can\'t figure correct resistance for teflon coated copper wire...

[Fox\'s Mercantile]

On 11/13/20 2:41 PM, Runner wrote:

On 11/13/20 3:07 PM, Fox\'s Mercantile wrote:
On 11/13/20 12:57 PM, legg wrote:
I don\'t recommend electric blankets. For a multitude
of reasons.

I just bought a new one.
I turn it one 20-30 minutes before I go to bed.
I turn it off when I go to bed.
But when I go to bed, the bed is nice and warm.
Beats the shit out of laying there swearing for 15-20
minutes waiting for the bed to finally get warm.



If a Sunbeam, good luck keeping it working.  I went through three in
five years before finally going the DIY route.  I\'m not sure what\'s
happened to them.  I couldn\'t even get any of the ones I bought to last
out the season.  I think it has something to do with the current circuit
they use and the blanket wiring.  Growing up, my parents and I had their
blankets and they lasted 15 years before I unfortunately tossed them a
decade ago.

My previous one was a Sunbeam, it went tits up after three years.
The new one is a Biddeford. Unlike the Subeam, it\'s soft and fuzzy.


--
\"I am a river to my people.\"
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

[Runner]

On 11/13/20 9:05 PM, Fox\'s Mercantile wrote:

On 11/13/20 2:41 PM, Runner wrote:
On 11/13/20 3:07 PM, Fox\'s Mercantile wrote:
On 11/13/20 12:57 PM, legg wrote:
I don\'t recommend electric blankets. For a multitude
of reasons.

I just bought a new one.
I turn it one 20-30 minutes before I go to bed.
I turn it off when I go to bed.
But when I go to bed, the bed is nice and warm.
Beats the shit out of laying there swearing for 15-20
minutes waiting for the bed to finally get warm.



If a Sunbeam, good luck keeping it working.  I went through three in
five years before finally going the DIY route.  I\'m not sure what\'s
happened to them.  I couldn\'t even get any of the ones I bought to
last out the season.  I think it has something to do with the current
circuit they use and the blanket wiring.  Growing up, my parents and I
had their blankets and they lasted 15 years before I unfortunately
tossed them a decade ago.

My previous one was a Sunbeam, it went tits up after three years.
The new one is a Biddeford. Unlike the Subeam, it\'s soft and fuzzy.

I didn\'t have much luck with Biddeford either. I tried one of their
heated mattress pads. It didn\'t last a season. Hopefully, you\'ll have
better luck with their blankets.

 

[Runner]

On 11/13/20 1:12 PM, Three Jeeps wrote:

On Friday, November 13, 2020 at 1:08:12 PM UTC-5, Three Jeeps wrote:

Just to add a bit of information to this guidance, joining nichrome wire to nichrome or copper can be a bit of a challenge if you are not aware of the metallurgy issues. It does not solder with lead free rosin core solder. Connections to nichrome wire are often done with a crimp style connector. This may not be a workable solution for an electric blanket, depending on the area where the splice is applied.
Nichrome can be soldered but you need a acid type flux and the degree of success is somewhat dependent on the type of nichrome (A: has no iron and behaves like stainless steel, B: contains some iron and can be more easily soldered).
I\'ve had good luck joining both types using Ruby fluid flux and in one case using flux for soldering copper pipe, e.g. plumbing flux. Some people have had good luck with 60/40 acid core flux but I have not tried it. My guess is that it would work better on C type nichrome.
I also have used a small tack welder but its not a common household or shop tool.
If you look on the web am sure you will find lots of alternatives.
J
whoops - typo - I have used 60/40 acid core with some success...(sorry, wrong sentence when doing 3 things at once...)
J

I never did go with the nichrome wire. I have some, but used it three
years ago to make some telescope dew heaters. The idea was to wrap the
front of the telescope with nichrome embedded in a fabric with just
enough wattage to keep dew away. Works great at 5 to 10 watts. For
that I believe I crimped it to the supply wires. When I started on the
blanket, there was no way I was going to try using nichrome for
something that large and went with some 22 ga Teflon coated wire I had
around for years. So far, it has been working out well. I can get up
to 80 watts, but I will mostly be running at half that or a little over
as there\'s much less heating to deal with. Today, the dimmer arrived
and I tried out a jacket I also wired. It too reaches 80 watts but
again I will only need about 50. 80 watts seems a bit too much even in
a cold house.

Initially, to hold the Teflon wiring in place, I used hot glue.
However, when 80 watts passed through, some of it began to not only
outgas but melt so I removed all of it and went with nylon ties. I
first tested the nylon and a bit of blanket fabric by heating in the
oven at 90 C for several hours and both came out fine. I was a bit
concerned as nylon seems advertised to hold well up to like 85 C, but I
don\'t see any issues.

Only other issue was temperature. The longer the blanket is on at the
max, the warmer it slowly creeps up. So, I have to either run it at
less power, which I will normally do, or have a duty cycle using a
timer. I have since incorporated a timer for when it gets colder in
here. I\'m going to try for a 33% time on and 2/3 time off and see how
it goes. Someone has suggested a thermostat, but not sure how other
than maybe using a probe attached to the blanket wires and then a relay
turns the blanket on and off as needed.

 

[ohg...@gmail.com]

On Friday, November 13, 2020 at 3:41:19 PM UTC-5, Runner wrote:

On 11/13/20 3:07 PM, Fox\'s Mercantile wrote:
On 11/13/20 12:57 PM, legg wrote:
I don\'t recommend electric blankets. For a multitude
of reasons.

I just bought a new one.
I turn it one 20-30 minutes before I go to bed.
I turn it off when I go to bed.
But when I go to bed, the bed is nice and warm.
Beats the shit out of laying there swearing for 15-20
minutes waiting for the bed to finally get warm.


If a Sunbeam, good luck keeping it working. I went through three in
five years before finally going the DIY route. I\'m not sure what\'s
happened to them. I couldn\'t even get any of the ones I bought to last
out the season. I think it has something to do with the current circuit
they use and the blanket wiring. Growing up, my parents and I had their
blankets and they lasted 15 years before I unfortunately tossed them a
decade ago.

Sunbeam blankets don\'t flat out quit, they slowly get colder over time. Not sure why that is. It\'s like they\'re programmed to do so. Too bad because their controllers are great. I switched to their mattress pads and they get inert over two or three seasons. Looking for another option right now.

 

[Runner]

On 11/14/20 6:47 AM, ohg...@gmail.com wrote:

On Friday, November 13, 2020 at 3:41:19 PM UTC-5, Runner wrote:
On 11/13/20 3:07 PM, Fox\'s Mercantile wrote:
On 11/13/20 12:57 PM, legg wrote:
I don\'t recommend electric blankets. For a multitude
of reasons.

I just bought a new one.
I turn it one 20-30 minutes before I go to bed.
I turn it off when I go to bed.
But when I go to bed, the bed is nice and warm.
Beats the shit out of laying there swearing for 15-20
minutes waiting for the bed to finally get warm.


If a Sunbeam, good luck keeping it working. I went through three in
five years before finally going the DIY route. I\'m not sure what\'s
happened to them. I couldn\'t even get any of the ones I bought to last
out the season. I think it has something to do with the current circuit
they use and the blanket wiring. Growing up, my parents and I had their
blankets and they lasted 15 years before I unfortunately tossed them a
decade ago.

Sunbeam blankets don\'t flat out quit, they slowly get colder over time. Not sure why that is. It\'s like they\'re programmed to do so. Too bad because their controllers are great. I switched to their mattress pads and they get inert over two or three seasons. Looking for another option right now.

Exactly right, don\'t just quit but lose warmth over time. Out of the
three Sunbeam blankets I owned and two heated throws, they all did this.
This was my main inspiration for my DIY revamping. There\'s actually a
fair amount of online info on the Sunbeams if you do a patent number
search. A circuit block will come up along with at least one schematic.
I thought the culprit might have been a small SMD voltage sampling
transistor inside the little box where the cord plugs into the blanket,
but replaced that and still no heating. I also swapped out controllers
for a different one to no avail. So, that left the blanket itself. I
suspect the changing of wire resistance from repeated heating is what
does it and of course there\'s no solution without either a revamping as
I have done, or a new blanket.

Patent numbers show that someone definitely designed their latest
circuitry. IMHO, probably due to lawsuits and other worries from the
past, it was overdesigned and thus now stops working after short order.
There is no easy solution unless one wants to try other brands and take
a chance that you might come across one that actually keeps working.

 

[Peter W.]

I don\'t get it. We purchased two Sunbeam extra-large heating pads with five (5) year warranties. One failed in short order and was replaced in short order. The other is going strong after four (4) years. We purchased through Amazon so there would be no nonsense with losing receipts. From what has been discussed here, they seem to fail on an hourly basis and no one invokes the warranty??

Peter Wieck
Melrose Park, PA

 

[Runner]

On 11/14/20 2:47 PM, Peter W. wrote:

I don\'t get it. We purchased two Sunbeam extra-large heating pads with five (5) year warranties. One failed in short order and was replaced in short order. The other is going strong after four (4) years. We purchased through Amazon so there would be no nonsense with losing receipts. From what has been discussed here, they seem to fail on an hourly basis and no one invokes the warranty??

Peter Wieck
Melrose Park, PA

Three of my Sunbeam blankets failed within the five year warranty
period. I returned and exchanged each for replacements direct from
Sunbeam. However, the big catch is with the shipping. Even with
blankets that fail, Sunbeam does not pay shipping cost to ship the
defective blanket to them, and when paying $15 for insured shipping,
this almost defeats the entire process when the blankets were purchased
on sale for around $20 to $25. Besides, by the third time, Sunbeam had
become far less responsive and I had to contact them a lot more to get
them moving on the final blanket. And, yes, they were strict about
receipts, blanket tags, and such so don\'t forget anything and keep
copies of all.

Why all this and not have a blanket that simply works? Not for a single
season, but for years like they once had. Beats me.

 

[Dave Platt]

In article <ros07f$acu$1@dont-email.me>, Runner <runners@aolnospam.com> wrote:

Why all this and not have a blanket that simply works? Not for a single
season, but for years like they once had. Beats me.

It is, unfortunately, \"the race to the bottom\". Price and features
drive sales; long-term reliability does not.

Sunbeam (and most other brands) thus have an incentive to \"buy cheap\",
from companies which are skilled at building stuff which will last
_just_ long enough. They count on most of the devices being out of
warranty by the time they fail, and on most consumers being unwilling
to go to the trouble and expense of keeping receipts and asserting
their warranty rights. That way, they get to sell you cheap things
every couple years, and collect a small profit each time, rather than
sell you something once every 10 years for only a slightly higher
profit.

Sadly, it shows the truth of an old rule of thumb. \"When somebody
asks \'Why X, it doesn\'t seem to make sense\', the answer is most
probably \'Money\'.\"