The future of microwave cooking is solid-state (2016) | Hacker News Reader

The future of microwave cooking is solid-state (2016)

electronicsweekly.com

87 pointsdmmalam93 comments

Fun video about microwave oven now vs thirty years ago:

https://www.youtube.com/watch?v=UiS27feX8o0

"The Antique Microwave Oven that's Better than Yours" by Technology Connections

When my friends' parents started getting microwave ovens (late seventies, early eighties I suppose) the received wisdom was to leave a cup of cold water in there when the oven wasn't being used. Does anyone else remember this?

Something got lost in translation. Putting a cup of water in the microwave is advisable over running the microwave with an empty chamber -- something to do with the microwaves getting reflected back into the magnetron and causing overheating. But there's no such concern while the appliance isn't running.

I think the advice was in case the microwave was started accidentally. My parents used to leave a cup of water in the microwave, and they explained it in that way.

I don't think it's gotten any less bad to run an empty microwave, but maybe we've realized starting it accidentally isn't that common, and/or we've gotten complacent.

That, and it's not as if the microwave will explode the instant you turn it on while empty. It'll take a few minutes before the magnetron overheats.

Modern microwaves also have resettable fuses and protection for the magentron overloading. Not suggesting you run it empty, but it's less of an issue now.

I still do it. Started because the children might turn it on empty. Now they are grown and I am getting older I do it in case I get forgetful!

Beat me in posting this!

Wow. Why is he so snarky and sarcastic? It's relentless. So toxic.

Some people call it humor

I think calling non-toxic things toxic is toxic.

He talks like everything is stupid, and everyone but him is stupid. It's superficial and doesn't consider why anything might be the way it is. It's nasty and corrosive.

No he doesn't.

I'm also not a big fan of his snark in this particular video but it's not that big of a deal and he doesn't usually come on as strong in his other videos.

You should watch his patreon video. He has no formal background in science or technology. He has a degree in hospitality. He is the least egotistical purveyor of technical information I’ve seen. Perhaps this is what you’re picking up on?

It's called a dry wit, you can be forgiven for not knowing what that is.

It's alright man, he's only doing this for fun. His videos are more valuable than his snark IMO.

I think mine is older than that. It's an 850 W Moulinex. It has no display. The timer is an electromechanical dial and the power control is also a dial. It has an additional small dial for times under 90 seconds and that is the extent of its sophistication.

I inherited it from my mother who had used it for years.

It is much easier to control than the ones with keypads; if I need extra time I just turn the dial.

> It is much easier to control than the ones with keypads; if I need extra time I just turn the dial.

Most modern ones allow you to add 30 seconds with just the push of a button.

does not help if one wants overtime that is not a multiple of 30s :)

#analogmasterrace

I have a model with the same features, it sits in one of the kitchen cabinets. I don’t know the brand or model, it’s been cleaned so many times that all prints have been fully erased. Never felt the need to “upgrade” because it works perfectly and is very easy to use.

When microwave ovens first were entering mass-production it was imagined that they would replace conventional ovens a lot more completely.

They were an emerging high-tech appliance for avant-garde consumers, they were going to be expensive so they had to be big and strong.

They were huge and heavy, you had to be able to cook a whole turkey.

I was an appliance-repairing college student at the time, when these went out it took two delivery operators to pick one up and put it on the customer's countertop. A refigerator usually only needed a single driver.

In the sales showroom they were giving free microwave cooking lessons to introduce the skills needed to make the transition. A factory representative would come regularly to conduct a culinary demo. In hindsight more of an appliance enthusiast than a food enthusiast. In the advanced classes they would prepare an entire holiday dinner, and we could partake in the surplus.

Few foresaw that more often younger unskilled family members than ever would one day be conveniently using ovens without supervision.

2016. Here's some of the slide from freescale/NXP about this from then: https://twitter.com/vivekgani/status/684893901602205696 .

Earlier version of myself used to obsess about ideas like this, these days more interested in appropriate technology rather than overall efficiency.

see also a demo video from then: https://www.youtube.com/watch?v=TR7fhBUTMso

Interesting technology but that steak in the video looks terrible.

I once about 23 years ago was invited over a girlfriends mom for a roast beef dinner. I watched her put the roast in a microwave and blast it. I was in shock but didn’t say anything. She used the oven and did up some Yorkshire puddings quickly and already had some mashed potatoes. Next thing I know dinner is done. I was certain leather was being served. But to my utter surprise the roast was cooked perfectly medium rare and was to this day the second best piece of meat I have tasted. I don’t have the guts to take a $23 piece of meat and risk trying it myself.

I think it's easy to fall into habits with appliances, whereby we artificially limit our use cases to safe / common ones.

I found an Oster blender recipe book from the early 60s with recipes for all kinds of food prep... in a blender. Baking mixes, egg dishes, etc.

Sure, part of it was marketing, but it made me realize how much familiarity circumscribes imagination.

I've been bored and messed around with non-standard microwave uses.

- spaghetti (hard to balance boilover)

- egg mcmuffin: bagel in toaster, egg in microwave using nordicware egg-n-muffin

I'll bet there are other easy + tasty ones

Appears to have stalled. The group behind it hasn't updated their site since 2017: http://rfenergy.org/press-room/

Everything related to Microwave ovens seems to have stalled - because of patents?

I wanted to buy a microwave oven with these two features:

a) Panasonic-style inverter tech - actual granular power control rather than just pausing for 10 seconds now and then (ultra-low frequency PWM) when running at less than 100% power.

b) Sharp-style "start immediately and run for 30-60 secs more for every button press" start button functionality

I've tried really hard to find a Microwave oven in Europe that does both a + b. It doesn't seem to exist.

> Everything related to Microwave ovens seems to have stalled - because of patents?

https://www.youtube.com/watch?v=UiS27feX8o0

Look at LG's NeoChef "Smart Inverter Magnetron" models. I have the .9 cu ft one. Inverter tech plus starts immediately and two "add time" controls: one adds in 30 second increments and a separate control that adds OR subtracts cooking time in 10 second intervals. We've had it about two years now, use the heck out of it and it is, unquestionably, the best microwave we've ever had. Plus, it looks good in stainless and black glass. About $130.

https://www.lg.com/us/counter-top-microwave

Intriguing. Maybe I'll have to import it from the US... (and then run it via some 230V/50 Hz to 110V/60 Hz thingie).

Do they not sell LG where you are?

They do, but unfortunately it seems like household products that the global manufacturers offer are very different region to region. I guess the Americas and Asia get the high-end microwave ovens... (but they're also quite different, I'm sure.)

A local appliance dealer who I have come to know on a personal level turned me on to the LG and special-ordered it for me. I had originally asked him about Panasonic inverter microwaves but he dissuaded me saying that the Panasonic ovens suffered from reliability problems.

The inverter cooking is fantastic and makes the oven a lot more useful for serious cooking. I will use 20-40% power for re-heating foods over a longer time and the results are that there are none of the weird molten-hot and still-cold pockets of food. Pre-packaged foods whose directions are, say, "heat for 3 minutes," I will instead heat for 5-6 minutes at 40-50% power and the results are considerably more consistent. Plus, I have found that I can get sous vide-like results at low and long settings. For example, I have discovered that heating a filet mignon cut gently at 10-20%, and periodically halting cooking for a minute to let heat distribute evenly through the cut, and then continuing slowly until it temps at 115°F, and then searing on rocket-hot cast iron produces great results. Better than sous vide, at least for beef tenderloin.

I know I will never go with a non-inverter microwave again as it turns a blunt instrument into a device capable of truly nuanced cooking. If something is going to tie-up counter space, it had better be worth it and the LG is worth it.

The next thing I am looking at is the Anova Precision Combi-Oven. https://anovaculinary.com/anova-precision-oven/

So the Anova is a combo dry convection and steam oven, correct? (Not microwave) Looks interesting.

I was wondering also if you know a model that combined variable inverter (not duty-cycle) microwave output, convection, and steam-sensor.

thanks for the info!

Yes, it is a non-microwave "combi oven" convection/steam with precise temperature and humidity control. The breakthrough here is price as traditional professional combi ovens are incredibly expensive. Electrolux makes a small countertop model for about $2k but it does not review very well. Gaggenau offers a consumer built-in that requires plumbing for water supply at about $8k. The gold standard are the Rational commercial combi-ovens which start at about $10k and go up sharply from there.

In roughly the 140° to 250°F range, the combi ovens are super precise unlike anything else. Nathan Mhyrvold in his tome "Modernist Cuisine" says, (roughly), that the combi oven the single most useful device in a kitchen.

For lower temps, sous vide is more precise but, overall, the combi is more versatile.

Anova, along with Sansaire, was one of the first to introduce affordable sous vide circulators to the market so I have high hopes for their $700 combi.

As for a microwave with a user-visible humidity sensor, I don't know of one but I haven't looked.

They seem to sell the Neochef models in Germany, what's different about them?

Ah, you're right! Thanks.

Converting between different grid frequencies would need a rectifier/inverter or rotary converter - and one that can handle high power (1200W+ sustained) as well. That's quite a bit of equipment to run just a microwave...

Edit: Looks like units capable of dealing with these kinds of power specs run for around $2300 USD, e.g. http://www.gohz.com/2kva-frequency-converter

What’s wrong with the low frequency PWM solution?

It's not optimal. Edit: Imagine trying to heat e.g. a pastry carefully. 10 seconds at full power is enough to make it start boiling, partially, because of the uneven microwave radiation pattern. Other parts will be cold.

This is a fundamental problem with standing waves in microwave ovens, and isn't really affected by pwm. You need to change the mean free path.

I've never tried a Panasonic inverter-style microwave oven, but I imagine it would solve this problem. It would be able to run at like say 30% for 30s while rotating the contents.

I have a Panasonic inverter microwave, and it does solve the problem quite well. The standing waves aren't solved, but the lower continual heating lets the energy conduct in the food without overheating parts.

We have a Bosch BFL834GC1[1] which I think has the inverter thing you're talking about. It does not have a swivel and from my experience heats quite nicely. I often use the lower settings like 180W for more delicate heating.

Pressing start sets to to run for 60 seconds by default, but to change the time you have to use the wheel. Pressing start again pauses it. So maybe that's a no-go for you.

[1]: https://www.bosch-home.no/produktliste/komfyr-ovn-platetopp-... (NO site)

https://www.bosch-home.com/de/produktliste/zu-allen-accent-l... (DE site)

Thanks - I forgot to specify that I'm looking for a standalone unit. The equivalent top-of-the-line standalone Siemens microwave requires one extra button press. And it doesn't have the inverter tech. (I think Bosch/Siemens merged their business units in this area.)

Ah, don't know about stand-alone. Hopefully it'll be there soon tho, these things trickle down.

Yes, Bosch and Siemens are one and the same, at least for a lot of models. Mostly just a single letter different in the model number and red vs blue highlights where relevant (say dishwasher).

Was told at least here in Norway that Siemens was targeted more towards kitchen builders, while Bosch was targeted for consumers directly.

> these things trickle down

Ah yes, I forgot that it's somehow aspirational to have a built-in microwave-oven now, so because of that it can cost €500 and then it's possible to spend $10 licensing those patents/tech.

I hate this world. :)

> aspirational to have a built-in microwave-oven now

The funny thing is, a lot of built-in microwaves aren't really built-in. They're just countertop models that sit in a cupboard with a predictable opening size, and it comes with a trim kit to make it built-in. You can totally just buy it without the trim kit and set it on the counter.

What would 'really' built-in mean? This is how all fitted units (fridge/freezer, dishwasher, oven, ...) work.

It makes even more sense to use a common model for microwaves and ovens than it does for the others, since they don't need or want fixings for mounting a door over them.

I wouldn't be surprised to find out a lot of e.g. fridges sold with (cosmetic) doors are actually the same model just with that extra part using the same fixings as the fitted cabinet doors.

> What would 'really' built-in mean?

This is subjective, of course. IMO a real built-in appliance wouldn't have feet on the bottom that it sits on, wouldn't have finished sides and back, it would be purpose-built to only work within cabinetry designed for that purpose.

My ovens don't work that way, as far as I know. It requires a certain opening, but it isn't designed to be free -standing so it couldn't be set on the floor. At least not safely. It's designed from the ground up to be inside a cabinet, there isn't just a trim kit to fake it.

My dishwasher for sure isn't designed to be free-standing. It would tip over when you opened the door. It does have feet, but it requires attachment to the counter. And if you pull it out, you are looking directly at the tub, not finished sides.

Not sure about the fitted fridges. Mine is not that fancy, so it's designed to be standalone. It sits inside a cabinet that is designed to accommodate it, but not as a built-in.

I replaced my built-in oven recently, and it said it could also be (approved for use I assume that means) 'built-under'; I didn't check but I assume you just get screw-in feet, slide it under the counter/hob, then put the kickboard back. Or maybe no feet it just goes in a cabinet with the door off/drawers out.

I suppose my point really was just that it's all standard sizes, it's not like fitted kitchens are custom built by electricians as well as cabinet makers with the guts hanging out of appliances, no enclosure to speak of.

It's shocking what these things cost though, compared to BOM. Ovens from £100-400 are basically all the same just with different fascias.. but if your kitchen is exposed enough that you don't want the oven fascia to look crap.. what can you do put stump up?

Heh, I meant trickle down as in the model we got was the top of the line, and the lower ends seem to have the rotary thing so I assume good old electronics there.

We chose built-in mainly because a built-in regular oven was better in terms of ergonomics for my gf, and due to specific constraints of our rather small kitchen a built-in micro above it was the best solution.

Seems like there's one shipping product. https://theappliancesreviews.com/review-of-innovative-built-...

No, it's not.

These are specialized RF mosfets that cost hundreds of dollars a piece, and you currently need at least four to come close to the output power of a weak consumer microwave. The power supply and control and protection circuitry is also exotic and expensive.

A 2 kW magnetron costs six bucks in quantity.

I bet it comes with the reliability of Windows Me as well

Stepping up the voltage with a DC-DC converter for the Magnetron is doable. Having a 2.4GHz 1kW amplifier just to heat food? Yeah doesn't look like a good idea.

And a freaking circulator at the output to keep reflections from frying the transistors? This design belongs in a cell tower, not a kitchen.

I don't need a stronger microwave. When I put non frozen food into a microwave it becomes too hot to eat after 2 minutes. If the food is just right after two minutes it is perfect.

Mine's a 1kW model, and the only powers I use are 270W max (defrost setting) and 450W (to reheat).

Not so much that I think it tastes better having heated more slowly, (untested) it just gives easier/less crucial times and more time to react, fits in better with whatever else is cooking that isn't in the microwave.

It is in the sense that they do exist (article is from 2016) - my previous employer had them in the kitchens for people bringing their own (not-yet-hot) lunch etc. Retail models, not catering kitchen equipment.

I don't know what they cost but they looked just mid-high end, not the cheapest thing you could get but certainly not the most expensive obscure brand. Just something in the middle with a huge markup for the particular fascia they're selling it with this year.

This should have [2016] on it

The standard Cavity Magnetron is pretty solid state already. Seems a strange way to phrase this. https://en.m.wikipedia.org/wiki/Cavity_magnetron

Technology based on electrons moving in a vacuum is not considered solid state. Vacuum tubes are an example of that kind of technology - the electronic switches that preceded transistors. I guess free electrons might be considered "plasma state," although that might be stretching the definition of plasma.

But I guess that if you want to modulate the frequency, you'd have to change the geometry (?)

Are these easier than magnetrons to I/Q modulate for the ultimate wifi experience?

Actually I would say the future of microwaves is things like the miele dialog oven, which uses essentially MIMO techniques to direct the microwaves (at about 2.4 GHz IIRC, so the thing has a lot of shielding build in). I find it amazing how microwaves have just become worse over the last decades. Lots more functions in the UI without being needed, because the oven can't actually do anything interesting. AFAIK, pretty much every microwave still does PWM to change power for example.

https://thespoon.tech/miele-shipping-the-dialog-their-oven-w...

Wow, 7,990 EUR!

Description from 2017: https://thespoon.tech/miele-introduces-the-dialog-a-high-end...

Yes at the moment this seems to be more aimed at professionals. So chefs have been doing quite interesting things with it. But the price is pretty out there.

Closer to a tool for creating art than cooking apparatus though, incredible.

>With solid-state sources, frequency can be shifted (2.4-2.5GHz, for example) to move nodes and anti-nodes around the cavity...

Probably not so great for WiFi...

WiFi has always used the microwave frequency range, and badly designed microwave ovens (that don’t fully isolate the waves inside) have always been a problem for WiFi. The use of 2.4 GHz in ovens is one of the primary reasons it’s an unlicensed frequency range. The interference is one of the reasons 5 GHz was added as another frequency to use for WiFi.

Commercial ovens, medical diathermy, and a few shenanigans from GE are why 2.4 is open. [1]

I don't believe it is correct to say 5G was added due to interference, the development time ines suggest it was more for throughput.

1: https://www.indiegogo.com/projects/why-2-4ghz-chasing-wirele...

5GHz wireless phones were deployed to deal with a crowded 2.4GHz band flooded by baby monitors and other BW hogs. This was all before wifi became ubiquitous.

Funny enough the rare digital spread spectrum 900MHz phones that came out just before the higher frequencies took over were great because of limited use by that time plus minimal interference from walls and analog phones.

Microwave isn't great for WiFi anyway. If the solid-state sources are more focused though, that could be better, it would mean less interference leaking outside the microwave.

Yeah, years ago my parents used to have trouble with the microwave and the old 2.4 ghz wifi and I fixed it for them by pinning the wifi channel. I don't know if this will take out all of them, or affect nothing (since we have multiple frequencies and better protocols)

What did you pin your Wifi to ?

Defrost

Presumably a subchannel in the 2.4GHz frequency range that said microwave wasn't spewing as much interference on.

https://en.m.wikipedia.org/wiki/List_of_WLAN_channels#2.4_GH...

Yes there's a plaque on most microwaves that says the frequency, which is 2.450ghz. That matches channels 7-11 on the page you linked. So you want channel 1.

It was the old wifi standard, 802.11b

The microwave had a label 2450 mhz which hit channels 7-11, so we put it on 1.

It's not an accident that that's an unlicensed band and it's the responsibility of your wifi set up to deal with it.

Someone should calculate the bandwidth required to run an even cooking pattern, and then strongly encourage all manufacturers to share the same narrow band.

Could this eventually be used to for example have a microwave that could make creme brulee by just targeting the top of the custard

> "We have cooked a whole egg."

That's pretty incredible. Does randomizing the nodes make it less dangerous to microwave metal?

My Bosch microwave is fine to put metal in. They actually recommend putting a spoon in water to avoid super heating it

no arcing ?

Nope, but instructions said don’t get metal too close to walls.

I wonder how the reliability is --- the newer inverter-based ovens often burn out the electronics long before the magnetron.

I still use the same Goldstar (the company is now LG) microwave oven I bought in the late 1980s. Still works fine. Even the original interior light still works. That is a high bar for reliability.

A bit off-topic, but anyone know what came of Panasonic's "cyclonic wave" technology? Does it work as well as it's advertised? It seems nice in theory so I'm kind of confused why it doesn't seem to be used in more models.

http://www.gojifoodsolutions.com/rf-cooking-technology

Microwaves made cooking quicker, which changed lives, which changed the way society was structured.

Anything that reduces home chores will increase the size and change the demographic of the workforce for instance.

Microwaves are also very flawed, it'd be like if rice cookers cooked rice only 85% as good and the rice was unhealthier.

This article is 2016 and nothing has changed.

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