Stupid Induction cooking TECHNICAL question

Probably so few folks listen to AM anymore that this may never have been reported.

Probably just electromagnetic noise on those frequencies.

 

Some cookers have an FCC license and the instruction manual should warn about the possible interference.

Some induction cookers generate radio frequencies, for example 400k cycles. AM radio is 540k -1600K cycles.

Those cookers act like a radio transmitter running at 400k cycles; and the harmonics at 800k, 1200k, and 1600k can be "heard" by a nearby AM radio.

Here is LG's note: " . . . This unit generates, uses and can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio communications. "

 

Induction cooker can be viewed as a very poorly designed radio transmitter. Radiating at about 1/40 the frequency of AM radio, but not tuned to a narrow frequency.

AM receiver makes 'noise' based on how much signal strength varies in the frequency (range) it is listening to. With an induction cooker nearby, this is a lot.

FM receiver makes 'noise' based on how much the strong signal in its frequency (range) varies in frequency. Not getting bigger or smaller; moving around. That, and the fact that it listens at about 100 times higher frequency than AM, cause the difference.

Sadly the question was posed not concerning how a crappy radio transmitter heats some cooking pans and not others. That is more fun. Even more fun are Maxwell's equations and how they came to be, So if you are as curious as claimed...

 

AM broadcasting - Wikipedia, the free encyclopedia might do it

 

Since we're linking Wikipedia articles, here's another:

Electromagnetic interference - Wikipedia, the free encyclopedia

Which states that AM radio is more susceptible to interference from EMI than FM radio. The EMI generated from your induction cooktop.

 

Wow ... that's not a stupid question. It might be a great example of the kind of question that's just hard to give a good lay answer to, though.

Probably as good as it gets at the shallow end is to say something like "when you send a signal over an electromagnetic wave, you can use the signal to modulate the wave's amplitude (AM), or to modulate the wave's frequency (FM) ... those aren't the only two choices, but they're the common ones. At the other end, the receiver will be picking up the wave you sent, mixed in with all the other waves coming from induction cookers, hair dryers, other radio stations, fluorescent lights, etc., and the receiver has an easier time picking your original signal back out of that mess if you sent it by modulating the frequency, than by modulating the amplitude."

But even an answer like that probably only makes you say one of two things:

• Ok, Chap's just snowing me with a bunch of jargon here, and he might as well just have waved his hands and said "it's magic, deal with it."
• Hmm, I guess I remember what amplitude and frequency meant for waves, and I wonder what it means to 'modulate' one or the other, and assuming I find a good explanation of that, then what's the explanation why modulating one makes it easier to extract the original signal than modulating the other??

... and if you take my answer the first way, I really haven't answered anything, and if you take it the second way, then in no time you'll be in places like this and this.

I'm not sure there's really any good middle ground. This link seems like it's trying to say something while staying less technical, but I'm not sure it works. At some point, there's still the question "ok, what did any of that actually mean?" and the answer either looks like math, or is just more handwaving.

So it ends up pretty much with a comment I still enjoy, written in my college electronics lab notebook by Prof. Thomas, after a question I had left in my lab report:

Sadly, I was taking Electronics my senior year, and never did have the chance to take Waves from him. (Edit: wouldn't have been from him anyway ... Prof. Casper was teaching Waves then.)

-Chap

 

Not the first time I've failed to interest civilians in wonders of Maxwell's equations. Too bad - he clearly merits membership in the big three (+Newton +Einstein) and arguably the nicest human among them. Newton being contrary example

Many (lower bod) ligament injuries heal way to slow because victims cannot be dissuaded from hobbling about and doing further damage. This is your most poorly vascularized tissue, thus slow to heal. Sadly, females seem less likely to use canes or crutches. Vanity I suppose. Don't be that girl.

 

Stay off the damn thing. You are balancing "I'm so sporty" validation now against 'good enough' mobility in later years. Young people are famous for making such choices poorly.

 

+1

When I was in Submarines, we were mostly 3-milers.
The Navy made us run 1.5 miles for our Performance Readiness Test....or PRT, every 6 months.......when we didn't gun-deck the paperwork.
The longest ship in the Navy is less than 1/4 mile in length, and the dirt sailors are taught how to shoot fairly well, so running is a pointless endevor, IMHO.
We literally had one sailor that was trying to stay in with a BMI deep into the 30's, a real 'hatch plug."
The standards were so lax back then (when we adhered to them) that we had one Chief actually fast-walk the "run" portion of the PRT while smoking an unfiltered Camel...........and get a passing score.
Those were the days!!!!

Then?
A bunch of diet and exercise nerds took over my beloved Navy AND I had the misfortune or fortune---depending on the year, of becoming a reservist.
GOD's sense of humor at work.
Since there is no such thing as a reserve submariner, I had to trade in my tactical sneakers for combat boots and my poopie suits for some nice, earth-toned wardrobe........and I had to %^#$@#$@! run.
3 miles.
In one day......
Every %^%$^@@@ day I was on duty.

Needless to say, as I advanced in years, some of my joints started grumbling and complaining as loudly as I did on my morning runs.

Unless you're being chased?
Running isn't a good mode of transportation. The only thing worse are the gym rats that blow out their shoulders at 30 years by trying to lift outside their depth band.

Lay off the endorphins for a while...

Good Luck!