"Nelson" wrote in message
.com...
Not really electronics, I know, but I'm hoping some one can throw me a
pointer. I'd like to test for both safety and shorts/opens/too much
resistance. The only thing I could find on the web is safety testing
by electric utilities.

Any DIY help would be appreciated.


If you have the slightest doubt as to its safety, dispose of it. Faulty
electric blankets are not only potentially lethal because of the shock
hazard- they are a very real fire risk as well.

I speak from experience.

Dave

Nelson wrote:
On Sat, 22 Jul 2006 15:40:38 -0400, Dave D wrote
(in article ):


"Nelson" wrote in message
ws.com...

Not really electronics, I know, but I'm hoping some one can throw me a
pointer. I'd like to test for both safety and shorts/opens/too much
resistance. The only thing I could find on the web is safety testing
by electric utilities.

Any DIY help would be appreciated.


If you have the slightest doubt as to its safety, dispose of it. Faulty
electric blankets are not only potentially lethal because of the shock
hazard- they are a very real fire risk as well.

I speak from experience.

Dave




Thanks for the "heads up". I have read that the new ones are "safe".
Can you comment?

Just a "comment", if, repeat if, you have ANY reservations on using
something that includes "speed of light" possible fatal media, discard it.
BTW, what happened to the hot water rubber bottle?
One of the _best_ replacements I met was a "dashhund" who liked to sleep
on human bent legs under blanket. Wonderful invention!.

Good luck.

Stanislaw
Slack user from Uladulla.

On Sat, 22 Jul 2006 18:36:09 -0400, Nelson wrote:

On Sat, 22 Jul 2006 15:40:38 -0400, Dave D wrote (in article
):


"Nelson" wrote in message
.com...
Not really electronics, I know, but I'm hoping some one can throw me a
pointer. I'd like to test for both safety and shorts/opens/too much
resistance. The only thing I could find on the web is safety testing
by electric utilities.

Any DIY help would be appreciated.


If you have the slightest doubt as to its safety, dispose of it. Faulty
electric blankets are not only potentially lethal because of the shock
hazard- they are a very real fire risk as well.

I speak from experience.

Dave



Thanks for the "heads up". I have read that the new ones are "safe". Can
you comment?

Well, according to the TeeVee Nooz lately in SoCal, one can be swallowed
by a 12 foot python, and all he got was indigestion. ;-)

Cheers!
Rich

"Nelson" wrote in message
.com...



Thanks for the "heads up". I have read that the new ones are "safe".
Can you comment?


Well, realistically they have to be pretty safe to meet modern regulations.
A new one is likely to be a negligible risk. However, I just don't like the
idea of mains electricity flowing through a blanket, and when they have some
wear on them it will inevitably affect the insulation and hence their
safety.

Personally, I can't recommend the use of electric blankets at all, but then
maybe I'm just over cautious ;-)
I would certainly never use one designed to be left on when you're in bed.
shudder

Dave

Well, realistically they have to be pretty safe to meet modern regulations.
A new one is likely to be a negligible risk. However, I just don't like the
idea of mains electricity flowing through a blanket, and when they have some
wear on them it will inevitably affect the insulation and hence their
safety.

Personally, I can't recommend the use of electric blankets at all, but then
maybe I'm just over cautious ;-)
I would certainly never use one designed to be left on when you're in bed.
shudder

Dave





Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

Yeah and my house could fall down in an earthquake in my sleep, or I
could trip and break my neck on my way to the bathroom at night, things
happen.

James Sweet wrote:


Well, realistically they have to be pretty safe to meet modern
regulations. A new one is likely to be a negligible risk. However, I
just don't like the idea of mains electricity flowing through a
blanket, and when they have some wear on them it will inevitably
affect the insulation and hence their safety.

Personally, I can't recommend the use of electric blankets at all, but
then maybe I'm just over cautious ;-)
I would certainly never use one designed to be left on when you're in
bed. shudder

Dave




Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

Yeah and my house could fall down in an earthquake in my sleep, or I
could trip and break my neck on my way to the bathroom at night, things
happen.
It IS scientificaly/statisticaly(chose one) proven that most people die
in bed, ergo sleep like a donkey, standing.

Have fun

Stanislaw
Slack user from Ulladulla.

James:
About 5 years ago I had a blanket that woke up both my wife and I with
what appeared to be dim lightning flashes in the room.... it turned
out that a short circuit or loose connection developed inside the
blanket. When we turned on the lights to investigate there was a
burnt spot on the blanket and we could hear a snapping sound. Even
thought the blanket was well past it's warranty and we had no receipt,
the service center we sent it to REPLACED with a new one, NO
CHARGE...... so from now on we are quite alert as to possible
problems.... and yes, we still use an electric blanket on our bed.
electricitym
..
..

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

Dont forget the fire risk

"James Sweet" wrote in message
news:VdUwg.10284$2u4.1944@trnddc06...


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?


Slim but possible, but that's perhaps not their primary danger.

Yeah and my house could fall down in an earthquake in my sleep, or I could
trip and break my neck on my way to the bathroom at night, things happen.

You would perhaps have a different attitude if you'd been in a house where
an electric blanket burst into flames and set the bed alight. Half an hour
later and my parents would have been under it and asleep. Lucky I was in the
house at the time- they didn't smell the burning at all but I did and we
managed to put it out quickly.

Dave

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of non-electric
blankets may be an undesireable choice due to the additional weight
required.)

As far as testing is concerned, perhaps a blanket could be soaked in a
saline solution in a conductive tub. Electrical leakage could be measured
between the tub and the blanket wiring. For a meaningful test, full
voltage (current limited) would be applied between the wiring and the
tub. For a safety factor, higher voltage might be used.

Passing such a test doesn't guarantee that leakage won't develop later
from normal wear and tear, so you're back where you started!

Fred

In article , (Fred McKenzie) wrote:
James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of non-electric
blankets may be an undesireable choice due to the additional weight
required.)

As far as testing is concerned, perhaps a blanket could be soaked in a
saline solution in a conductive tub. Electrical leakage could be measured
between the tub and the blanket wiring. For a meaningful test, full
voltage (current limited) would be applied between the wiring and the
tub. For a safety factor, higher voltage might be used.

Passing such a test doesn't guarantee that leakage won't develop later
from normal wear and tear, so you're back where you started!

The test would only trip the integral ground fault interupter
if there was leakage. I have a feeling most all blankets now come with
fault interupters. Is that true??

greg

On Tue, 25 Jul 2006 12:25:30 -0400, (Fred McKenzie) put
finger to keyboard and composed:

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of non-electric
blankets may be an undesireable choice due to the additional weight
required.)

I'd suggest dispensing with the electric blanket and pre-warming the
bed with a portable fan heater.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Franc Zabkar wrote in message
...
On Tue, 25 Jul 2006 12:25:30 -0400, (Fred McKenzie) put
finger to keyboard and composed:

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of non-electric
blankets may be an undesireable choice due to the additional weight
required.)

I'd suggest dispensing with the electric blanket and pre-warming the
bed with a portable fan heater.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Even more fires are started by clothing draped over fires which this is
equivalent to - highly dangerous. Restricted air supply leads to excessive
heat build up. The traditional hinged double copper "frying pans" on a broom
handle with hot coals from the fire, sounds much safer.
On a related matter the local fire service had a black museum. One of its
seized exhibits was a home-made bed warmer. Someone started with a soldiers
steel helmet, nailed some wooden dowels on the inside, nails in the other
ends to wrap the element wire from an electric fire around.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Nelson wrote in message
.com...
On Wed, 26 Jul 2006 02:35:52 -0400, Franc Zabkar wrote
(in article ):

On Tue, 25 Jul 2006 12:25:30 -0400, (Fred McKenzie) put
finger to keyboard and composed:

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of
non-electric
blankets may be an undesireable choice due to the additional weight
required.)

I'd suggest dispensing with the electric blanket and pre-warming the
bed with a portable fan heater.

- Franc Zabkar


I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson


One thing you might consider is a heavy duty "space-blanket" sold in outdoor
pursuit shops, not the thin emergency types as used at the end of marathons
but the mesh reinforced ones. It, of course, does not pre-heat the bed but
does reflect your own body heat back to you during the night which is
probably the main concern.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Nelson wrote in message
.com...
On Wed, 26 Jul 2006 02:35:52 -0400, Franc Zabkar wrote
(in article ):

On Tue, 25 Jul 2006 12:25:30 -0400, (Fred McKenzie) put
finger to keyboard and composed:

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of
non-electric
blankets may be an undesireable choice due to the additional weight
required.)

I'd suggest dispensing with the electric blanket and pre-warming the
bed with a portable fan heater.

- Franc Zabkar


I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson


My recommendation would be a mixture of low tec and high tec and no electric
blanket.
A conventional hot water bottle to pre-heat the bed and an underblanket of
reinforced mylar space blanket.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson

Most electric blankets build up resistance over time. I've only had one
last(put out full heat) more than 5 years. Most just out of warranty. The
one I have now says it doesn't do that and is a little past that age. It's
still working fine. Would have to look the brand name up. Hadn't heard of it
before purchase. IIRC it has Mills in the name.

Nelson wrote:

On Wed, 26 Jul 2006 02:35:52 -0400, Franc Zabkar wrote
(in article ):

On Tue, 25 Jul 2006 12:25:30 -0400, (Fred McKenzie) put
finger to keyboard and composed:

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of non-electric
blankets may be an undesireable choice due to the additional weight
required.)

I'd suggest dispensing with the electric blanket and pre-warming the
bed with a portable fan heater.

- Franc Zabkar


I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson


Use an AC ammeter to check the current draw, and compare it to the
specifications on the controller.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

In article , Nelson
wrote:

I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

Nelson-

Of even more concern than fire and shock, is that a temperature she likes
may actually be too hot and cause harm.

You should ask a doctor about this. We "do gooders" may be giving you
advice that would roast your wife!

The hot water bottle(s) sounds like a good idea. If she were sufficiently
comfortable to fall asleep, would she remain asleep after it cooled?

Fred

On Wed, 26 Jul 2006 07:54:51 +0100, "n cook" put
finger to keyboard and composed:

Franc Zabkar wrote in message
.. .
On Tue, 25 Jul 2006 12:25:30 -0400, (Fred McKenzie) put
finger to keyboard and composed:

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of non-electric
blankets may be an undesireable choice due to the additional weight
required.)

I'd suggest dispensing with the electric blanket and pre-warming the
bed with a portable fan heater.

- Franc Zabkar

Even more fires are started by clothing draped over fires which this is
equivalent to - highly dangerous. Restricted air supply leads to excessive
heat build up.

I lift the blanket and warm the bed with the heater while holding both
in my hands. Sorry if I implied otherwise. I find that one minute is
more than enough.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Nelson wrote in message
.com...
On Wed, 26 Jul 2006 15:33:26 -0400, Fred McKenzie wrote
(in article ):

In article , Nelson
wrote:

I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

Nelson-

Of even more concern than fire and shock, is that a temperature she
likes
may actually be too hot and cause harm.

You should ask a doctor about this. We "do gooders" may be giving you
advice that would roast your wife!

The hot water bottle(s) sounds like a good idea. If she were
sufficiently
comfortable to fall asleep, would she remain asleep after it cooled?

Fred

I assume by "cause harm" you are referring to possible burns. I don't
know about that but you reminded me of an interesting point which I
hadn't considered and that is that MS patients are frequently
negatively affected by heat... they get noticibly weaker (Uhthoff's
Phenomenon).

I think I am going to try the "Space Blanket"/Hot Water Bottle
combination. I appreciate all the helpful suggestions and the group's
patience with this "Off Topic" subject.

--
Nelson


If anyone needs convincing about space blanket effectiveness, borrow one or
buy a cheap thin emergency one and try this. Cover your hand with a pillow
case or T shirt or something to avoid direct skin contact (then has opposite
effect of conducting heat out) and place inside a folded section of the
blanket - a few seconds and your hand will begin feeling warmer.
Such an effect and a blanket top and bottom would probably be too effective

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"Michael A. Terrell" wrote in message
...
Nelson wrote:

On Wed, 26 Jul 2006 02:35:52 -0400, Franc Zabkar wrote
(in article ):

On Tue, 25 Jul 2006 12:25:30 -0400, (Fred McKenzie) put
finger to keyboard and composed:

James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of
non-electric
blankets may be an undesireable choice due to the additional weight
required.)

I'd suggest dispensing with the electric blanket and pre-warming the
bed with a portable fan heater.

- Franc Zabkar


I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson


Use an AC ammeter to check the current draw, and compare it to the
specifications on the controller.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Most electric blankets use diodes in the power selector switch - this might
confuse an AC ammeter!

ian field wrote:

Most electric blankets use diodes in the power selector switch - this might
confuse an AC ammeter!


I've never seen diodes in any I've worked on. They just had a
mechanical thermostat that switched the element on and off.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote in message
...
ian field wrote:

Most electric blankets use diodes in the power selector switch - this
might
confuse an AC ammeter!


I've never seen diodes in any I've worked on. They just had a
mechanical thermostat that switched the element on and off.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Were they made in the 30's?

ian field wrote:

"Michael A. Terrell" wrote in message
...

I've never seen diodes in any I've worked on. They just had a
mechanical thermostat that switched the element on and off.

Were they made in the 30's?


No, in the '70s and '80s, here in the US.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

"Michael A. Terrell" wrote in message
...
ian field wrote:

"Michael A. Terrell" wrote in message
...

I've never seen diodes in any I've worked on. They just had a
mechanical thermostat that switched the element on and off.

Were they made in the 30's?


No, in the '70s and '80s, here in the US.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

I suppose there's some merit to using a simmerstat since ambient temp
influences on time and therefore heating level, but the constant clicking
does tend to keep some people awake!

All the modern ones I've seen used very thin element wire, and presumably a
large PTC for self regulation with switch selected diodes for power control.
The last one I opened the switch unit had a lot of diodes the element was
sort of co-axial, the centre wire was thinner than a human hair and the
second element was spiral wound thicker wire round the inner insulation, I
think the switch se;selected various combinations of one, other or both
elements with or without series diodes to give about 5 different power
levels.

You might try a heating mattress pad instead. If you cannot afford
one, send me a response & I'll have one shipped to you free of charge.
Bob
Nelson wrote:
On Wed, 26 Jul 2006 15:33:26 -0400, Fred McKenzie wrote
(in article ):

In article , Nelson
wrote:

I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

Nelson-

Of even more concern than fire and shock, is that a temperature she likes
may actually be too hot and cause harm.

You should ask a doctor about this. We "do gooders" may be giving you
advice that would roast your wife!

The hot water bottle(s) sounds like a good idea. If she were sufficiently
comfortable to fall asleep, would she remain asleep after it cooled?

Fred

I assume by "cause harm" you are referring to possible burns. I don't
know about that but you reminded me of an interesting point which I
hadn't considered and that is that MS patients are frequently
negatively affected by heat... they get noticibly weaker (Uhthoff's
Phenomenon).

I think I am going to try the "Space Blanket"/Hot Water Bottle
combination. I appreciate all the helpful suggestions and the group's
patience with this "Off Topic" subject.

--
Nelson

Dave D wrote:
"James Sweet" wrote in message
news:VdUwg.10284$2u4.1944@trnddc06...


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?



Slim but possible, but that's perhaps not their primary danger.


Yeah and my house could fall down in an earthquake in my sleep, or I could
trip and break my neck on my way to the bathroom at night, things happen.


You would perhaps have a different attitude if you'd been in a house where
an electric blanket burst into flames and set the bed alight. Half an hour
later and my parents would have been under it and asleep. Lucky I was in the
house at the time- they didn't smell the burning at all but I did and we
managed to put it out quickly.

Dave




Well I have a smoke alarm on the ceiling over my bed, as everyone
should. The blanket provides comfort that I'm willing to take a small
risk to enjoy.

T Shadow wrote:
I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson


Most electric blankets build up resistance over time. I've only had one
last(put out full heat) more than 5 years. Most just out of warranty. The
one I have now says it doesn't do that and is a little past that age. It's
still working fine. Would have to look the brand name up. Hadn't heard of it
before purchase. IIRC it has Mills in the name.




Maybe they're just not built like they used to be. My grandma has one
that's at least 40 years old, it's on the bed in a spare room now and
when I've stayed there I still never turn it up past 3 or so, set it to
5 or 6 and I'm sweating, it goes all the way up to 10.

Nelson,
Although I don't like Terrel's attitude, he had one of the best answers
about measuring the AC current. Gives an incomplete assessment, but a
good indicator. The other thought is to use a "voltage sniffer" if you
have one, to check various areas of the blanket to see if they are
working (getting voltage/current). My daughter always liked the effect
of the heating mattress pad. Because heat rises, it was more "toasty"
for her.
Bob

Nelson wrote:
On Sat, 29 Jul 2006 20:45:03 -0400, Bob wrote
(in article .com):

Bob,

You might try a heating mattress pad instead.

I was unaware that they existed until you pointed it out. Most seem to
operate on low voltage DC which is, of course, inherently safer. And I
notice that there are even some blankets that do also. I think I will
definitely try one if the "space blanket" solution doesn't pan out.

If you cannot afford one, send me a response & I'll have one shipped
to you free of charge.

I think I can swing one if necessary, but I appreciate your generous
offer. I am frequently amazed at the kindness of strangers on usenet.

--
Nelson

James Sweet wrote:
T Shadow wrote:
I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson


Most electric blankets build up resistance over time. I've only had one
last(put out full heat) more than 5 years. Most just out of warranty. The
one I have now says it doesn't do that and is a little past that age.
It's
still working fine. Would have to look the brand name up. Hadn't heard
of it
before purchase. IIRC it has Mills in the name.




Maybe they're just not built like they used to be. My grandma has one
that's at least 40 years old, it's on the bed in a spare room now and
when I've stayed there I still never turn it up past 3 or so, set it to
5 or 6 and I'm sweating, it goes all the way up to 10.

That's nothing...I used to have one that went all the way up to *11*!
G

jak

"jakdedert" wrote in message
...
James Sweet wrote:
T Shadow wrote:
I appreciate all those who have given constructive suggestions. For
the record, my wife has Multiple Sclerosis one symptom of which is
poor
blood circulation. She is always "cold" even in the summer. More
blankets, which only keep body heat in, don't help. What is needed is
a heat source other than her body. Hence the electric blanket. She
still complains it isn't warm enough and I have no idea how to test if
it is working properly merely from a heating perspective. It feels
warm but not hot. I assume, without taking the thing apart, that
there
are a bunch of resistive elements wired in parallel. Thus some could
be open and the blanket still heat.

The other concern is safety since, unfortunately, another of her
symptoms is incontinence.

The blankets we have are perhaps 20 years old. They still seem to
work,
but do not get very warm. On the other hand, I don't recall how warm
they are supposed to get. I am sure they are regulated so that you
don't inadvertently burn yourself from a high setting. I would have
just gone out and bought a new one if money weren't an issue.

In searching the web, I noticed many Electric Utilities offer "safety
tests" for electric blankets, so there must be some protocol. I was
just hoping someone here knew it although it is hardly "electronics".

Another article I found suggested that they "used to be unsafe" but
newer standards have been adopted which make them safe.

Leaving out the "tin foil hat" concern about electromagnetic fields, I
assume the main risks are shock and fire. My presumption was that the
UL certification covered those and the ones I have carry UL
certification.

I suppose the best thing to do is to just buy a new one. And yet,
without understanding the failure modes of the old ones, there still
remains in my mind a safety concern.

--
Nelson


Most electric blankets build up resistance over time. I've only had one
last(put out full heat) more than 5 years. Most just out of warranty.
The
one I have now says it doesn't do that and is a little past that age.
It's
still working fine. Would have to look the brand name up. Hadn't heard
of it
before purchase. IIRC it has Mills in the name.




Maybe they're just not built like they used to be. My grandma has one
that's at least 40 years old, it's on the bed in a spare room now and
when I've stayed there I still never turn it up past 3 or so, set it to
5 or 6 and I'm sweating, it goes all the way up to 10.

That's nothing...I used to have one that went all the way up to *11*!
G

jak

So you don't really know how much the blanket was actually used. Ours are in
daily seasonal use. My wife never uses less than 5 even on new blankets so
that must shorten the life considerably. Not unusual to wake up sweating
just from the heat from her side.

Present blanket goes all the way to Hi. :^b

GregS wrote:

In article , (Fred McKenzie) wrote:
James Sweet wrote:


Ah it's the greatest thing in cold winters, the wires are heavily
insulated, they're inside a blanket, and over a sheet. Cloth doesn't
conduct, what are the chances of actually getting electrocuted?

James-

I think the chances are slim, but the OP had a special problem.
Considering the risks, one might decide to avoid use of an electric
blanket in some circumstances, unless there was an additional plastic
sheet between the user and the blanket. (The alternative of non-electric
blankets may be an undesireable choice due to the additional weight
required.)

As far as testing is concerned, perhaps a blanket could be soaked in a
saline solution in a conductive tub. Electrical leakage could be measured
between the tub and the blanket wiring. For a meaningful test, full
voltage (current limited) would be applied between the wiring and the
tub. For a safety factor, higher voltage might be used.

Passing such a test doesn't guarantee that leakage won't develop later
from normal wear and tear, so you're back where you started!

The test would only trip the integral ground fault interupter
if there was leakage. I have a feeling most all blankets now come with
fault interupters. Is that true??

I think I've seen blankets with them. I know I've seen hair dryers with
them. If the OP suspects his current (no pun intended) blanket as having
a defect, perhaps it would be better to discard it and obtain one with
the latest safety features.

--
Paul Hovnanian
------------------------------------------------------------------
Power corrupts. And atomic power corrupts atomically.