D
David
Guest
Your tax dollars at work, Sigh^2.
David
David
M
Meat Plow
Guest
On Sun, 17 Oct 2010 20:12:59 -0500, Klaatu wrote:
--
Live Fast, Die Young and Leave a Pretty Corpse
1100 watt GE here. Now 6 years old, works good as new."Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns9E138A1338FF3jyaniklocalnetcom@216.168.3.44...
"Arfa Daily" <arfa.daily@ntlworld.com> wrote in
newsXhuo.1843$jH7.1212@newsfe29.ams2:
"Meat Plow" <mhywatt@yahoo.com> wrote in message
news
On Sat, 16 Oct 2010 03:57:47 -0700, William Sommerwerck wrote:
I'd normally agree, but the fact the unit /slowly/ declined
suggests that something other than a voltage loss is going on.
Well, not really. Analogue power supplies, such as the ones in
microwave ovens usually are, will die gracefully as a result of bad
electrolytics getting worse.
I've never seen this, but I sure don't know everything. Anyhow, what
about the fact that some buttons "failed" before others? (That's a
rhetorical question.)
The microwave as I understood was above a stove and was probably
cleaned frequently because of its location. I've seen many control
panels permanently damaged by cleaning fluids on not only microwaves
but also other home appliances and electronics. This fact can
certainly account for button failure.
--
Agreed. I was just thinking of a scenario that would account for both
progressive failure of buttons, and then ultimately (apparent) total
failure of the unit to operate at all.
Arfa
grease infiltration into the keypad could be the first problem,and then
grease making a conductive path and the HV shorting out and blowing the
line fuse.
I finally "retired" my 30 year old,$350USD Sharp MW,replaced it with a
$99 GE from Wal-Mart;1.8Cu.Ft.,1100W.
Had to return the first one,the turntable didn't turn....
then I realized how much the power had dropped on the older 700W Sharp.
;-)
I don't expect the GE to last half as long as the Sharp did.
--
Jim Yanik
jyanik
at
localnet
dot com
If it has GE on the front, you'll be lucky to make it past the first
year. ESPECIALLY if you bought it at Wal-Mart.
--
Live Fast, Die Young and Leave a Pretty Corpse
F
Fred McKenzie
Guest
In article <throb6lgnkk4keed3en422a5ts49u68n81@4ax.com>,
Jeff Liebermann <jeffl@cruzio.com> wrote:
My impression is that the referenced article refers to efficiency, not
power output. It talks about such things as magnetron filament current
and warm-up time.
Somewhere on the web I found a procedure for measuring power. You heat
a liter of water for a certain amount of time, measuring temperature
before and after. Using a formula, temperature rise correlates to power
output.
I think such a procedure is basic, and don't see how it could be
challenged other than for "hot spots" in an oven. In my case, the oven
has a carousel to compensate.
My old 900 Watt Sharp microwave actually puts out 650 Watts according to
the procedure. I adjust cooking times meant for 1100 Watt units,
multiplying by 1100/650. The food appears to be getting the right
amount of heat.
An old Sharp "Half Pint" is rated for 450 Watts. The above procedure
agrees exactly.
Fred
Jeff Liebermann <jeffl@cruzio.com> wrote:
Jeff-
My impression is that the referenced article refers to efficiency, not
power output. It talks about such things as magnetron filament current
and warm-up time.
Somewhere on the web I found a procedure for measuring power. You heat
a liter of water for a certain amount of time, measuring temperature
before and after. Using a formula, temperature rise correlates to power
output.
I think such a procedure is basic, and don't see how it could be
challenged other than for "hot spots" in an oven. In my case, the oven
has a carousel to compensate.
My old 900 Watt Sharp microwave actually puts out 650 Watts according to
the procedure. I adjust cooking times meant for 1100 Watt units,
multiplying by 1100/650. The food appears to be getting the right
amount of heat.
An old Sharp "Half Pint" is rated for 450 Watts. The above procedure
agrees exactly.
Fred
J
Jeff Liebermann
Guest
On Mon, 18 Oct 2010 11:41:03 -0500, "David" <someone@somewhere.com>
wrote:
around since 1990.
<http://www1.eere.energy.gov/buildings/appliance_standards/residential/docs/krtp1003.txt>
Place about a liter of water in the oven. Measure temperature. Apply
power. Measure temperature again after a specific cooking time.
Power = (Volume_of_water) x (Temp_rise) x 4.1868 / (Cook_time)
4.1868 is joules/calorie (specific heat of water)
Power = Watts
Volume = Cubic centimeters or Milliliters
Temp rise = Celsius
Cooking time = Seconds
Every oven I've tested (6 ovens) with a liter flask and about a minute
runtime has resulted in measurements of 15% to 30% less than the rated
power. If a use more water and a longer runtime, even less (because
the magnetron decreases in RF output as it gets hot). This is not
because the manufacturers all lie, but because the IEC-705 standard
method generates inflated results for power output. This might also
offer a clue why the DoE can't seem to find a workable procedure that
produces the same results as IEC-705.
I've also measured the efficiency of these ovens. All are about 60%
(using the above test procedure).
Perhaps what's needed is a multi-million dollar research grant to
study methods of measuring microwave oven power output. However,
should such a study succeed, I'm certain the method will be ultra
complexicated and designed to sell plenty of specialized hardware and
certified testing labs. With luck, maybe even a bureaucracy to
oversee the muddle.
Hint: Don't use a big heavy Pyrex glass bowl as it becomes part of
the thermal mass and wrecks the results. Use thin chemistry glassware
or if really careful, light plastic bowls. A 10C to 20C temp rise is
sufficient. No need to boil the water. Don't leave the thermometer
inside the oven when running. Let the water temperature stabilize for
30 seconds or more at the end of a run as microwave heating is rather
uneven.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
wrote:
Yeah, it's really a tough problem. Never mind IEC-705 which has been
around since 1990.
<http://www1.eere.energy.gov/buildings/appliance_standards/residential/docs/krtp1003.txt>
Place about a liter of water in the oven. Measure temperature. Apply
power. Measure temperature again after a specific cooking time.
Power = (Volume_of_water) x (Temp_rise) x 4.1868 / (Cook_time)
4.1868 is joules/calorie (specific heat of water)
Power = Watts
Volume = Cubic centimeters or Milliliters
Temp rise = Celsius
Cooking time = Seconds
Every oven I've tested (6 ovens) with a liter flask and about a minute
runtime has resulted in measurements of 15% to 30% less than the rated
power. If a use more water and a longer runtime, even less (because
the magnetron decreases in RF output as it gets hot). This is not
because the manufacturers all lie, but because the IEC-705 standard
method generates inflated results for power output. This might also
offer a clue why the DoE can't seem to find a workable procedure that
produces the same results as IEC-705.
I've also measured the efficiency of these ovens. All are about 60%
(using the above test procedure).
Perhaps what's needed is a multi-million dollar research grant to
study methods of measuring microwave oven power output. However,
should such a study succeed, I'm certain the method will be ultra
complexicated and designed to sell plenty of specialized hardware and
certified testing labs. With luck, maybe even a bureaucracy to
oversee the muddle.
Hint: Don't use a big heavy Pyrex glass bowl as it becomes part of
the thermal mass and wrecks the results. Use thin chemistry glassware
or if really careful, light plastic bowls. A 10C to 20C temp rise is
sufficient. No need to boil the water. Don't leave the thermometer
inside the oven when running. Let the water temperature stabilize for
30 seconds or more at the end of a run as microwave heating is rather
uneven.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
D
Dave Platt
Guest
In article <i9hebi$u0v$1@news.eternal-september.org>,
William Sommerwerck <grizzledgeezer@comcast.net> wrote:
When it gave up the ghost, I replaced it with a Panasonic "inverter"
model... one of the higher-end consumer-grade microwaves. This died
early this year less than three years of service. Looking at the
consumer-grade microwaves available at the time gave me no confidence
at all.
I bought an Amana "medium volume commercial setting" model (ALD10T) as
a replacement. It's roughly twice the price of the better
consumer-grade type, but does seem to have a substantially better
build quality, and the magnetron has a 3-year warranty as opposed to 1
year (or less) for consumer-grade models. My hope is that it will
have a substantially longer lifetime than today's race-to-the-bottom
consumer junk. Biggest negative noted so far (from my wife'w point of
view) is that the fan continues to run for 30 seconds to a minute
after the cooking cycle is complete - this clears out the steam and
odors from inside the oven, but she hates the noise.
The companion model ALD10D has a mechanical timer and dial, and only a
single power setting... less to go wrong.
--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
William Sommerwerck <grizzledgeezer@comcast.net> wrote:
We had a Kenmore which had lasted us almost 20 years.
When it gave up the ghost, I replaced it with a Panasonic "inverter"
model... one of the higher-end consumer-grade microwaves. This died
early this year less than three years of service. Looking at the
consumer-grade microwaves available at the time gave me no confidence
at all.
I bought an Amana "medium volume commercial setting" model (ALD10T) as
a replacement. It's roughly twice the price of the better
consumer-grade type, but does seem to have a substantially better
build quality, and the magnetron has a 3-year warranty as opposed to 1
year (or less) for consumer-grade models. My hope is that it will
have a substantially longer lifetime than today's race-to-the-bottom
consumer junk. Biggest negative noted so far (from my wife'w point of
view) is that the fan continues to run for 30 seconds to a minute
after the cooking cycle is complete - this clears out the steam and
odors from inside the oven, but she hates the noise.
The companion model ALD10D has a mechanical timer and dial, and only a
single power setting... less to go wrong.
--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
J
Jeff Liebermann
Guest
On Mon, 18 Oct 2010 13:39:25 -0400, Fred McKenzie <fmmck@aol.com>
wrote:
power meter. The power output is using the calorimetric water heater
method. I can throw in defrost, pre-heat, warm-up, cool-down, and
such if you insist.
<http://www1.eere.energy.gov/buildings/appliance_standards/residential/docs/krtp1003.txt>
<http://www1.eere.energy.gov/buildings/appliance_standards/residential/pdfs/home_appl_micro_oven_tp_fr.pdf>
They're measuring "useful cooking energy" which is similar to the
exaggerated numbers produced by "peak music power" in hi-fi.
<http://www.ebsciences.com/papers/microwave_quality.htm>
<http://www.zyra.info/micropwr.htm>
paying) tests.
<http://www.flir.com/thermography/americas/us/content/?id=24072>
What got my attention was the rather bizarre pattern of heating on a
small pizza in the microwave oven. Of course, the carousel and
stirrer fan help reduce hot spots, but it still takes time for the
heat to move around in a liter of water.
watts.
paragraph at:
<http://www.gallawa.com/microtech/output.html>
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
wrote:
Yep. I measure the power input to the microwave with a Kill-a-watt
power meter. The power output is using the calorimetric water heater
method. I can throw in defrost, pre-heat, warm-up, cool-down, and
such if you insist.
What was dropped was:
<http://www1.eere.energy.gov/buildings/appliance_standards/residential/docs/krtp1003.txt>
<http://www1.eere.energy.gov/buildings/appliance_standards/residential/pdfs/home_appl_micro_oven_tp_fr.pdf>
They're measuring "useful cooking energy" which is similar to the
exaggerated numbers produced by "peak music power" in hi-fi.
<http://www.gallawa.com/microtech/output.html>
<http://www.ebsciences.com/papers/microwave_quality.htm>
<http://www.zyra.info/micropwr.htm>
I was borrowing an FLIR i7 infrared camera to do some unrelated (and
paying) tests.
<http://www.flir.com/thermography/americas/us/content/?id=24072>
What got my attention was the rather bizarre pattern of heating on a
small pizza in the microwave oven. Of course, the carousel and
stirrer fan help reduce hot spots, but it still takes time for the
heat to move around in a liter of water.
My cheap junk Welbilt something oven claims 950 watts and delivers 800
watts.
That's because IEC-705 was designed to inflate the ratings. See first
paragraph at:
<http://www.gallawa.com/microtech/output.html>
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
J
Jeff Liebermann
Guest
On Mon, 18 Oct 2010 10:52:53 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
<http://global.ihs.com/doc_detail.cfm?currency_code=USD&customer_id=2125482C3B0A&shopping_cart_id=282758232F4950244D595D58240A&rid=Z56&input_doc_number=iec%20705&mid=5280&input_doc_number=iec%20705&country_code=US&lang_code=ENGL&item_s_key=00133560&item_key_date=930931&input_doc_number=iec%20705&input_doc_title=&org_code=IEC>
For only $143, you too can learn how governments rate microwave ovens
or maybe P-IEC 60705 {Ed.3.2}
<http://www.iec.ch/cgi-bin/procgi.pl/www/iecwww.p?wwwlang=e&wwwprog=cat-det.p&progdb=db1&wartnum=035873>
<http://www.iecchallenge.net/cgi-bin/procgi.pl/www/iecwww.p?wwwlang=english&wwwprog=pro-det.p&progdb=db1&He=IEC&Pu=60705&Pa=&Se=&Am=1&Fr=&TR=&Ed=3>
for $170.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
wrote:
New and improved IEC-705 is now IEC 60705:
<http://global.ihs.com/doc_detail.cfm?currency_code=USD&customer_id=2125482C3B0A&shopping_cart_id=282758232F4950244D595D58240A&rid=Z56&input_doc_number=iec%20705&mid=5280&input_doc_number=iec%20705&country_code=US&lang_code=ENGL&item_s_key=00133560&item_key_date=930931&input_doc_number=iec%20705&input_doc_title=&org_code=IEC>
For only $143, you too can learn how governments rate microwave ovens
or maybe P-IEC 60705 {Ed.3.2}
<http://www.iec.ch/cgi-bin/procgi.pl/www/iecwww.p?wwwlang=e&wwwprog=cat-det.p&progdb=db1&wartnum=035873>
<http://www.iecchallenge.net/cgi-bin/procgi.pl/www/iecwww.p?wwwlang=english&wwwprog=pro-det.p&progdb=db1&He=IEC&Pu=60705&Pa=&Se=&Am=1&Fr=&TR=&Ed=3>
for $170.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
M
Meat Plow
Guest
On Mon, 18 Oct 2010 09:34:05 -0700, Jeff Liebermann wrote:
things like window cleaners directly on them. Without any punctures.
While talking to the customer I try to ask how they cleaned their stuff
without trying to point blame. People don't like to readily admit to the
over zealous spraying of cleaners that can and do eventually seep into
membrane panels. I cringed in horror once watching my girlfriend cleaning
my then 2 year old GE oven, She sprayed the front with copious amounts of
window cleaner. I told her from now on she was to lightly spray it on a
clean cloth first then wipe the membrane. On everything. Not too many
realize this is a serious problem unfortunately.
--
Live Fast, Die Young and Leave a Pretty Corpse
I've seen the corruption of membrane switch panels from users spraying
things like window cleaners directly on them. Without any punctures.
While talking to the customer I try to ask how they cleaned their stuff
without trying to point blame. People don't like to readily admit to the
over zealous spraying of cleaners that can and do eventually seep into
membrane panels. I cringed in horror once watching my girlfriend cleaning
my then 2 year old GE oven, She sprayed the front with copious amounts of
window cleaner. I told her from now on she was to lightly spray it on a
clean cloth first then wipe the membrane. On everything. Not too many
realize this is a serious problem unfortunately.
--
Live Fast, Die Young and Leave a Pretty Corpse
K
Klaatu
Guest
"Meat Plow" <mhywatt@yahoo.com> wrote in message
newsan.2010.10.18.14.55.19@lmao.lol.lol...
news
an.2010.10.18.14.55.19@lmao.lol.lol...On Sun, 17 Oct 2010 20:12:59 -0500, Klaatu wrote:
"Jim Yanik" <jyanik@abuse.gov> wrote in message
news:Xns9E138A1338FF3jyaniklocalnetcom@216.168.3.44...
"Arfa Daily" <arfa.daily@ntlworld.com> wrote in
news
"Meat Plow" <mhywatt@yahoo.com> wrote in message
news
On Sat, 16 Oct 2010 03:57:47 -0700, William Sommerwerck wrote:
I'd normally agree, but the fact the unit /slowly/ declined
suggests that something other than a voltage loss is going on.
Well, not really. Analogue power supplies, such as the ones in
microwave ovens usually are, will die gracefully as a result of bad
electrolytics getting worse.
I've never seen this, but I sure don't know everything. Anyhow, what
about the fact that some buttons "failed" before others? (That's a
rhetorical question.)
The microwave as I understood was above a stove and was probably
cleaned frequently because of its location. I've seen many control
panels permanently damaged by cleaning fluids on not only microwaves
but also other home appliances and electronics. This fact can
certainly account for button failure.
--
Agreed. I was just thinking of a scenario that would account for both
progressive failure of buttons, and then ultimately (apparent) total
failure of the unit to operate at all.
Arfa
grease infiltration into the keypad could be the first problem,and then
grease making a conductive path and the HV shorting out and blowing the
line fuse.
I finally "retired" my 30 year old,$350USD Sharp MW,replaced it with a
$99 GE from Wal-Mart;1.8Cu.Ft.,1100W.
Had to return the first one,the turntable didn't turn....
then I realized how much the power had dropped on the older 700W Sharp.
;-)
I don't expect the GE to last half as long as the Sharp did.
--
Jim Yanik
jyanik
at
localnet
dot com
If it has GE on the front, you'll be lucky to make it past the first
year. ESPECIALLY if you bought it at Wal-Mart.
1100 watt GE here. Now 6 years old, works good as new.
See Jeffery Angus' reply. Try to keep up.....