Op amps problem Gain Calculation

[William Gothberg]

On Sat, 29 Dec 2018 18:27:21 -0000, Arthur Conan Doyle <dont@bother.com> wrote:

"William Gothberg" <William_Gothberg@internet.co.is> wrote:

Why is it called an invertor?

Typical microwaves use fixed AC power to drive the magnetron. Inverter driven
magnetrons use DC power, which can be variable.

So they rectify the AC, then boost the DC voltage as required by the user setting?

But even without an invertor, surely you could have a few tappings on a transformer to change the AC voltage to the magnetron? It's not like you need infinite control, just 3 or 4 would do.

 

[William Gothberg]

On Sat, 29 Dec 2018 18:48:38 -0000, trader_4 <trader4@optonline.net> wrote:

On Saturday, December 29, 2018 at 1:21:48 PM UTC-5, Arthur Conan Doyle wrote:
"William Gothberg" <William_Gothberg@internet.co.is> wrote:

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.

The idea is not to cook the food as its defrosting. Full power is fine if you
want the end item hot. It's not good if you want something room tempurature or
slightly cooler to use as a part of preparation of something else.

+1

I already tried to explain that to him with my frozen tomato sauce example.
You put a quart plastic container in the microwave and even on the defrost
setting, where it runs at like 30% power and also pulses that on for maybe
75 secs, then off for 20 or so, the bottom gets hot to the point that the
plastic container can start to soften, while the upper portion is still
frozen solid. You're right, defrosting meat is an even better example.
You'd be cooking part of it while the rest is still frozen. It already
happens with the current ovens, if you're not careful.

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

 

[William Gothberg]

On Sat, 29 Dec 2018 18:50:02 -0000, trader_4 <trader4@optonline.net> wrote:

On Saturday, December 29, 2018 at 1:45:03 PM UTC-5, William Gothberg wrote:
On Sat, 29 Dec 2018 18:21:45 -0000, Arthur Conan Doyle <dont@bother.com> wrote:

"William Gothberg" <William_Gothberg@internet.co.is> wrote:

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.

The idea is not to cook the food as its defrosting. Full power is fine if you
want the end item hot. It's not good if you want something room tempurature or
slightly cooler to use as a part of preparation of something else.

Then I just use less cooking time. Full power will defrost to room temperature much faster than that pointless defrost mode. And if you're about to say it won't be even, so what? If it's for part of preparation of something else, it has plenty time to even out.

The so what is that the plastic container will melt or part of the meat
will be cooked via steaming, instead of being able to make it into a
burger and grill it. Capiche? No, of course not.

I don't seem to have that problem, full power defrosts things evenly enough. Some bits are probably a bit hotter than others, but it's evened out by the time I eat it.

 

[Andrew Gabriel]

In article <op.zusqdvwu7uplkq@desktop-ga2mpl8.lan>,
"William Gothberg" <William_Gothberg@internet.co.is> writes:

On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder <clare@snyder.on.ca> wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com> 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/familiarize-yourself-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.

To run a 5kV magnetron from 240V.

> 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!

Microwaves do not penetrate all the way through larger volumes of
food - the heating is done in the outer 1-2cm. Heating the middle
is done by conduction (and by convection if the food is a fluid).
If you pile in energy faster than it can conduct all the way through,
you will have a burned outside and a cold middle.

Domestic microwave food products are not designed to be heated in
2kW ovens. Many would fail to cook properly/safely.
Commercial microwave food products (some anyway) are designed to be
heated in 2kW microwaves.

And in reference to your other post, it's not simply a matter of
dividing the cooking time by two. The amount of energy absorbed by
a food product also depends on the surface area exposed to the
microwaves (1 pea in a 2kW oven will not absord 2kW), so the cooking
time in a 2kW oven depends on the size and shape of the item - it
would have to be calculated by the manufacturer and included on the
packaging, but in practice, most domestic food products will not have
sufficient heat conduction to be able to absord 2kW and cook properly.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

 

[William Gothberg]

On Sat, 29 Dec 2018 19:02:23 -0000, Andrew Gabriel <andrew@cucumber.demon.co.uk> wrote:

In article <op.zusqdvwu7uplkq@desktop-ga2mpl8.lan>,
"William Gothberg" <William_Gothberg@internet.co.is> writes:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder <clare@snyder.on.ca> wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com> 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/familiarize-yourself-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.

To run a 5kV magnetron from 240V.

That could be done with a transformer, with a few tappings to allow lower power.

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!

Microwaves do not penetrate all the way through larger volumes of
food - the heating is done in the outer 1-2cm. Heating the middle
is done by conduction (and by convection if the food is a fluid).
If you pile in energy faster than it can conduct all the way through,
you will have a burned outside and a cold middle.

I never have that problem, water (which most foods are primarily made of) conducts pretty quick.

Domestic microwave food products are not designed to be heated in
2kW ovens. Many would fail to cook properly/safely.
Commercial microwave food products (some anyway) are designed to be
heated in 2kW microwaves.

And in reference to your other post, it's not simply a matter of
dividing the cooking time by two. The amount of energy absorbed by
a food product also depends on the surface area exposed to the
microwaves (1 pea in a 2kW oven will not absord 2kW), so the cooking
time in a 2kW oven depends on the size and shape of the item - it
would have to be calculated by the manufacturer and included on the
packaging, but in practice, most domestic food products will not have
sufficient heat conduction to be able to absord 2kW and cook properly.

Most meals are way bigger than a pea. Everything I cook is in a dish and about 1 inch deep. I'm sure that most if it would be hit by microwaves directly.

 

[Rod Speed]

"William Gothberg" <William_Gothberg@internet.co.is> wrote in message
newsp.zusqdvwu7uplkq@desktop-ga2mpl8.lan...

On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder <clare@snyder.on.ca
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com> 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/familiarize-yourself-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?

Because that's how it works.

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

As usual, you are so stupid that you havent even noticed
that most words have more than one meaning.

https://en.wikipedia.org/wiki/Microwave_oven

In most ovens, the magnetron is driven by a linear transformer
which can only feasibly be switched completely on or off. (One
variant of the GE Spacemaker had two taps on the transformer
primary, for high and low power modes.) Usually choice of
power level doesn't affect intensity of the microwave radiation;
instead, the magnetron is cycled on and off every few seconds,
thus altering the large scale duty cycle. Newer models use inverter
power supplies that use pulse-width modulation to provide
effectively continuous heating at reduced power settings, so that
foods are heated more evenly at a given power level and can be
heated more quickly without being damaged by uneven heating.

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!

Yeah, you know it all, no microwave designer knows anything.

 

[Rod Speed]

"Arthur Conan Doyle" <dont@bother.com> wrote in message
news:n1ff2el7b5fc6megbeihv069t05gouso10@None...

"William Gothberg" <William_Gothberg@internet.co.is> wrote:

Why is it called an invertor?

Typical microwaves use fixed AC power to drive the magnetron. Inverter
driven
magnetrons use DC power, which can be variable.

Pulse width modulation, actually.

https://en.wikipedia.org/wiki/Microwave_oven

 

[Peeler]

On Sat, 29 Dec 2018 12:27:21 -0600, Arthur Conan Doyle, another mentally
challenged, troll-feeding senile Yankietard, blathered:

Why is it called an invertor?

Typical microwaves use fixed AC power to drive the magnetron. Inverter driven
magnetrons use DC power, which can be variable.

The abnormal troll asks, and the abnormal senile Yankietard delivers,
inevitably! LOL

 

[Peeler]

On Sun, 30 Dec 2018 06:59:14 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

Yeah, you know it all, no microwave designer knows anything.

Yeah, he obviously doesn't yet know that YOU *REALLY REALLY* know it all,
eh, senile Mr Know-it-all? LOL

--
pamela about Rot Speed:
"His off the cuff expertise demonstrates how little he knows..."
MID: <XnsA90B720A381A2D4AM2@81.171.92.183>

 

[Peeler]

On Sat, 29 Dec 2018 12:25:05 -0600, Arthur Conan Doyle, another mentally
challenged, troll-feeding senile Yankietard, blathered:

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.

Good Lord! Not the SAME shit again! How OFTEN have you retarded senile Yanks
and the troll you like to suck off so much been through with the same shit
over the last year? <tsk>

 

[mike]

On 12/29/2018 10:16 AM, William Gothberg wrote:

On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder <clare@snyder.on.ca
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com> 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/familiarize-yourself-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.

Foods don't explode on low power like they used to.

Food is not uniform. The effectiveness of microwaves decreases
as the food thickness increases. There's a thermal time constant.
So, if you cook at lower average power for longer time,
you can warm the inside without seriously overcooking the outside
or having local boiling that makes food explode.

The minimum on-time really helps with that. I haven't had food
explode since I got an Inverter microwave. The defrost cycle
really does work well.

They're slightly more expensive, but it's worth it.

 

[William Gothberg]

On Sat, 29 Dec 2018 21:23:55 -0000, mike <ham789@netzero.net> wrote:

On 12/29/2018 10:16 AM, William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder <clare@snyder.on.ca
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com> 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/familiarize-yourself-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.

Foods don't explode on low power like they used to.

Food is not uniform. The effectiveness of microwaves decreases
as the food thickness increases. There's a thermal time constant.
So, if you cook at lower average power for longer time,
you can warm the inside without seriously overcooking the outside
or having local boiling that makes food explode.

The minimum on-time really helps with that. I haven't had food
explode since I got an Inverter microwave. The defrost cycle
really does work well.

They're slightly more expensive, but it's worth it.

I've never exploded food on a non-invertor microwave. Maybe I don't cook thick enough stuff. Or maybe they should work more on making the microwaves more even so you don't get so many hotspots.

 

[Peeler]

On Sat, 29 Dec 2018 13:23:55 -0800, mike, another mentally challenged
troll-feeding senile Yankietard, blathered:


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

Yeah, and you troll-feeding senile Yanks have been instrumental to it!

 

[Chris Green]

Boring

--
Chris Green
¡

 

[87213]

"William Gothberg" <William_Gothberg@internet.co.is> wrote in message
newsp.zusz2vco7uplkq@desktop-ga2mpl8.lan...

On Sat, 29 Dec 2018 21:23:55 -0000, mike <ham789@netzero.net> wrote:

On 12/29/2018 10:16 AM, William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder <clare@snyder.on.ca
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com> 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/familiarize-yourself-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.

Foods don't explode on low power like they used to.

Food is not uniform. The effectiveness of microwaves decreases
as the food thickness increases. There's a thermal time constant.
So, if you cook at lower average power for longer time,
you can warm the inside without seriously overcooking the outside
or having local boiling that makes food explode.

The minimum on-time really helps with that. I haven't had food
explode since I got an Inverter microwave. The defrost cycle
really does work well.

They're slightly more expensive, but it's worth it.

I've never exploded food on a non-invertor microwave.

Try microwaving an egg in its shell sometime.

> Maybe I don't cook thick enough stuff.

Yep, you vegys don't.

Or maybe they should work more on making the microwaves more even so you
don't get so many hotspots.

That's not the problem. The problem is that with something
large like a leg of lamb, the microwaves get absorbed on
the outside so that if you blast it with full power of say 2KW
you will burn the outside and leave the inside uncooked.

 

[William Gothberg]

On Sat, 29 Dec 2018 22:49:05 -0000, 87213 <87213@gmail.com> wrote:

"William Gothberg" <William_Gothberg@internet.co.is> wrote in message
newsp.zusz2vco7uplkq@desktop-ga2mpl8.lan...
On Sat, 29 Dec 2018 21:23:55 -0000, mike <ham789@netzero.net> wrote:

On 12/29/2018 10:16 AM, William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder <clare@snyder.on.ca
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com> 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/familiarize-yourself-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.

Foods don't explode on low power like they used to.

Food is not uniform. The effectiveness of microwaves decreases
as the food thickness increases. There's a thermal time constant.
So, if you cook at lower average power for longer time,
you can warm the inside without seriously overcooking the outside
or having local boiling that makes food explode.

The minimum on-time really helps with that. I haven't had food
explode since I got an Inverter microwave. The defrost cycle
really does work well.

They're slightly more expensive, but it's worth it.

I've never exploded food on a non-invertor microwave.

Try microwaving an egg in its shell sometime.

People are free to microwave at a lower power if they wish Rod. Nothing wrong with increasing the maximum available Mr Speed.

Maybe I don't cook thick enough stuff.

Yep, you vegys don't.

We eat real food Rod, not pre-prepared stuff already digested Mr Speed. I guess this is why my cats shit so much, because there's so little nutrition in meat that they have to eat so much of it.

Or maybe they should work more on making the microwaves more even so you
don't get so many hotspots.

That's not the problem. The problem is that with something
large like a leg of lamb, the microwaves get absorbed on
the outside so that if you blast it with full power of say 2KW
you will burn the outside and leave the inside uncooked.

Not everything in a microwave is large Rod. You're always free to select a different output level for larger pieces of meat Mr Speed.

 

[Peeler]

On Sat, 29 Dec 2018 22:47:40 +0000, Chris Green, another mentally challenged
senile troll-lover, babbled:

> Boring

NOT for me, you laughable senile troll-lover! LOL

 

[Bob F]

On 12/29/2018 1:23 PM, mike wrote:

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/familiarize-yourself-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.

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.

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.

Foods don't explode on low power like they used to.

I was all ready to concede that I was wrong. Then you came along and
proved otherwise. Thanks for educating me.

Obviously, I've never had an "inverter microwave".

 

[Rod Speed]

"William Gothberg" <William_Gothberg@internet.co.is> wrote in message
newsp.zus7tdgb7uplkq@desktop-ga2mpl8.lan...

On Sun, 30 Dec 2018 00:06:53 -0000, 87213 <87213@gmail.com> wrote:



"William Gothberg" <William_Gothberg@internet.co.is> wrote in message
newsp.zus3lxpe7uplkq@desktop-ga2mpl8.lan...
On Sat, 29 Dec 2018 22:49:05 -0000, 87213 <87213@gmail.com> wrote:



"William Gothberg" <William_Gothberg@internet.co.is> wrote in message
newsp.zusz2vco7uplkq@desktop-ga2mpl8.lan...
On Sat, 29 Dec 2018 21:23:55 -0000, mike <ham789@netzero.net> wrote:

On 12/29/2018 10:16 AM, William Gothberg wrote:
On Sat, 29 Dec 2018 17:38:04 -0000, Clare Snyder
clare@snyder.on.ca
wrote:

On Sat, 29 Dec 2018 08:07:42 -0800, Bob F <bobnospam@gmail.com
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/familiarize-yourself-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.

Foods don't explode on low power like they used to.

Food is not uniform. The effectiveness of microwaves decreases
as the food thickness increases. There's a thermal time constant.
So, if you cook at lower average power for longer time,
you can warm the inside without seriously overcooking the outside
or having local boiling that makes food explode.

The minimum on-time really helps with that. I haven't had food
explode since I got an Inverter microwave. The defrost cycle
really does work well.

They're slightly more expensive, but it's worth it.

I've never exploded food on a non-invertor microwave.

Try microwaving an egg in its shell sometime.

People are free to microwave at a lower power if they wish Rod. Nothing
wrong with increasing the maximum available Mr Speed.

Maybe I don't cook thick enough stuff.

Yep, you vegys don't.

We eat real food Rod,

But not in big enough chunks to
see the effect being discussed.

Fuck off Rod.

Go and fuck yourself, PHucker.

 

[William Gothberg]

On Sun, 30 Dec 2018 00:21:51 -0000, Clare Snyder <clare@snyder.on.ca> wrote:

On Sat, 29 Dec 2018 10:25:56 -0800 (PST), angelicapaganelli@yahoo.com
wrote:

On Saturday, December 29, 2018 at 1:06:23 PM UTC-5, William Gothberg wrote:
On Sat, 29 Dec 2018 17:57:35 -0000, Bill Gill <billnews2@cox.net> wrote:

On 12/29/2018 11:34 AM, William Gothberg wrote:
On Sat, 29 Dec 2018 16:56:35 -0000, trader_4 <trader4@optonline.net> wrote:

On Saturday, December 29, 2018 at 11:27:53 AM UTC-5, William Gothberg
wrote:
On Sat, 29 Dec 2018 14:23:37 -0000, Bill Gill <billnews2@cox.net> 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).

Not a problem in Europe where everything is 240V. Another reason you
ought to stop that low voltage crap! Do you seriously have to hard
wire all your washing machines, dishwashers, tumble dryers, etc,
etc? And what on earth do you do with hoovers?

No. Of those only a dishwasher is hardwired, typically. The rest are
plug
and cord, 240V in the case of electric dryers. Works for me.

So you do have sockets where you can plug in 240V 3kW devices, just like
in the UK. So no problem with a more powerful microwave then.
If you don't mind going to the garage/laundry room/etc. to use your
microwave.

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. I thought the USA had 240V sockets in rooms where they're likely to be needed, like the kitchen? And where do you plug in a 2kW hoover? I plug mine in any room I'm hoovering.

If there's a 240V socket in the kitchen, it's quite likely behind the stove,
which is plugged into it.

I wasn't conveniently able to find the power consumption of my vacuum
cleaner, but I'm sure it isn't 2 kW. My floors are hardwood, so that
kind of power isn't required.

Cindy Hamilton
My central Vac

By Vac you mean vacuum cleaner? Central? WTF?

is 1680 watts rated - actually runs about 1450 and can
pull 1700 starting.

I doubt that, motors are almost a dead short on starting.

It runs on a high magnetic 15 amp brealer on 120
volts.

Brealer? Do you mean breaker?

As for 15 amps, my vacuum only needs 5 amps, as it's 1200W on 240V, thinner flex, much more convenient.

[crosspost repaired, stop fucking about]