Driver to drive?

Robert Macy · Apr 5, 2012

On Apr 5, 9:00 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:

On Thu, 5 Apr 2012 05:52:39 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 4, 7:15 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
Robert Macy wrote:
On Apr 3, 3:13 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

...snip...
if air current movement is all that is being looked for, then, the
simple mass air flow sensor I made with 0.005 bronze wire as the sensor
would work great..
That was so sensitive with a 6 foot center tapped wire that one could
stand ~ 10-15 feet away and blow just slightly through their lips and it
would react to it. Of course, that meant setting the threshold to a
critical point.

jamie

FASCINATING! Elaborate?

Where did you get 36 Awg bronze wire? What is the mechanism of
conversion from air mass movement to electrical signal? How accurate
must the center tap be? ....

I have an advantage when it comes to getting the wire, I work at a
place where we make many cables, wires etc, products. Fine bronze wire
is just one of those components we use in braid. I just walked out and
grab some from stock

Any way, you can get it on small rolls from various places. We used a
comparator circuit. We just set a fixed reference that can be trimmed on
one input and a voltage divided reference via the bronze wire on the
other input.

If you place one half of the tapped, lets say the lower side in the
area of interest but not in the breeze way, it'll be able to be at the
ambient temperature as the top half. The top half will be exposed to
the expected air flow.

The top side of this voltage divider is connected to the (+) rail
where a small amount of current will be present and cause the wire to
heat up
just a little bit.

When the top wire cools due to air flow around it, the R value on the
top side will drop. This drop will of course cause more current and
force the lower side to heat up even more and raise in R at the same
time. So the effect works for you in both aspects.

In the end, you get a nice effect and it reacts very quickly.

Since comparators and op-amps have such a high gain to start with, it
does not take much to fully switch the state. One could clean it up a
bit with a little hysteresis added.

If you need a basic ASCII schematic I can plop one where.

Jamie

EXCELLENT description. I never thought of running current through the
wire!

Is that an ASCII netlist? like PSpice .cir file?

If in LTspice, the .asc file is also ASCII, starts with line that says
version 4.

post here or send direclty to me

....apologies to original poster for hijacking his original thread.

However, I still recommend to him to get a fast updating altimeter -
that is a low frequency microphone. Didn't say how low? I think it's
called a geophone, or something like that.

For my Bachelor's thesis at MIT (in conjunction with Harvard Med
School) I used two very small thermistors on the end of a catheter,
one with current to heat it, one without, to measure blood flow in the
heart...

www.analog-innovations.com/BS_Thesis_JE_Thompson_1962.pdf

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Isn't Doppler less intrusive?

Jim Thompson · Apr 5, 2012

On Thu, 5 Apr 2012 15:06:09 -0700 (PDT), Robert Macy
<robert.a.macy@gmail.com> wrote:

On Apr 5, 9:51 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Thu, 5 Apr 2012 09:39:53 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 5, 9:00 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Thu, 5 Apr 2012 05:52:39 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 4, 7:15 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
Robert Macy wrote:
On Apr 3, 3:13 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

...snip...
if air current movement is all that is being looked for, then, the
simple mass air flow sensor I made with 0.005 bronze wire as the sensor
would work great..
That was so sensitive with a 6 foot center tapped wire that one could
stand ~ 10-15 feet away and blow just slightly through their lips and it
would react to it. Of course, that meant setting the threshold to a
critical point.

jamie

FASCINATING! Elaborate?

Where did you get 36 Awg bronze wire? What is the mechanism of
conversion from air mass movement to electrical signal? How accurate
must the center tap be? ....

I have an advantage when it comes to getting the wire, I work at a
place where we make many cables, wires etc, products. Fine bronze wire
is just one of those components we use in braid. I just walked out and
grab some from stock

Any way, you can get it on small rolls from various places. We used a
comparator circuit. We just set a fixed reference that can be trimmed on
one input and a voltage divided reference via the bronze wire on the
other input.

If you place one half of the tapped, lets say the lower side in the
area of interest but not in the breeze way, it'll be able to be at the
ambient temperature as the top half. The top half will be exposed to
the expected air flow.

The top side of this voltage divider is connected to the (+) rail
where a small amount of current will be present and cause the wire to
heat up
just a little bit.

When the top wire cools due to air flow around it, the R value on the
top side will drop. This drop will of course cause more current and
force the lower side to heat up even more and raise in R at the same
time. So the effect works for you in both aspects.

In the end, you get a nice effect and it reacts very quickly.

Since comparators and op-amps have such a high gain to start with, it
does not take much to fully switch the state. One could clean it up a
bit with a little hysteresis added.

If you need a basic ASCII schematic I can plop one where.

Jamie

EXCELLENT description. I never thought of running current through the
wire!

Is that an ASCII netlist? like PSpice .cir file?

If in LTspice, the .asc file is also ASCII, starts with line that says
version 4.

post here or send direclty to me

....apologies to original poster for hijacking his original thread.

However, I still recommend to him to get a fast updating altimeter -
that is a low frequency microphone. Didn't say how low? I think it's
called a geophone, or something like that.

For my Bachelor's thesis at MIT (in conjunction with Harvard Med
School) I used two very small thermistors on the end of a catheter,
one with current to heat it, one without, to measure blood flow in the
heart...

www.analog-innovations.com/BS_Thesis_JE_Thompson_1962.pdf

...Jim Thompson
[snip]

Isn't Doppler less intrusive?

(1) _50_ years ago.

(2) The doctor researchers were using it to evaluate _energy_ input to
the heart.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.

In 1977 I designed ultrasonic echocardiography instrumentation for
Smith Kline. Doppler was used then to 'profile' the flow across the
diameter of the aorta, thereby calculating blood flow volume. Hmmm
2012-1977=45 years. Oh, so we were new on the block, eh?

Robert Macy · Apr 6, 2012

On Apr 5, 9:51 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:

On Thu, 5 Apr 2012 09:39:53 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 5, 9:00 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Thu, 5 Apr 2012 05:52:39 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 4, 7:15 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
Robert Macy wrote:
On Apr 3, 3:13 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

...snip...
if air current movement is all that is being looked for, then, the
simple mass air flow sensor I made with 0.005 bronze wire as the sensor
would work great..
That was so sensitive with a 6 foot center tapped wire that one could
stand ~ 10-15 feet away and blow just slightly through their lips and it
would react to it. Of course, that meant setting the threshold to a
critical point.

jamie

FASCINATING! Elaborate?

Where did you get 36 Awg bronze wire? What is the mechanism of
conversion from air mass movement to electrical signal? How accurate
must the center tap be? ....

I have an advantage when it comes to getting the wire, I work at a
place where we make many cables, wires etc, products. Fine bronze wire
is just one of those components we use in braid. I just walked out and
grab some from stock

Any way, you can get it on small rolls from various places. We used a
comparator circuit. We just set a fixed reference that can be trimmed on
one input and a voltage divided reference via the bronze wire on the
other input.

If you place one half of the tapped, lets say the lower side in the
area of interest but not in the breeze way, it'll be able to be at the
ambient temperature as the top half. The top half will be exposed to
the expected air flow.

The top side of this voltage divider is connected to the (+) rail
where a small amount of current will be present and cause the wire to
heat up
just a little bit.

When the top wire cools due to air flow around it, the R value on the
top side will drop. This drop will of course cause more current and
force the lower side to heat up even more and raise in R at the same
time. So the effect works for you in both aspects.

In the end, you get a nice effect and it reacts very quickly.

Since comparators and op-amps have such a high gain to start with, it
does not take much to fully switch the state. One could clean it up a
bit with a little hysteresis added.

If you need a basic ASCII schematic I can plop one where.

Jamie

EXCELLENT description. I never thought of running current through the
wire!

Is that an ASCII netlist? like PSpice .cir file?

If in LTspice, the .asc file is also ASCII, starts with line that says
version 4.

post here or send direclty to me

....apologies to original poster for hijacking his original thread.

However, I still recommend to him to get a fast updating altimeter -
that is a low frequency microphone. Didn't say how low? I think it's
called a geophone, or something like that.

For my Bachelor's thesis at MIT (in conjunction with Harvard Med
School) I used two very small thermistors on the end of a catheter,
one with current to heat it, one without, to measure blood flow in the
heart...

www.analog-innovations.com/BS_Thesis_JE_Thompson_1962.pdf

...Jim Thompson
[snip]

Isn't Doppler less intrusive?

(1) _50_ years ago.

(2) The doctor researchers were using it to evaluate _energy_ input to
the heart.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.

In 1977 I designed ultrasonic echocardiography instrumentation for
Smith Kline. Doppler was used then to 'profile' the flow across the
diameter of the aorta, thereby calculating blood flow volume. Hmmm
2012-1977=45 years. Oh, so we were new on the block, eh?

Jim Thompson · Apr 6, 2012

On Fri, 6 Apr 2012 06:39:25 -0700 (PDT), Robert Macy
<robert.a.macy@gmail.com> wrote:

On Apr 5, 3:38 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Thu, 5 Apr 2012 15:06:09 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
[snip]

In 1977 I designed ultrasonic echocardiography instrumentation for
Smith Kline. Doppler was used then to 'profile' the flow across the
diameter of the aorta, thereby calculating blood flow volume. Hmmm
2012-1977=45 years. Oh, so we were new on the block, eh?

You need to hone up on your math skills... 2012-1977=35 years ;-)

I actually had Doppler tests, and everything else imaginable, February
7-16.

...Jim Thompson
[snip]

ARRRRGGGG!!!! ...you sure, 35 years? Guess that roll over in 2000
did a trip to the brain. That's my story and I'm sticking to it.

50 years ago, circa 1962. hmmm. the next summer, I was at University
studying physics and geology, and trying to keep out of trouble on the
field trips, everything from avoiding paternity suits to almost being
shot at by some redneck gas station owner in Wisconsin.

I was graduating from MIT. 50th Reunion in June!

Check up in Feb. Everything came up ok? Soooooo, you discovered why
it's called 'practice medicine' eh?

Robert Macy · Apr 6, 2012

On Apr 5, 3:38 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:

On Thu, 5 Apr 2012 15:06:09 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 5, 9:51 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Thu, 5 Apr 2012 09:39:53 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 5, 9:00 am, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
On Thu, 5 Apr 2012 05:52:39 -0700 (PDT), Robert Macy

robert.a.m...@gmail.com> wrote:
On Apr 4, 7:15 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
Robert Macy wrote:
On Apr 3, 3:13 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

...snip...
if air current movement is all that is being looked for, then, the
simple mass air flow sensor I made with 0.005 bronze wire as the sensor
would work great..
That was so sensitive with a 6 foot center tapped wire that one could
stand ~ 10-15 feet away and blow just slightly through their lips and it
would react to it. Of course, that meant setting the threshold to a
critical point.

jamie

FASCINATING! Elaborate?

Where did you get 36 Awg bronze wire? What is the mechanism of
conversion from air mass movement to electrical signal? How accurate
must the center tap be? ....

I have an advantage when it comes to getting the wire, I work at a
place where we make many cables, wires etc, products. Fine bronze wire
is just one of those components we use in braid. I just walked out and
grab some from stock

Any way, you can get it on small rolls from various places. We used a
comparator circuit. We just set a fixed reference that can be trimmed on
one input and a voltage divided reference via the bronze wire on the
other input.

If you place one half of the tapped, lets say the lower side in the
area of interest but not in the breeze way, it'll be able to be at the
ambient temperature as the top half. The top half will be exposed to
the expected air flow.

The top side of this voltage divider is connected to the (+) rail
where a small amount of current will be present and cause the wire to
heat up
just a little bit.

When the top wire cools due to air flow around it, the R value on the
top side will drop. This drop will of course cause more current and
force the lower side to heat up even more and raise in R at the same
time. So the effect works for you in both aspects.

In the end, you get a nice effect and it reacts very quickly..

Since comparators and op-amps have such a high gain to start with, it
does not take much to fully switch the state. One could clean it up a
bit with a little hysteresis added.

If you need a basic ASCII schematic I can plop one where.

Jamie

EXCELLENT description. I never thought of running current through the
wire!

Is that an ASCII netlist? like PSpice .cir file?

If in LTspice, the .asc file is also ASCII, starts with line that says
version 4.

post here or send direclty to me

....apologies to original poster for hijacking his original thread..

However, I still recommend to him to get a fast updating altimeter -
that is a low frequency microphone. Didn't say how low? I think it's
called a geophone, or something like that.

For my Bachelor's thesis at MIT (in conjunction with Harvard Med
School) I used two very small thermistors on the end of a catheter,
one with current to heat it, one without, to measure blood flow in the
heart...

www.analog-innovations.com/BS_Thesis_JE_Thompson_1962.pdf

...Jim Thompson
[snip]

Isn't Doppler less intrusive?

(1) _50_ years ago.

(2) The doctor researchers were using it to evaluate _energy_ input to
the heart.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.

In 1977 I designed ultrasonic echocardiography instrumentation for
Smith Kline. Doppler was used then to 'profile' the flow across the
diameter of the aorta, thereby calculating blood flow volume. Hmmm
2012-1977=45 years. Oh, so we were new on the block, eh?

You need to hone up on your math skills... 2012-1977=35 years ;-)

I actually had Doppler tests, and everything else imaginable, February
7-16.

...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon athttp://www.analog-innovations.com| 1962 |

I love to cook with wine. Sometimes I even put it in the food.

ARRRRGGGG!!!! ...you sure, 35 years? Guess that roll over in 2000
did a trip to the brain. That's my story and I'm sticking to it.

50 years ago, circa 1962. hmmm. the next summer, I was at University
studying physics and geology, and trying to keep out of trouble on the
field trips, everything from avoiding paternity suits to almost being
shot at by some redneck gas station owner in Wisconsin.

Check up in Feb. Everything came up ok? Soooooo, you discovered why
it's called 'practice medicine' eh?

linnix · Apr 6, 2012

On Apr 4, 10:38 pm, miso <m...@sushi.com> wrote:

http://www.amazon.com/La-Crosse-Technology-BC-9009-AlphaPower/dp/B000...

With such a wide range of good AA/AAA chargers and a dearth of AA/AAA/9V
chargers, I might get a dedicated 9V charger just to take care of those....

Thanks,
Dave

If you go the dedicated 9V charger route, just buy Sayno ENELOOPs with
their charger and junk your old batteries. It is really hard to beat
this technology.

I refuse to buy anything that uses a 9V battery. I often decide between
similar products based on the battery. I pick the prdocut that uses AA
over AAA cell. There is nothing like AA cells. No matter where you go,
you can find AA cells.

AAA are everywhere too, if you look hard enough. One nice thing about
AAA is that with the right adapter, you can fit several of them in a
standard C or D holder. For example, the harbour freight free LED
light has a 3 AAA holder. I want them just for the holder, after
using up the batteries of course. I am building something that could
use 12 AAA rechargeable, so four sets of holders in D battery holder.
I want independently accessible cells so i can monitor all voltages
individually.

notme · Apr 7, 2012

Been using this one, love it.

http://www.lsdbattery.com/chargers/maha-mh-c801d-eight-cell-1-hr-charger/

Greg

And...?

gregz · Apr 7, 2012

"Mr.CRC" <crobcBOGUS@REMOVETHISsbcglobal.net> wrote:

William Sommerwerck wrote:
I own an Energizer CHM4FC, which you can get for around $25. It handles AAA,
AA, C, D, and 9V. There's a NiCd / NiMH switch for cell type. I use it for
5400mAh C cells, and it works fine.

http://data.energizer.com/PDFs/chm4fc.pdf

The catch is... The maximum charge current is ~ 500mA, and you have no
control over what the charger does.

Get a MAHA PowerEx MH-C9000. It does only AA and AAA cells, * but you won't
regret it. You can pick the charge rate, and there are functions (such as
refresh and capacity) not on simple chargers. You can see exactly what's
going on.

http://www.thomasdistributing.com/Maha-Powerex-MH-C9000-AA--AAA-Battery-Chargerbr_p_134.html

The current $52 price seems high (I have two, purchased at around $40 each),
but Thomas occasionally has sales.

* MAHA told me it has no intention of making a C adapter. Rats.

I have that MAHA charger and it can't correctly discharge Sanyo Eneloops
(I think they have a little higher impedance than other cells) and the
charger uses some horrible high current pulse mode.

Then on charge one day it put >3.6Ah into one of my 2Ah cells. I don't
use it anymore.

Then again, I have had troubles with the Lacrosse BC-900 type chargers
too. Only they just break after a while, but work Ok in general.

There are also hobby chargers. I have a Thunderpower at work for some
LiPo cells.

Been using this one, love it.

http://www.lsdbattery.com/chargers/maha-mh-c801d-eight-cell-1-hr-charger/

Greg

gregz · Apr 8, 2012

notme <notme@notme.org> wrote:

Been using this one, love it.

http://www.lsdbattery.com/chargers/maha-mh-c801d-eight-cell-1-hr-charger/

Greg

And...?

Love it.

Greg

notme · Apr 8, 2012

notme <notme@notme.org> wrote:
Been using this one, love it.

http://www.lsdbattery.com/chargers/maha-mh-c801d-eight-cell-1-hr-charger/

Greg

And...?

Love it.

Greg

Because...?

miso · Apr 8, 2012

Battery capacity is proportional to volume, which for a cylinder is
proportional to the radius squared. You make the battery slightly
bigger, you get a lot more capacity. If something needs to be thin,
better to just engineer it to run on rechargeable lithium ion or variants.

So the capacity of the AA is greater than that of the AAA, and at the
same time is about 30% cheaper. You gain both ways.

If you look at say external battery holders for high end cameras, they
use AA cells. If you are a photojournalist working in some hell hole,
you can always get AA cells. GPSs use AA cells. Basically items where
you really need it to work run from AA cells.

In every country on the planet, there are AA cells, AK47 ammo, chickens,
and rental women.

Jasen Betts · Apr 8, 2012

On 2012-04-08, miso <miso@sushi.com> wrote:

Battery capacity is proportional to volume, which for a cylinder is
proportional to the radius squared. You make the battery slightly
bigger, you get a lot more capacity. If something needs to be thin,
better to just engineer it to run on rechargeable lithium ion or variants.

So the capacity of the AA is greater than that of the AAA, and at the
same time is about 30% cheaper. You gain both ways.

If you look at say external battery holders for high end cameras, they
use AA cells. If you are a photojournalist working in some hell hole,
you can always get AA cells. GPSs use AA cells. Basically items where
you really need it to work run from AA cells.

In every country on the planet, there are AA cells, AK47 ammo, chickens,
and rental women.

Even Vatican City?
I mean I'm fairly sure the Swiss Guards don't use AK47s

--
ââ 100% natural

--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

Tom Del Rosso · Apr 27, 2012

Jim Thompson wrote:

http://www.youtube.com/watch?v=CZ-4gnNz0vc&feature=player_embedded

If I wanted America to fail I'd put 45 mammals on the endangered species
list, and 46 clams.

I'd make the cost of regulatory compliance 10% of GDP, not including the
cost of time waiting for approvals.

But that's just what I'd have done in the 20th century. I'd do all sorts of
new things now.

--

Reply in group, but if emailing add one more
zero, and remove the last word.

Jon Elson · Apr 27, 2012

Paul Hovnanian P.E. wrote:

I'm attempting to diagnose some strange electronics behavior. And it seems
to be coming down to this question:

What types of components have failure modes that are temperature
independent and are self healing over a time period of days?

Electrolytic caps immediately come to mind as the most

likely suspect. I have sure seen this sort of thing before.
This can happen with either aluminum or tantalum caps.

There are other things like bad solder joints and internal wire
bonds that can be intermittent, but they usually are not predictable.

Jon

tm · Apr 27, 2012

"Paul Hovnanian P.E." <paul@hovnanian.com> wrote in message
news:q66dnQa4cohKawfSnZ2dnUVZ_qadnZ2d@posted.isomediainc...

I'm attempting to diagnose some strange electronics behavior. And it seems
to be coming down to this question:

What types of components have failure modes that are temperature
independent
and are self healing over a time period of days?

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
Don't anthropomorphize computers. They hate that.

RoHS solder joints. Hands down.

amdx · Apr 27, 2012

On 4/27/2012 2:44 PM, Paul Hovnanian P.E. wrote:

I'm attempting to diagnose some strange electronics behavior. And it seems
to be coming down to this question:

What types of components have failure modes that are temperature independent
and are self healing over a time period of days?

The self healing part is questionable but, when I repaired vcr's I
had a brand with an intermittent tuner. The problem would come and go
according to the customers. But when I saw the problem 2 or 3 drops of
cold mist on the proper capacitor would make it work.
It took a while to isolate the capacitor on the first one, but after
that I'd cool the same capacitor and the problem would correct.

Or to make a long story short; capacitor
Mikek

Les Cargill · Apr 27, 2012

Paul Hovnanian P.E. wrote:

I'm attempting to diagnose some strange electronics behavior. And it seems
to be coming down to this question:

What types of components have failure modes that are temperature independent
and are self healing over a time period of days?

Are the failures microphonic ( does Fonzing* the thing make them start
or stop; is vibration a factor? )

*Ayyyyyyyy.....

--
Les Cargill

spamtrap1888 · Apr 27, 2012

On Apr 27, 12:44 pm, "Paul Hovnanian P.E." <p...@hovnanian.com> wrote:

I'm attempting to diagnose some strange electronics behavior. And it seems
to be coming down to this question:

What types of components have failure modes that are temperature independent
and are self healing over a time period of days?

Are these failures occuring in development circuits you've actively
been working with, or in returned product? Because product that's been
out in the field can have problems like dendritic growth shorting
adjacent pins (that can open up if enough current goes through it),
parallel circuit paths caused by crud that becomes conductive under
humidity, etc.

Arfa Daily · Apr 28, 2012

"Paul Hovnanian P.E." <paul@hovnanian.com> wrote in message
news:q66dnQa4cohKawfSnZ2dnUVZ_qadnZ2d@posted.isomediainc...

I'm attempting to diagnose some strange electronics behavior. And it seems
to be coming down to this question:

What types of components have failure modes that are temperature
independent
and are self healing over a time period of days?

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
Don't anthropomorphize computers. They hate that.

Not really enough information to make an informed comment. Virtually any
component can have odd failure modes including intermittent ones, but I
don't think I can come up with any examples that are consistently allied to
any particular component type, and that are not temperature related. By far
the most common time related failures these days, are down to bad
electrolytics, but if you dig down, there is almost always a temperature
angle to the failure. For instance, caps or resistors in the startup supply
of a switcher, will often fail due to heat issues, but you don't notice
because as long as the item remains powered, the cap or resistor does not
cause a problem. Now remove the power completely, and try and restart it a
few hours later. Chances are, it won't now come back on. But leave it a few
days, and it might well restart the next time ...

Another possibility is bad joints, particularly with anything manufactured
in the last 5 years, which will make use of lead-free solder. Bad joints in
this hateful stuff, can give rise to the most bizarre intermittent symptoms,
which can on occasion have apparent self-healing behaviour.

You need to tell us a bit more about the actual failures you are seeing, and
what the actual equipment is.

Arfa

Jamie · Apr 28, 2012

Paul Hovnanian P.E. wrote:

I'm attempting to diagnose some strange electronics behavior. And it seems
to be coming down to this question:

What types of components have failure modes that are temperature independent
and are self healing over a time period of days?

capacitors, especially the electrolytics.

Jamie

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