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LP0 ON FIRE
Jan 25, 2006

beep boop


excuse me

i think i found a programming bug that seems apparent in just about all conventional microwaves driven by a microcontroller. after the timer runs to 0, the microwave seems to continue to run while beeping multiple times. the fan and lights might be just running and not actually creating microwaves to cook the food, but if this is true, why do i have the option to press the stop button and cancel all that nonsense? my theory is that it is actually continuing to cook the food during that duration which leads me to believe the duration of cooking time the user inputs ends up being inaccurate by several seconds

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EMILY BLUNTS
Jan 1, 2005



try this. type in 90 seconds and see what it does

theadder
Dec 29, 2011




so wheres the interesting question op

Dr. Honked
Jan 9, 2011

eat it you slaaaaaaag


disable the door interlock, put your head in there, and stick your tongue out. run the microwave for ten minutes. see if your tongue is still boiling while the beeps are going. then eat ten packs of mentos and drink two litres of coca cola as fast as you can, then set fire to yourself and jump out of the window. all your questions will be answered.

LP0 ON FIRE
Jan 25, 2006

beep boop


all microwaves are flawed and no one took notice until now (me)



Dr. Honked posted:

disable the door interlock, put your head in there, and stick your tongue out. run the microwave for ten minutes. see if your tongue is still boiling while the beeps are going. then eat ten packs of mentos and drink two litres of coca cola as fast as you can, then set fire to yourself and jump out of the window. all your questions will be answered.


that doesn't prove anything about my theory!

minivanmegafun
Jul 27, 2004



op read this and get back to us

http://www.repairfaq.org/sam/micfaq.htm

minivanmegafun
Jul 27, 2004



Cross section diagram of typical magnetron

The really extraordinary ASCII art below represents (or is supposed to represent) a cross section of the 2M214 type magnetron (not to scale) through the center as viewed from the side.

code:
                                ________
                               |  ____  |
                               |_|    |_|  Antenna cap
                               / |____| \
                              |  | || |  | Antenna insulator
                              |  | || |  |
                      xxxxxxxx|__| || |__|xxxxxxxx RF sealing gasket
          ____________________|    ||    |____________________ 
         |        |       (5)||    ||    ||       (5)|        |
         |        |   Top    ||    ||    ||   Top    |        |
         |        |  Magnet  ||    ||    ||  Magnet  |        | Outer case
         |        |__________||    ||    ||__________|        |
         |              ______|     \\   |______              |
         |             /____    (7)   \\    ____\             |
         |____________||    \__  ______ \\ /    ||____________|
         |            ||_______ |__  __| _\\ ___||            |
         |____________||       | o || o |  ||(4)||____________|
         |            ||       | o || o |       ||        (6) | Heat sink fins
         |____________|| Vane  | o || o |  Vane ||____________|
         |            || (3)   | o || o |  (3)  ||            |
         |____________||       | o || o |       ||____________| o: Filament
         |            ||_______|(1)|| o |_______||            |    helix
         |____________||     __ |_||||_| __     ||____________|
         |            ||____/   || ||      \____||<-- (2)     |
         |             \______   \\ \\    ______/             |
         |         __________ |  ||  ||  | __________         |
         |        |       (5)||  ||  ||  ||       (5)|        |
         |        |  Bottom  ||  ||  ||  ||  Bottom  |        |
         |        |  Magnet  ||  ||  ||  ||  Magnet  |        |
         |________|__________||  ||  ||  ||__________|________|
             |                |__||__||__|                |
             |                 | ||  || |  Filament       |
             |                 | ||  || |  insulator      |
             |   (RF chokes    |_||__||_|                 |
             |    not shown)     ||  ||  Filament/cathode |
             |                   ||  ||  connections      |
             |____________________________________________|

minivanmegafun
Jul 27, 2004



Microwave generator circuit diagram

Nearly all microwave ovens use basically the same design for the microwave generator. This has resulted in a relatively simple system manufactured at low cost.
The typical circuit is shown below. This is the sort of diagram you are likely to find pasted inside the metal cover. Only the power circuits are likely included (not the controller unless it is a simple motor driven timer) but since most problems will be in the microwave generator, this schematic may be all you need.

code:
                                      || +------------------------+
                                      ||( 3.3 VAC, 10 A, typical  |
                        TP  Relay or  || +------------+------+FA F| Magnetron
       _    I       I   __    Triac   ||              |    +-|----|-+
   o--- _---/ --+---/ --  ----/ ----+ || +------||----+    | |_  _| |
                |                    )||( HV Cap      |    |   \/   |
  AC           I \ I=Interlock       )||(           __|__  |   ___  |
 Line           |  TP=Thermal Prot.  )||( 2,000 VAC _\_/_  +----|:--+
   o------------+-------------------+ ||( 0.5 A       | HV      |'--> Micro-
                                      ||( typical     | Diode   |      waves
       (Controller not shown)         || +------------+---------+
                                                     _|_ 
                                                      -  Chassis ground

minivanmegafun
Jul 27, 2004



High frequency inverter type HV power supplies

While the vast majority of microwave ovens - perhaps every single one you will ever see - use minor variations on the tried and trusted half wave doubler circuit, a few models have been designed using solid state high frequency inverters - in many ways similar to the deflection/HV flyback power supply of a TV or monitor.
A typical circuit (from a Sharp microwave oven) uses full wave rectified but mostly unfiltered pulsating DC as the power to a large ferrite inverter transformer which sort of looks like a flyback on steroids. See High Voltage Inverter Power Supply from Sharp Microwave Oven. This means that the microwave output is pulsing at both 60 Hz and the frequency of the inverter!
code:

        Bridge Rectifier         Inverter Transformer            Magnetron
                                       o
  H o----+---|>|------+--------+-------+    +--------------------------+
        ~|            |+      _|_ Drive )::( Filament 1T #18           |
         +---|<|---+  |       ---   25T ):: +--------------+------+    |
 115 VAC           |  |        |    #12 )::   HV Cap       |    +-|----|-+
         +---|>|---|--+        +-------+ :: +-------||-----+    | |_  _| |
         |         |           |         ::(    .018 uF    |    |   \/   |
  N o----+---|<|---+   Drive |/ C        ::(    2,400 V  __|__  |   ___  |
        ~          |-    o---|   Chopper ::( HV          _\_/_  +----|:--+
 (Interlocks and   |         |\ E        ::( 250T          | HV      |'-->
  fuses/protectors |           |         ::( #26   Sense   | diode   | uWaves
  not shown)       +-----------+            +--+---/\/\----+---------+
                                             o  |    1.2   _|_
 (Except for filament, # turns estimated)       o H1        -  Chassis Ground

Sweevo
Nov 8, 2007

i sometimes throw cables away

i mean straight into the bin without spending 10+ years in the box of might-come-in-handy-someday first

im a fucking monster



LP0 ON FIRE posted:

i think i found a programming bug that seems apparent in just about all conventional microwaves driven by a microcontroller. after the timer runs to 0, the microwave seems to continue to run while beeping multiple times.

mine doesn't :smug:

LP0 ON FIRE
Jan 25, 2006

beep boop


minivanmegafun those diagrams and explanations are cool but i think all the microwaves are doing is not ending the cook routine before the "Done beeping" routine, and for some reason all microwaves i've ever seen use this


Sweevo posted:

mine doesn't :smug:

i don't believe you. you must be misunderstanding. show me a video please

LP0 ON FIRE
Jan 25, 2006

beep boop


i checked out the panasonic website, and they had this for an answer:




http://eng.faq.panasonic.com/app/answers/detail/a_id/10680/~/my-microwave-seems-to-run-after-the-cooking-has-finished.


they are admitting it's flawed right there, because if i press the stop button, everything stops immediately. the cooling fan routine "to cool down the elements inside" never happens. so does this mean i'm causing potential damage to my microwave just by hitting the stop button and not waiting for the timer to finish?

Dr. Honked
Jan 9, 2011

eat it you slaaaaaaag


Valeyard
Mar 30, 2012




Grimey Drawer


lol

<a href="#" onClick="alert("lol");">lol</a>

LP0 ON FIRE
Jan 25, 2006

beep boop


yeah it's probably every day i use a microwave it reminds me of microwave's mom and how much i still wish she was mine

Valeyard
Mar 30, 2012




Grimey Drawer

she could warm my meat up in 60 seconds :smugmrgw:

Farecoal
Oct 15, 2011

There he go


idgi :( :( :(

Dr. Honked
Jan 9, 2011

eat it you slaaaaaaag



http://forums.somethingawful.com/dictionary.php?act=3&topicid=1955

LP0 ON FIRE
Jan 25, 2006

beep boop


Valeyard posted:

she could warm my meat up in 60 seconds :smugmrgw:

Sweevo
Nov 8, 2007

i sometimes throw cables away

i mean straight into the bin without spending 10+ years in the box of might-come-in-handy-someday first

im a fucking monster



LP0 ON FIRE posted:

i don't believe you. you must be misunderstanding. show me a video please

look on my works, ye mighty, and despair

LP0 ON FIRE
Jan 25, 2006

beep boop



no. loving. way.

what kind of microwave is that??

edit: and question - did turning off the beep sound affect this?

Sweevo
Nov 8, 2007

i sometimes throw cables away

i mean straight into the bin without spending 10+ years in the box of might-come-in-handy-someday first

im a fucking monster



the beeper is still on, it's just got very quiet over the years. the mic doesn't pick it up very well either for some reason which makes it sound even quieter

LP0 ON FIRE
Jan 25, 2006

beep boop


okay i think i hear it, it's that chirping sound

lazydog
Apr 15, 2003


when i was little we had a microwave with a mechanical dial timer that made a satisfying "ding" when it was finished.

someone should bring back appliances with actual bells and whistles instead of piezoelectric buzzers

computer toucher
Jan 8, 2012



mine does that too and I guess it's so that you don't forget you have food there.

Nintendo Kid
Aug 4, 2011

by Smythe


i wish i had a nice big microwave with working popcorn autosensor thingy again

echinopsis
Apr 13, 2004



microwaves suck but they have their uses from time to time


pro tip leave the food for a bit after (do this with most cooking but esp with a 'wave)

Captain Cool
Oct 23, 2004

This is a song about messin' with people who've been messin' with you

lazydog posted:

when i was little we had a microwave with a mechanical dial timer that made a satisfying "ding" when it was finished.

someone should bring back appliances with actual bells and whistles instead of piezoelectric buzzers
most toaster ovens are like this

the problem is that if the thing is unplugged it will still wind and tick and ding like normal

LP0 ON FIRE
Jan 25, 2006

beep boop


echinopsis posted:


pro tip leave the food for a bit after (do this with most cooking but esp with a 'wave)

haha you're joking right? are you scared of microwave radiation or are you just saying this to have it cool off? remember, microwaves are non-ionizing

Sweevo
Nov 8, 2007

i sometimes throw cables away

i mean straight into the bin without spending 10+ years in the box of might-come-in-handy-someday first

im a fucking monster



i've met grown adults who think microwaves are radioactive

echinopsis
Apr 13, 2004



LP0 ON FIRE posted:

haha you're joking right? are you scared of microwave radiation or are you just saying this to have it cool off? remember, microwaves are non-ionizing

because microwaves heat food so fast they often heat just the outside or certain parts*, and leaving it allows the temperature through the food to come to equilibrium... unless you enjoy bites of your food that are both hot and cold at the same time


this happens with a traditional oven too but since food has often been in the oven for long-time the effect is very small compared to microwave


*often if you cook a food in a container than has better temperature conductivity than the food itself, the outside of the food will heat but the bowl will absorbe that heat from the food preferentially instead of the rest of the food so you end up with a hot bowl and cold food. another reason to let it rest

MancXVI
Feb 14, 2002



Toilet Rascal

microwaves

https://www.youtube.com/watch?v=g91xkISmp2g

LP0 ON FIRE
Jan 25, 2006

beep boop


echinopsis posted:

because microwaves heat food so fast they often heat just the outside or certain parts*, and leaving it allows the temperature through the food to come to equilibrium... unless you enjoy bites of your food that are both hot and cold at the same time


this happens with a traditional oven too but since food has often been in the oven for long-time the effect is very small compared to microwave


*often if you cook a food in a container than has better temperature conductivity than the food itself, the outside of the food will heat but the bowl will absorbe that heat from the food preferentially instead of the rest of the food so you end up with a hot bowl and cold food. another reason to let it rest

ah yes. good tips.

did you know contrary to previously thought, microwaves were proven to be the healthiest form of cooking, meaning it maintains nutrition in the food more than any other form of cooking

Dr. Honked
Jan 9, 2011

eat it you slaaaaaaag



yikes

LP0 ON FIRE
Jan 25, 2006

beep boop


geez where's their safety glasses?

theadder
Dec 29, 2011




echinopsis posted:

pro tip leave the food for a bit after (do this with most cooking but esp with a 'wave)

yep

lazydog
Apr 15, 2003


when i heat up things like chicken nuggets, after i microwave them, i stick them in the toaster oven for a minute to make them crispy

A Wheezy Steampunk
Jul 16, 2006

High School Grads Eligible!


i don't even own a microwave :smug:

A Wheezy Steampunk
Jul 16, 2006

High School Grads Eligible!


https://www.youtube.com/watch?v=ZDrgMLTZd60

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echinopsis
Apr 13, 2004



A Wheezy Steampunk posted:

i don't even own a microwave :smug:

I ised to keep ours in our garage so it hardly for used


thu are useful for heating things up. NEVER for cooking

LP0 ON FIRE posted:

ah yes. good tips.

did you know contrary to previously thought, microwaves were proven to be the healthiest form of cooking, meaning it maintains nutrition in the food more than any other form of cooking

yeah that might be true but on the other hand who cares make food delicious!!! yum yum

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