Toshiba TV29C90 problem; Image fades to black...

[Robert Latest]

["Followup-To:" header set to sci.electronics.design.]
John Larkin wrote:

What I really should do is arrange to recover some of the
heat in wastewater, like an outgoing/incoming heat exchanger or
something.

The house we're building is going to have that not for water, but for air
(outgoing warm air heats up the incoming air in a heat exchanger). This
makes a difference only in extremely well-insulated houses though.

robert

 

[Spurious Response]

On Fri, 06 Jul 2007 11:01:19 +0100, Paul Burke <paul@scazon.com> wrote:

Spurious Response wrote:

You also have to account for losses at the kettle itself. They do not
transfer 100% of the energy, and the higher wattage units radiate a lot
more, so they are slightly lossy-er.

I'll stick with my infinitely (FAIAP) variable gas, thanks.

Work it out. The element is entirely surrounded by the water you want to
heat.

Only foil coil immersion types. Our "kettles" over here have enclosed
heating elements under the kettle, so it would lose a bunch.

So all the energy, apart from that conducted bak into the cable,
passes into the water.

Immersion heating elements are about as efficient as one can get.

We used to place a few coiled rubber bands between two spoons, and hook
'em up, and that would boil water pretty quick too.

Gives "Direct Current" a new meaning.

Most electric kettles these days are plastic, so
not much gets throgh the sides.

Most "plastics" that can handle those temperatures also conduct heat
pretty well.

Rather more escapes through the top,
especially while the kettle is actually boiling-

Stick a lid on it. Once the water is boiling, one can reduce heat and
retain boil, another good reason for gas.

I use this energy to
preheat the teapot. So efficiency is pretty good.

I love finding uses for wafting, otherwise wasted heat.

A more powerful kettle
is better because there is less heat lost through the top and sides when
you are heating it.

A smaller "vat" has less exposed surface area, and is quite valid to
consider as a spoiler to your claim. It all comes down to using the right
heated pot for any given volume considered.

Why do you think solder pots are short and squat, and not some eight or
ten inch diameter device? It isn't just the handling issues. It has a
lot to do with conservation.

As for gas, most of the energy simply wafts round the outside of the
kettle,

When I put water on to boil, I start with *very* low heat, and most of
it hits the mark, and that which wafts, heats those same sides. The
flame barely leaves the burner head, and the gas meter barely moves, and
I boil water much better with a long slow process than a "stick a torch
to it and GO" method, so not much "spills" up the sides.

I am very lean on consumption. My carbon footprint barely exists at
all. Been riding a bike to and from work for the last twelve years.

and never heats the water at all- it just heats the universe.
Which isn't to say that it's not generally the best way to cook.

Gas is definitely the best, most controlled application of heat,
therefore is the best way to cook.

I wish microwave ovens were wattage controlled, instead of duty cycle
controlled. I would have many more uses for it then. Still, it is my
second choice. Electric burner stoves, and cooking accessories are the
most wasteful use of juice there is. The only proper electric stove
would have skillets, pots, and pans with integrated elements in them.

Otherwise there is a lot of loss with electrics as well. I'll take gas
any day.

 

[Riscy]

On Jul 5, 8:37 am, Thomas Tornblom <tho...@Hax.SE> wrote:

Spurious Response <SpuriousRespo...@cleansignal.org> writes:
On Wed, 04 Jul 2007 11:05:44 +0100, "Dave Plowman (News)"
d...@davenoise.co.uk> wrote:

A 1000 watt kettle would take forever to boil. UK ones are normally
2500/3000 watts.

If you paid California electric rates, you wouldn't use it very many
times a year.

It takes the same amount of energy to boil a quantity of water whether
you're using a 1 kW or 3 kW kettle. Infact it would probably take less
energy with the 3kW kettle as it gets the job done quicker, which
means less losses.



It must be nice to be able to build everything higher output, more
consumptive. We have to conserve here. Miniaturize.

Agreed, but you can't really save on a kettle, unless you switch to
some alternate energy source.



What types of appliances get used in Japan? High wattage? Low?
Other places?

Not an appliance, and in Sweden, not Japan, but I have lowered my
hosehold energy consumption from 40+ MWh annually to around 18 by
converting from direct electrical heating to a rock heat pump, and
paying attention to the consumption of appliances.

I have a 200 m drilled collector in my back yard that feeds the heat
pump. The collector is also used as a source (drain?) for cooling in
the summer. One only needs to pump the +8° brine coming from the
collector through a few convectors, no need to run any compressor.

I'm currently installing the air conditioning parts of the system,
which when finished will provide about 10 kW of cooling power for about
300 W of input power to run a brine pump and the fans in the
convectors. Theoretically it will also warm up the collector slightly,
which improves winter operation, but that is marginal, if any.

Oh, and while were talking about electrical systems, domestic feeds in
Sweden are almost universally 400V three phase.

My main fuses are 25A. When we bought the house in 1987 it had 20A
fuses, and electrical heating. One of the main fuses would
occasionally trip in the winter when the washer and stove was used,
while the radiators were running on full blast. Switching to 25A fuses
solved that. After the heatpump conversion I can most likely go back
to 20A fuses and save some on the electrical bill.

When we bought the house, the stove, washer, dryer, boiler and sauna
were all wired for three phase 400V operation. The radiators were 400V
two phase. The new washer and dryer are single phase 230V units, and
we've ripped out the sauna and the heatpump produces the hot water, so
the stove and heatpump are the only remaining three phase consumers.

Hi
I'm thinking of heat pump system at my home.
How big is your house, what is the heat demand and size of the heat
pump and who make them, was is NIBE.
It seem you have passive cooling and active heating arrangement. This
is very good arrangement because it much cheaper to cool house via
ground source.
Was is possible to email me the design plan of the system and the
calculation?
Thanks
Richard Payne.

 

[Riscy]

On Jul 5, 1:03 pm, bz <bz+...@ch100-5.chem.lsu.edu> wrote:

Thomas Tornblom <tho...@Hax.SE> wrote innews:x0d4z7e1x4.fsf@Hax.SE:

Switching to 25A fuses
solved that. After the heatpump conversion I can most likely go back
to 20A fuses and save some on the electrical bill.

How would going to 20A fuses save some on the electric bill?

--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+...@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

Because the heating system now driven by ground source heat pump
system, which take 3-4 time less power for same amount of heat. This
is a key feature and will reduce electric bill by 3-4 time, cheaper
than gas heater.
You no longer requires 25A and hence reduces to 20A as orginal circuit
design limits may allows. You may risk damage to cable and connection
if you keep 25A fuse.

 

[Eeyore]

Riscy wrote:

Because the heating system now driven by ground source heat pump
system, which take 3-4 time less power for same amount of heat. This
is a key feature and will reduce electric bill by 3-4 time, cheaper
than gas heater.

Unfortunately in the UK, electricity costs ~ 3 times more than electricity per
kWh so the efficiency of heat pumps saves you no money on your heating bill here
if you have gas available.

Graham

 

[Dave Plowman (News)]

In article <g6pt83lp08k01iorq1p1mbuicmr9t05sce@4ax.com>,
Spurious Response <SpuriousResponse@cleansignal.org> wrote:

You also have to account for losses at the kettle itself. They do
not transfer 100% of the energy, and the higher wattage units radiate
a lot more, so they are slightly lossy-er.

I'll stick with my infinitely (FAIAP) variable gas, thanks.

Work it out. The element is entirely surrounded by the water you want
to heat.

Only foil coil immersion types. Our "kettles" over here have enclosed
heating elements under the kettle, so it would lose a bunch.

So where is it lost to? BTW I've never seen a kettle where the element
isn't in the water.

So all the energy, apart from that conducted bak into the cable,
passes into the water.

Immersion heating elements are about as efficient as one can get.

We used to place a few coiled rubber bands between two spoons, and hook
'em up, and that would boil water pretty quick too.

Gives "Direct Current" a new meaning.

Most electric kettles these days are plastic, so
not much gets throgh the sides.

Most "plastics" that can handle those temperatures also conduct heat
pretty well.

Eh? Most plastics are poor conductors of heat.

Rather more escapes through the top,
especially while the kettle is actually boiling-

Stick a lid on it. Once the water is boiling, one can reduce heat and
retain boil, another good reason for gas.

If you're there to reduce the heat, why not simply use the boiling water?

I use this energy to preheat the teapot. So efficiency is pretty good.

I love finding uses for wafting, otherwise wasted heat.

A more powerful kettle is better because there is less heat lost
through the top and sides when you are heating it.

A smaller "vat" has less exposed surface area, and is quite valid to
consider as a spoiler to your claim. It all comes down to using the
right heated pot for any given volume considered.

Why do you think solder pots are short and squat, and not some eight or
ten inch diameter device? It isn't just the handling issues. It has a
lot to do with conservation.

Never seen a 'jug' kettle? Not much use with gas, though.

As for gas, most of the energy simply wafts round the outside of the
kettle,

When I put water on to boil, I start with *very* low heat, and most of
it hits the mark, and that which wafts, heats those same sides. The
flame barely leaves the burner head, and the gas meter barely moves, and
I boil water much better with a long slow process than a "stick a torch
to it and GO" method, so not much "spills" up the sides.

Good grief. Most just want that cup of tea *now*.

I am very lean on consumption. My carbon footprint barely exists at
all. Been riding a bike to and from work for the last twelve years.

and never heats the water at all- it just heats the universe.
Which isn't to say that it's not generally the best way to cook.

Gas is definitely the best, most controlled application of heat,
therefore is the best way to cook.

You don't cook with a kettle. Well most don't.

I wish microwave ovens were wattage controlled, instead of duty cycle
controlled. I would have many more uses for it then. Still, it is my
second choice. Electric burner stoves, and cooking accessories are the
most wasteful use of juice there is. The only proper electric stove
would have skillets, pots, and pans with integrated elements in them.

Integrated elements would have to be covered at all times. The only other
appliance where this makes sense is a deep fat frier.

Otherwise there is a lot of loss with electrics as well. I'll take gas
any day.

In the UK most use gas for the hob and electricity for the oven. But
pretty well all use an electric kettle for boiling water. The reason being
we've always had a 3 kW kitchen electrical socket.

--
*I'm really easy to get along with once people learn to worship me

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.

 

[Thomas Tornblom]

Spurious Response <SpuriousResponse@cleansignal.org> writes:

Gas is definitely the best, most controlled application of heat,
therefore is the best way to cook.

Actually I believe that induction cooking is better, more easily
controlled and safer than gas.

Snippet from http://theinductionsite.com/how-induction-works.shtml

---
The U.S. Department of Energy has established that the typical
efficiency of induction cooktops is 84%, while that of gas cooktops is
40% (more exactly, 39.9%)--figures right in line with the range of
claims made for each, and thus quite believable.
---

When we replaced our kitchen equipment around ten years ago I asked
about an induction stove. All the sales droids looked at me with blank
faces. Now they are everywhere ;-)

 

[James Sweet]

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:468F35D1.E19DA21@hotmail.com...

Riscy wrote:

Because the heating system now driven by ground source heat pump
system, which take 3-4 time less power for same amount of heat. This
is a key feature and will reduce electric bill by 3-4 time, cheaper
than gas heater.

Unfortunately in the UK, electricity costs ~ 3 times more than electricity
per
kWh so the efficiency of heat pumps saves you no money on your heating
bill here
if you have gas available.

Natural gas is the standard heating fuel in most part of the US.
Unfortunately the cost has more than tripled in the last decade or so,
making heat pumps an attractive alternative. I installed an air source heat
pump in my house a few years ago and saw significant savings.

 

[krw]

In article <TLQji.1142$nQ4.543@trndny01>, jamessweet@hotmail.com
says...

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:468F35D1.E19DA21@hotmail.com...


Riscy wrote:

Because the heating system now driven by ground source heat pump
system, which take 3-4 time less power for same amount of heat. This
is a key feature and will reduce electric bill by 3-4 time, cheaper
than gas heater.

Unfortunately in the UK, electricity costs ~ 3 times more than electricity
per
kWh so the efficiency of heat pumps saves you no money on your heating
bill here
if you have gas available.




Natural gas is the standard heating fuel in most part of the US.
Unfortunately the cost has more than tripled in the last decade or so,
making heat pumps an attractive alternative. I installed an air source heat
pump in my house a few years ago and saw significant savings.

Are the "lifetime" savings significant? Of course this all depends
on the local costs of both electricity and gas. Both vary widely
across the country (some places even resistive heat is cheaper than
gas).

--
Keith

 

[James Sweet]

"krw" <krw@att.bizzzz> wrote in message
news:MPG.20f9a695c545dbde98a6fb@news.individual.net...

In article <TLQji.1142$nQ4.543@trndny01>, jamessweet@hotmail.com
says...

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:468F35D1.E19DA21@hotmail.com...


Riscy wrote:

Because the heating system now driven by ground source heat pump
system, which take 3-4 time less power for same amount of heat. This
is a key feature and will reduce electric bill by 3-4 time, cheaper
than gas heater.

Unfortunately in the UK, electricity costs ~ 3 times more than
electricity
per
kWh so the efficiency of heat pumps saves you no money on your heating
bill here
if you have gas available.




Natural gas is the standard heating fuel in most part of the US.
Unfortunately the cost has more than tripled in the last decade or so,
making heat pumps an attractive alternative. I installed an air source
heat
pump in my house a few years ago and saw significant savings.

Are the "lifetime" savings significant? Of course this all depends
on the local costs of both electricity and gas. Both vary widely
across the country (some places even resistive heat is cheaper than
gas).

--
Keith

Well I wanted air con anyway so given the difference in cost between AC and
a heat pump it's already paid for itself and then some, but then I did use
scratch & dent surplus equipment and installed it myself so it didn't really
cost very much to do. Electricity is about $0.08/kwh and gas is about
$1.30/Therm.

 

[krw]

In article <23Sji.3612$qu4.417@trndny06>, jamessweet@hotmail.com
says...

"krw" <krw@att.bizzzz> wrote in message
news:MPG.20f9a695c545dbde98a6fb@news.individual.net...
In article <TLQji.1142$nQ4.543@trndny01>, jamessweet@hotmail.com
says...

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:468F35D1.E19DA21@hotmail.com...


Riscy wrote:

Because the heating system now driven by ground source heat pump
system, which take 3-4 time less power for same amount of heat. This
is a key feature and will reduce electric bill by 3-4 time, cheaper
than gas heater.

Unfortunately in the UK, electricity costs ~ 3 times more than
electricity
per
kWh so the efficiency of heat pumps saves you no money on your heating
bill here
if you have gas available.




Natural gas is the standard heating fuel in most part of the US.
Unfortunately the cost has more than tripled in the last decade or so,
making heat pumps an attractive alternative. I installed an air source
heat
pump in my house a few years ago and saw significant savings.

Are the "lifetime" savings significant? Of course this all depends
on the local costs of both electricity and gas. Both vary widely
across the country (some places even resistive heat is cheaper than
gas).

--
Keith


Well I wanted air con anyway so given the difference in cost between AC and
a heat pump it's already paid for itself and then some, but then I did use
scratch & dent surplus equipment and installed it myself so it didn't really
cost very much to do.

I've been told that heat pumps have a fairly short life, at least
compared to furnaces/boilers. My boiler is 21YO and going strong. Of
course, air-source heat pumps are out here and ground source is still
way too expensive.

Electricity is about $0.08/kwh and gas is about $1.30/Therm.

Our electricity is $.13/kWh, and gas somewhere around $1.40/therm.

We're considering moving soon, and air-source heat pumps seem to be
all the rage where we're considering (hence my interest). Of course
electricity is about $.06/kWh there, with far milder winters too.

--
Keith

 

[Rich Grise]

On Fri, 06 Jul 2007 11:01:19 +0100, Paul Burke wrote:

Spurious Response wrote:

You also have to account for losses at the kettle itself. They do not
transfer 100% of the energy, and the higher wattage units radiate a lot
more, so they are slightly lossy-er.

I'll stick with my infinitely (FAIAP) variable gas, thanks.

Work it out. The element is entirely surrounded by the water you want to
heat. So all the energy, apart from that conducted bak into the cable,
passes into the water. Most electric kettles these days are plastic, so
not much gets throgh the sides. Rather more escapes through the top,
especially while the kettle is actually boiling- I use this energy to
preheat the teapot. So efficiency is pretty good. A more powerful kettle
is better because there is less heat lost through the top and sides when
you are heating it.

As for gas, most of the energy simply wafts round the outside of the
kettle, and never heats the water at all- it just heats the universe.
Which isn't to say that it's not generally the best way to cook.

So you need pots and pans with heatsink fins on the bottom. ;-)

Cheers!
Rich

 

[bz]

Riscy <riscy00@googlemail.com> wrote in
news:1183788934.914370.181740@n2g2000hse.googlegroups.com:

On Jul 5, 1:03 pm, bz <bz+...@ch100-5.chem.lsu.edu> wrote:
Thomas Tornblom <tho...@Hax.SE> wrote innews:x0d4z7e1x4.fsf@Hax.SE:

Switching to 25A fuses
solved that. After the heatpump conversion I can most likely go back
to 20A fuses and save some on the electrical bill.

How would going to 20A fuses save some on the electric bill?

--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is
an infinite set.

bz+...@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

Because the heating system now driven by ground source heat pump
system, which take 3-4 time less power for same amount of heat. This
is a key feature and will reduce electric bill by 3-4 time, cheaper
than gas heater.
You no longer requires 25A and hence reduces to 20A as orginal circuit
design limits may allows. You may risk damage to cable and connection
if you keep 25A fuse.

If the 25A fuse was no risk during the time when it was needed, then it
should be no risk when it is unnecessary.

I understand that if the heat pump requires less current, then you can
save money, but changing the fuses from 25 A to 20 A will make little or
no difference, by itself, in the bill (unless the 25 a fuse has high
internal resistance. And I would expect a 25 A fuse to have LOWER internal
resistance than a 20 A fuse, so I don't think the fuse makes the
difference.



--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

bz+ser@ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap

 

[James Sweet]

I've been told that heat pumps have a fairly short life, at least
compared to furnaces/boilers. My boiler is 21YO and going strong. Of
course, air-source heat pumps are out here and ground source is still
way too expensive.

I have no idea how long a boiler lasts, but heat pumps can and do last 20 or
more years if it's a decent system properly installed, I know of at least
one old GE unit from the mid 70s which is still trucking along. Thousands of
them are needlessly replaced due to small issues that could be easily fixed,
but HVAC contractors are always eager to sell a new system and will come up
with every excuse they can to do so.

 

On 5 Jul, 14:45, Thomas Tornblom <tho...@Hax.SE> wrote:

bz <bz+...@ch100-5.chem.lsu.edu> writes:
Thomas Tornblom <tho...@Hax.SE> wrote innews:x0d4z7e1x4.fsf@Hax.SE:

Switching to 25A fuses
solved that. After the heatpump conversion I can most likely go back
to 20A fuses and save some on the electrical bill.

How would going to 20A fuses save some on the electric bill?

There are two parts to the bill, one consumption part, which obviosuly
is not affected by this, and then a fixed part, which is dependent on
the installed main fuse. The weaker the fuse, the less the fixed part
is.

When we moved in there was different tariffs for 16, 20, 25, 35A, but
after a few years they dropped the 16 and 20 A tariffs. Now they are
reinstating them.

It will increase the fixed part by about $150 a year, which is not
enough for me to bother. I rather not have to get out and replace
blown fuses.

Installing some load management to save 150 a year might be worth it,
perhaps an opening for a product there.


NT

 

On 6 Jul, 02:27, Spurious Response <SpuriousRespo...@cleansignal.org>
wrote:

On Thu, 05 Jul 2007 07:37:47 GMT, Thomas Tornblom <tho...@Hax.SE> wrote:

It takes the same amount of energy to boil a quantity of water whether
you're using a 1 kW or 3 kW kettle. Infact it would probably take less
energy with the 3kW kettle as it gets the job done quicker, which
means less losses.

You also have to account for losses at the kettle itself. They do not
transfer 100% of the energy,

yes they do. There isnt anywhere else for it to go.

and the higher wattage units radiate a lot
more, so they are slightly lossy-er.

no, they radiate less total energy because they take 1/3 the time and
radiated power is no different to a 1kW unit, since that depends
entirely on water temp and kettle shape & finish.


NT

 

On 6 Jul, 16:12, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Fri, 06 Jul 2007 11:03:55 +0100, Paul Burke <p...@scazon.com
wrote:

Oy! It's the other way round here, you pay 22p/kWhr for the first N
units, then about 15p thereafter. It's supposed to cover fixed costs
like the meter (which was there years ago and must have payed for itself
many times over at that rate).

"P" is pence? Roughly 44 cents/kwh? Yikes!

Yes, but its not as bad as it sounds. Bills are made up of charge per
kWh and a fixed standing charge for the supply. The 44c/kWh rate only
occurs where people choose a no standing charge deal, where the first
so many units are hiked in price to add the standing charge. Its just
a marketing game.


NT

 

[Spurious Response]

On Sat, 07 Jul 2007 08:52:03 +0100, "Dave Plowman (News)"
<dave@davenoise.co.uk> wrote:

Eh? Most plastics are poor conductors of heat.

Read what I said again. Sure, most plastics are poor conductors of
heat, however, most, if not all plastics with high temperature capacity
are much better conductors of heat than their intolerant relatives.

In other words, if it is a high temp tolerant plastic, it conducts heat
far better than any plastic you might be thinking of. Kinda goes with the
territory.

Now silicone, SOFT plastic types do insulate thermally. That is
different, and there are not a large number of them in that category. We
are talking about solid, construction capable type materials here.
The plastic that would be used on a vat of boiling water as a major
element of its containment would likely be a fair conductor of heat.

The reason low tolerance plastic types have such a low tolerance is
because of their lack of thermal conduction. Apply heat to the surface,
and it stays there. This is a bad thing when said heat can make said
surface reach a melting temperature fairly fast.

 

[Spurious Response]

On Sat, 07 Jul 2007 08:52:03 +0100, "Dave Plowman (News)"
<dave@davenoise.co.uk> wrote:

If you're there to reduce the heat, why not simply use the boiling water?

A lot of dishes require a maintained boil point... Like pasta, for
example.

So things like lids allow continued boiling even after heat reduction.
No lid... no boil... Unless you bring the heat back up. Which is what
the lid id good for.

 

[Spurious Response]

On Sat, 07 Jul 2007 08:52:03 +0100, "Dave Plowman (News)"
<dave@davenoise.co.uk> wrote:

Good grief. Most just want that cup of tea *now*.

I am willing to extend my "now" period in order to conserve a few
dollars at the end of the month when the gas bill arrives.