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Microwave oven PWM frequency

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ogden:

--- Quote from: Zero999 on August 15, 2019, 09:53:29 pm ---I often eat things which are quicker to cook than that, such as fried eggs or some fish I already have cooked and just needs reheating.

--- End quote ---

Fish which is already cooked, can be cooked quicker than that. Good one  8)


--- Quote ---I have steamed vegetables before and although I agree it's better, than microwaving, I don't think the difference is great enough to warrant the extra time and cleaning of kitchen utensils, for a single portion.

--- End quote ---

Agreed :) Cooking/eating is not "discrete" if I can say so. As long as your microwaved, steamed or caramelized in pan vegetables are what you like - enjoy! :)

Ilima:
Actually, pulse width modulation.... is 100% on, then completely, 0% off, then on, then off, and repeat.

The trick is, they just turn on and off much faster than relays can manage by using more advanced switches (usually semiconductors).

So, no. PWM controlled microwaves do not output 495 watts for 100% of the time. Rather, over the course of, say, one second, they switch on and off rapidly enough that the sum energy output for that second is 495 Joules.

David Hess:

--- Quote from: Psi on August 12, 2019, 03:43:14 am ---Microwaves that control the power level by ~0.25 HZ pwm are pretty annoying.
I would recommend replacing it with an inverter microwave.
--- End quote ---

But they work pretty well and without the added complexity of an inverter, they are more reliable.


--- Quote from: John Heath on February 13, 2018, 09:31:28 am ---I can see there are more than a few who are not buying the microwave oven problem in the 802 IEEE standards for WIFI , XBEE and  blue tooth. I can understand why as you would think they would be smart enough to separate 1000 watt microwave oven frequency from .1 watt communication frequencies. Sadly they did not separate them. Even Sadder if it is your phone that rings when computer communications are down.
--- End quote ---

I have never had a microwave which did *not* completely trash 2.4 GHz WiFi.  But the frequency selection for WiFi was no accident.  The ISM bands were available *because* industrial and commercial devices like microwave ovens render them useless for reliable communications.  If microwave ovens were not polluting the 2.4 GHz band, then the 2.4 GHz band would not have been available for WiFi and general use.

tooki:

--- Quote from: David Hess on June 23, 2020, 01:06:29 pm ---
--- Quote from: Psi on August 12, 2019, 03:43:14 am ---Microwaves that control the power level by ~0.25 HZ pwm are pretty annoying.
I would recommend replacing it with an inverter microwave.
--- End quote ---

But they work pretty well and without the added complexity of an inverter, they are more reliable.

--- End quote ---
The primary manufacturer of inverter microwaves is Panasonic, whose microwave ovens have a great reputation, and AFAIK no issues whatsoever with longevity. (They’re all I’ve used for 20 years, and I’ve never had one die. I’ve only gotten new ones because of moving to a country with different mains voltage, or to upgrade to one with new features.)

coppice:

--- Quote from: tooki on June 23, 2020, 03:52:05 pm ---The primary manufacturer of inverter microwaves is Panasonic, whose microwave ovens have a great reputation, and AFAIK no issues whatsoever with longevity. (They’re all I’ve used for 20 years, and I’ve never had one die. I’ve only gotten new ones because of moving to a country with different mains voltage, or to upgrade to one with new features.)

--- End quote ---
When I bought a Panasonic microwave oven 20 years ago they were not inverter types and they did last well. The early inverter ones had a poor reputation for reliability and longevity. I don't know if that has improved.

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