sci.electronics.repair@googlegroups.com

Today's topics:

* Simple Question about Thermal Cutoff (tco) & Fuses - 1 messages, 1 author
http://groups.google.com/group/sci.electronics.repair/t/9522848ef646160c?hl=en
* Pet hates ? - 8 messages, 5 authors
http://groups.google.com/group/sci.electronics.repair/t/e7925b5c2233e9ec?hl=en
* Reduce power of a microwave oven? - 13 messages, 9 authors
http://groups.google.com/group/sci.electronics.repair/t/76e6c7ef368fc8a0?hl=en
* Repair or replacing a GE Spacemaker Microwave? - 2 messages, 2 authors
http://groups.google.com/group/sci.electronics.repair/t/c1d6b4bd44bdd1d7?hl=en
* How to repair an invisible machine from the 23rd century? - 1 messages, 1
author
http://groups.google.com/group/sci.electronics.repair/t/e431feeea64c740f?hl=en

==============================================================================
TOPIC: Simple Question about Thermal Cutoff (tco) & Fuses
http://groups.google.com/group/sci.electronics.repair/t/9522848ef646160c?hl=en
==============================================================================

== 1 of 1 ==
Date: Wed, Jan 19 2011 9:55 am
From: j barnes

On Jan 18, 6:19 pm, Jim Yanik <jya...@abuse.gov> wrote:
> Fred McKenzie <fm...@aol.com> wrote innews:fmmck-007CC7.23000717012011@5ad64b5e.bb.sky.com:
>
>
>
>
>
>
>
>
>
> > In article
> ><65201db0-66d6-46b9-be6d-67de7495a...@glegroupsg2000goo.googlegroups.com
> >>,
> >  j barnes <slywink...@gmail.com> wrote:
>
> >> Would it be safe for me to replace the 4AMPTCOwith a 10amp 152C and
> >> simply add a 4ampfuseimmediately before or after theTCO?
>
> > JB-
>
> > I can't imagine the tea kettle cost much over $30, so it is not cost
> > effective to buy the exact part.  The price appears to be calculated
> > to encourage you to buy a new samovar instead of repairing yours.
>
> > From where did you obtain the specifications for the original part?  
> > What are the samovar's electrical ratings for voltage and power?  They
> > may be on the bottom or next to the electrical wire.
>
> > Several coffee makers I checked all use power in the 600 to 800 watt
> > range.  If the samovar operates close to 480 watts (4 Amperes at 120
> > Volts), you would not want thefuseto blow at 4 Amperes.  I suspect
> > the function of the original part was to protect against a fire when
> > the pot was operated after all the liquid had boiled away.  So the 4
> > Ampere rating is a maximum operating current, not necessarily the
> > current at which it blows.
>
> > How were you going to install the replacement?  Soldering is not a
> > good idea.  Solder could melt under normal operating conditions, and
> > soldering might damage theTCOif you aren't careful.  Crimping is the
> > better approach, but it is difficult to get a good crimp with solid
> > wires.  Some TCOs come with a "crimping ferrule".  It is a small metal
> > tube (brass?) that you insert two wires into and crimp them together.
>
> > Fred
>
> I have a Presto Fry Granddaddy deep fryer that theTCOblew when the
> bimetal thermostat contacts welded together. AFAIK,they don't make the
> Grandaddy anymore,so I unstuck and filed the contacts,then bought a newTCO
> at Radio Shack !! that was a few deg C lower than the original,but same
> current rating.It's been working fine ever since. I bought new crimp
> ferrules at Skycraft Surplus.(local store,Orlando,FL.!)
>
> --
> Jim Yanik
> jyanik
> at
> localnet
> dot com

Thank you everyone for all the helpful advice and suggestions! I'm
glad everyone reminded me to crimp rather than solder. I can be a
real space case when I get caught up in repairs so it was a great
reminder.

For the curious, the $30 part is for a $170+ Samovar so I don't think
they are trying to force a new sale. It is hoity-toity expensive
German made samovar used for shi-shi-fu-fu parties. Looking at the
thing, I would have never guessed somebody would pay so much for it.
I'm certain it cost a fraction of what it sold for to make it and
there were dozens of happy people along the chain of sale between
Germany and here who tacked on a nice healthy profit for themselves.

Personally, I'm the kind of dude who would bust out with my trusty
decades old plastic coffee-stained Mr. Coffee or my newer Proctor
Silex tea kettle if I need quick boiling water, if my friends don't
respect me because of that they aren't my friends. However, this is
the female species I am dealing with here. Such uncouthness as mine
displayed by the hostess who is requesting the repair would bring many
years of shame and embarrassment on her family for generations to
come.

Of course I'm just kidding about the shame and embarrassment lasting
for generations, but this repair is bound up in culture and psuedo-
sophistication rather than pure utility.

Thanks again!

==============================================================================
TOPIC: Pet hates ?
http://groups.google.com/group/sci.electronics.repair/t/e7925b5c2233e9ec?hl=en
==============================================================================

== 1 of 8 ==
Date: Wed, Jan 19 2011 10:00 am
From: "Arfa Daily"

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:ih744h$odu$1@news.eternal-september.org...
> Lab1 <.@...> wrote in message
> news:ih6ugq$mee$1@news.eternal-september.org...
>> On 1/19/2011 9:54 AM, N_Cook wrote:
>> > Great dollops of that white goo between metal to metal thermally
> conductive
>> > surfaces. Heatsink to metal casing in amplifiers etc. I'm not sure why
> it is
>> > even necessary with perhaps 20 square inches of contact and bolts
> between. I
>> > always wipe away with paper etc on first parting but always some gets
>> > on
> my
>> > clothing - I've not worn white lab coats for many a year.
>>
>> Heat sink compound is usually very necessary.
>>
>> One of my pet hates is torx screws with a pin in the center.
>>
>
>
> The harware that I always have problems with in the UK , never organised a
> stock of, is UNF and UNC nuts and bolts for USA kit. And of course,vice
> versa, repairers in USA never have metric (and lesser extent BA) for UK
> and
> Japanese kit
>
>

I once got in a lot of trouble with my boss when I was young and worked for
a U.S. based company. At that time, I didn't understand that there was a big
difference between British 'tongue-in-cheek' humour, and the much more
direct U.S. type. I was talking on the phone to one of the designers of a
piece of equipment that we sold here in the UK, and asked the guy if he
could arrange to send me some screws for the cabinet, as they were a thread
that we didn't readily get over here. He asked if I knew exactly what size
they were so I replied, quick as a flash, thinking that I was being funny,
"I guess that they are round about 3/16ths APF." "What's APF ?" the guy
asked. "American Piss Fit", said I ...

Stony silence on the phone. Half an hour later, I was summoned to the boss's
office. Apparently, the guy had been really offended by this, thinking that
it was a slur on what he considered to be good American engineering, and had
called my boss to complain about me. Just goes to show how easily offence
can be caused between nations, even when they speak what's basically the
same language ... :-)

Arfa

== 2 of 8 ==
Date: Wed, Jan 19 2011 10:40 am
From: Lab1 <.@...>

On 1/19/2011 1:00 PM, Arfa Daily wrote:

> I once got in a lot of trouble with my boss when I was young and worked
> for a U.S. based company. At that time, I didn't understand that there
> was a big difference between British 'tongue-in-cheek' humour, and the
> much more direct U.S. type. I was talking on the phone to one of the
> designers of a piece of equipment that we sold here in the UK, and asked
> the guy if he could arrange to send me some screws for the cabinet, as
> they were a thread that we didn't readily get over here. He asked if I
> knew exactly what size they were so I replied, quick as a flash,
> thinking that I was being funny, "I guess that they are round about
> 3/16ths APF." "What's APF ?" the guy asked. "American Piss Fit", said I ...
>
> Stony silence on the phone. Half an hour later, I was summoned to the
> boss's office. Apparently, the guy had been really offended by this,
> thinking that it was a slur on what he considered to be good American
> engineering, and had called my boss to complain about me. Just goes to
> show how easily offence can be caused between nations, even when they
> speak what's basically the same language ... :-)

While on vacation in the Dominican Republic we ran into a really nice
group from the UK who were there for a wedding. We would hang out and
talk with them down at the in-pool bar almost every evening. I never
quite got used to them asking me to bum a fag. I'm from the US and I
smoke cigarettes, not fags.

--
-Scott

== 3 of 8 ==
Date: Wed, Jan 19 2011 10:51 am
From: "William Sommerwerck"

> I once got in a lot of trouble with my boss when I was young and worked
for
> a U.S. based company. At that time, I didn't understand that there was a
big
> difference between British 'tongue-in-cheek' humour, and the much more
> direct U.S. type. I was talking on the phone to one of the designers of a
> piece of equipment that we sold here in the UK, and asked the guy if he
> could arrange to send me some screws for the cabinet, as they were a
thread
> that we didn't readily get over here. He asked if I knew exactly what size
> they were so I replied, quick as a flash, thinking that I was being funny,
> "I guess that they are round about 3/16ths APF." "What's APF ?" the guy
> asked. "American Piss Fit", said I ...

> Stony silence on the phone. Half an hour later, I was summoned to the
boss's
> office. Apparently, the guy had been really offended by this, thinking
that
> it was a slur on what he considered to be good American engineering, and
had
> called my boss to complain about me. Just goes to show how easily offence
> can be caused between nations, even when they speak what's basically the
> same language ... :-)

It's hard /not/ to interpret such a description as an intentional insult. I
can't imagine what it actually means -- in any innocuous sense, anyway.

== 4 of 8 ==
Date: Wed, Jan 19 2011 11:25 am
From: Meat Plow

On Wed, 19 Jan 2011 14:54:35 +0000, N_Cook wrote:

> Great dollops of that white goo between metal to metal thermally
> conductive surfaces. Heatsink to metal casing in amplifiers etc. I'm not
> sure why it is even necessary with perhaps 20 square inches of contact
> and bolts between. I always wipe away with paper etc on first parting
> but always some gets on my clothing - I've not worn white lab coats for
> many a year.

Overuse of that stuff is worse for thermal conductivity than none at all.
I've clean up gobs of it since they started using it decades ago.

--
Live Fast, Die Young and Leave a Pretty Corpse

== 5 of 8 ==
Date: Wed, Jan 19 2011 11:50 am
From: "Michael A. Terrell"

Lab1 wrote:
>
> On 1/19/2011 9:54 AM, N_Cook wrote:
> > Great dollops of that white goo between metal to metal thermally conductive
> > surfaces. Heatsink to metal casing in amplifiers etc. I'm not sure why it is
> > even necessary with perhaps 20 square inches of contact and bolts between. I
> > always wipe away with paper etc on first parting but always some gets on my
> > clothing - I've not worn white lab coats for many a year.
>
> Heat sink compound is usually very necessary.
>
> One of my pet hates is torx screws with a pin in the center.

Can't afford $5 for a set of security bits?

--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

== 6 of 8 ==
Date: Wed, Jan 19 2011 11:50 am
From: "Michael A. Terrell"

William Sommerwerck wrote:
>
> Poodles.

Puddles. Under Poodles. ;-)

--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

== 7 of 8 ==
Date: Wed, Jan 19 2011 12:02 pm
From: Lab1 <.@...>

On 1/19/2011 2:50 PM, Michael A. Terrell wrote:
>
> Lab1 wrote:
>>
>> On 1/19/2011 9:54 AM, N_Cook wrote:
>>> Great dollops of that white goo between metal to metal thermally conductive
>>> surfaces. Heatsink to metal casing in amplifiers etc. I'm not sure why it is
>>> even necessary with perhaps 20 square inches of contact and bolts between. I
>>> always wipe away with paper etc on first parting but always some gets on my
>>> clothing - I've not worn white lab coats for many a year.
>>
>> Heat sink compound is usually very necessary.
>>
>> One of my pet hates is torx screws with a pin in the center.
>
>
> Can't afford $5 for a set of security bits?

Yes, but given the frequency that I run into those I find my punch set
and hammer tend to do the trick - security torx to just torx! ;)

--
-Scott

== 8 of 8 ==
Date: Wed, Jan 19 2011 12:22 pm
From: Lab1 <.@...>

On 1/19/2011 2:25 PM, Meat Plow wrote:

>> Great dollops of that white goo between metal to metal thermally
>> conductive surfaces.

> Overuse of that stuff is worse for thermal conductivity than none at all.
> I've clean up gobs of it since they started using it decades ago.

This is something I'm currently wondering about. I have a fridge-like
thermo-electric cooler than has two sections, top and bottom, with
different temperatures. The top suddenly stopped getting cool at all, so
I took it apart to figure out why. The fans and voltages were all there
so I broke down the heat sinks on the bad one to get to the Peltier
device. With it isolated, I powered it up briefly and much to my
surprise the Peltier device got hot real quickly with the opposite side
getting cooler. So the device works, it has to be something with the
heat sinks?
They did use white goop on both sides, but very little and it was
already dried. The heat sinks are milled flat where they make contact
with the Peltier device, so my thinking is they need new goop.
Looking around I found that Star heat sink compound is about the best
you can get, so I ordered some. It just arrived the other day so I'm
planning to clean up the old goop, put on some new goop and hope for the
best. I don't think too much would be an issue in this case, I want it
as cold as possible.

--
-Scott

==============================================================================
TOPIC: Reduce power of a microwave oven?
http://groups.google.com/group/sci.electronics.repair/t/76e6c7ef368fc8a0?hl=en
==============================================================================

== 1 of 13 ==
Date: Wed, Jan 19 2011 10:27 am
From: PeterD

On Wed, 19 Jan 2011 05:57:24 -0800, "William Sommerwerck"
<grizzledgeezer@comcast.net> wrote:

>> Bacon, eggs, burger were some examples.
>
>A microwave oven is ideal for bacon, because all it needs is a thorough
>heating. Which is all a microwave oven does... It doesn't actully /cook/
>anything.
>

let's face it, most cooking is just heating.

== 2 of 13 ==
Date: Wed, Jan 19 2011 10:29 am
From: PeterD

On Wed, 19 Jan 2011 05:55:03 -0800, "William Sommerwerck"
<grizzledgeezer@comcast.net> wrote:

>>> Can you return the oven? You can use the argument
>>> that it's not fit for its intended purpose. Which it isn't.
>
>> Nope, my inability to forecast the consequences is not
>> the fault of the seller.
>
>If your description is correct, the oven is grossly misdesigned. You do not
>implement variable power by turning the magenetron on for 15 seconds, then
>letting it sit for a minute! I've /never/ seen a microwave oven that works
>that way. My home GE works fine, as do all those I've seen where I've
>worked.
>

Huh? Virtually all the ones I've seen do just that: run a 10 to 15
second on/off time cycle. The magnetron is turned on with a relay, so
rapid cycling just begs to blow that relay.

== 3 of 13 ==
Date: Wed, Jan 19 2011 10:54 am
From: "William Sommerwerck"

>> If your description is correct, the oven is grossly misdesigned.
>> You do not implement variable power by turning the magenetron
>> on for 15 seconds, then letting it sit for a minute! I've /never/ seen
>> a microwave oven that works that way. My home GE works fine...

> Huh? Virtually all the ones I've seen do just that: run a 10 to 15
> second on/off time cycle. The magnetron is turned on with a relay, so
> rapid cycling just begs to blow that relay.

I could easily test this with frozen bagels. Do you want me to? I'm not much
in the mood.

== 4 of 13 ==
Date: Wed, Jan 19 2011 11:25 am
From: Jeff Layman

On 19/01/2011 06:39, Dave Platt wrote:
> In article<ih5hng$bfu$1@news.eternal-september.org>,
> mike<spamme9@gmail.com> wrote:
>
>> Yep, that's the way most of 'em work. The problem is the filament in
>> the magnetron. Much shorter and you don't get any power out cause
>> the filament ain't hot yet. With enough mass inside the oven, it
>> averages out pretty well. For a single frozen hamburger at 1100W, not
>> so much.
>>
>> Yes, you can buy a microwave with fine-grained setting of continuous
>> power at most any retailer...for 3X the price.
>> They have to keep the filament hot while reducing the power. Much more
>> complicated and not a commodity item>> much higher price.
>
> Not that much higher these days, I think. The Toshiba "inverter"
> microwave ovens have a variable power level of this general sort, and
> they're commodity items to the extent of being buyable at Costco and
> probably other big-box stores. They're somewhat more expensive than
> ovens fixed-power magnetrons, but not all that much.
>
> However... I had one, and it died within a couple of years in home
> use. Our previous microwave had lasted for a couple of decades. I'm
> not sure whether this was an odd failure in this unit, or was
> characteristic of Toshiba inverter microwaves in general, or just an
> result of the "race to the bottom, in price and in quality" which
> seems to be affecting the whole consumer-electronics business these
> days.
>
> I bought a fixed-power-output commercial-service Amana as a
> replacement, in the hopes that it'll last rather longer than the
> Toshiba did.
>
My Panasonic has an inverter. Works OK, and and an energy meter
confirmed that it doesn't just cycle from full power to off when running
at lower power levels.

But it does tempt you to experiment. Even though the guidebook warns
against trying to "boil" a perfectly cooked egg in its shell, I thought
it worth trying using lower power levels. The first egg was perfect,
using a rather complicated cooking schedule. The second was very soft -
barely cooked. The third I'd rather forget, but it took a long time to
clean the oven, and SWMBO wasn't amused as she was standing almost next
to the door when it was blown open. It also took me some time to repair
the safety lock...

--

Jeff

== 5 of 13 ==
Date: Wed, Jan 19 2011 11:45 am
From: "Michael A. Terrell"

PeterD wrote:
>
> On Tue, 18 Jan 2011 20:35:49 -0500, "Michael A. Terrell"
> <mike.terrell@earthlink.net> wrote:
>
> >
> >mike wrote:
> >>
> >> My 27 year old microwave oven was down below 400W output and taking a long
> >> time to heat my coffee.
> >> So, I went out and bought a 1100W one.
> >> Big mistake.
> >> It works fine on coffee, but WAY overcooks small stuff.
> >> Yes, it has a power level setting, but the on-time is 15 seconds
> >> and they modulate the off-time.
> >> I tried to heat a frozen hamburger patty. It boils the liquid around
> >> the outside for 15 seconds, but the inside is still frozen.
> >> This really messes up the cheese stuck to it. If I leave it in
> >> the frozen burger, it comes out awful.
> >>
> >> What are my options for reducing power?
> >> Yes, I can stick in a pot of water to absorb energy, but I'm
> >> looking for a more elegant solution.
> >> I assume there's nothing I can do on the primary side, cause of the
> >> filament voltage requirements.
> >> Assuming I can find a switch that can take the voltage and current,
> >> can I switch the value of the big cap? Not much else in there to play with.
> >>
> >> Alternatively, there's stuff they put in the bottom of microwave popcorn
> >> that heats up from microwaves. What is that stuff? Maybe I can find a
> >> pan with that in the bottom to average out the energy over time.
> >> There's a "as seen on TV" serving plate that you heat in the microwave.
> >> It's made of granite. What is it in the granite that gets heated?
> >> IF I could find a square of floor tile in ceramic or granite, ceramic is
> >> more easily available, I could stick one of them in the bottom of the oven.
> >>
> >> Suggestions?
> >
> >
> > RTFM to see how to set the cook power.
>
> Or use the defrost cycle!

Why do things right, when you can whine online? ;-)

--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

== 6 of 13 ==
Date: Wed, Jan 19 2011 11:55 am
From: "Michael A. Terrell"

mike wrote:
>
> Michael A. Terrell wrote:
> > mike wrote:
> >> My 27 year old microwave oven was down below 400W output and taking a long
> >> time to heat my coffee.
> >> So, I went out and bought a 1100W one.
> >> Big mistake.
> >> It works fine on coffee, but WAY overcooks small stuff.
> >> Yes, it has a power level setting, but the on-time is 15 seconds
> >> and they modulate the off-time.
> >> I tried to heat a frozen hamburger patty. It boils the liquid around
> >> the outside for 15 seconds, but the inside is still frozen.
> >> This really messes up the cheese stuck to it. If I leave it in
> >> the frozen burger, it comes out awful.
> >>
> >> What are my options for reducing power?
> >> Yes, I can stick in a pot of water to absorb energy, but I'm
> >> looking for a more elegant solution.
> >> I assume there's nothing I can do on the primary side, cause of the
> >> filament voltage requirements.
> >> Assuming I can find a switch that can take the voltage and current,
> >> can I switch the value of the big cap? Not much else in there to play with.
> >>
> >> Alternatively, there's stuff they put in the bottom of microwave popcorn
> >> that heats up from microwaves. What is that stuff? Maybe I can find a
> >> pan with that in the bottom to average out the energy over time.
> >> There's a "as seen on TV" serving plate that you heat in the microwave.
> >> It's made of granite. What is it in the granite that gets heated?
> >> IF I could find a square of floor tile in ceramic or granite, ceramic is
> >> more easily available, I could stick one of them in the bottom of the oven.
> >>
> >> Suggestions?
> >
> >
> > RTFM to see how to set the cook power.
>
> Amazing!!!
> RTFM reply when I stated EXACTLY how the power setting works.
> How about RTFOP?

Then stick a damn glass of water in the oven to adsorb some of the
energy.

--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

== 7 of 13 ==
Date: Wed, Jan 19 2011 12:08 pm
From: "Wild_Bill"

I suppose the issue could go round 'n round (usenet style), but the term
cooked means different things in different contexts.

Not raw.. safe to eat.
Beef color changed from pink to grey.
Internal temp of 180 F.

Cooked, meaning not raw, is hardly properly prepared to taste. A piece of
beef could be boiled to an internal temp of 180 F, and it's cooked, but I
wouldn't care to eat it prepared that way.. some people do.

If beef doesn't sear from being in contact with blazing hot air/reflected IR
heat (real oven), metal and/or fire, ya might as well be eating soy.
Beef roasted in a real oven will brown on the top/outside, but not in a
typical MWO.

For my tastes, the searing/browning of meats is what gives them good flavor,
not so much the seasoning.. with a few exceptions, fried chicken, for
example.

I prefer real oven or covered grill baked potatoes (or roasted in hot coals)
over microwaved potatoes.. it's a matter of preference. I haven't been able
to get crispy skins in a MWO.
Sure, the MWO potatoes are edible, but far less flavorful.

Many MWO dishes are pre-cooked processed stuff anyway.. not good food when
taken out of the package, but better when eaten warm/hot.

--
Cheers,
WB
.............

"Arfa Daily" <arfa.daily@ntlworld.com> wrote in message
news:7qEZo.371$S16.147@newsfe20.ams2...
>
> I seem to remember that we had this discussion once before some years
> back. It depends on how you define the word "cook". Using the traditional
> definition of 'preparing food by use of heat' I would contend that this is
> exactly what a microwave oven does - or am I missing something ... ? If I
> am, then what *is* cooking that a conventional oven does differently ?
>
> Arfa

== 8 of 13 ==
Date: Wed, Jan 19 2011 12:25 pm
From: David Nebenzahl

On 1/19/2011 9:24 AM William Sommerwerck spake thus:

> Oddly, the Wikipedia article claims that microwave cooking heats food more
> evenly than any other method, when, in fact, it heats from the outside in,
> as does every other cooking method, and can be extremely uneven, if part of
> the dish is sitting in a standing-wave node.

... which should give further pause to those who claim that Wikipedia is
full of good, accurate information ...

--
Comment on quaint Usenet customs, from Usenet:

To me, the *plonk...* reminds me of the old man at the public hearing
who stands to make his point, then removes his hearing aid as a sign
that he is not going to hear any rebuttals.

== 9 of 13 ==
Date: Wed, Jan 19 2011 12:25 pm
From: "larry moe 'n curly"

mike wrote:

> My 27 year old microwave oven was down below 400W output and taking a long
> time to heat my coffee.
> So, I went out and bought a 1100W one.
> Big mistake.
> It works fine on coffee, but WAY overcooks small stuff.
> Yes, it has a power level setting, but the on-time is 15 seconds
> and they modulate the off-time.

> Suggestions?

Put in a smaller high voltage capacitor?

Get an oven with inverter power control, like a Panasonic?

== 10 of 13 ==
Date: Wed, Jan 19 2011 12:29 pm
From: mike

Michael A. Terrell wrote:
> mike wrote:
>> Michael A. Terrell wrote:
>>> mike wrote:
>>>> My 27 year old microwave oven was down below 400W output and taking a long
>>>> time to heat my coffee.
>>>> So, I went out and bought a 1100W one.
>>>> Big mistake.
>>>> It works fine on coffee, but WAY overcooks small stuff.
>>>> Yes, it has a power level setting, but the on-time is 15 seconds
>>>> and they modulate the off-time.
>>>> I tried to heat a frozen hamburger patty. It boils the liquid around
>>>> the outside for 15 seconds, but the inside is still frozen.
>>>> This really messes up the cheese stuck to it. If I leave it in
>>>> the frozen burger, it comes out awful.
>>>>
>>>> What are my options for reducing power?
>>>> Yes, I can stick in a pot of water to absorb energy, but I'm
>>>> looking for a more elegant solution.
>>>> I assume there's nothing I can do on the primary side, cause of the
>>>> filament voltage requirements.
>>>> Assuming I can find a switch that can take the voltage and current,
>>>> can I switch the value of the big cap? Not much else in there to play with.
>>>>
>>>> Alternatively, there's stuff they put in the bottom of microwave popcorn
>>>> that heats up from microwaves. What is that stuff? Maybe I can find a
>>>> pan with that in the bottom to average out the energy over time.
>>>> There's a "as seen on TV" serving plate that you heat in the microwave.
>>>> It's made of granite. What is it in the granite that gets heated?
>>>> IF I could find a square of floor tile in ceramic or granite, ceramic is
>>>> more easily available, I could stick one of them in the bottom of the oven.
>>>>
>>>> Suggestions?
>>>
>>> RTFM to see how to set the cook power.
>> Amazing!!!
>> RTFM reply when I stated EXACTLY how the power setting works.
>> How about RTFOP?
>
>
> Then stick a damn glass of water in the oven to adsorb some of the
> energy.
>
You're just DETERMINED NOT TO READ the original posting...where I
mentioned that too.
Although, I'd not considered adsorption as a relevant process.

== 11 of 13 ==
Date: Wed, Jan 19 2011 12:34 pm
From: "William Sommerwerck"

"David Nebenzahl" <nobody@but.us.chickens> wrote in message
news:4d374867$0$2362$822641b3@news.adtechcomputers.com...
> On 1/19/2011 9:24 AM William Sommerwerck spake thus:

>> Oddly, the Wikipedia article claims that microwave cooking heats food
more
>> evenly than any other method, when, in fact, it heats from the outside
in,
>> as does every other cooking method, and can be extremely uneven, if part
of
>> the dish is sitting in a standing-wave node.

> ... which should give further pause to those who claim that Wikipedia is
> full of good, accurate information ...

It is. No one is claiming it's always absolutely perfect.

== 12 of 13 ==
Date: Wed, Jan 19 2011 12:43 pm
From: mike

PeterD wrote:
> On Tue, 18 Jan 2011 20:35:49 -0500, "Michael A. Terrell"
> <mike.terrell@earthlink.net> wrote:
>
>> mike wrote:
>>> My 27 year old microwave oven was down below 400W output and taking a long
>>> time to heat my coffee.
>>> So, I went out and bought a 1100W one.
>>> Big mistake.
>>> It works fine on coffee, but WAY overcooks small stuff.
>>> Yes, it has a power level setting, but the on-time is 15 seconds
>>> and they modulate the off-time.
>>> I tried to heat a frozen hamburger patty. It boils the liquid around
>>> the outside for 15 seconds, but the inside is still frozen.
>>> This really messes up the cheese stuck to it. If I leave it in
>>> the frozen burger, it comes out awful.
>>>
>>> What are my options for reducing power?
>>> Yes, I can stick in a pot of water to absorb energy, but I'm
>>> looking for a more elegant solution.
>>> I assume there's nothing I can do on the primary side, cause of the
>>> filament voltage requirements.
>>> Assuming I can find a switch that can take the voltage and current,
>>> can I switch the value of the big cap? Not much else in there to play with.
>>>
>>> Alternatively, there's stuff they put in the bottom of microwave popcorn
>>> that heats up from microwaves. What is that stuff? Maybe I can find a
>>> pan with that in the bottom to average out the energy over time.
>>> There's a "as seen on TV" serving plate that you heat in the microwave.
>>> It's made of granite. What is it in the granite that gets heated?
>>> IF I could find a square of floor tile in ceramic or granite, ceramic is
>>> more easily available, I could stick one of them in the bottom of the oven.
>>>
>>> Suggestions?
>>
>> RTFM to see how to set the cook power.
>
> Or use the defrost cycle!

When I ask a question on line, I go to great lengths to describe the issue
in detail to keep the discussion from running off in all directions.
It rarely works, but I keep hoping that people will actually read the
info before shooting from the hip.

With this, and every other low-end non-inverter microwave oven I've ever
encountered, the power is adjusted by pulsing the magnetron in bursts
of approximately 15 seconds followed by an off-time required to get the
average power you programmed.
The RELEVANT number is the 15 second MINIMUM on-time. Doesn't matter
what buttons you push, you can't get an on-time less than 15 seconds unless
you program a single burst that's shorter.
If 15 seconds is long enough to boil the liquid in part of the payload,
defrosting can make a mess of things.

In this case, the "defrost" button has some algorithm that they don't
disclose
and I've been too lazy to reverse-engineer, but the minimum on-time
is still about 15 seconds.
It's a fundamental property of the design.

== 13 of 13 ==
Date: Wed, Jan 19 2011 12:51 pm
From: Lab1 <.@...>

On 1/19/2011 3:34 PM, William Sommerwerck wrote:
> "David Nebenzahl"<nobody@but.us.chickens> wrote in message
> news:4d374867$0$2362$822641b3@news.adtechcomputers.com...
>> On 1/19/2011 9:24 AM William Sommerwerck spake thus:
>
>>> Oddly, the Wikipedia article claims that microwave cooking heats food
> more
>>> evenly than any other method, when, in fact, it heats from the outside
> in,
>>> as does every other cooking method, and can be extremely uneven, if part
> of
>>> the dish is sitting in a standing-wave node.
>
>> ... which should give further pause to those who claim that Wikipedia is
>> full of good, accurate information ...
>
> It is. No one is claiming it's always absolutely perfect.

Reminds me of this interesting video showing how microwave energy is
distributed inside a standard microwave...
http://www.youtube.com/watch?v=kAAXpKdQ-mk

--
-Scott

==============================================================================
TOPIC: Repair or replacing a GE Spacemaker Microwave?
http://groups.google.com/group/sci.electronics.repair/t/c1d6b4bd44bdd1d7?hl=en
==============================================================================

== 1 of 2 ==
Date: Wed, Jan 19 2011 10:57 am
From: Lab1 <.@...>

On 1/19/2011 12:55 PM, BSAKing wrote:

> I was wondering if anyone knows if there is a secondary fuse I could
> check on this model before I turf it? Obviously main one is good as
> everything else powers on.

I don't think there is a secondary fuse, I may be wrong.

> The second question is that I remember installing this thing and
> having to adapt a hole in the wall to an outside vent etc to fit it. I
> am hoping that maybe a new model of the same make would have roughly
> the same vent location so I do not have to rebuild that part to put in
> a new one.
>
> Or maybe it is standard for all microwaves? Does anyone know?

I've installed several of those and they always have optional vents out
the back or the top. Configurable with removable plates or I seem to
recall one had a slider deal on the inside that you reposition to open
either the top or rear vent. On some (if not all) you can shut them both
off and it will vent out the front or bottom.

Unfortunately the wall hangers and the top mounting holes are not always
in the same location from model to model, which means you'll be making
swiss cheese out of your wall/cabinet. :(

--
-Scott

== 2 of 2 ==
Date: Wed, Jan 19 2011 11:36 am
From: Meat Plow

On Wed, 19 Jan 2011 09:55:22 -0800, BSAKing wrote:

> I have one of these guys and it has served me very well for probably 15+
> years, so I have no quarrel with it.
>
> From the manual, the model number is a JVM 250 BVC or JVM 250 WVC
> (probably a white or black model).
>
> In any event, this morning old Betsy decided not to heat anything up.
> All the bells and whistles are there, fan runs, etc, lights action,
> keypad works, just no heat. So I suspect more than likely the magnetron
> or xformer.
>
> I was wondering if anyone knows if there is a secondary fuse I could
> check on this model before I turf it? Obviously main one is good as
> everything else powers on.
>
> The second question is that I remember installing this thing and having
> to adapt a hole in the wall to an outside vent etc to fit it. I am
> hoping that maybe a new model of the same make would have roughly the
> same vent location so I do not have to rebuild that part to put in a new
> one.
>
> Or maybe it is standard for all microwaves? Does anyone know?
>
> Any clues or input appreciated.
>
> TIA, BSA

There might exist a high voltage fuse but not always the case. If it
failed from age rather than from a short in one of the high voltage
components it's possible you wouldn't notice it failing. However if it
failed from a short you would have possibly heard a short loud hum and
the inside lamp dim before the fuse blew. There might also exist a
solenoid or triac to switch on the high voltage. If one of these failed
it would cause the symptom you are seeing.

--
Live Fast, Die Young and Leave a Pretty Corpse

==============================================================================
TOPIC: How to repair an invisible machine from the 23rd century?
http://groups.google.com/group/sci.electronics.repair/t/e431feeea64c740f?hl=en
==============================================================================

== 1 of 1 ==
Date: Wed, Jan 19 2011 12:28 pm
From: DarkwaterBlight

On Jan 19, 5:44 am, Jeff Urban <jurb6...@gmail.com> wrote:
> You people of the past know nothing.
>
> Pick up a T factor chip for the SW7 (you DO have an SW7 I hope) and
> install it. Then you simply go back in time and prevent the occurance
> of the faualt. Make sure to use VF9 antigrator so you are not affected
> by the timeline. Sorry about your family, but you can write a nice
> hefty repair bill on that. I mean 35,890 KW of energy and all that.
> You migtht have to do a bit of customer relations to make them
> understand that this awesome power does not grow on trees.
>
> Terminator four.

Ya, uhh... energy is measured in Joules not Kilowatts genius! Just get
some spray paint like Lab 1 suggested. :)

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