The Great Microwave Oven Debacle

Thread Starter

MrAl

Joined Jun 17, 2014
11,575
Hello there,

This problem seems to have prevailed for years now. Apparently, there is not one manufacturer out there who knows what a consumer wants in a microwave oven. They all fall short in one way or another.

I had just purchased a new microwave oven, a 2023 model made by Toshiba, and the last one I purchased 11 years ago a model made by Panasonic. They both incorporate "inverter technology", which means they do not (or they should not) pulse the full power on and off to get lower power settings instead they actually lower the output power the same way you would lower the output voltage on a voltage regulator. These ovens do work better than non-inverter types though, that's a plus. As to the basic operation though, they seem to be just randomly programmed by some designer who never used a microwave oven.

There is also an issue with the operation of the inverter where they only use the fully linear operation down to power level 3 (or 30 on the newer model). For levels 2 and 1 (20 or 10) they pulse the oven just like the older types with no inverter, but at a linear power level of 3 (or 30). That's an improvement, but I have to wonder why they just don't lower the power for those two lower levels too. It could be a drive issue though so I won't worry about that for now.

What is really nutty though is the way they present the settings for both power and for time settings. When something is to be cooked, you have to set the power and the time to cook. That's about the size of it for any oven like this, inverter or not. The way the settings are actually set though changed from the earlier microwaves. Apparently, each manufacturer thinks they have the best idea for allowing the operator to set the power and time. That also means they do it differently.
In the distant past, you would have a push button set that is like a calculator, and you press "Power" and then a number like "3" to set the power to level 3 (or 30). Then you press the buttons for the time, like 5-0-0 for five minutes. Then you press Start, then it starts to cook.
Well, somehow they got the idea that is just not good enough, they would like to have you press the Power button 7 times to get to power level 3, then press 5-0-0 for 5 minutes, then press start. That seems to be the method being used for a lot of these ovens.
That, apparently, was just not good enough either. Toshiba would allow you to do it that way (only for the power setting though, it has no keypad), but also has a knob on the front like a knob for a volume control. You turn the knob to set the power and to set the time.
The knob is actually turning a rotory encoder not a potentiometer, so that's a good sign. Also, you only have to turn it by three clicks to get to power level 3 (which is 30 on this oven). When you go to set the cook time though, it's a lot different. Are you ready for this?
To set the time, you have to turn the knob. That's the only way. Each click (18 clicks per full revolution) is worth 10 seconds, and luckily it starts at 1:00 not 0:00, so when you click it once it goes to 1:10 which is one minute and 10 seconds, then the next click 1:20, etc., up to 5 minutes 5:00, and then it increments by 1 full minute, 6:00, 7:00, 8:00, etc. That's not too bad I guess, unless you want to go up to around 20 minutes or more, then you end up rotating the knob about 3 full revolutions from 1:00 to 20:00 or so. That's kind of crazy if you regularly cook at those longer time settings. If you have to go up near the full 95 minute setting, you better have a portable drill with you cause you got to turn that dang thing over and over again.

Ok, so the lower power settings are easier to set, and that's a blessing for me because I like to use those settings almost exclusively. As to the time settings, I do not have to cook for long periods most of the time either so that's not too bad for me, but I do have to feel for other people who intend to cook for larger crowds and have to use the longer time settings more often.

So what's the deal here. Are these manufacturers that dumb? Microcontrollers that can do wonderous things have been around for more than 20 years now, and with even the cheaper models you can control a motor or tube or just about anything in a host of different ways and modes, so why the limitations? I can't see it being a cost issue either because microcontrollers are cheap. So what's the story here.

Now you would also think that's the end of the story, but alas, it's certainly not. There are models that do microwave plus convection plus air fry plus broil. For those I hardly want to get into the workings because they are so off the wall I don't want to waste the time, except to say that the settings are so presumptuous and ridiculous that someone must have come into work drunk that day or just put their hat on backwards that day or something. If you happen to be cooking something with a weight of 11 ounces you got it made. There are about 20 or so settings for that weight. If not, you will not be able to use any of those settings because they will either overcook or undercook the food. What on earth is this magical 11 ounces. What if I want to cook 12 ounces, or 6 ounces.

I can say another good thing about this newer oven though. It cooks more evenly than any microwave oven I have ever had. It's almost too hard to believe since all the past ovens even the Panaonic that was also an inverter type, did not come close to cooking the food evenly at even the lower settings unless I went very low like power level 1. I cooked a couple hamburgers and even the middle cooked correctly as well as the edges. I should mention though that I often make rectangular shaped hamburgers because I use a half of a roll for one hamburger and a rectangular shape fits better on those. With the Panaonic that did not help either though, I would have to break it in half, and even the two halves would cook unevenly. Maybe better than the older ovens, but not as well as this new one.
So that's kind of a big plus for this Toshiba. As to the settings though, they must be smoking some bad granola.

Any ideas about any of this would be interesting to hear, as well as personal experiences with microwaves or related like air fryers or convection ovens. Thanks.
 

Sensacell

Joined Jun 19, 2012
3,475
This comment relates to modern product design in general- microwave ovens are just one of the offenders.

The marketing/sales cycle and the actual use of the product seem to exist in unrelated parallel universes, and the marketing part always wins.
Marketing is all about MORE MORE MORE, all of which muddles the core concept - into oblivion.

I see no way out of this vicious cycle.

I worked in special effects for the TV commercial industry for a spell, one day, there was a need for a "no brand" VCR to populate the shelf on an 'Imaginary Livingroom' set.
They were not allowed to use any recognizable existing products.
The prop guys had to make a fake VCR out of random stuff, it was totally simplified to the barest of functions, and the layout of the controls was entirely basic.

Everyone working on the job remarked how they would buy this imaginary VCR over all the others that were currently available in the marketplace.
The simplicity was what people found so compelling, all it could theoretically do is play, stop, FF, and rewind.

Isn't there a brand that has the balls to make products that are simple, clear and clean designs?
 

Thread Starter

MrAl

Joined Jun 17, 2014
11,575
This comment relates to modern product design in general- microwave ovens are just one of the offenders.

The marketing/sales cycle and the actual use of the product seem to exist in unrelated parallel universes, and the marketing part always wins.
Marketing is all about MORE MORE MORE, all of which muddles the core concept - into oblivion.

I see no way out of this vicious cycle.

I worked in special effects for the TV commercial industry for a spell, one day, there was a need for a "no brand" VCR to populate the shelf on an 'Imaginary Livingroom' set.
They were not allowed to use any recognizable existing products.
The prop guys had to make a fake VCR out of random stuff, it was totally simplified to the barest of functions, and the layout of the controls was entirely basic.

Everyone working on the job remarked how they would buy this imaginary VCR over all the others that were currently available in the marketplace.
The simplicity was what people found so compelling, all it could theoretically do is play, stop, FF, and rewind.

Isn't there a brand that has the balls to make products that are simple, clear and clean designs?
That's very convincing, thanks.
The funny part is that I bet that if either your or I designed the Toshiba (or other members here) it would be the highest rated microwave on the market and set a new standard for microwave ovens. It could have both simple functions for the simple minded and more extravagant functions for the people who want to really USE their microwave oven.

We are not alone in this either as I am sure you know. Almost all the reviews say the same thing, the functions are archaic or just seemingly randomly selected.

All it takes is a few little changes and BOOM, everyone in the world would want one.

This really does tell me something about the designers because they don't seem to know what "acceleration" in button and knob and other controls means. Acceleration is the way the increments change as a user keeps pressing the same button or performing the same function. For example, that knob that goes from incrementing from 10 seconds to 1 minute then to 5 minutes, if it used the concept of acceleration in the software it would allow setting small time settings or longer ones just like a lot of software does today on platforms like Window. Turning the knob a little would increment by 10 seconds, but turning it for more than maybe 3 seconds would change the increment to 30 seconds, then maybe to 1 minute, then to 2 minutes, then to 5 minutes, something like that. I don't really like that a lot, but it would be better than it is now. Alternately just 9 little power buttons (touch buttons so nothing wears out) all you would have to do is touch one and boom it's set.
It does not have a keypad which is kind of good, and for what 'buttons' it does have they are 'touch' controls not physical like the old ovens. You don't actually press anything you just touch the surface like a tablet computer. That's all except the Start button which is kind of squishy feeling also which is strange, but at least it works.
The touch surface should allow a long life because physical buttons wear out, even the membrane ones. That was a good improvement.
 

Ya’akov

Joined Jan 27, 2019
9,237
Two things:

Toshiba still sells direct entry types, for example:

1711365580466.jpeg
And, it appears that on models with the interface you describe, you can either press the Power button repeatedly, or rotate the knob after pressing it once:

1711365731577.png

And, as an explanation of the new user interface I would say it is probably a matter of good research by Toshiba. I, like you, prefer direct entry but my empirical observation of microwave user behavior—and undoubtedly the outcome of Toshiba‘s focus groups and user observation—is that most people today use only one button on the microwave:

1711366013220.png
Microwave cooking for the overwhelming majority of users that I have had the opportunity to observe is a blunt instrument. There is nothing subtle: no power changes, no special modes—just increments of 30s selected by repeatedly pressing the +30s button.

Most meals or meal components being prepared in microwave require ≤5 minutes, so while it is annoying to press that button as many as 10 times, it’s easier than “thinking” about it. Even for this majority I think it would be possible to improve the interface, but it wouldn’t look like the old days direct entry, not to start.

If cost weren’t an object (of course it is, these are low margin commodities engineered for production and penny-shaved everywhere—but let’s say this is a premium model) the first thing I would do is go to a touch screen so the controls would be just what is needed in context and nothing more.

So on the Ya’akov oven you’d have a direct entry keypad if you wanted or needed one. (N.B.: if voice control was offered, the keypad and any other controls, save perhaps STOP, might never get touched, and if my new “feature” was included, even more so.) The second thing I would do is to make sure that the controls most happy-making to the user were the ones they would see. So, but default you’d have something along the lines of:

1711368338353.png
You’d also have a history display, something like the last 5 times—deduped so it becomes a kind of automated “favorites”. But I would also add another feature, one that really wouldn’t be very ”hard” to do and I do think it would be game changing: a bar code reader.

The idea is that you scan the UPC on a package and the microwave can cook according to even the most complicated procedure, including thing like displaying/saying “peel back plastic lid about one inch” and after n minutes of cooking, pause and display/say “stir the potatoes”—&c.

All of this with a constantly updating library of instructions for everything microwavable. For the “I won’t ever connect my microwave to the Internet crowd” we can allow it to simply be a way to manage your own library...

Al: *SCAN*
YM: Hi @MrAl! I don’t recognize that, I hope it is something yummy! Please tell me what it is!
Al: It‘s one of my favorites, Uncle Wemus’ Bourbon and Hickory Mac & Cheese with Black Truffle.
YM: OK! It does sound delish—I will add it to your favorites! How do I cook it?
Al: Let’s see it says pull back the film about one inch, then cook on high for three minutes and thirty seconds then take it out peel back film and and stir it, re-cover it with the film, then another minute on high.
YM: That sounds easy… let’s try it!
Al: OK, go for it.

Al leaves the room for something, so about three minutes and 30 seconds later…
Al’s phone announces a message:

Your Mac & Cheese needs to be stirred!

About 30 seconds later:
YM: [Appropriate Alert Sound, chosen by Al] Your Mac and Cheese is done! Please try it right away so we can make sure the instructions are good!
Al: This needs about another 30 seconds.
YM: OK, put it back in and I‘ll nuke it for you!

30 seconds later…
Al: Perfect.
YM: Got it, Uncle Wemus’ Bourbon and Hickory Mac & Cheese with Black Truffle is in the library and on your favorites list. Do you want to call it anything else?
Al: Yeah, ”Ambrosia”.
YM: OK then, food of the gods it is, Al. Enjoy.

You get the idea. Time to stop writing…
 

Tonyr1084

Joined Sep 24, 2015
7,957
Just bought my wife the GE Cafe' microwave to go with her stove and fridge. Those things have TONS of options, none of which we ever use. We want to boil water - put a pan on the stove and turn the dial to High. We want our food stored in a cold environment we open a door, push something into it, close the door. The microwave is always used on "Cook time" and "Timer". For all the other uses - those buttons don't get dirty. You can tell which buttons are pressed most frequently. Those buttons and the turn of a dial for my wife. For me it's "Add 30 min" repeatedly until I get the desired time. There has never been a circumstance where I needed 31 seconds or 39 seconds.
simplicity was what people found so compelling
Popcorn, Beverage, Baked Potato, Fresh Vegetable, Frozen Vegetable, Hold Warm, all things I never touch. Yes, simplicity works for me. The same way breaker points on a car worked for me. Simple and easily serviced. Forget the computer science degree just to change a crank shaft position sensor.
play, stop, FF, and rewind.
What more would we ever need?

What bugs me is the TV remote. There's one button for volume up and down AND for mute. There's a button directly above that button for switching back and forth between two channels. Then there's the other button for channel up and down AND for the channel guide. Directly above that is a button that is unsupported. I'm forever pushing the wrong button. When streaming - pushing the wrong button means you have to go back into the streaming service and reselect that provider and program just to pick up where you left off - um - I mean screwed up.

Volume up and down can be one button. Mute, as has been the case for so darn long works fine for me. Same with channels and the guide. All the other buttons besides the On/Off button never get used. Except for when in channel guide you use the up/down/left/right/center button to navigate to the program you want to watch.

How I miss the old days. I don't know what I'd miss from these days if I went back to the old days, except maybe for GPS. That's something I find useful.
 

ElectricSpidey

Joined Dec 2, 2017
2,837
The only complaint I have with my Panasonic inverter microwave is the beeper is not loud enough.

The last microwave I owned the beeper was too loud.
 

MisterBill2

Joined Jan 23, 2018
19,008
Magnetrons usually operate at a specific voltage or just a narrow band of voltages, from what I have seen. Not sure how they could work with variable power levels.
The best microwave oven we owned was purchased about 45 years ago. It was a NORELCO brand, and it had a knob timer, the first half rotation was seconds, the second half was minutes, up to 60 seconds and then up to 30 minutes. There was also a button to select a lower power mode. It was still working 25 years later, when I was harangued into accepting a replacement because it was cooking a bit slower. During that 25 years I had to replace a glass fuse once or twice, I think. The replacement lasted about 5 years and quit, its replacement also lasted 2 years. Now a simple Panasonic brand inverter, one of the earlier models with lots of unused buttons plus the nimerical keypad arrangement has lasted a while, but needs to have the mechanical part for the door latch re-lubricated every year or so..

Now I am wondering, because I picked up a used one and rescued that inverter supply just to see what it can be used for. It is half the size of a MW transformer and aside from the magnetron heater connections and the Hig voltage common ground, there are only three leads that connect to two opto-isolators. A fairly high frequency high power inverter could be a really interesting experimenter item. so has anyone experimented with one? Or even found a published circuit for it??
 

MisterBill2

Joined Jan 23, 2018
19,008
"FEATURES" is what marketing is all about!!
I did get a marketing class textbook just to see what they taught. It reminded me a bit about the class back in high school where we learned to recognize propaganda, except from the opposite point of view. Nasty stuff, really. But it makes clear the motivation for "Feature Bloat" that we see.
 

Tonyr1084

Joined Sep 24, 2015
7,957
The only complaint I have with my Panasonic inverter microwave is the beeper is not loud enough.
Yeah, mine is the same way. Have wondered if maybe when they assembled it they forgot to take the protective cover off of the piezo.
Not sure how they could work with variable power levels.
Right now they work with varying power. Suppose you select power level 5 (regular MO). It's on full power for 10 seconds then off for 10 seconds. That's the very definition of PWM. I BET (I don't know this but I bet) the inverter MO's operate on a higher frequency of PWM than a 20 second cycle (or whatever cycle it works on).
 

MisterBill2

Joined Jan 23, 2018
19,008
I hope that somebody who looks at this has access to the circuit of those inverters. The core of the inverter transformer looks a lot like the core for the flyback transformer for about a 17 inch CRT B/W tv set of many years ago. Ferrite, but not a huge lot of it.The fact that the whole package, on a single 2 inch by 4 inch PCB, weighing about 9 ounces, replaces the big heavy 4 pound transformer is impressive.
 

Thread Starter

MrAl

Joined Jun 17, 2014
11,575
The only complaint I have with my Panasonic inverter microwave is the beeper is not loud enough.

The last microwave I owned the beeper was too loud.
Wow, that's interesting because when I first got my Panasonic the first thing I wanted to do is kill that damn beeper. It was too loud ha ha.
After searching on the internet, I found there was no way to mute it, so I had to take the cover off and screw a screw into the hole in the top of the piezo beeper. That silenced the thing without modifying anything at all about the circuit itself. After that, it was silent and I never needed a beeper because the buzz of the transformer inside was enough to let me know when the time was up. It was not super loud but loud enough to tell when the time was up as the buzzing would stop.

That's another thing I can say about this new Toshiba oven. The thing is whisper quiet. I never heard a microwave oven that made almost no noise at all. Maybe the very slight sound of a small cooling fan, that's it, but it's barely noticeable. Plus, it does have the mute function, thankfully, because I needed that too. You do hear a 'click' when the time is up, it must be a relay inside opening up.

I wish that Panasonic oven was not so heavy I'd like to be able to throw it as far as I could (ha ha). In Panasonic's defense, it is 11 years old so the technology improved a little since then.
 

Thread Starter

MrAl

Joined Jun 17, 2014
11,575
Magnetrons usually operate at a specific voltage or just a narrow band of voltages, from what I have seen. Not sure how they could work with variable power levels.
The best microwave oven we owned was purchased about 45 years ago. It was a NORELCO brand, and it had a knob timer, the first half rotation was seconds, the second half was minutes, up to 60 seconds and then up to 30 minutes. There was also a button to select a lower power mode. It was still working 25 years later, when I was harangued into accepting a replacement because it was cooking a bit slower. During that 25 years I had to replace a glass fuse once or twice, I think. The replacement lasted about 5 years and quit, its replacement also lasted 2 years. Now a simple Panasonic brand inverter, one of the earlier models with lots of unused buttons plus the nimerical keypad arrangement has lasted a while, but needs to have the mechanical part for the door latch re-lubricated every year or so..

Now I am wondering, because I picked up a used one and rescued that inverter supply just to see what it can be used for. It is half the size of a MW transformer and aside from the magnetron heater connections and the Hig voltage common ground, there are only three leads that connect to two opto-isolators. A fairly high frequency high power inverter could be a really interesting experimenter item. so has anyone experimented with one? Or even found a published circuit for it??
Hi,

Yes you are right so maybe they use high frequence PWM.
However, I did tests a long time ago with a standard non-inverter microwave oven and found you could lower the linear power output by using a variac to power the oven. You turn the input voltage down, and the cooking power goes down as well. You can adjust it to various levels. The drawback here though is that as you say the range is limited, and that means it is also NARROW. The range is narrow so once you adjust it if the line voltage changes a little or the oven impedance changes even a little, the power level changes. That's because small changes in that narrow range causes changes in the cooking power level. What this means in turn is you would need to add a regulator to regulate the input power from the variac or whatever you use to reduce the voltage. The regulator would keep the power level more constant. That also means you need feedback and I am not sure if the input current from the variac is a good observer or not, you may have to monitor something else like the cooking power itself with a sensor inside the oven. I did not take it that far though, I just wanted to prove that you could lower the power by reducing the input voltage as that would be the first step to designing your own "inverter" oven without the inverter.
As someone said, they may use higher frequency PWM turning it on and off faster than the usual standard oven which uses on for 20 seconds off for 20 seconds or whatever. That would mean it would still be applying full power, but the average power could be much less. I never tested for that but maybe I should.
I don't want to take this one apart though. The mute function keeps it quiet so it's good enough for now.

I also found that the "defrost" functions do not work at all. You can set it to defrost by time or by weight, and neither one actually defrosts, it actually COOKS the food. That's pretty nutty. Measuring the input power, the power for any defrost function is the same as just setting the oven to a lower cooking power like level 30. That's just plain stupid because the food defrosts that's for sure, but it also cooks to a rather large degree. Defrosting is not the same as cooking so that's very strange.
 

Thread Starter

MrAl

Joined Jun 17, 2014
11,575
"FEATURES" is what marketing is all about!!
I did get a marketing class textbook just to see what they taught. It reminded me a bit about the class back in high school where we learned to recognize propaganda, except from the opposite point of view. Nasty stuff, really. But it makes clear the motivation for "Feature Bloat" that we see.
Oh that's interesting and that's probably what we all were thinking. Say anything, deliver anything even if not what you said it was, just make it sound good.
 

Thread Starter

MrAl

Joined Jun 17, 2014
11,575
Yeah, mine is the same way. Have wondered if maybe when they assembled it they forgot to take the protective cover off of the piezo.

Right now they work with varying power. Suppose you select power level 5 (regular MO). It's on full power for 10 seconds then off for 10 seconds. That's the very definition of PWM. I BET (I don't know this but I bet) the inverter MO's operate on a higher frequency of PWM than a 20 second cycle (or whatever cycle it works on).
Yes that's a good thought, that could be what they do with the inverter type ovens. I'd have to test for that and I have not done that yet.
 

Thread Starter

MrAl

Joined Jun 17, 2014
11,575
The beeper sound can be greatly reduced with a piece of tape covering the opening.
Wouldn't the tape start to loosen up over time as the heat inside got hotter as cooking went on day after day?
I did not want to have to take that oven cover metal off more than once it's a pain to get back on (ha ha).
Maybe tape plus a good quality tie wrap or two?
 

MisterBill2

Joined Jan 23, 2018
19,008
Some kinds of tape will never come off, while other kinds will fall off while you watch. The older, tan colored masking tape will tend to become permanent after awhile. After a few weeks it needs to be scraped off, after 2 months you need a disc grinder to remove it..
 

Janis59

Joined Aug 21, 2017
1,855
Once was that every MW cooker consisted by MOT transformer, capacitive voltage doubler and magnetron. The only detail what was able to malfunction was diodes, and that was easy to repair. Mine I use rarely, as I clearly KNOW (had exactly measured) how much free radicals it produces in the food, and stomach cancer is not my wished friend. But when it is needed I use it still. Machine was produces at 1969. And still in the good order. Of course, such machines makes the bankruptcy for it producer firms, THEREFORE the electronics was insisted to solve the problem. Now the microprocessor based SMPS-based cookers is full the World, and none works longer than warranty period plus one day. Such is the life - You get what You pay.
 

Jon Chandler

Joined Jun 12, 2008
1,072
Our oven beeps once quietly when the timer is done. Our microwave beeps incessantly for a couple minutes, then less frequently after that.

The oven, where what's inside continues to cook and may burn if not attended to, beeps once.

The microwave, where what's inside has stopped cooking when the beeper goes off, screams for immediate attention until it gets in.

Am I the only one who thinks the beeping should be the other way around???
 

MisterBill2

Joined Jan 23, 2018
19,008
Many cooking processes require fairly close attention to assure that the results are as intended. At least that is my experience. The microwave oven beeping is a very cheap add-on feature/function and thus subject to the marketing department bloating edicts. Primarily microwave cooking is also very short term internal heat energy application, much different from the much slower than the "traditional" external heat application ovens that have been used for all of recorded history. So the use and functioning is quite different.
As for microwave cooking "producing free radicals" in the cooked food, that sounds very much like the rantings of those who do not let total ignorance slow their speaking at all. Not everything that is published is correct, is what I have observed over the years. Modern word processors have allowed even the most ignorant to publish fairly coherent writings totally devoid of any accurate information. Poor spelling and sentence structure are no longer the handy warnings that we used to have.
 
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