UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #161   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 03:20:28 -0000, Bill Wright wrote:

On 29/12/2018 17:42, William Gothberg wrote:
I was just asking WHY. And people have already said that commercial
ones are 2kW, so it's entirely possible.


They are used judiciously.


Domestic ones already have power level control. Simply use that if you cook weird stuff.
  #163   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 03:02:10 -0000, FMurtz wrote:

William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:22 -0000, Arthur Conan Doyle
wrote:

"William Gothberg" wrote:

I don't need a MW, but the usual 600W to 900W in domestic ovens is
pitiful. What's wrong with 2kW?

There are higher rating consumer units, but you have to look for them.
I had a
1.2kw range hood type that worked much better than the 900w types. I
think
commerical units (i.e. convenience store) can be found that are 1.8kw.

That said, what I find annoying is that the power control for every
consumer
microwave I've seen is duty cycle based. That is, so many seconds of
full power
followed by so many seconds of no power.

Some foods and defrosting would work much better if the actual power
level could
be adjusted. Panasonic claims to make an inverter based design, but
I'm not
convinced they actually adjust the outpout power.


I'm unsure how magnetrons work, but what's the big deal with running
them at half power? Do they have to be on full power, and also can't be
cycled more quickly?

Anyway, I've never used a microwave on anything other than full power -
even when defrosting, which for some reason people think you have to
select "defrost". Why? It just takes longer. I can defrost food much
faster on full power.


Because that is not defrosting it is cooking, Not remotely like
defrosting, methinks thou art a dill.


Funny how the food ends up at eating temperature whereas it was -20C. Therefore it's defrosted. Apply heat to a frozen thing, thing gets warmer, simple physics.

Another weird thing my current (Hyundai 800W) microwave does is to
switch off the heating completely for the last 15 seconds but continue
to run the fan, light, and turntable (if you've selected at least 4
minutes time). So er like why not just remove the food 15 seconds
earlier? Which I often do. Funnily enough nothing ever exploded.


  #164   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 88
Default Slow microwave ovens

So Mr Mouth when will you have this product on the market and how
much will it cost??




"William Gothberg" wrote in message
news : It was a question, not an answer.
:
:
: On Sat, 29 Dec 2018 19:38:34 -0000, ..shadow, me & my
wrote:
:
: So just aother mouth with no real answers...
: are you lymeboi or bod's off spring?
:
:
:
: "William Gothberg" wrote in message
: news : :I was just asking WHY. And people have already said that commercial
ones
: are 2kW, so it's entirely possible.
: :
: : On Sat, 29 Dec 2018 17:19:48 -0000, ..shadow, me & my
: wrote:
: :
: : So Mr Mouth when will you have this product on the market and how
: : much will it cost??
: :
: : "William Gothberg" wrote in
message
: : news : : ::
: : : It can take 5 minutes to warm something from frozen to eating
: temperature.
: : I see no reason that couldn't be made into 2 minutes.
: :
: :
:
:


  #165   Report Post  
Posted to uk.d-i-y,alt.electronics.alt.home.repair,alt.sci.physics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 05:47:48 -0000, Johnny B Good wrote:

On Sat, 29 Dec 2018 13:23:55 -0800, mike wrote:

On 12/29/2018 10:16 AM, William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F wrote:

On 12/29/2018 6:37 AM, trader_4 wrote:
On Saturday, December 29, 2018 at 9:23:42 AM UTC-5, Bill Gill wrote:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW?
They were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always better.

Bill

+1

That about covers it. Not sure how useful more power would be. For
example,
last night I was thawing out a tomato sauce in a quart plastic
container.
The Panasonic has a defrost mode that uses about 30% power and
cycles that.


It gets the 30% power by cycling the 100% power on 30% of the time.

(By the way, adjusting the level does not actually change the
wattage.
It simply means the microwave will pulse on and off at its fixed
wattage until the desired level is reached.)

https://lifehacker.com/5974788/famil...elf-with-your-

microwaves-power-settings-to-make-microwave-cooking-a-joy

That was true of the first generation of Microwaves, but the current
"inverter" driver units actually CAN throttle the power. Inverter
microwaves are much better for defrosting AND cooking.

We've had ours for about 2 years now - replacing our original that we
bought in about 1985.

BIG difference (but the old one would likely still be working by the
time this one dies)

Why is it called an invertor? I thought an invertor was a device to
increase the voltage - like running 240V devices off a 12V car battery.

And why on earth would you not want to cook on full power? I've never
had a reason to lower the power from the maximum of 800W. I want the
meal as soon as possible!


There's been a lot of nitpicking in this thread.

All microwaves reduce power by cycling between 0 and 100% power. The
relative power level is the duty factor of that on/off cycle.

Older microwaves switch the INPUT to the power transformer.
That also runs the filament. The time to heat up the filament is the
limiting factor in how short you can make the on-time.
You get a minimum of about 10 seconds on-time.
That minimum time is plenty to make food explode.

Better microwaves are called "Inverter" microwaves.
I believe they're all licensed from Panasonic.
When I bought mine, it seemed that all the licensees had dried up
leaving Panasonic as the only locally available units.

It's my understanding that they heat the filament independently and can
have very short on-times. Duty factor is the same as the older
microwaves, but the on-time can be much shorter.

I knew the inverter types could still only rely upon variable duty cycle
heating control like the earlier voltage doubling HT transformer/
rectifier/HV capacitor designs did. I just wasn't quite sure what the
benefit of an inverter over a simple voltage doubling circuit was until
you let on about the cathode heater/filament being able to remain fully
powered throughout the whole cycling period.

This 'cathode filament/heater always on' aspect isn't the only benefit
of an inverter type allowing a higher cycling frequency to be employed,
it also provides a well regulated HT voltage, free of the 50/60 Hz ripple
which spoils the efficiency of the magnetron in the older designs.

The HT voltage (and anode current - no longer affected by heating/
cooling cycles imposed upon the cathode) has to be kept to within a
fairly tight tolerance (by the standards typical of domestic white goods)
for optimum operation at the correct microwave frequencies.

The effect of changing anode voltage is analogous to the effect of how
hard you blow across the open top of a beer bottle (empty or partially
empty) to generate a musical tone. The stronger you blow, the higher the
sudden jump in pitch will be. The microwave frequency produced by a
magnetron is likewise affected by how strong a voltage is applied to its
anode and will jump in frequency just like a blown beer bottle and for
exactly the same analogous reason (electrons rather than air molecules
being involved in this case).

In short, the only way to control the power output of a magnetron
without detuning it from its optimum 'microwaving' frequency is by using
variable duty on/off cycling. There's no smooth continuous analogue power
control option in this case.

As for those large 2 and 3 KW microwave ovens used in commercial
kitchens, they use a much larger cooking cavity so that a bunch of "Five
Minute Meals" can be heated concurrently in the recommended 5 minutes
rather than be processed in batches of just one or two at a time.

The microwave energy doesn't magically focus in the deep interior of the
food and heat it from the inside outwards. The microwaves only penetrate
the first centimetre or two before losing sufficient of their energy in
this process so as to have insignificant effect on the deeper interior
which therefore relies upon conduction from the hotter outer portions to
raise its temperature sufficiently to kill any pathogenic micro-organisms
so as to eliminate the risk of food poisoning.


Can we not have a different frequency which goes deeper before being absorbed? Or even a combination of more than one frequency? Or a choice depending on the food you're cooking?

This, as has already been pointed out, takes time and, surprise
surprise, doubling the rate at which microwave energy is being poured
into the outer layers of the foodstuff in question, does not halve the
time required to complete the cooking process.

Indeed, as has also been pointed out, such an increased rate of energy
input will tend to overheat the outer layers so much so as to overcook
them. The increased temperature will simply result in a higher rate of
radiative and convective heat loss back into the cooking cavity with
rather less than you may have imagined making any useful contribution to
raising the deep interior temperature of the foodstuff in question.


Depends what you're cooking/heating in there. If I put in a large bowl of vegetables in cold water, it takes quite a while to get to boiling point before the veg starts to cook. And since it's chopped veg in water, everything gets heated, nothing is more than a cm deep. Doubling the power would heat them up way faster.


  #166   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire wrote:

William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW? They
were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always
better.

Most commercial microwave ovens are higher power - typically twice
that of a domestic oven (they often use a pair of magnetrons).
We have them in the office kitchen areas (I think they are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted on
the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical part
of the process, and the ability of food to conduct heat limits
the power input some food products can absorb without burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most countries.
In Europe and many other countries outside America, standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination ovens with
convection, fan, and infra-red (grill) heating too, and often
run at 2.5kW when using combination heating (with a 1kW magnetron).
In a domestic environment, combination heating is generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional heating
won't even get going in that time.

is that what your wife said


I'm not stupid enough to marry.


https://www.youtube.com/watch?v=xXyT1vy3BII


[insert very rude comment about Lynn]
  #167   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair,alt.electronics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

I don't own a design company, I was asking WHY. FFS just answer the question.


On Sun, 30 Dec 2018 16:13:31 -0000, ..shadow, me & my wrote:

So Mr Mouth when will you have this product on the market and how
much will it cost??




"William Gothberg" wrote in message
news : It was a question, not an answer.
:
:
: On Sat, 29 Dec 2018 19:38:34 -0000, ..shadow, me & my
wrote:
:
: So just aother mouth with no real answers...
: are you lymeboi or bod's off spring?
:
:
:
: "William Gothberg" wrote in message
: news : :I was just asking WHY. And people have already said that commercial
ones
: are 2kW, so it's entirely possible.
: :
: : On Sat, 29 Dec 2018 17:19:48 -0000, ..shadow, me & my
: wrote:
: :
: : So Mr Mouth when will you have this product on the market and how
: : much will it cost??
: :
: : "William Gothberg" wrote in
message
: : news : : ::
: : : It can take 5 minutes to warm something from frozen to eating
: temperature.
: : I see no reason that couldn't be made into 2 minutes.
: :
: :
:
:


  #168   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 03:09:29 -0000, FMurtz wrote:

William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F wrote:

On 12/29/2018 6:37 AM, trader_4 wrote:
On Saturday, December 29, 2018 at 9:23:42 AM UTC-5, Bill Gill wrote:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW? They
were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always better.

Bill

+1

That about covers it. Not sure how useful more power would be. For
example,
last night I was thawing out a tomato sauce in a quart plastic
container.
The Panasonic has a defrost mode that uses about 30% power and
cycles that.


It gets the 30% power by cycling the 100% power on 30% of the time.

(By the way, adjusting the level does not actually change the wattage.
It simply means the microwave will pulse on and off at its fixed wattage
until the desired level is reached.)

https://lifehacker.com/5974788/famil...-cooking-a-joy

That was true of the first generation of Microwaves, but the current
"inverter" driver units actually CAN throttle the power. Inverter
microwaves are much better for defrosting AND cooking.

We've had ours for about 2 years now - replacing our original that we
bought in about 1985.

BIG difference (but the old one would likely still be working by the
time this one dies)


Why is it called an invertor? I thought an invertor was a device to
increase the voltage - like running 240V devices off a 12V car battery.


Why do you persist in posting waffle about which you know absolutely
nothing, twould be better to post on subjects you know or ask and
educate yourself about the other


I know what a ****ing invertor is, I built my own solar panel system.
  #169   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair,alt.electronics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 09:10:46 -0000, Andy Bennet wrote:

On 29/12/2018 18:21, % wrote:
On 2018-12-29 10:43 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 17:29:50 -0000, William Gothberg wrote:

On 2018-12-29 10:26 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:46:52 -0000, Andy Bennet wrote:

On 29/12/2018 13:43, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW? They
were invented decades ago.

High power microwaves (1MW) are used in industry in for example ore
extraction/rock pulverizing.
1MW into a cup of water is not pretty, explodes the water contents and
breaks the cup.

I don't need a MW, but the usual 600W to 900W in domestic ovens is
pitiful. What's wrong with 2kW?

too expensive

You can get a 700W microwave for £30. Surely 2kW would be less than
triple that, so under £90.


and then re wire the house and when you use it ,
you can watch the hydro disk spin like a top


LOL. I have a 14.4kW electric boiler. That's what I call spin.


Spin? Does anyone still have those old mechanical meters? Mine just blinks an LED. If I were you I'd test it to see if it's charging you correctly, apparently they can go off calibration with age.
  #170   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair,alt.electronics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 03:34:41 -0000, Bill Wright wrote:

On 29/12/2018 17:26, William Gothberg wrote:


I don't need a MW, but the usual 600W to 900W in domestic ovens is
pitiful. What's wrong with 2kW?


I don't find much use for the 1,200W setting. The only real use is for
heating water quickly when the kettle's broken. Even jacket spuds are
cooked unevenly. Thick soup needs to be stirred during cooking. Meat is
hopeless.


I can't comment on the meat as I'm a vegetarian, but surely soup, once any part reaches boiling or near boiling, is going to bubble about and convect by moving the liquid about. When I cook soup, I just stir it when it's finished.

Anyway, for bigger things like a roast, what we need is a different frequency of microwaves that penetrates deeper. Must be possible.


  #171   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair,alt.electronics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 10:21:46 -0000, Max Demian wrote:

On 30/12/2018 03:18, Bill Wright wrote:
On 29/12/2018 17:35, William Gothberg wrote:
On Sat, 29 Dec 2018 17:15:05 -0000, Bill Wright
wrote:

On 29/12/2018 16:27, William Gothberg wrote:

It can take 5 minutes to warm something from frozen to eating
temperature. I see no reason that couldn't be made into 2 minutes.

Conduction

Which would be way faster if the water content the microwaves were
hitting was heated hotter.


But the difference in temp between the outside and the inside of the
food would be greater and this could result in food that was both over-
and under-cooked. This is why microwave ovens have low settings, so food
can cook slowly and evenly. Anyone who uses a microwave a lot will be
well aware of this. For items where convection can assist conduction
higher power can be fine, but not for large solid lumps of food.


I can't say many things I cook have large solid lumps. All ready meals are pretty much fluid, so convection and conduction can take place, and almost everything I cook is a dish of something which is only 2 inches deep.

I don't know what the low settings are for. All the instructions I've
seen - e.g. on ready meals - say "full power". There is the defrost
setting, but microwaves aren't very good at defrosting as they don't
heat frozen water very well.


Mine thaws a frozen (already cooked) pizza extremely well, on full power. It turns a -20C pizza into a +40C pizza in 4 minutes.
  #172   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,454
Default Slow microwave ovens

William Gothberg wrote:
On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few
kW? They were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always
better.

Most commercial microwave ovens are higher power - typically
twice that of a domestic oven (they often use a pair of
magnetrons). We have them in the office kitchen areas (I think they
are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted on
the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical part
of the process, and the ability of food to conduct heat limits
the power input some food products can absorb without burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most
countries. In Europe and many other countries outside America,
standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination
ovens with convection, fan, and infra-red (grill) heating too,
and often run at 2.5kW when using combination heating (with a 1kW
magnetron). In a domestic environment, combination heating is
generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional
heating won't even get going in that time.

is that what your wife said

I'm not stupid enough to marry.


https://www.youtube.com/watch?v=xXyT1vy3BII


[insert very rude comment about Lynn]


My wife of 28 years died in April.


  #173   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 17:00:35 -0000, trader_4 wrote:

On Sunday, December 30, 2018 at 11:45:09 AM UTC-5, William Gothberg wrote:
I don't own a design company, I was asking WHY. FFS just answer the question.


And it's been answered, by many posters, many times now. All agree, but
you won't accept it. Much of what you post is just stupid, like not
understanding, or pretending not to understand, that with too much
power you will COOK parts of something
that you just want to DEFROST, because the heating is not even. Anyone
who has used a microwave to defrost things understands that.


Funny how I can defrost stuff on full power just fine.

As do the microwave oven manufacturers, that have defrost settings, that use low
power and even give that off time after about a minute and a half, so
that the food won't overheat and cook in areas. If you have a frozen
pork chop that you want to DEFROST, so you can brine it, marinate it,
grill it, etc., you want it DEFROSTED, not half cooked.


I don't microwave huge lumps of food like that. So, you could have a 2kW microwave where anyone cooking a roast could still turn it down to what they used to use, but if you want to heat soup, or defrost a pizza, you can use 2kW and get it done very quickly.

And the same
principle applies to things you want to cook. Because the heating is
not perfectly even, if you give it too much power, parts will be overcooked,
while other parts are not done.


Only if your food is more than twice as thick as the microwave penetration distance.

Even with today's ovens I use 70%
or less power many times just to reheat leftovers. Higher power, parts
start to spatter, overheat, cheese starts to separate into oil, etc.,
while other parts are still cold.


Doesn't happen to me at all. List some of the foods that go wrong when reheated on full power.
  #174   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,523
Default Slow microwave ovens

On 30/12/2018 17:16, Mr Pounder Esquire wrote:

My wife of 28 years died in April.


It's been a hell of a year for quite a few of us in the group, I think.

Bill
  #175   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 479
Default Slow microwave ovens

On 12/30/2018 12:09 PM, William Gothberg wrote:
On Sun, 30 Dec 2018 03:09:29 -0000, FMurtz wrote:

William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F wrote:

On 12/29/2018 6:37 AM, trader_4 wrote:
On Saturday, December 29, 2018 at 9:23:42 AM UTC-5, Bill Gill wrote:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW?
They
were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use.* Getting warming times down to a couple of
seconds might not be a good idea.* More speed is not always better.

Bill

+1

That about covers it.* Not sure how useful more power would be.* For
example,
last night I was thawing out a tomato sauce in a quart plastic
container.
The Panasonic has a defrost mode that uses about 30% power and
cycles that.


It gets the 30% power by cycling the 100% power on 30% of the time.

(By the way, adjusting the level does not actually change the wattage.
It simply means the microwave will pulse on and off at its fixed
wattage
until the desired level is reached.)

https://lifehacker.com/5974788/famil...-cooking-a-joy


*That was true of the first generation of Microwaves, but the current
"inverter" driver units actually CAN throttle the power. Inverter
microwaves are much better for defrosting AND cooking.

We've had ours for about 2 years now - replacing our original that we
bought in about 1985.

BIG difference (but the old one would likely still be working by the
time this one dies)

Why is it called an invertor?* I thought an invertor was a device to
increase the voltage - like running 240V devices off a 12V car battery.


Why do you persist in posting waffle about which you know absolutely
nothing, twould be better to post on subjects you know* or ask and
educate yourself about the other


I know what a ****ing invertor is, I built my own solar panel system.



LMFAO! There it is again. Nobody else brags about you therefore, brag
about yourself when nobody asked. LMFAO! Pathetic ******.


  #176   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,523
Default Slow microwave ovens

On 30/12/2018 10:21, Max Demian wrote:

I don't know what the low settings are for. All the instructions I've
seen - e.g. on ready meals - say "full power". There is the defrost
setting, but microwaves aren't very good at defrosting as they don't
heat frozen water very well.


I've just heated some sardines. Low power is OK but medium or high and
the bones explode.

Bill
  #177   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,523
Default Slow microwave ovens

I use the simmer setting a lot. Very useful for keeping things warm when
doing a complicated meal.

Bill
  #178   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 17:16:37 -0000, Mr Pounder Esquire wrote:

William Gothberg wrote:
On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few
kW? They were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always
better.

Most commercial microwave ovens are higher power - typically
twice that of a domestic oven (they often use a pair of
magnetrons). We have them in the office kitchen areas (I think they
are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted on
the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical part
of the process, and the ability of food to conduct heat limits
the power input some food products can absorb without burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most
countries. In Europe and many other countries outside America,
standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination
ovens with convection, fan, and infra-red (grill) heating too,
and often run at 2.5kW when using combination heating (with a 1kW
magnetron). In a domestic environment, combination heating is
generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional
heating won't even get going in that time.

is that what your wife said

I'm not stupid enough to marry.

https://www.youtube.com/watch?v=xXyT1vy3BII


[insert very rude comment about Lynn]


My wife of 28 years died in April.


In that case I deeply apologise. I am truly sorry to hear that, no matter how much we hate each other.
  #179   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 17:28:31 -0000, Meanie wrote:

On 12/30/2018 12:09 PM, William Gothberg wrote:
On Sun, 30 Dec 2018 03:09:29 -0000, FMurtz wrote:

William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F wrote:

On 12/29/2018 6:37 AM, trader_4 wrote:
On Saturday, December 29, 2018 at 9:23:42 AM UTC-5, Bill Gill wrote:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW?
They
were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always better.

Bill

+1

That about covers it. Not sure how useful more power would be. For
example,
last night I was thawing out a tomato sauce in a quart plastic
container.
The Panasonic has a defrost mode that uses about 30% power and
cycles that.


It gets the 30% power by cycling the 100% power on 30% of the time.

(By the way, adjusting the level does not actually change the wattage.
It simply means the microwave will pulse on and off at its fixed
wattage
until the desired level is reached.)

https://lifehacker.com/5974788/famil...-cooking-a-joy


That was true of the first generation of Microwaves, but the current
"inverter" driver units actually CAN throttle the power. Inverter
microwaves are much better for defrosting AND cooking.

We've had ours for about 2 years now - replacing our original that we
bought in about 1985.

BIG difference (but the old one would likely still be working by the
time this one dies)

Why is it called an invertor? I thought an invertor was a device to
increase the voltage - like running 240V devices off a 12V car battery.

Why do you persist in posting waffle about which you know absolutely
nothing, twould be better to post on subjects you know or ask and
educate yourself about the other


I know what a ****ing invertor is, I built my own solar panel system.


LMFAO! There it is again. Nobody else brags about you therefore, brag
about yourself when nobody asked. LMFAO! Pathetic ******.


I wasn't bragging, I was stating I know how inverters work. Why on earth would you see that as bragging? You have some weird mental problem.
  #180   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 39,563
Default Slow microwave ovens

On 30/12/2018 17:31, Bill Wright wrote:
I use the simmer setting a lot. Very useful for keeping things warm when
doing a complicated meal.

I have an aga warming oven for that...

Bill



--
If you tell a lie big enough and keep repeating it, people will
eventually come to believe it. The lie can be maintained only for such
time as the State can shield the people from the political, economic
and/or military consequences of the lie. It thus becomes vitally
important for the State to use all of its powers to repress dissent, for
the truth is the mortal enemy of the lie, and thus by extension, the
truth is the greatest enemy of the State.

Joseph Goebbels





  #181   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,454
Default Slow microwave ovens

Bill Wright wrote:
On 30/12/2018 17:16, Mr Pounder Esquire wrote:

My wife of 28 years died in April.


It's been a hell of a year for quite a few of us in the group, I
think.
Bill


Yes, and all of the best for 2019.


  #182   Report Post  
Posted to uk.d-i-y
external usenet poster
 
Posts: 2,523
Default Slow microwave ovens

On 30/12/2018 05:47, Johnny B Good wrote:

The microwave energy doesn't magically focus in the deep interior of the
food and heat it from the inside outwards. The microwaves only penetrate
the first centimetre or two before losing sufficient of their energy in
this process so as to have insignificant effect on the deeper interior
which therefore relies upon conduction from the hotter outer portions to
raise its temperature sufficiently to kill any pathogenic micro-organisms
so as to eliminate the risk of food poisoning.

"What's he on about Grandad?"

"Well, he says when you put stuff in the micro it gets hot more on the
outside than on the inside. Microwaves work by invisible waves, little
tiny ones."

"Could I see them with my microscope?"

"Well no because as well as being tiny they're invisible."

"How do people know they're there then?"

"Err, because they warm food up, for one thing."

"What else?"

"Well, erm, they make television work. That's why we have aerials, to
pick the waves up."

"Do the aerials get warmed up by the waves then?"

"No."

"Why not? If the food gets warmed up..."

"Look, let's get back to the microwave oven. You see, the waves can only
go into the food about half an inch..."

"Is that about ten centimeters?"

"Tell you what. How about if you have another go on your X Box?"

******

The microwave energy doesn't magically focus in the deep interior of
the food and heat it from the inside outwards. The microwaves only
penetrate the first centimetre or two before losing sufficient of their
energy in this process so as to have insignificant effect on the deeper
interior which therefore relies upon conduction from the hotter outer
portions to raise its temperature sufficiently to kill any pathogenic
micro-organisms so as to eliminate the risk of food poisoning. (77
words; many of them long)


Shorter version for those who fall asleep half way through long paragraphs:
The microwaves heat food from the outside. They don't penetrate very
far, so the inner parts of the food are cooked by conduction. If these
parts get hot enough the germs are killed. (33 words)

Bill


  #183   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,454
Default Slow microwave ovens

William Gothberg wrote:
On Sun, 30 Dec 2018 17:16:37 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few
kW? They were invented decades ago.
Higher powered microwaves would require higher powered
electric outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always
better.

Most commercial microwave ovens are higher power - typically
twice that of a domestic oven (they often use a pair of
magnetrons). We have them in the office kitchen areas (I think
they are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted
on the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical
part of the process, and the ability of food to conduct heat
limits the power input some food products can absorb without
burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most
countries. In Europe and many other countries outside America,
standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination
ovens with convection, fan, and infra-red (grill) heating too,
and often run at 2.5kW when using combination heating (with a
1kW magnetron). In a domestic environment, combination heating
is generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional
heating won't even get going in that time.

is that what your wife said

I'm not stupid enough to marry.

https://www.youtube.com/watch?v=xXyT1vy3BII

[insert very rude comment about Lynn]


My wife of 28 years died in April.


In that case I deeply apologise. I am truly sorry to hear that, no
matter how much we hate each other.


Thank you for your kind words.
Hate? I do not hate you.


  #184   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,523
Default Slow microwave ovens

On 30/12/2018 09:26, Andy Bennet wrote:

That's why microwave ovens operate at 2.4GHz - the resonant
frequency/maximum absorption of energy in water molecules.


No it isn't.

Bill
  #185   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 18:15:46 -0000, Mr Pounder Esquire wrote:

William Gothberg wrote:
On Sun, 30 Dec 2018 17:16:37 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few
kW? They were invented decades ago.
Higher powered microwaves would require higher powered
electric outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always
better.

Most commercial microwave ovens are higher power - typically
twice that of a domestic oven (they often use a pair of
magnetrons). We have them in the office kitchen areas (I think
they are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted
on the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical
part of the process, and the ability of food to conduct heat
limits the power input some food products can absorb without
burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most
countries. In Europe and many other countries outside America,
standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination
ovens with convection, fan, and infra-red (grill) heating too,
and often run at 2.5kW when using combination heating (with a
1kW magnetron). In a domestic environment, combination heating
is generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional
heating won't even get going in that time.

is that what your wife said

I'm not stupid enough to marry.

https://www.youtube.com/watch?v=xXyT1vy3BII

[insert very rude comment about Lynn]

My wife of 28 years died in April.


In that case I deeply apologise. I am truly sorry to hear that, no
matter how much we hate each other.


Thank you for your kind words.
Hate? I do not hate you.


If you don't hate me, then why the er.... [consults dictionary] animosity in every post to me? You don't enter any discussion, you just say "prick", "******", etc.


  #186   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 2,783
Default Slow microwave ovens

On Sun, 30 Dec 2018 17:09:49 +0000, William Gothberg wrote:

I know what a ****ing invertor is, I built my own solar panel system.


There's an outstanding non-sequitur if ever there was one. "I know how to
build a ****ing house; I built my own sand castle."



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.
  #187   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 2,454
Default Slow microwave ovens

William Gothberg wrote:
On Sun, 30 Dec 2018 18:15:46 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sun, 30 Dec 2018 17:16:37 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few
kW? They were invented decades ago.
Higher powered microwaves would require higher powered
electric outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would
be practical for use. Getting warming times down to a
couple of seconds might not be a good idea. More speed is
not always better.

Most commercial microwave ovens are higher power - typically
twice that of a domestic oven (they often use a pair of
magnetrons). We have them in the office kitchen areas (I
think they are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted
on the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical
part of the process, and the ability of food to conduct heat
limits the power input some food products can absorb without
burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most
countries. In Europe and many other countries outside
America, standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination
ovens with convection, fan, and infra-red (grill) heating
too, and often run at 2.5kW when using combination heating
(with a 1kW magnetron). In a domestic environment,
combination heating is generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional
heating won't even get going in that time.

is that what your wife said

I'm not stupid enough to marry.

https://www.youtube.com/watch?v=xXyT1vy3BII

[insert very rude comment about Lynn]

My wife of 28 years died in April.

In that case I deeply apologise. I am truly sorry to hear that, no
matter how much we hate each other.


Thank you for your kind words.
Hate? I do not hate you.


If you don't hate me, then why the er.... [consults dictionary]
animosity in every post to me? You don't enter any discussion, you
just say "prick", "******", etc.


Those words do not mean hate.



  #188   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
% % is offline
external usenet poster
 
Posts: 1,776
Default Slow microwave ovens

On 2018-12-30 11:22 a.m., William Gothberg wrote:
On Sun, 30 Dec 2018 18:15:46 -0000, Mr Pounder Esquire
wrote:

William Gothberg wrote:
On Sun, 30 Dec 2018 17:16:37 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
*** Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few
kW? They were invented decades ago.
Higher powered microwaves would require higher powered
electric outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use.* Getting warming times down to a couple of
seconds might not be a good idea.* More speed is not always
better.

Most commercial microwave ovens are higher power - typically
twice that of a domestic oven (they often use a pair of
magnetrons). We have them in the office kitchen areas (I think
they are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted
on the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical
part of the process, and the ability of food to conduct heat
limits the power input some food products can absorb without
burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most
countries. In Europe and many other countries outside America,
standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination
ovens with convection, fan, and infra-red (grill) heating too,
and often run at 2.5kW when using combination heating (with a
1kW magnetron). In a domestic environment, combination heating
is generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional
heating won't even get going in that time.

is that what your wife said

I'm not stupid enough to marry.

https://www.youtube.com/watch?v=xXyT1vy3BII

[insert very rude comment about Lynn]

My wife of 28 years died in April.

In that case I deeply apologise.* I am truly sorry to hear that, no
matter how much we hate each other.


Thank you for your kind words.
Hate? I do not hate you.


If you don't hate me, then why the er.... [consults dictionary]
animosity in every post to me?* You don't enter any discussion, you just
say "prick", "******", etc.


i think that says it all
  #189   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 18:31:39 -0000, Mr Pounder Esquire wrote:

William Gothberg wrote:
On Sun, 30 Dec 2018 18:15:46 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sun, 30 Dec 2018 17:16:37 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sun, 30 Dec 2018 14:06:34 -0000, Mr Pounder Esquire
wrote:
William Gothberg wrote:
On Sat, 29 Dec 2018 17:34:10 -0000, William Gothberg wrote:

On 2018-12-29 10:32 a.m., William Gothberg wrote:
On Sat, 29 Dec 2018 14:56:26 -0000, Andrew Gabriel
wrote:

In article ,
Bill Gill writes:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few
kW? They were invented decades ago.
Higher powered microwaves would require higher powered
electric outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would
be practical for use. Getting warming times down to a
couple of seconds might not be a good idea. More speed is
not always better.

Most commercial microwave ovens are higher power - typically
twice that of a domestic oven (they often use a pair of
magnetrons). We have them in the office kitchen areas (I
think they are 2kW).
One problem is that retail food products do not state cooking
times in commercial microwave ovens - we have warnings posted
on the ovens that they are much more powerful.

Is the average person not able to divide by two?

Also, not all food can
be heated faster - often heat conduction is still a critical
part of the process, and the ability of food to conduct heat
limits the power input some food products can absorb without
burning
whilst other areas are still cold.

Then the oven needs to have a more even waveform.

There's no problem with standard socket outlets in most
countries. In Europe and many other countries outside
America, standard
sockets are designed to provide 3kW or 3.5kW (depending on
country). Many domestic microwaves in Europe are combination
ovens with convection, fan, and infra-red (grill) heating
too, and often run at 2.5kW when using combination heating
(with a 1kW magnetron). In a domestic environment,
combination heating is generally more
useful than simply a more powerful microwave.

Not when I want to heat something in 2 minutes, conventional
heating won't even get going in that time.

is that what your wife said

I'm not stupid enough to marry.

https://www.youtube.com/watch?v=xXyT1vy3BII

[insert very rude comment about Lynn]

My wife of 28 years died in April.

In that case I deeply apologise. I am truly sorry to hear that, no
matter how much we hate each other.

Thank you for your kind words.
Hate? I do not hate you.


If you don't hate me, then why the er.... [consults dictionary]
animosity in every post to me? You don't enter any discussion, you
just say "prick", "******", etc.


Those words do not mean hate.


I tend not to call people that unless I hate them. I hate people who don't drive properly, so I shout "******".

So, you still love me then?
  #190   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 18:30:02 -0000, Cursitor Doom wrote:

On Sun, 30 Dec 2018 17:09:49 +0000, William Gothberg wrote:

I know what a ****ing invertor is, I built my own solar panel system.


There's an outstanding non-sequitur if ever there was one. "I know how to
build a ****ing house; I built my own sand castle."


How do you think a 12V or 24V solar panel gets 240V AC out of it?


  #191   Report Post  
Posted to uk.d-i-y,alt.electronics,alt.home.repair,alt.sci.physics
external usenet poster
 
Posts: 50
Default Slow microwave ovens



"William Gothberg" wrote in message
news
On Sun, 30 Dec 2018 05:47:48 -0000, Johnny B Good
wrote:

On Sat, 29 Dec 2018 13:23:55 -0800, mike wrote:

On 12/29/2018 10:16 AM, William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F wrote:

On 12/29/2018 6:37 AM, trader_4 wrote:
On Saturday, December 29, 2018 at 9:23:42 AM UTC-5, Bill Gill wrote:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW?
They were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always better.

Bill

+1

That about covers it. Not sure how useful more power would be. For
example,
last night I was thawing out a tomato sauce in a quart plastic
container.
The Panasonic has a defrost mode that uses about 30% power and
cycles that.


It gets the 30% power by cycling the 100% power on 30% of the time.

(By the way, adjusting the level does not actually change the
wattage.
It simply means the microwave will pulse on and off at its fixed
wattage until the desired level is reached.)

https://lifehacker.com/5974788/famil...elf-with-your-

microwaves-power-settings-to-make-microwave-cooking-a-joy

That was true of the first generation of Microwaves, but the current
"inverter" driver units actually CAN throttle the power. Inverter
microwaves are much better for defrosting AND cooking.

We've had ours for about 2 years now - replacing our original that we
bought in about 1985.

BIG difference (but the old one would likely still be working by the
time this one dies)

Why is it called an invertor? I thought an invertor was a device to
increase the voltage - like running 240V devices off a 12V car battery.

And why on earth would you not want to cook on full power? I've never
had a reason to lower the power from the maximum of 800W. I want the
meal as soon as possible!

There's been a lot of nitpicking in this thread.

All microwaves reduce power by cycling between 0 and 100% power. The
relative power level is the duty factor of that on/off cycle.

Older microwaves switch the INPUT to the power transformer.
That also runs the filament. The time to heat up the filament is the
limiting factor in how short you can make the on-time.
You get a minimum of about 10 seconds on-time.
That minimum time is plenty to make food explode.

Better microwaves are called "Inverter" microwaves.
I believe they're all licensed from Panasonic.
When I bought mine, it seemed that all the licensees had dried up
leaving Panasonic as the only locally available units.

It's my understanding that they heat the filament independently and can
have very short on-times. Duty factor is the same as the older
microwaves, but the on-time can be much shorter.

I knew the inverter types could still only rely upon variable duty cycle
heating control like the earlier voltage doubling HT transformer/
rectifier/HV capacitor designs did. I just wasn't quite sure what the
benefit of an inverter over a simple voltage doubling circuit was until
you let on about the cathode heater/filament being able to remain fully
powered throughout the whole cycling period.

This 'cathode filament/heater always on' aspect isn't the only benefit
of an inverter type allowing a higher cycling frequency to be employed,
it also provides a well regulated HT voltage, free of the 50/60 Hz ripple
which spoils the efficiency of the magnetron in the older designs.

The HT voltage (and anode current - no longer affected by heating/
cooling cycles imposed upon the cathode) has to be kept to within a
fairly tight tolerance (by the standards typical of domestic white goods)
for optimum operation at the correct microwave frequencies.

The effect of changing anode voltage is analogous to the effect of how
hard you blow across the open top of a beer bottle (empty or partially
empty) to generate a musical tone. The stronger you blow, the higher the
sudden jump in pitch will be. The microwave frequency produced by a
magnetron is likewise affected by how strong a voltage is applied to its
anode and will jump in frequency just like a blown beer bottle and for
exactly the same analogous reason (electrons rather than air molecules
being involved in this case).

In short, the only way to control the power output of a magnetron
without detuning it from its optimum 'microwaving' frequency is by using
variable duty on/off cycling. There's no smooth continuous analogue power
control option in this case.

As for those large 2 and 3 KW microwave ovens used in commercial
kitchens, they use a much larger cooking cavity so that a bunch of "Five
Minute Meals" can be heated concurrently in the recommended 5 minutes
rather than be processed in batches of just one or two at a time.

The microwave energy doesn't magically focus in the deep interior of the
food and heat it from the inside outwards. The microwaves only penetrate
the first centimetre or two before losing sufficient of their energy in
this process so as to have insignificant effect on the deeper interior
which therefore relies upon conduction from the hotter outer portions to
raise its temperature sufficiently to kill any pathogenic micro-organisms
so as to eliminate the risk of food poisoning.


Can we not have a different frequency which goes deeper before being
absorbed?


The frequency used is already the one where water has the best absorption
band.

Or even a combination of more than one frequency?


No point when those are worse.

Or a choice depending on the food you're cooking?


It doesn't.

This, as has already been pointed out, takes time and, surprise
surprise, doubling the rate at which microwave energy is being poured
into the outer layers of the foodstuff in question, does not halve the
time required to complete the cooking process.

Indeed, as has also been pointed out, such an increased rate of energy
input will tend to overheat the outer layers so much so as to overcook
them. The increased temperature will simply result in a higher rate of
radiative and convective heat loss back into the cooking cavity with
rather less than you may have imagined making any useful contribution to
raising the deep interior temperature of the foodstuff in question.


Depends what you're cooking/heating in there. If I put in a large bowl of
vegetables in cold water, it takes quite a while to get to boiling point
before the veg starts to cook.


Because there is a lot more water to heat.

And since it's chopped veg in water, everything gets heated, nothing is
more than a cm deep. Doubling the power would heat them up way faster.


Yes but you shouldn't be using that much water when microwaving chopped veg.
When you microwave it with the right amount of water it will cook much
faster.

  #192   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 50
Default Slow microwave ovens



"William Gothberg" wrote in message
news
On Sun, 30 Dec 2018 03:09:29 -0000, FMurtz wrote:

William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F wrote:

On 12/29/2018 6:37 AM, trader_4 wrote:
On Saturday, December 29, 2018 at 9:23:42 AM UTC-5, Bill Gill wrote:
On 12/29/2018 7:43 AM, William Gothberg wrote:
Shouldn't we have faster microwaves by now giving out a few kW?
They
were invented decades ago.
Higher powered microwaves would require higher powered electric
outlets, probably 220VAC (in the USA).

Also it is questionable whether higher powered ovens would be
practical for use. Getting warming times down to a couple of
seconds might not be a good idea. More speed is not always better.

Bill

+1

That about covers it. Not sure how useful more power would be. For
example,
last night I was thawing out a tomato sauce in a quart plastic
container.
The Panasonic has a defrost mode that uses about 30% power and
cycles that.


It gets the 30% power by cycling the 100% power on 30% of the time.

(By the way, adjusting the level does not actually change the wattage.
It simply means the microwave will pulse on and off at its fixed
wattage
until the desired level is reached.)

https://lifehacker.com/5974788/famil...-cooking-a-joy

That was true of the first generation of Microwaves, but the current
"inverter" driver units actually CAN throttle the power. Inverter
microwaves are much better for defrosting AND cooking.

We've had ours for about 2 years now - replacing our original that we
bought in about 1985.

BIG difference (but the old one would likely still be working by the
time this one dies)

Why is it called an invertor? I thought an invertor was a device to
increase the voltage - like running 240V devices off a 12V car battery.


Why do you persist in posting waffle about which you know absolutely
nothing, twould be better to post on subjects you know or ask and
educate yourself about the other


I know what a ****ing invertor is, I built my own solar panel system.


Not the same as an inverter microwave oven.

  #193   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair,alt.electronics
external usenet poster
 
Posts: 50
Default Slow microwave ovens



"William Gothberg" wrote in message
news
On Sun, 30 Dec 2018 03:34:41 -0000, Bill Wright
wrote:

On 29/12/2018 17:26, William Gothberg wrote:


I don't need a MW, but the usual 600W to 900W in domestic ovens is
pitiful. What's wrong with 2kW?


I don't find much use for the 1,200W setting. The only real use is for
heating water quickly when the kettle's broken. Even jacket spuds are
cooked unevenly. Thick soup needs to be stirred during cooking. Meat is
hopeless.


I can't comment on the meat as I'm a vegetarian, but surely soup, once any
part reaches boiling or near boiling, is going to bubble about and convect
by moving the liquid about. When I cook soup, I just stir it when it's
finished.

Anyway, for bigger things like a roast, what we need is a different
frequency of microwaves that penetrates deeper. Must be possible.


Not it is not.

  #194   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 50
Default Slow microwave ovens



"William Gothberg" wrote in message
news
On Sun, 30 Dec 2018 18:30:02 -0000, Cursitor Doom
wrote:

On Sun, 30 Dec 2018 17:09:49 +0000, William Gothberg wrote:

I know what a ****ing invertor is, I built my own solar panel system.


There's an outstanding non-sequitur if ever there was one. "I know how to
build a ****ing house; I built my own sand castle."


How do you think a 12V or 24V solar panel gets 240V AC out of it?


A different way to how inverter microwaves do it. Inverter
microwaves use PWM, solar panel inverters don't.

  #195   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair
external usenet poster
 
Posts: 1,980
Default Slow microwave ovens

On 12/29/18 11:26 AM, William Gothberg wrote:

[snip]

I don't need a MW, but the usual 600W to 900W in domestic ovens is
pitiful.* What's wrong with 2kW?


Microwave heating instructions usually say what power they're for. Most
I've seen recently say 1 or 1.1KW. Maybe that's the normal for the new
units.

BTW, I have a 700W microwave about 30 years old.

--
Mark Lloyd
http://notstupid.us/

"Why has a religious turn of mind always a tendency to narrow and harden
the heart?" -- Robert Burns


  #196   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair,alt.electronics
external usenet poster
 
Posts: 170
Default Slow microwave ovens

On Sun, 30 Dec 2018 19:37:27 -0000, Mark Lloyd wrote:

On 12/29/18 11:26 AM, William Gothberg wrote:

[snip]

I don't need a MW, but the usual 600W to 900W in domestic ovens is
pitiful. What's wrong with 2kW?


Microwave heating instructions usually say what power they're for. Most
I've seen recently say 1 or 1.1KW. Maybe that's the normal for the new
units.

BTW, I have a 700W microwave about 30 years old.


The heating instructions are based on what is commercially available. If there were 2kW units around, they'd have those listed too, with shorter cooking times.
  #197   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.sci.physics,alt.electronics
external usenet poster
 
Posts: 1,980
Default Slow microwave ovens

On 12/29/18 12:06 PM, William Gothberg wrote:

[snip]

In the UK we don't have that problem, my kitchen is full of 13A 240V
sockets, just like every other room, it's what I plug my kettle,
dishwasher, washing machine, bread maker, etc, etc into.* All of which
would be utterly useless on a 120V circuit.


Here, I use a kettle you put on the stove, and all the others are 120V.

I thought the USA had 240V
sockets in rooms where they're likely to be needed, like the kitchen?


Some kitchens have a 240V 40A outlet for a stove. Mine is built-in and
hardwired.

Some older houses have 240V (15 or 20A) sockets (for window air
conditioners).

And where do you plug in a 2kW hoover?* I plug mine in any room I'm
hoovering.


Probably get by with a smaller unit.

--
Mark Lloyd
http://notstupid.us/

"Why has a religious turn of mind always a tendency to narrow and harden
the heart?" -- Robert Burns
  #198   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.sci.physics,alt.electronics
external usenet poster
 
Posts: 1,980
Default Slow microwave ovens

On 12/29/18 12:25 PM, Arthur Conan Doyle wrote:
"William Gothberg" wrote:

I thought the USA had 240V sockets in rooms where they're likely to be needed, like the kitchen?


In the US 240v sockets are typically found in the kitchen for use by an electric
range, or in a dedicated laundry room for use by an electric dryer. Sometimes
they can be found in a garage. The interior outlets are typicaly located behind
the appliance - in effect dedicated for that appliance and not intended for
general use.


I know of one house around here that has a 240V socket in a storage room
in the yard. I think one of the former owners put it in for a welder. I
know of a later owner who used it for a porcelain kiln.

--
Mark Lloyd
http://notstupid.us/

"Why has a religious turn of mind always a tendency to narrow and harden
the heart?" -- Robert Burns
  #199   Report Post  
Posted to alt.sci.physics,uk.d-i-y,alt.home.repair,alt.electronics
% % is offline
external usenet poster
 
Posts: 1,776
Default Slow microwave ovens

On 2018-12-30 12:50 p.m., William Gothberg wrote:
On Sun, 30 Dec 2018 19:37:27 -0000, Mark Lloyd wrote:

On 12/29/18 11:26 AM, William Gothberg wrote:

[snip]

I don't need a MW, but the usual 600W to 900W in domestic ovens is
pitiful.* What's wrong with 2kW?


Microwave heating instructions usually say what power they're for. Most
I've seen recently say 1 or 1.1KW. Maybe that's the normal for the new
units.

BTW, I have a 700W microwave about 30 years old.


The heating instructions are based on what is commercially available.
If there were 2kW units around, they'd have those listed too, with
shorter cooking times.


have you tried your dick in the micro yet ,
set it on high for 30 seconds ,
that will tell you if the microwave is ,
heating quickly enough
  #200   Report Post  
Posted to alt.home.repair,uk.d-i-y,alt.electronics,alt.sci.physics
external usenet poster
 
Posts: 1,980
Default Slow microwave ovens

On 12/29/18 12:52 PM, William Gothberg wrote:

[snip]

Microwaving something in a cheap **** plastic container is insane.* I
always cook or eat things in a real pot bowl.* Plastic melts!


The first thing I heated in a microwave was frozen macaroni and cheese.
The instructions said to cover it in plastic wrap. It didn't take me
long to figure out that it was a really bad idea, consider trying to
separate melted plastic from melted cheese.

--
Mark Lloyd
http://notstupid.us/

"Why has a religious turn of mind always a tendency to narrow and harden
the heart?" -- Robert Burns
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
What mostly makes a small engine "wheeze" fast & slow, fast & slow, fast & slow? ultred ragnusen Home Repair 32 February 26th 18 07:29 PM
Slow, slow, slow charlieb Woodturning 5 October 14th 09 04:43 PM
Any microwave ovens available with pop sensors? Doug Warner Home Repair 32 January 4th 06 05:56 PM
Microwave ovens thermal fuse/link/tco Sidney Electronics Repair 2 September 29th 04 05:50 AM


All times are GMT +1. The time now is 02:47 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"