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What happened to RF cooking?

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Marco:
Inverter is cheaper than a transformer.

For European kitchens I think one 45cm height combi and one 60cm oven is the most natural setup. Why waste space on a microwave when you can combine it with a convection oven with grill?

tom66:
Magnetrons are dirt cheap 2.45GHz RF sources.  Unstable, poorly regulated, but dirt cheap.

You can improve them to some degree with power control, which is what inverter microwaves do.  These can vary the power between about 40% and 100%, at less than 40% I guess the magnetron isn't stable so they cycle the power instead (maybe there's another reason but my Panasonic inverter microwave does this.)

RF power electronics would need to fall towards the $25 or so a microwave oven transformer, magnetron and capacitor achieve to go truly mass market, and at least be within the $100-$200 cost region to be at least in the premium market (say for a $500 oven.)  It's a big ask, it may well happen eventually but it will take some time if it does.

Marco:
The Ampleon amplifiers are at the same time remarkably cheap and at the same time still way to expensive to compete with magnetron tubes. The more even space filling possible with multiple emitters and some frequency modulation is nice, but not that nice.

tom66:

--- Quote from: IanB on June 14, 2023, 02:57:45 am ---
--- Quote from: jmw on June 13, 2023, 11:40:10 pm ---I remember about five years ago there was a big splash about improving microwave ovens and RF cooking: replace magnetrons with adjustable output solid-state RF power amps, with some ideas about specialty defrosters using HF & low-VHF frequencies. There was a prototype oven from Miele for an insane price, NXP made a line of transistors that are now unobtainium, although one part seems to live on in the MRF300. Then the buzz died and nothing was brought to market. Anyone know why things stopped?

--- End quote ---

Engineering is why things stopped. Engineers figured out how the reduce the manufacturing cost of microwave ovens to the absolute minimum, because the only thing that sells consumer products these days is "Cheap! Cheap! Cheaper!"

Put two competing products on the retail shelf, one costing $50 and the other costing $75, and the $50 product will outsell it 10:1. Try making a product costing $150 and it will sit on the shelf forever gathering dust, no matter how much better the quality or performance.

I've stood next to people in shops and watched them buy the crap product instead of the good product, because the crap product was cheaper. It's depressing, and is the reason why it becomes increasingly difficult to buy quality products these days.

--- End quote ---

There are still premium products out there.  But really to make this work we need manufacturers to have enforced warranties.  The EU originally had 2 years minimum on products but that should be 5 years.  This would mean that there's little incentive to produce crap appliances.

One kitchen appliance we have is an ice maker.   I bought it second hand from a charity shop.  It's about 3.5 years old now.  Since then I've replaced:  the tray motor (died), cooling fan (bearing went),  microswitches to detect the tray position (plastic case on one just cracked and switch fell apart), and the piping for the water pump (as the pipe began to disintegrate and leak), and most recently the IR detection barrier - the LED/photodiode combination failed as the leads rusted so I replaced those.   Really, about the only thing that hasn't broken is the compressor and refrigeration circuit.  I imagine most people would have thrown the product in the bin by now, and it was probably sold with a 1 year warranty.  Such badly built products shouldn't be allowed to be marketed.

BradC:

--- Quote from: IanB on June 14, 2023, 02:57:45 am ---I've stood next to people in shops and watched them buy the crap product instead of the good product, because the crap product was cheaper. It's depressing, and is the reason why it becomes increasingly difficult to buy quality products these days.
--- End quote ---

I've met plenty of people who've saved for months just to be able to afford to buy the base level crap product (oh lets let's say it's an aluminium electric kettle with a steel element that will rapidly succumb to dissimilar metal corrosion). When it fails 35 milliseconds outside of the warranty period they then get screwed again. Damned if you do, and damned if you don't.

On the flip side, we have my great grandmothers treadle singer sewing machine. When she died and we inherited it we gave it a "birthday" and found the payment book in the bottom drawer. She paid it off over 2 years starting in the late 1920's, used it to provide for the family for 30 years as a seamstress and it's still serviceable.

There's a message in those two paragraphs, but buggered if I can figure out what it is. I've always been taught "A poor man pays twice".

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