Microwave Ovens with Inverter Technology Really Cook

Do you happen to know anything about differences in the Model Nos of Panasonic’s Microwave Ovens?  I cannot get a substantive response from Panasonic support. 

Our NN-SN651W (Inverter) died after several years of use.  We liked it, except for its size.  We found a larger model - NN-SN975S - at Sam’s Club, but the Panasonic website only lists an NN-SD975S model, nothing about the NN-SN975S. 

From photos, I can see that the NN-SD975S has a knob, but the NN-SN975S does not.  I can’t tell what that means or whether there are any other differences between these two.  I’ve sent emails and made phone calls, but I cannot get anyone at Panasonic who will tell me the differences between these two models. 

Do you know or have any suggestions? 

Thanks.

Seems too much like an advertisement.

To be believable it needs to have the bad points as well.. there are always some

What, if anything, is the difference between “inverter” & “cyclonic wave inverter”. If the latter is better, is it in all Panasonic inverter microwaves and in no other brands with inverters e.g. L G.?

Unlike Mr. Kirchner, I use the microwave for EVERYTHING. I do have a stove with an oven which I use every couple of months.  My Panasonic inverter MW is a nightmare to use.  You have to reduce the power level for everything except heating coffee and you have to reduce it more for ‘dense foods’.  No one can explain what a ‘dense food’ is.  I offered to send Panasonic a list of the microwave meals I normally eat and have them tell me whether they were dense or not and they told me they wouldn’t be able to tel!!!  The MW has been getting weaker lately and when I called Panasonic they suggested I drive it over to a repair facility in a nearby state!!!!  Unbelievable.  I intend to sell this one on Craig’s list for a dollar with appropriate warnings.

After many years of use, my old Sharp model has died. That one allowed selecting a sequence of stages. For example full power for 90 seconds followed by 20% power for three minutes would bring oatmeal to a boil and the cook it for three minutes without overflowing the bowl. I can not find that same sort of “steps” sequence being specifically noted on any but commercial models. Is that chaining together of steps available on most of the current middle to upper level homeowner models, say $200 -$300 (US)?

I have now been using Panasonic microwaves for almost 20 years.  Started when their (at that time) newly PATENTED Inverter technology caught my attention, as I was working with 10kW (and larger) semiconductors used as invertors in some advanced welding equipment.  I have from then until now wondered why they seem to be the only brand of touch pad controlled microwave that does not use the “touch power button, touch number for power” scheme of programming.  I say this because no one else in family / friends have a Panasonic and all are baffled how to set power on it. 
As to the inverter used to provide “variable output power from the magnetron” it in fact DOES NOT.  In a “normal” microwave the magnetron is pulsed on and off at various rates so that over a 1 MINUTE time the AVERAGE power is reduced.  This is because a magnetron is operated by a high DC voltage that causes pulses or “oscillations” of electrons at extreme high frequencies (gHz / “microwave”), determined by the exact voltage and mechanical construction of the magnets around the central vacuum tube.  It can only be on or off - similar to a fluorescent light.  All the invertor does is take advantage of the extreme speed and WATTAGE that has become available in semiconductors.  Instead of a mechanical relay switching the power to the HV transformer on or off every few seconds,  the HV power supply is in continuous operation but applied through semiconductors in a “pulsed” fashion at something like a 100kHz rate.  So now by eliminating a variable percentage of the “pulses” you get the appearance of variable power because the averaging is being done across a 1 millisecond duration rather than a 1 minute duration.  So at 10% power a non-inverter microwave’s magnetron is probably on for 3 seconds, then off for 27 - not much use, eh?  The invertor microwave at 10% power is also off the same relative time, but does it by 3 milliseconds on then 27 milliseconds off or similar, repeating this high speed cycle at a hundred times a second or similar.  Though your food is still being blasted by full power, it is in extremely short pulses and the energy averaging works much better, allowing heat to propagate into the food rather than just heating the surface.
Second, I don’t understand the frequent comments through this thread about recommended oven wattage not being listed for foods.  “Microwave meals” and recipes / heating instructions on almost everything I have dealt with for 20 years have almost invariably finished with “times based on a #### Watt oven” - usually 1000 Watts these days, 15 years ago was more common to see 700 or 800.  I think too many people don’t read the full instruction, and also some use an * to try to get you to look for “fine print” at the bottom.
Third - you cannot actually “steam cook” anything in a microwave.  While it is true that microwave are most effective on water, it is also true that you can’t boil water in a microwave - watery mixtures, (like oatmeal) possibly, but water - no.  It is physics stopping you and you aren’t going to change the laws of physics.  When you put something in a stovetop steamer, it receives all of its heat from the water vapor at approx 210 degrees, and may absorb some of the water as well.  I you try that in the microwave you get far less steam, and A LOT of direct heating of the food from the microwaves themselves.  So if you are trying to make chinese steamed dumplings the centers may still be cold while the outside is hot and wet on top but nearly dry on the bottom facing the dish.
Because the watts per second can be reduced I have found I not only don’t have to set butter out to soften an hour before starting to make cookie dough, I can take it straight from the freezer, thaw and soften it without melting any of it.  And crispy bacon without burning it?  A couple minutes at 8,9, or 10 to “cook” it, them a few minutes at 3 to dry it out - makes it real crisp and you have to overshoot the low power time by several minutes before it becomes unusable for crumbled bacon.