably offsets the power savings the
circuit's supposed to be providing. Anyone know if the industrial version is
really good to -40F? What's different about the chip?
*mutter* Any better suggestions?
Comments
>I expect the short answer is going to be, get the industrial BS2. But that's
>$54, and I want to check my facts first.
>
>I have a BS2 that controls a pump, and runs it when water gets cold (to
>prevent it from freezing). The circuit lives outside, in a sealed box, in
>Massachusetts winters, where sub-32F is fairly common and sub-0F is
>possible. I thought the power transformer would generate enough heat to keep
>the BS2 happy. I was wrong. The circuit failed when it got below 30F
>outside. True to spec, the BS2 acted up, and didn't get normal until it was
>brought inside for ten minutes. (The way it acted up was odd: it booted when
>power was applied, ran well enough to flash the initial "I'm starting up"
>LED, and then rebooted itself a few seconds later, probably when it tried to
>signal the relay to close. Does the BS2 get more voltage sensitive when it
>gets cold?)
>
>Anyway, my options are
>
>1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage: easy
>solution. Disadvantage: the circuit's supposed to save power by only running
>a pump when needed. Running a light bulb all the time defeats the point.
>Also, in the summer, the bulb might drive the temp in there over the BS2's
>other temperature limit.
>
>2) Have the light bulb only go on when it's cold - the BS2 is watching the
>temp anyway. But this means redesigning the circuit, adding another relay,
>larger enclosure... very big pain.
>
>3) Industrial BS2. Good to -40F, which covers any winter I expect to see
>here, but a $54 solution, which probably offsets the power savings the
>circuit's supposed to be providing. Anyone know if the industrial version is
>really good to -40F? What's different about the chip?
>
>*mutter* Any better suggestions?
Before I did anything that costs money, I'd temporarily cover the outside
of the box with black cloth or black paper. See if the sun will help in keeping
the enclosure warmer. The "right" answer is to use the Industrial BS-2 which
is designed for that kind of environment.
Regards,
Bruce Bates
sounds like it could be a power supply problem.
If I were to approach this, I'd try to breadboard the pieces separately and
run parts of them in my deep freeze and study how they fail.
You probably should have the industrial Stamp, but it would be a shame to
put it in only to find out something else is failing at temperature.
Since you have a power transformer, I wonder if you could stuff the box with
fiberglass insulation to trap more of the heat? I also think that if I were
going to heat with 5W, I would use a piece of nichrome or a big resistor and
not a bulb (the bulb will burn out).
Regards,
Al Williams
AWC
* Universal Relay Card: http://www.al-williams.com/kp1.htm
>
Original Message
> From: Scott [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=SSItREGF-C0Kkc0dhjlHxAsA9MBAZmXQG0qdHMJzaFGVaXs2iY-I93EZbYceqFVlTHYWrVM]scott@m...[/url
> Sent: Saturday, January 03, 2004 9:53 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
>
>
> I expect the short answer is going to be, get the industrial
> BS2. But that's $54, and I want to check my facts first.
>
> I have a BS2 that controls a pump, and runs it when water
> gets cold (to prevent it from freezing). The circuit lives
> outside, in a sealed box, in Massachusetts winters, where
> sub-32F is fairly common and sub-0F is possible. I thought
> the power transformer would generate enough heat to keep the
> BS2 happy. I was wrong. The circuit failed when it got below
> 30F outside. True to spec, the BS2 acted up, and didn't get
> normal until it was brought inside for ten minutes. (The way
> it acted up was odd: it booted when power was applied, ran
> well enough to flash the initial "I'm starting up" LED, and
> then rebooted itself a few seconds later, probably when it
> tried to signal the relay to close. Does the BS2 get more
> voltage sensitive when it gets cold?)
>
> Anyway, my options are
>
> 1) put a 5w bulb in the enclosure, to keep it warm in there.
> Advantage: easy solution. Disadvantage: the circuit's
> supposed to save power by only running a pump when needed.
> Running a light bulb all the time defeats the point. Also, in
> the summer, the bulb might drive the temp in there over the
> BS2's other temperature limit.
>
> 2) Have the light bulb only go on when it's cold - the BS2 is
> watching the temp anyway. But this means redesigning the
> circuit, adding another relay, larger enclosure... very big pain.
>
> 3) Industrial BS2. Good to -40F, which covers any winter I
> expect to see here, but a $54 solution, which probably
> offsets the power savings the circuit's supposed to be
> providing. Anyone know if the industrial version is really
> good to -40F? What's different about the chip?
>
> *mutter* Any better suggestions?
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
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>
> To visit your group on the web, go to:
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>
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>
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> http://docs.yahoo.com/info/terms/
>
>
>
>
I like the heat when cold scheme. You could control the bulb with a
transistor, less space and easy to "scab" onto the project.
Electronics Goldmine used to have (and may still) little flexible heating
elements with a sticky backing. Might be a good solution and use less power
than the bulb. Add a little insulation too maybe.
You forgot one solution: Move to where it never gets cold. Then you can use
the Stamp for something else ;-)
Jonathan
www.madlabs.info
Original Message
From: "Scott" <scott@m...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, January 03, 2004 7:53 AM
Subject: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
> I expect the short answer is going to be, get the industrial BS2. But
that's
> $54, and I want to check my facts first.
>
> I have a BS2 that controls a pump, and runs it when water gets cold (to
> prevent it from freezing). The circuit lives outside, in a sealed box, in
> Massachusetts winters, where sub-32F is fairly common and sub-0F is
> possible. I thought the power transformer would generate enough heat to
keep
> the BS2 happy. I was wrong. The circuit failed when it got below 30F
> outside. True to spec, the BS2 acted up, and didn't get normal until it
was
> brought inside for ten minutes. (The way it acted up was odd: it booted
when
> power was applied, ran well enough to flash the initial "I'm starting up"
> LED, and then rebooted itself a few seconds later, probably when it tried
to
> signal the relay to close. Does the BS2 get more voltage sensitive when it
> gets cold?)
>
> Anyway, my options are
>
> 1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage:
easy
> solution. Disadvantage: the circuit's supposed to save power by only
running
> a pump when needed. Running a light bulb all the time defeats the point.
> Also, in the summer, the bulb might drive the temp in there over the BS2's
> other temperature limit.
>
> 2) Have the light bulb only go on when it's cold - the BS2 is watching the
> temp anyway. But this means redesigning the circuit, adding another relay,
> larger enclosure... very big pain.
>
> 3) Industrial BS2. Good to -40F, which covers any winter I expect to see
> here, but a $54 solution, which probably offsets the power savings the
> circuit's supposed to be providing. Anyone know if the industrial version
is
> really good to -40F? What's different about the chip?
>
> *mutter* Any better suggestions?
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/basicstamps/
>
> To unsubscribe from this group, send an email to:
> basicstamps-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>
>
>
not getting any condensation on any of your electronics that could be
problematic. I used to work in the irrigation industry and we put
heating elements in golf course controllers to drive out moisture,
temperature was rarely a factor (the controllers didn't run, but were
left powered during the winter months to prevent condensation-related
problems).
Of your choices, #2 is probably the easiest to implement. And if it is
indeed the Stamp that isn't tolerating the cold, you might just switch
on a power resister that is physically close to the Stamp.
-- Jon Williams
-- Parallax
Original Message
From: Scott [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=SPvFw4VgKNCp5eAZnp8IHY7J2cdYY6gp0UfEmlsTL6gtDQeTc23Zl1A9zM0wgNP3kVPyCzD3vlw]scott@m...[/url
Sent: Saturday, January 03, 2004 9:53 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
I expect the short answer is going to be, get the industrial BS2. But
that's $54, and I want to check my facts first.
I have a BS2 that controls a pump, and runs it when water gets cold (to
prevent it from freezing). The circuit lives outside, in a sealed box,
in Massachusetts winters, where sub-32F is fairly common and sub-0F is
possible. I thought the power transformer would generate enough heat to
keep the BS2 happy. I was wrong. The circuit failed when it got below
30F outside. True to spec, the BS2 acted up, and didn't get normal until
it was brought inside for ten minutes. (The way it acted up was odd: it
booted when power was applied, ran well enough to flash the initial "I'm
starting up" LED, and then rebooted itself a few seconds later, probably
when it tried to signal the relay to close. Does the BS2 get more
voltage sensitive when it gets cold?)
Anyway, my options are
1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage:
easy solution. Disadvantage: the circuit's supposed to save power by
only running a pump when needed. Running a light bulb all the time
defeats the point. Also, in the summer, the bulb might drive the temp in
there over the BS2's other temperature limit.
2) Have the light bulb only go on when it's cold - the BS2 is watching
the temp anyway. But this means redesigning the circuit, adding another
relay, larger enclosure... very big pain.
3) Industrial BS2. Good to -40F, which covers any winter I expect to see
here, but a $54 solution, which probably offsets the power savings the
circuit's supposed to be providing. Anyone know if the industrial
version is really good to -40F? What's different about the chip?
*mutter* Any better suggestions?
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
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abuse@p....
water you're pumping around. It not hot water you're running i guess
but i don't think it's -30F.
It's a bit like water cooling but then the reverse way.
You can also put the stamp a few foot under the ground (with the
enclosure [noparse]:)[/noparse]. Don't think it will get that cold down there.
Both will also work if the power is the problem.
Peter
--- In basicstamps@yahoogroups.com, "Scott" <scott@m...> wrote:
> I expect the short answer is going to be, get the industrial BS2.
But that's
> $54, and I want to check my facts first.
>
> I have a BS2 that controls a pump, and runs it when water gets cold
(to
> prevent it from freezing). The circuit lives outside, in a sealed
box, in
> Massachusetts winters, where sub-32F is fairly common and sub-0F is
> possible. I thought the power transformer would generate enough
heat to keep
> the BS2 happy. I was wrong. The circuit failed when it got below 30F
> outside. True to spec, the BS2 acted up, and didn't get normal
until it was
> brought inside for ten minutes. (The way it acted up was odd: it
booted when
> power was applied, ran well enough to flash the initial "I'm
starting up"
> LED, and then rebooted itself a few seconds later, probably when it
tried to
> signal the relay to close. Does the BS2 get more voltage sensitive
when it
> gets cold?)
>
> Anyway, my options are
>
> 1) put a 5w bulb in the enclosure, to keep it warm in there.
Advantage: easy
> solution. Disadvantage: the circuit's supposed to save power by
only running
> a pump when needed. Running a light bulb all the time defeats the
point.
> Also, in the summer, the bulb might drive the temp in there over
the BS2's
> other temperature limit.
>
> 2) Have the light bulb only go on when it's cold - the BS2 is
watching the
> temp anyway. But this means redesigning the circuit, adding another
relay,
> larger enclosure... very big pain.
>
> 3) Industrial BS2. Good to -40F, which covers any winter I expect
to see
> here, but a $54 solution, which probably offsets the power savings
the
> circuit's supposed to be providing. Anyone know if the industrial
version is
> really good to -40F? What's different about the chip?
>
> *mutter* Any better suggestions?
possibility. One way to test for this is chilling spray (used to use Freon
until it tore a hole in the ozone layer, etc... but I think there's 'zone
friendly versions available now). That and a hair dryer will usually force
any temperature sensitive components or connections to fail.
What to check for???? Well, I've seen more solder connections fail than I
can count. Most of the time that's due to an oxidized surface on a wire
that's not been cleaned and tinned properly before soldering. That or using
too low of a temp iron. This produces a mechanical connection rather than a
eutectic bond at the molecular level which is the heart of a good solder
joint. You can see where a temperature change can cause this mechanical
joint to loosen up and fail, which is typically the case. Also, I've seen
this be the cause of a lot of vibration failure, where you tap on the board
and it mysteriously starts or stops working. Nine out of ten times, it's a
failed solder joint of some sort. Let the fires be hot, I always say.
On that topic, I did a stint supervising military component soldering a
while back where we built D/A converters used in missile guidance systems.
The soldering wave tanks we were using had become contaminated with gold
(washed off from the gold plated resistor leads) which caused the solder
bond to fail, producing a mechanical joint instead. After bouncing around in
a submarine for 18 months, the missile using this component was shot off as
part of a war games exercise. And guess what??? That solder joint failed at
the worst possible time, causing the missile to do a hard 90 degree turn and
head towards civilization. It had to be destroyed before hitting anything
important. The military guys wouldn't tell me exactly where this happened,
but they were REALLY mad. That's why I say that when we screw up, worlds can
collide. Very nearly did that day....
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "Al Williams" <alw@a...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, January 03, 2004 11:23 AM
Subject: RE: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
> One thought: make sure the Stamp is the only part failing. What you
describe
> sounds like it could be a power supply problem.
>
> If I were to approach this, I'd try to breadboard the pieces separately
and
> run parts of them in my deep freeze and study how they fail.
>
> You probably should have the industrial Stamp, but it would be a shame to
> put it in only to find out something else is failing at temperature.
>
> Since you have a power transformer, I wonder if you could stuff the box
with
> fiberglass insulation to trap more of the heat? I also think that if I
were
> going to heat with 5W, I would use a piece of nichrome or a big resistor
and
> not a bulb (the bulb will burn out).
>
> Regards,
>
> Al Williams
> AWC
> * Universal Relay Card: http://www.al-williams.com/kp1.htm
>
>
> >
Original Message
> > From: Scott [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=TaY4_FYNG6oQizl9xlD-5gVMtWIiLK0kDxXYFTFl37zYGZKnTFuk3IL5y2OAFMp-g3NA7-T7]scott@m...[/url
> > Sent: Saturday, January 03, 2004 9:53 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
> >
> >
> > I expect the short answer is going to be, get the industrial
> > BS2. But that's $54, and I want to check my facts first.
> >
> > I have a BS2 that controls a pump, and runs it when water
> > gets cold (to prevent it from freezing). The circuit lives
> > outside, in a sealed box, in Massachusetts winters, where
> > sub-32F is fairly common and sub-0F is possible. I thought
> > the power transformer would generate enough heat to keep the
> > BS2 happy. I was wrong. The circuit failed when it got below
> > 30F outside. True to spec, the BS2 acted up, and didn't get
> > normal until it was brought inside for ten minutes. (The way
> > it acted up was odd: it booted when power was applied, ran
> > well enough to flash the initial "I'm starting up" LED, and
> > then rebooted itself a few seconds later, probably when it
> > tried to signal the relay to close. Does the BS2 get more
> > voltage sensitive when it gets cold?)
> >
> > Anyway, my options are
> >
> > 1) put a 5w bulb in the enclosure, to keep it warm in there.
> > Advantage: easy solution. Disadvantage: the circuit's
> > supposed to save power by only running a pump when needed.
> > Running a light bulb all the time defeats the point. Also, in
> > the summer, the bulb might drive the temp in there over the
> > BS2's other temperature limit.
> >
> > 2) Have the light bulb only go on when it's cold - the BS2 is
> > watching the temp anyway. But this means redesigning the
> > circuit, adding another relay, larger enclosure... very big pain.
> >
> > 3) Industrial BS2. Good to -40F, which covers any winter I
> > expect to see here, but a $54 solution, which probably
> > offsets the power savings the circuit's supposed to be
> > providing. Anyone know if the industrial version is really
> > good to -40F? What's different about the chip?
> >
> > *mutter* Any better suggestions?
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Yahoo! Groups Links
> >
> > To visit your group on the web, go to:
> > http://groups.yahoo.com/group/basicstamps/
> >
> > To unsubscribe from this group, send an email to:
> > basicstamps-unsubscribe@yahoogroups.com
> >
> > Your use of Yahoo! Groups is subject to:
> > http://docs.yahoo.com/info/terms/
> >
> >
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/basicstamps/
>
> To unsubscribe from this group, send an email to:
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>
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> http://docs.yahoo.com/info/terms/
>
>
>
> You forgot one solution: Move to where it never gets cold.
> Then you can use the Stamp for something else ;-)
That's my answer! I always say the human body is something like 70% water.
Water freezes at 0C and boils at 100C. So don't live where it drops below 0C
or goes above 100C. Now it gets hot in Houston, but it hasn't been to 100C
yet.
Al Williams
AWC
http://www.al-williams.com/awce
It's not a soldier joint. I don't soldier my circuits, I leave them in Radio
Shack breadboards. My thinking is the breadboard is 10-14$, and my time for
soldering even ten or so components is significant (I'm not graceful with
irons) - plus I'll probably fry some temperature-sensitive component in the
process. Breadboards are great. And when I no longer need the circuit,
disassembly is trivial. :-)
Burying the enclosure is tempting, I think at 3' under, temperature is
stable at about 45-50F. Wish I'd though of this before the ground froze.
This might be my solution come Spring.
I don't think it's the other components. There was no condensation inside
(and the enclosure was sealed with aquarium sealant), and the only other
components are a pn2907, a pn2222a, some 7805s, bridge rectifiers, some
caps, diodes and resistors, and the sealed relay. These are all well behaved
in cold, dry air as far as I know: and the BS2 specifically states it will
fail at 32F. The behaviour was exactly that of a BS2 rebooting as soon as it
tried to turn on the relay, via the 2222. The first thing I did when I
pulled it inside was check the supply voltage; it was a solid 5v. The BS2
didn't work for ten minutes after that. At any rate, if the one of the other
components had failed, like the RC for the temperature sensor or the
transistor that checks water level, the BS2 was set up to flash an error
pattern on the LED. It didn't.
Pumping the water near the BS2. Makes me nervous. And the water might be
near 32F.
Moving somewhere warm... tempting. Someday, maybe. :-)
Probably time for the industrial BS2. *mutter*
especialy temperture extreams thermal expansion in the
board will cause you to get loose connections just
like some of the old ic sockets you will be better off
getting the pc board that matches the solderless board
and soldering the connections you will never get a
long term stable circuit on the bread board good luck
--- Scott <scott@m...> wrote:
> Thanks for the many suggestions!
>
> It's not a soldier joint. I don't soldier my
> circuits, I leave them in Radio
> Shack breadboards. My thinking is the breadboard is
> 10-14$, and my time for
> soldering even ten or so components is significant
> (I'm not graceful with
> irons) - plus I'll probably fry some
> temperature-sensitive component in the
> process. Breadboards are great. And when I no longer
> need the circuit,
> disassembly is trivial. :-)
>
> Burying the enclosure is tempting, I think at 3'
> under, temperature is
> stable at about 45-50F. Wish I'd though of this
> before the ground froze.
> This might be my solution come Spring.
>
> I don't think it's the other components. There was
> no condensation inside
> (and the enclosure was sealed with aquarium
> sealant), and the only other
> components are a pn2907, a pn2222a, some 7805s,
> bridge rectifiers, some
> caps, diodes and resistors, and the sealed relay.
> These are all well behaved
> in cold, dry air as far as I know: and the BS2
> specifically states it will
> fail at 32F. The behaviour was exactly that of a BS2
> rebooting as soon as it
> tried to turn on the relay, via the 2222. The first
> thing I did when I
> pulled it inside was check the supply voltage; it
> was a solid 5v. The BS2
> didn't work for ten minutes after that. At any rate,
> if the one of the other
> components had failed, like the RC for the
> temperature sensor or the
> transistor that checks water level, the BS2 was set
> up to flash an error
> pattern on the LED. It didn't.
>
> Pumping the water near the BS2. Makes me nervous.
> And the water might be
> near 32F.
>
> Moving somewhere warm... tempting. Someday, maybe.
> :-)
>
> Probably time for the industrial BS2. *mutter*
>
>
>
> To UNSUBSCRIBE, just send mail to:
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>
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the problem.
1) condensation forms in a thin layer on circuit boards when
temperature drops rapidly. This is particularly a problem with
enclosures that are exposed directly to sun and sky, because the
pressure and temperature changes will be extreme. -- Put the
enclosure in a sheltered location, or inside a second box and
radiation shield -- Be sure the seals on the box are tight,
alternatively, use a goretex vent to keep the inside and outside
pressure equalized -- if the seal is pressure tight, use a silica
gel desiccant inside the enclosure -- coat the circuit boards with
silicone resin conformal coating.
2) Increase the capacitance of your filter capacitors. Sprinkle
around more bypass capacitors. It sounds like you have a reset
problem. Some capacitors, particularly electrolytic types, are
temperature dependent, so you have to double up in the cold, and add
a low ESR bypass.
3) Use good grounding and avoid ground loops. When the earth gets
wet and condensation forms on surfaces, the whole ground plane
situation changes. Wires running close to the ground are more
susceptible to ground current effects. Films of moisture on your
enclosure can act either as an antenna or a shield.
5) Inspect the circuit carefully for weak connections and cold
solder joints, (like Mike suggested in that crazy missile example.
Gulp.)
6) If all the above precautions are taken, then start thinking
about an industrial Stamp. (Most garden variety Stamps would
probably test good for industrial specs--it is all in the
qualification process at all levels of manufacturing and deployment.)
-- regards,
Tracy Allen
electronically monitored ecosystems
mailto:tracy@e...
http://www.emesystems.com
>I expect the short answer is going to be, get the industrial BS2. But that's
>$54, and I want to check my facts first.
>
>I have a BS2 that controls a pump, and runs it when water gets cold (to
>prevent it from freezing). The circuit lives outside, in a sealed box, in
>Massachusetts winters, where sub-32F is fairly common and sub-0F is
>possible. I thought the power transformer would generate enough heat to keep
>the BS2 happy. I was wrong. The circuit failed when it got below 30F
>outside. True to spec, the BS2 acted up, and didn't get normal until it was
>brought inside for ten minutes. (The way it acted up was odd: it booted when
>power was applied, ran well enough to flash the initial "I'm starting up"
>LED, and then rebooted itself a few seconds later, probably when it tried to
>signal the relay to close. Does the BS2 get more voltage sensitive when it
>gets cold?)
>
>Anyway, my options are
>
>1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage: easy
>solution. Disadvantage: the circuit's supposed to save power by only running
>a pump when needed. Running a light bulb all the time defeats the point.
>Also, in the summer, the bulb might drive the temp in there over the BS2's
>other temperature limit.
>
>2) Have the light bulb only go on when it's cold - the BS2 is watching the
>temp anyway. But this means redesigning the circuit, adding another relay,
>larger enclosure... very big pain.
>
>3) Industrial BS2. Good to -40F, which covers any winter I expect to see
>here, but a $54 solution, which probably offsets the power savings the
>circuit's supposed to be providing. Anyone know if the industrial version is
>really good to -40F? What's different about the chip?
>
>*mutter* Any better suggestions?
"thermal ratcheting" where temperature cycling caused IC chips to walk up
out of their sockets after a few months of being turned on and off. This
resulted in the contacts ending up on a little oxide pad, resulting in
failure. Popping the IC's back down with your fingers would correct the
problem for a while, but 6 months later the board would fail again. The only
two methods we found foolproof were "properly" soldered connections, and
wire-wrap connections. A properly done wire-wrap connection is gas-tight,
eliminating the oxide issue. It's what the phone company uses for its
connections, and if memory serves Bell Labs claimed they've never had a
properly made wire-wrap connection fail due to corrosion or thermal
ratcheting issues.
That being said, I really like breadboards for testing circuits, but always
commit to soldering for anything that's permanent. Don't fear solder. A
properly done solder connection is a thing of beauty, jewel-like in
appearance. And a solder sucker and some wire-braid is all that's needed to
take them apart. Most intermittent "electronic" failures are a connection
issue of some sort. Even an IC that itself is intermittently bad is
typically some sort of internal connection failure you can't get at.
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "kenneth magers" <kenneth_m_73149@y...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, January 03, 2004 3:12 PM
Subject: Re: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
> solderless breadboards are great but after a time and
> especialy temperture extreams thermal expansion in the
> board will cause you to get loose connections just
> like some of the old ic sockets you will be better off
> getting the pc board that matches the solderless board
> and soldering the connections you will never get a
> long term stable circuit on the bread board good luck
>
> --- Scott <scott@m...> wrote:
> > Thanks for the many suggestions!
> >
> > It's not a soldier joint. I don't soldier my
> > circuits, I leave them in Radio
> > Shack breadboards. My thinking is the breadboard is
> > 10-14$, and my time for
> > soldering even ten or so components is significant
> > (I'm not graceful with
> > irons) - plus I'll probably fry some
> > temperature-sensitive component in the
> > process. Breadboards are great. And when I no longer
> > need the circuit,
> > disassembly is trivial. :-)
> >
> > Burying the enclosure is tempting, I think at 3'
> > under, temperature is
> > stable at about 45-50F. Wish I'd though of this
> > before the ground froze.
> > This might be my solution come Spring.
> >
> > I don't think it's the other components. There was
> > no condensation inside
> > (and the enclosure was sealed with aquarium
> > sealant), and the only other
> > components are a pn2907, a pn2222a, some 7805s,
> > bridge rectifiers, some
> > caps, diodes and resistors, and the sealed relay.
> > These are all well behaved
> > in cold, dry air as far as I know: and the BS2
> > specifically states it will
> > fail at 32F. The behaviour was exactly that of a BS2
> > rebooting as soon as it
> > tried to turn on the relay, via the 2222. The first
> > thing I did when I
> > pulled it inside was check the supply voltage; it
> > was a solid 5v. The BS2
> > didn't work for ten minutes after that. At any rate,
> > if the one of the other
> > components had failed, like the RC for the
> > temperature sensor or the
> > transistor that checks water level, the BS2 was set
> > up to flash an error
> > pattern on the LED. It didn't.
> >
> > Pumping the water near the BS2. Makes me nervous.
> > And the water might be
> > near 32F.
> >
> > Moving somewhere warm... tempting. Someday, maybe.
> > :-)
> >
> > Probably time for the industrial BS2. *mutter*
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> > Text in the Subject and Body of the message will be
> > ignored.
> >
> >
> > Yahoo! Groups Links
> >
> > To visit your group on the web, go to:
> > http://groups.yahoo.com/group/basicstamps/
> >
> > To unsubscribe from this group, send an email to:
> > basicstamps-unsubscribe@yahoogroups.com
> >
> > Your use of Yahoo! Groups is subject to:
> > http://docs.yahoo.com/info/terms/
> >
> >
>
>
> __________________________________
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>
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stability!
Al Williams
AWC
*New kits: http://www.al-williams.com/kits.htm
>
Original Message
> From: Scott [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=eeSfbUBftK6_IWowAVST2MFUdkm2lmz8FP7Bsy6KYaQwd5sHx_y1pNlqa-Wy61dhpybXHWQ]scott@m...[/url
> Sent: Saturday, January 03, 2004 12:59 PM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
>
>
> Thanks for the many suggestions!
>
> It's not a soldier joint. I don't soldier my circuits, I
> leave them in Radio Shack breadboards. My thinking is the
> breadboard is 10-14$, and my time for soldering even ten or
> so components is significant (I'm not graceful with
> irons) - plus I'll probably fry some temperature-sensitive
> component in the process. Breadboards are great. And when I
> no longer need the circuit, disassembly is trivial. :-)
>
> Burying the enclosure is tempting, I think at 3' under,
> temperature is stable at about 45-50F. Wish I'd though of
> this before the ground froze. This might be my solution come Spring.
>
> I don't think it's the other components. There was no
> condensation inside (and the enclosure was sealed with
> aquarium sealant), and the only other components are a
> pn2907, a pn2222a, some 7805s, bridge rectifiers, some caps,
> diodes and resistors, and the sealed relay. These are all
> well behaved in cold, dry air as far as I know: and the BS2
> specifically states it will fail at 32F. The behaviour was
> exactly that of a BS2 rebooting as soon as it tried to turn
> on the relay, via the 2222. The first thing I did when I
> pulled it inside was check the supply voltage; it was a solid
> 5v. The BS2 didn't work for ten minutes after that. At any
> rate, if the one of the other components had failed, like the
> RC for the temperature sensor or the transistor that checks
> water level, the BS2 was set up to flash an error pattern on
> the LED. It didn't.
>
> Pumping the water near the BS2. Makes me nervous. And the
> water might be near 32F.
>
> Moving somewhere warm... tempting. Someday, maybe. :-)
>
> Probably time for the industrial BS2. *mutter*
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/basicstamps/
>
> To unsubscribe from this group, send an email to:
> basicstamps-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to:
> http://docs.yahoo.com/info/terms/
>
>
>
>
I think Tracy is on the right path with the noise capacitors. I think if you
buy the Industrial Stamp you will still have to fix the problem.
When it gets cold, does the pump have a harder time starting?
Are you using a relay to power the pump?
Do the relay contacts arc more when it is cold/harder to start the pump?
If so then I would add filtering to all the I/O pins and power to the stamp.
Move the circuit from the breadboard to a PC Board or wirewrap it to get
better environmentally connections.
If the programming cable is left connected for Debug reasons, make sure it is
shielded and far away from the motor relay. This seems to be more sensitive
to noise than the reset pin, and will reset the stamp.
Been there done that, got the postcard.
Hope this helps,
Alan Bradford
Plasma Technologies
In a message dated 1/3/2004 10:55:10 AM Eastern Standard Time,
scott@m... writes:
I expect the short answer is going to be, get the industrial BS2. But that's
$54, and I want to check my facts first.
I have a BS2 that controls a pump, and runs it when water gets cold (to
prevent it from freezing). The circuit lives outside, in a sealed box, in
Massachusetts winters, where sub-32F is fairly common and sub-0F is
possible. I thought the power transformer would generate enough heat to keep
the BS2 happy. I was wrong. The circuit failed when it got below 30F
outside. True to spec, the BS2 acted up, and didn't get normal until it was
brought inside for ten minutes. (The way it acted up was odd: it booted when
power was applied, ran well enough to flash the initial "I'm starting up"
LED, and then rebooted itself a few seconds later, probably when it tried to
signal the relay to close. Does the BS2 get more voltage sensitive when it
gets cold?)
Anyway, my options are
1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage: easy
solution. Disadvantage: the circuit's supposed to save power by only running
a pump when needed. Running a light bulb all the time defeats the point.
Also, in the summer, the bulb might drive the temp in there over the BS2's
other temperature limit.
2) Have the light bulb only go on when it's cold - the BS2 is watching the
temp anyway. But this means redesigning the circuit, adding another relay,
larger enclosure... very big pain.
3) Industrial BS2. Good to -40F, which covers any winter I expect to see
here, but a $54 solution, which probably offsets the power savings the
circuit's supposed to be providing. Anyone know if the industrial version is
really good to -40F? What's different about the chip?
*mutter* Any better suggestions?
[noparse][[/noparse]Non-text portions of this message have been removed]
>Thanks for the many suggestions!
>
>I don't think it's the other components. There was no condensation inside
>(and the enclosure was sealed with aquarium sealant), and the only other
>components are a pn2907, a pn2222a, some 7805s,
First thing I'd be looking at is the 7805 regulators - I still have some
hanging around here that make nice, reliable thermostats at -20C. Warmer
than -20C, they work just fine. Colder than -20C, they shut down. Go out
and purchase some 7805BT parts - they are good down to -40. The standard
7805CT parts you get everywhere are only rated down to 0C.
dwayne
--
Dwayne Reid <dwayner@p...>
Trinity Electronics Systems Ltd Edmonton, AB, CANADA
(780) 489-3199 voice (780) 487-6397 fax
Celebrating 19 years of Engineering Innovation (1984 - 2003)
.-. .-. .-. .-. .-. .-. .-. .-. .-. .-
`-' `-' `-' `-' `-' `-' `-' `-' `-'
Do NOT send unsolicited commercial email to this email address.
This message neither grants consent to receive unsolicited
commercial email nor is intended to solicit commercial email.
capsules. Inside of them, it rarely drops below 30, but will during descent. I
haven't
had a problem with the BS2 in the cold temps and low air pressures of the deep
stratosphere.
Paul
> I'm will Al and don't think it's the Stamp. That said, make sure you're
> not getting any condensation on any of your electronics that could be
> problematic. I used to work in the irrigation industry and we put
> heating elements in golf course controllers to drive out moisture,
> temperature was rarely a factor (the controllers didn't run, but were
> left powered during the winter months to prevent condensation-related
> problems).
>
> Of your choices, #2 is probably the easiest to implement. And if it is
> indeed the Stamp that isn't tolerating the cold, you might just switch
> on a power resister that is physically close to the Stamp.
>
> -- Jon Williams
> -- Parallax
>
>
>
Original Message
> From: Scott [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=MxVpQjGTAut4gg3KfKBdjD3Ge_vWCXj3LHtYwnPnfbFNZqs4w09q45VOUwZ87zzZs_46eXMnzA]scott@m...[/url
> Sent: Saturday, January 03, 2004 9:53 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
>
>
> I expect the short answer is going to be, get the industrial BS2. But
> that's $54, and I want to check my facts first.
>
> I have a BS2 that controls a pump, and runs it when water gets cold (to
> prevent it from freezing). The circuit lives outside, in a sealed box,
> in Massachusetts winters, where sub-32F is fairly common and sub-0F is
> possible. I thought the power transformer would generate enough heat to
> keep the BS2 happy. I was wrong. The circuit failed when it got below
> 30F outside. True to spec, the BS2 acted up, and didn't get normal until
> it was brought inside for ten minutes. (The way it acted up was odd: it
> booted when power was applied, ran well enough to flash the initial "I'm
> starting up" LED, and then rebooted itself a few seconds later, probably
> when it tried to signal the relay to close. Does the BS2 get more
> voltage sensitive when it gets cold?)
>
> Anyway, my options are
>
> 1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage:
> easy solution. Disadvantage: the circuit's supposed to save power by
> only running a pump when needed. Running a light bulb all the time
> defeats the point. Also, in the summer, the bulb might drive the temp in
> there over the BS2's other temperature limit.
>
> 2) Have the light bulb only go on when it's cold - the BS2 is watching
> the temp anyway. But this means redesigning the circuit, adding another
> relay, larger enclosure... very big pain.
>
> 3) Industrial BS2. Good to -40F, which covers any winter I expect to see
> here, but a $54 solution, which probably offsets the power savings the
> circuit's supposed to be providing. Anyone know if the industrial
> version is really good to -40F? What's different about the chip?
>
> *mutter* Any better suggestions?
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject
> and Body of the message will be ignored.
>
>
> Yahoo! Groups Links
>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/basicstamps/
>
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>
>
>
>
> This message has been scanned by WebShield. Please report SPAM to
> abuse@p....
>
>
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of the message will be ignored.
>
>
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>
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/basicstamps/
>
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>
>
How are you powering the BS2?
How cold can a battery get and still work?
It's possible the batteries are reducing
their voltage -- which a new BS2 wouldn't
fix.
The 5-watt lightbulb may be overkill in the
heater departement. Perhaps a low-value
high wattage resistor could provide enough
heat? Some experimentation may be in order.
--- In basicstamps@yahoogroups.com, "Scott" <scott@m...> wrote:
> I expect the short answer is going to be, get the industrial BS2.
But that's
> $54, and I want to check my facts first.
>
> I have a BS2 that controls a pump, and runs it when water gets cold
(to
> prevent it from freezing). The circuit lives outside, in a sealed
box, in
> Massachusetts winters, where sub-32F is fairly common and sub-0F is
> possible. I thought the power transformer would generate enough
heat to keep
> the BS2 happy. I was wrong. The circuit failed when it got below 30F
> outside. True to spec, the BS2 acted up, and didn't get normal
until it was
> brought inside for ten minutes. (The way it acted up was odd: it
booted when
> power was applied, ran well enough to flash the initial "I'm
starting up"
> LED, and then rebooted itself a few seconds later, probably when it
tried to
> signal the relay to close. Does the BS2 get more voltage sensitive
when it
> gets cold?)
>
> Anyway, my options are
>
> 1) put a 5w bulb in the enclosure, to keep it warm in there.
Advantage: easy
> solution. Disadvantage: the circuit's supposed to save power by
only running
> a pump when needed. Running a light bulb all the time defeats the
point.
> Also, in the summer, the bulb might drive the temp in there over
the BS2's
> other temperature limit.
>
> 2) Have the light bulb only go on when it's cold - the BS2 is
watching the
> temp anyway. But this means redesigning the circuit, adding another
relay,
> larger enclosure... very big pain.
>
> 3) Industrial BS2. Good to -40F, which covers any winter I expect
to see
> here, but a $54 solution, which probably offsets the power savings
the
> circuit's supposed to be providing. Anyone know if the industrial
version is
> really good to -40F? What's different about the chip?
>
> *mutter* Any better suggestions?
affects on an enclosure.
Heat....air expands and pushes out seals -- no longer a hermetic seal.
Cold....box contracts and sucks in air through previous pushed out
seals....now draws in moisture.
If you don't have a goretex vent or some sort of membrane.
Just grab some dessicant and leave that in the box (can't have enough of
this stuff).
Drill a hole in the box and using grommets or bits of tubing....secure a
balloon in this new opening. Now, the box will stay dry (dessicant) and it
will allow for expansion without destruction (balloon).
I've seen guys use condoms in a pinch...but be sure they're
non-lubed....ribbed works fine!
sb
Original Message
From: Jon Williams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=xQ3addxvfl6PnYxUpZx4Lkdnz88qGOH45zhoNir44YX1mqb1o-zsEIrqb7XvEvMWTelvbPvoWshF3_xS7g]jwilliams@p...[/url
Sent: January 3, 2004 08:47
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
I'm will Al and don't think it's the Stamp. That said, make sure you're not
getting any condensation on any of your electronics that could be
problematic. I used to work in the irrigation industry and we put heating
elements in golf course controllers to drive out moisture, temperature was
rarely a factor (the controllers didn't run, but were left powered during
the winter months to prevent condensation-related problems).
Of your choices, #2 is probably the easiest to implement. And if it is
indeed the Stamp that isn't tolerating the cold, you might just switch on a
power resister that is physically close to the Stamp.
-- Jon Williams
-- Parallax
Original Message
From: Scott [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=r8Ihyq4KyKZtQptvF8cYgVL040W5FKPzxz8UNeJ5Ugk0qmvgZC4o4eMnsWTKo_qyZBZ3GX9S]scott@m...[/url
Sent: Saturday, January 03, 2004 9:53 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
I expect the short answer is going to be, get the industrial BS2. But that's
$54, and I want to check my facts first.
I have a BS2 that controls a pump, and runs it when water gets cold (to
prevent it from freezing). The circuit lives outside, in a sealed box, in
Massachusetts winters, where sub-32F is fairly common and sub-0F is
possible. I thought the power transformer would generate enough heat to keep
the BS2 happy. I was wrong. The circuit failed when it got below 30F
outside. True to spec, the BS2 acted up, and didn't get normal until it was
brought inside for ten minutes. (The way it acted up was odd: it booted when
power was applied, ran well enough to flash the initial "I'm starting up"
LED, and then rebooted itself a few seconds later, probably when it tried to
signal the relay to close. Does the BS2 get more voltage sensitive when it
gets cold?)
Anyway, my options are
1) put a 5w bulb in the enclosure, to keep it warm in there. Advantage: easy
solution. Disadvantage: the circuit's supposed to save power by only running
a pump when needed. Running a light bulb all the time defeats the point.
Also, in the summer, the bulb might drive the temp in there over the BS2's
other temperature limit.
2) Have the light bulb only go on when it's cold - the BS2 is watching the
temp anyway. But this means redesigning the circuit, adding another relay,
larger enclosure... very big pain.
3) Industrial BS2. Good to -40F, which covers any winter I expect to see
here, but a $54 solution, which probably offsets the power savings the
circuit's supposed to be providing. Anyone know if the industrial version is
really good to -40F? What's different about the chip?
*mutter* Any better suggestions?
To UNSUBSCRIBE, just send mail to:
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> capsules. Inside of them, it rarely drops below 30, but will during
descent. I haven't
> had a problem with the BS2 in the cold temps and low air pressures of the
deep
> stratosphere.
I have to admit, I threw the whole circuit into my freezer and ran it for
hours, and it didn't act up once, even driving the same sort of load. So I
have no idea what went wrong, but I think I've cleared my BS2 of the charge
of failing at 32F. Experimentation continues.
went well until the temperature dropped below 20 degrees, then I started getting
false pulses in the circuit after several hours of operation. From what I
have found there is a way to debounce the pulses, which might have solved that
problem. I guess I'll have to wait till next year to try it.
[noparse][[/noparse]Non-text portions of this message have been removed]
SOME of the components on it can handle the
low temps, some can't.
The Industrial version has low-temp versions
of all components.
In any group of IC's, some will handle low
temperatures better than others. In the BS2,
there are so many components (eeprom,
regulator, 232 transistors, PIC, resonator)
that getting a complete set that will
handle low temps (down to -20 C) is unlikely
unless Parallax selected the components
themselves.
Having said that, I thought the non-low-temp
BS2 would handle down to 0 C, which is why
our posts have suggested some other cause
for your current problem.
--- In basicstamps@yahoogroups.com, "Scott" <scott@m...> wrote:
> > I fly BS2s into near space where the temps drop to -60 degrees
outside the
> > capsules. Inside of them, it rarely drops below 30, but will
during
> descent. I haven't
> > had a problem with the BS2 in the cold temps and low air
pressures of the
> deep
> > stratosphere.
>
> I have to admit, I threw the whole circuit into my freezer and ran
it for
> hours, and it didn't act up once, even driving the same sort of
load. So I
> have no idea what went wrong, but I think I've cleared my BS2 of
the charge
> of failing at 32F. Experimentation continues.
totally yet), the stamp will go off into limbo. Some of this I traced to
brush noise from a nearby motor-fixed that<G>. I also soldered a 1 uF cap
across the power pins of the stamp, right at the bottom of the socket.
I also put a small cap .047 on the rs232 talk back line to the computer and
this fixed another occasional leap into limbo. I was using debug statements
running almost continuously to let me know what was going on. When the line
wasn't loaded with a computer, a hic-up would occur.
Note that this is an odd thing, and I consider it a normal part of circuit
debugging. Not slamming the stamp one bit!! Good beast<G>.
Original Message
From: maxiomega@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=zys858_inzNbau3xW2fkPyQQkUeBpoiMYz1KIpK3Z0Qjxq3b1YYGaNhdjitGH3VpMG9XA9k4dyCjxdLc]maxiomega@a...[/url
Sent: Monday, January 05, 2004 7:52 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
I had 4-BS2's running 17,400 Christmas lights for Christmas. I found all
went well until the temperature dropped below 20 degrees, then I started
getting
false pulses in the circuit after several hours of operation. From what I
have found there is a way to debounce the pulses, which might have solved
that
problem. I guess I'll have to wait till next year to try it.
[noparse][[/noparse]Non-text portions of this message have been removed]
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of series inductance, making them "open up" at radio frequencies. So tack a
little disc cap of a few hundred pico-farads in parallel with a 10 ufd
electorlytic cap on your power supply feed and you'll shunt out both the
low-frequency noise and the high-frequency noise. That's why you sometime
see little disc caps on top of big electrolytic cans... for the rf noise.
I also found out the hard way that a standard jelly-roll electorlytic cap
doesn't like living in a switched-mode power supply for the same reason.
They use folded element caps with low inductance in those applications for
the same reason.
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "Grover Richardson" <grover.richardson@g...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, January 06, 2004 11:54 AM
Subject: RE: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
> I have found that under certain conditions (which I haven't figured out
> totally yet), the stamp will go off into limbo. Some of this I traced to
> brush noise from a nearby motor-fixed that<G>. I also soldered a 1 uF cap
> across the power pins of the stamp, right at the bottom of the socket.
>
> I also put a small cap .047 on the rs232 talk back line to the computer
and
> this fixed another occasional leap into limbo. I was using debug
statements
> running almost continuously to let me know what was going on. When the
line
> wasn't loaded with a computer, a hic-up would occur.
>
> Note that this is an odd thing, and I consider it a normal part of circuit
> debugging. Not slamming the stamp one bit!! Good beast<G>.
>
>
Original Message
> From: maxiomega@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=tdz4weLY-uURd7PmqoHSbSMqiNb-pjlO1wRJ-M_0vi_tP10mqZqO68dMbRQreDWz1opmed57Dw]maxiomega@a...[/url
> Sent: Monday, January 05, 2004 7:52 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] BS2 gets cold and reboots...
>
>
> I had 4-BS2's running 17,400 Christmas lights for Christmas. I found all
> went well until the temperature dropped below 20 degrees, then I started
> getting
> false pulses in the circuit after several hours of operation. From what I
> have found there is a way to debounce the pulses, which might have solved
> that
> problem. I guess I'll have to wait till next year to try it.
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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> Body of the message will be ignored.
>
>
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>
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>
This might be a project worth describing. :-)