Talk:Induction cooking

Dangers of Metal Rings worn during use
I saw nothing regarding any possible dangers of a chef wearing metal rings while using a stove like this. Im not sure if it is a real danger or if there are precautions but it seems worth a mention. Say someone with a metal ring gets a bit too close to the stove without making contact. Will it get red hot, burn their finger and be extremely painful (and difficult) to remove quickly enough to prevent injury. It seems a red hot ring on your finger can be very dangerous with little way (in a panic) to get it off your finger quickly enough. - Debeo Morium: to be morally bound (Talk | Contribs) 21:07, 23 February 2012 (UTC)
 * Have you read anything (credible) about this happening? Surely in these litiginous times we would have been amply warned to remove all rings, watch bands, belt buckles, Prince Albert piercings and other small metal objects from our persons before approaching the cooktop. Seems vanishingly unlikely; if you can get your hand between the pot and the cooktop, you'd get burnt anyway no matter what jewelry you were wearing. Ferromagnetic rings tend to rust and so don't get used. A small ring isn't going to allow the cooker to start (try it!) and if you got your hand close to a hot frying pan, surely the pan bottom is a bigger threat than any ring. An object has to be rather close to the top to pick up enough field to heat - lift a pan a few inches and the stove cuts off. I've never noticed my non-ferrous wedding ring or austentic SS pinky ring getting warm when I fry eggs, and I like to show off how close I can hold my hand to the pan when cooking (but that's original research and inadmissable). (Do gas stove manuals warn you not to hold your finger in the fire?) --Wtshymanski (talk) 22:09, 23 February 2012 (UTC)
 * No I have not. I am not saying this would happen. What I am after is an explanation as to WHY it isnt dangerous. Common sense tells me it should be, but I suspect there is some reason it isnt dangerous. This should be explained int he article as a point of interest either way. - Debeo Morium: to be morally bound (Talk | Contribs) 01:57, 3 March 2012 (UTC)
 * Does the article not already mention that if a pan is lifted off the surface, or if the metal object is too small, the power cuts off? If not, it should. I imagine a few spoons got melted in the early days before they decided dumping 3 kW into a spoon was not what the consumer intended. --Wtshymanski (talk) 17:18, 3 March 2012 (UTC)
 * All units are designed to require a minimum threshhold mass of ferrous material, and it is not trivial; in fact, one minor but common nag is that induction units will not power up for 4-inch-diameter pans, such as "butter warmers". So neither rings or other personal jewelry, even if placed directly in contact with the surface over an element, will receive power.  (Nor, more realistically, will a utensil, such as a fork or spatula, laid down by inadvertence).Eric Walker (talk) 08:57, 31 January 2013 (UTC)
 * Rings are typically made of gold, silver or perhaps other non-ferrous materials. It would be very rare for anyone to be wearing an iron ring, and even then the arguments above would apply. Non ferrous (iron) materials will not heat up to any noticeable degree.Djp (talk) 10:11, 12 April 2015 (UTC)

Ovens
Under "Drawbacks" it states that "it is not advisable to fit an induction cooker above an oven". That is wrong. Most cooktop makers include express and exact information in their installation manuals about how to install the unit over an oven. The problem, such as it is, is that many makers try to channel the customer into using only an oven of the same make as the cooktop. Others are less restrictive in their advice.

Here is a sample from an installation manual: "Check the cooktop base for an approved installation label. Verify approved oven model numbers that can be installed with your cooktop model number. If you do not find this label, your cooktop may not be approved for use over an undercounter built-in oven. Contact your dealer to confirm that your cooktop is approved. Ovens approved for this type of installation will have an approval label located on the top of the oven. If you do not find this label, contact your dealer to confirm that your oven is approved."

I have modified the text accordingly. Eric Walker (talk) 00:16, 21 January 2010 (UTC)

Limitations
I think that material from deep in the article could usefully be summarised under "Limitations" for readers looking to make a direct comparison.

The section currently says, about cookware: "must have a flat bottom since the magnetic field drops rapidly with distance from the surface. Induction rings are a metal plate that heat up a non-ferrous pot by contact, but these sacrifice much of the power and efficiency of direct use of induction in a compatible cooking vessel."

However, the extent of the limitations are likely to remain unclear to the reader. The bottom section "Induction cooking pans" makes these points: - Ferromagnetic pans which are effective for induction are not good heat conductors. - For frying and making thick sauces a steel plate pressed into an aluminium pan is be preferable. - Not all stainless steel pans are ferromagnetic.

It is these considerations which, for me, significantly swing the weight of argument against purchasing induction hobs, and I guess it will be significant to other readers. These limitations could be explained directly in the "Limitations" section, or else a link could be added ("See 'Induction cooking pans', below")

It's also worth considering whether the section title "Induction cooking pans" could be improved along the lines "Suitable cookware" or "Cookware considerations". Tsuchan (talk) 09:43, 9 May 2011 (UTC)
 * Well, if we keep reorganizing the article so that important stuff is at the top, we'd have everything in the lead. Anyone who's ever picked up a metal pot handle knows that steel conducts heat. From an engineering perspective it would be nice to see a paper that discuses temperature gradients across a cooking vessel against material type, and to set significant criteria of tolerable gradients based on type of food being cooked.  I'd like to see something discussing the distribution of heat generation in an induction-heated pan-seems to me that the eddy current heat would be distributed over the bottom, better than settng a pan on a hot wire.  Probably not a subject for Mythbusters because there's not enough explosions. We should be wary of phrasing things like a buyer's guide; we're not selling pots here, at best we're explaining the physics behind induction cooking so that you can understand the gabble that the salesfolks repeat. You probably meant an aluminum layer inside stainless; the aluminum shields the stainless if its on the outside, as does a copper layer - shiny copper-bottom pans won't work well on induction. Cast iron works well for induction, but my wife won't let me buy a cast fry pan because she's worried about banging the ceramic top. --Wtshymanski (talk) 14:23, 9 May 2011 (UTC)
 * The quoted sentence--Ferromagnetic pans which are effective for induction are not good heat conductors. - For frying and making thick sauces a steel plate pressed into an aluminium pan is be preferable. - Not all stainless steel pans are ferromagnetic.--is misleading; it is true for cast iron, which virtually all cooks know; but stainless-steel cookware is invariably "clad", meaning multi-layered: the bottom layer is ferrous steel (formerly known as "18/0", meaning nickel-free), the inmost layer is stainless probably of 18/8 or 18/10 shiny steel, and the middle layer is of a metal that is a good heat conductor, typically aluminum, sometimes copper. (Some cladware has even more layers.)  Cladware intended for use on induction, which is an ever-larger percentage, combines the virtues of ferrous metal to absorb the induction-field energy and high-heat-conductivity metal to assure fast, even heating.  And yes, the heat is more or less restricted to the vessel bottom, and the handles do not get hot.Eric Walker (talk) 09:04, 31 January 2013 (UTC)
 * (weeks later)On the other hand, my favorite spaghetti-boiler is a very flimsy stainless pot which makes no claims to "cladding" or layers. OR, yes. But "invariably" probably should only apply to cookware that isn't sold as a 12 piece set for $50. --Wtshymanski (talk) 21:42, 1 March 2013 (UTC)

Electrical characteristics
What is the frequency of oscillations? What is the average voltage, current, and resistance of the winding? Is the temperature adjusted by varying the frequency? by varying the voltage? or both? Is it a lot like a switching power supply? Thanks. DG —Preceding unsigned comment added by 24.145.62.13 (talk) 02:54, 9 April 2010 (UTC)


 * Observations of an induction hob user:


 * The table top induction hobs that I own both use switching as part of their power control, particularly at low power settings. The switching cycle time is a few seconds in total; that is, the induction is active for a second or more and then inactive for a second or more, repeated indefinitely.


 * Because the thermal mass of the heated material in an induction cooker system is due to only the base material of the cooking pot, it responds quickly to the applied power, and on my hobs a simmering liquid can be seen to bubble vigorously for a second or so and then to be calm for a second or so. Not ideal for simmering in my opinion. I would prefer that the switching cycle was much shorter, say one second in total, so that a simmer on 10% power would be ON for 0.1s and OFF for 0.9s repeatedly, which would be more readily averaged out to a near constant simmer by the relatively small thermal mass of the pot.


 * The longer switching cycle time that my induction hobs actually use is likely a hangover from the days of radiant rings and solid plate electric hobs where the thermal mass of the heated metal was much larger, and the thermal time constant consequently much longer and compatible with a several second switching cycle time. 79.77.243.243 (talk) 19:21, 14 April 2010 (UTC)


 * As I understand it, there are two modes of operation: one uses a thermostat to measure temperature and cycle the element on and off at maximum power depending on the temperature the thermostat senses. This is much like the way a conventional gas or electric oven works. The other mode applies an adjustable amount of power to the element on a full-time basis. The only temperature regulation is through dissipation to the surrounding environment. This is similar to the way a hot plate or stove burner works, as there is no sensing of the temperature to regulate the heating. — Preceding unsigned comment added by 69.12.176.20 (talk) 20:09, 28 February 2014 (UTC)

Responding to this decades-old section to note that two above to responses are using the word "switching" in different ways, so they are essentially talking past each other. I think that was originally understood, but it's going to be confusing to lay readers of this Talk section (all two of them?) DG/24.145.62.13 asked about frequency of oscillations, and if it were like a switching power supply; those oscillations are typically 20 kHz or higher, or 0.00005 seconds or shorter (that's one twentieth of a millisecond or shorter), not directly observable by humans. But 69.12.176.20 addressed how often the hob switches on or off, for those hobs that appear to maintain a low heat level by heating at full power for a second or two and then supplying no heat for a similar time. (As far as I can determine, the lower end induction hobs exhibit this behavior, but better induction hobs that use an inverter and/or PWM can produce low power levels continuously without visible cycling; good luck finding a reference to support this!) jhawkinson (talk) 18:34, 28 May 2023 (UTC)


 * In a Rangemaster catalogue there is advice for people with cardiac pacemakers or implanted insulin pumps to ensure that these medical devices are not affected by the induction hob which operates over a frequency range of 20kHz to 60kHz. 79.74.235.218 (talk) 16:15, 23 April 2010 (UTC)

Cost
"Small stand-alone induction cookers are relatively inexpensive, priced from around $60 USD."

They may well be in the US. In P. R.China they are about $25. Perhaps this needs removing or specifying. I favour removal as it looks like original research. Candy (talk) 00:54, 21 August 2010 (UTC)

How about the cost of the energy consumed? 76.130.134.87 (talk) 21:45, 9 August 2022 (UTC)

Conversion of magnetic field to electricity in the bottom of the cookware
While reading this very informative article I wondered about the magnetic field and its conversion to electric current in the bottom of the cookware.

Is the magnetic field actually converted into electricity (i.e. is it 'gone' then) or does it induce electricity and then propagate further into the cookware and the surroundings?

Thanks for the clarification. —Preceding unsigned comment added by 84.186.223.15 (talk) 20:24, 21 August 2010 (UTC)


 * "Is the magnetic field actually converted into electricity (i.e. is it 'gone' then)"
 * Yes - Conservation of Energy. The more electricity induced, the less magnetism remains. Not 100% conversion, though. --195.137.93.171 (talk) 11:42, 26 November 2014 (UTC)

It is not only magnetic energy that is producing heat; it is the electromagnetic field that heats both by hysteresis and eddy current. One is contributed by the magnetic field and the other by the electric field. chami 10:42, 26 January 2016 (UTC)

Manufacturers
I have deleted Schott as a manufacturer. Schott AG is a specialist glass manufacturer that makes the ceramic tops for many induction and other hobs. However, they don't manufacture the finished product.

Comments
I wish all that great history of early induction tops had some references. I'm glad I found that IEEE article, it explains the skin depth a little better than what we had before; I used the table data here to show the ratio fo resistance. Hmm, 0.0005 inch household aluminum foil is only 0.022 skin depths in aluminum, so would have 44 times the resistance of one skin depth...I bet aluminum foil heats like a son of a gun on an induction top, which is why they warn you to keep it away from the top. (Must try this - but safely, don't want to wreck the new cooktop!) --Wtshymanski (talk) 22:04, 7 January 2011 (UTC)
 * Yep, heats up just fine - but the moment a steam bubble forms under the foil and lifts it out of water, it melts through. Picture on the way. --Wtshymanski (talk) 02:27, 8 January 2011 (UTC)

Sales statistics needed
Lots of hype on the Web saying things like 'induction sales are up 40% this year' but no visible numbers of units sold. The claims for Japan and the rest of Asia are undocumented. The German wp has a table from 2004 with no sources given. I think a trend line showing units sold from, say, 1972 to last year, by continent, would be of great interest. But I'm too cheap to shell out $4900 for the report that claims to give this sort of information. User:Owlcroft, do you have anything for sales statistics? --Wtshymanski (talk) 20:49, 8 January 2011 (UTC)

Current and voltage needed
I'd like to get a reference for the current and voltage induced in the bottom of a pot. Some back-of-the-envelope calculations for 1 kilowatt, a 6 inch diameter pot, and all the resistance due to one skin depth in mild steel indicates current on the order of 150 amps and implies only a fraction of a volt to drive it, but my methods are crude and I'd like to see an authoritative source;(aside from the problem of WP:OR). I know they are *safe*, they wouldn't be approved for sale otherwise, but it would be illustrate the point if we could say how many amps are circulating in the bottom of the pot. --Wtshymanski (talk) 20:21, 9 January 2011 (UTC)

Confusing article
This article contains way too much jargon which makes non-physicists like me scratch their heads. Yeah, I got this whole mess about eddy currents, permeability, hysteresis, and so forth, but I'm still not entirely sure I really understand what's going on. 89.139.7.56 (talk) 08:10, 19 February 2011 (UTC)
 * It would really help if you explained where the article went off into the weeds for you. Ideally someone reading an article reads as far into it as he needs to for the amount of understanding he requires, and skips the fine details that are of no immediate interest. I thought it was important, for instance, to make the general observation that only magnetic pots and pans work in the lead, then get into the details later on for those who wonder why some stainless steels work and others don't. That's where the physics comes in, and even if someone doesn't think of permeability as being as familiar a property as weight,  it perhaps shows what the physical difference is that makes one work and not the other. You won't get this explanation at the cookware store.  It's difficult to boil down a 10 or 15 page technical article into a couple of paragraphs and still keep the sense of it for non-specialists. More feedback is extremely helpful! We've got thousands of hyphen-fixers and HTML bashers, scores who add content, but not one editor in a hundred says "This is confusing, how do you get from A, B, and C to X,Y and Z, maybe it's obvious to an expert but the rest of us need a hint at the 20 letters in betweeen."  --Wtshymanski (talk) 23:01, 19 February 2011 (UTC)
 * Thanks for caring to clarify. I truly appreciate it. I'll do my best to explain my confusion. First of all, in no way do I want WP articles to be dumbed down. I learn so much thanks to the depth of these articles. Unfortunately, many technical articles (especially in math and biology) are written to a non-general audience. It's as if a biologist is summarizing a subject for other biologists or students of biology, which is great but kinda misses the point of Wikipedia, in my opinion. It's not the depth which is the problem but the jargon. It's great when new concepts which are relied upon are linked, and I'm one of those who follow these links pretty deep, but when you get to the third level and you still don't understand what's going on, or when you hit an overly technical article downstream then you can't understand the article upstream, which is what happened here. What I think is missing is a short explanation in the first paragraph that ties everything together in a simple accessible language. And maybe some expanding sentences following some of the technical terms. That's what people like me who go to buy a stove-top look for - understanding this magical "induction" thingy.
 * What I "understood" from gnawing at the article is that induction cooking happens by having an electric current in a coil generate a rapidly flipping magnetic field which in turn generates an electric current in the pot. I kinda understood it's not a regular current you can get electrocuted by, but I didn't understand why (pot too resistant?). The moving electrons in the pot bump into the metal lattice thereby producing heat. In addition, the rapid magnetization and demagnetization of the pot cause some sort of expansion and contraction (physical?) which also heat the pot, but much less than the bumping electrons. The more magnetic a pot is, the more efficient these processes work. I don't know exactly why. This means that metals that are less magnetic will still get heated, but much more slowly (how much more slowly?). Did I get any of it right? From the mess of this explanation, you can see I didn't quite get it and even if I did get some of it, I don't know which part I got right and which I got wrong. 89.139.7.56 (talk) 12:00, 20 February 2011 (UTC)
 *  By George, he/she's got it! That's an excellent summary of what's going on, at least as far as I understand it. I'm still looking for a reference that shows the magnitude of currents and voltages induced in the pan, but since you're not warned about the voltage, obviously it's small. If you've gotten this much from the article and you're not an electrical engineer, the article is in much better shape than I'd feared.  I will try to rework the opening paragraph to emphasize some of the things that you'd identified as missing. Thanks for the detailed feedback. --Wtshymanski (talk) 14:51, 20 February 2011 (UTC)
 * I'm glad I got the gist of it. However, I was left with plenty of questions (mentioned in the grandparent comment), and it did take a lot of persistence and reading on my part to figure out, so there is definitely room for improvement. Thanks so much for your help, Wtshymanski. 89.139.7.56 (talk) 16:37, 20 February 2011 (UTC)
 * Just getting an article to the point where someone cares enough to give it some criticism is a minor triumph around here. There are hundreds of thousands, perhaps millions, of article which no-one reads and which no-one cares enough about to criticize. I've had another whack at the lead section, it still needs more work. As Snoopy said, "Good writing is hard." --Wtshymanski (talk) 01:50, 22 February 2011 (UTC)
 * Everything2 got it right. Update: They got the eddy current right as well. Short, simple, and clear. 109.186.64.3 (talk) 19:29, 8 March 2011 (UTC)

Sigh. That is pretty good. (But look at what this was like before I had a whack at it!) More simplification of the lead is in order... then we can get into the good stuff. --Wtshymanski (talk) 22:30, 8 March 2011 (UTC)

Eddy current vs Magnetic Hysteresis
I think the Eddy current portion of the heating, as it is mentioned now in the article is wrong. Eddy currents are reduced by increasing resistance of a material (see e.g. transformer design). The main component of heating in ferromagnetic pots and pans is, in fact, magnetic hysteresis losses. I do not have a reference for this, but at least the physics makes sense this way since the manufacturers seem to recommend ferromagnetic materials and they will have _higher_ resistance and consequently _lower_ eddy losses. 128.84.69.132 (talk) 21:11, 10 April 2011 (UTC)
 * You'd be a long time finding a reference for that. The IEEE paper doesn't consider hysteresis to be significant, and if you look at the photos, you'll see an induction cooktop can melt aluminum foil, a metal that has insignificant magnetic hysteresis. The reason that only magnetic pots work is due to the combination of small penetration of magnetic fields into ferromagnetic materials, and the relatively high resistance in that thin penetration depth; in non-magnetic material like aluminum, the current spreads out too deep and so encounters little resistance, unless you have only a thin layer of metal. --Wtshymanski (talk) 02:08, 11 April 2011 (UTC)
 * Your sentence from "The reason that only magnetic pots work" till the end should somehow be incorporated into the fourth paragraph in the introduction. From your comment I think I finally understood why it's important to use a pot with magnetic properties despite the stove-top (and not the pot) creating a magnetic field. There are two interacting magnetic fields in action, right? One is created by the pot and one by the stove-top. This seems important. 93.172.36.181 (talk) 20:44, 2 May 2011 (UTC)
 * I think the valid point in the IEEE paper is that higher voltages will be induced in a magnetic material because of higher permeability. This can be understood because the circuit will now have higher mutual inductance. I agree with this part. I think the other part about higher resistance of a magnetic material being better is incorrect because higher resistance _reduces_ heat loss in a material for a fixed voltage compared to a lower resistance. This effect is what is used in transformer design to _reduce_ eddy currents by increasing the resistance of the core. I think the article should correct this inaccuracy.

128.84.69.132 (talk) 05:42, 11 April 2011 (UTC)
 * No. Fixed voltage is an un-necessary assumption. Think of the system like a current transformer - the more resistance a constant current has to ovecome, the more work it does. It would be as valid to think of the bottom of the pot as a single-turn secondary winding, with some equivalent resistance in circuit. A thick aluminum pot will not even be sensed by the cooktop as a valid load, whereas thin foil, with a high resistance (high areal resistance, specifically) heats just fine, though is liable to melt owing to its thin section. Nothing to do with hysteresis in any case. --Wtshymanski (talk) 13:36, 11 April 2011 (UTC)
 * I am not sure if fixed voltage is an unnecessary assumption. From Maxwell's equations, for a varying magnetic field, you induce an electric field and hence a voltage in the secondary loop. It is not a constant current flowing - it is a constant voltage. So, for increased resistance, one will dissipate less power. —Preceding unsigned comment added by 128.84.68.146 (talk) 20:57, 19 April 2011 (UTC)

Can I support the fixed voltage assumption. I'm not sure what people mean by a current transformer here. The driver coil is generating a varying magnetic field, which must induce an emf in the secondary coil - the pan base. What, if any, current is generated must depend on the conductivity of the pan. We do not have the conditions for a current transformer (100% flux linkage and negligible resistance in the secondary circuit, I think.)

This question is very germane to the operation of this device and to the qualities required of the pan. If we have effectively a high leakage voltage transformer, then I think we are looking at (V^2)/R heating. If it were a constant current source then you would have (I^2)R heating. These lead to opposite conclusions about the conductivity of the pans (but not necessarily about the material of the pan!) If it is a voltage transformer, then improving the flux linkage (by having a ferromagnetic material) increases the induced emf and hence the (V^2)/R heating. It is still desirable to have a low resistance material, but because of V^2, doubling the flux balances quadruple the resistance. If the geometry is suitable, a steel base which reduced the magnetic path length by say 70%, could have about 9x the resistance of a non-ferromagnetic material like Cu and still produce greater heating.

I mention geometry and path length because the flux does not increase proportionally with the permeability of the pan. Flux is limited essentially by the air path length through which it passes. Cu and Al have marginally lower permeability than air, but this is insignificant and they can be treated as air. Ferromagnetic materials have very much higher permeability than air: as long as there is significant air in the path, the ferromagnetic part can be ignored - a magnetic short circuit. Obviously there is not a simple one dimensional magnetic path and one would have to integrate over the relevant space to get the flux, but one can think about an average path. This would go from one pole of the coil's core through air, ceramic. air, pan, air, pan, air, ceramic and back to the other pole.

For Eg. If with no pan that distance were say 10cm, then if the pan were ferromagnetic and most of the flux passed across through the base of the pan, then that effective path might be reduced to only a cm or so. This could increase the flux by as much as 10x and thus the emf 10x compared to a Cu pan which did nothing to improve the magnetic circuit. The ferromagnetic pan base could have a resistance up to 100x that of a Cu pan and still generate as much (V^2)/R heating as well as some hysteresis heating.

I am not in a position to do any accurate calculations of this, not knowing the geometry of a cooker nor the specific properties of "iron" pans. Nor have I seen the IEEE article ref17 to see what they say about this. Merlin3189 (talk) 16:23, 6 February 2015 (UTC)Don Brown
 * It's probably too simplistic to say "constant voltage" or "constant current". Recall that foil melts, but a thick aluminum pot doesn't even register - more resistance, more heat. You've got to use all of Maxwell's equations and don't forget Lenz' Law - that changing field induces a voltage,which causes a current to flow that tends to oppose that field. There's only one magnetic field but it's the resultant of two currents, one in the stove coil, one in the pot.--Wtshymanski (talk) 21:36, 2 May 2011 (UTC)
 * A thicker Al foil doesn't "register" because it has higher mass and as a consequence, higher heat capacity. I understand there's only one magnetic field. This is a simple transformer problem. I think someone else with a working knowledge of transformers needs to weigh in. — Preceding unsigned comment added by 128.84.69.5 (talk) 05:15, 1 June 2011 (UTC)

Archived old discussions
See the archived talk page for previous discussions on hob vs. cooker vs. cooktop, hysteresis, cookware, and other items. These discussions haven't been active for a while. New additions should go on this talk page, not in the archived page. --Wtshymanski (talk) 02:58, 11 April 2011 (UTC)

Benefits
"'The time to boil a certain amount of water is inversely proportional to the power; a 3,600-watt induction element is three times as fast as a 1,200-watt element. The actual time depends upon the amount of water but it is typically a few minutes. Heating is much faster without water, e.g., for stir frying — a thin pan containing three tablespoons of oil may heat up to stir-fry temperature in as little as ten seconds.'" What is the value of this paragraph? There is little information and much of it is irrelevant. The very subjective words "thin", "three tablespoons", "stir-fry temperature" and "as little as ten seconds" found in the same sentence make the statement particularly imprecise and informal. I recommend this paragraph be deleted. -Furthermost (talk) 06:08, 9 September 2011 (UTC)
 * I think this paragraph used to say something meanignful, but it's been up on the garage roof all summer and the color and meaning got leached out of it. I've replaced it with something that at least I think is more meaningful. --Wtshymanski (talk) 13:26, 9 September 2011 (UTC)

Strange move
This article is about a class of objects, not about an activity. Put it back to "induction cooker". --Wtshymanski (talk) 14:19, 13 December 2011 (UTC)
 * Hi WTS, moving the talk to here was of course the right thing to do.  I'm not keen on the term cooker because it is too vague and confused between British and American English, in fact I just made it a disambiguation page.  I note that you might also have issue with pressure cooker which redirects to pressure cooking.  While cooktops are the most common appliance using induction, with a look at amazon I found that there are rice cookers with an induction heating system, so it may make sense to have an induction cooking article cover all the appliances which use induction, rather than a separate article for each appliance.  I'm not sure there are actually any inductive ovens available on the market (I haven't found any), but it seems induction cooktop ranges are often combined with convection ovens, which seems to be yet another cooking technology. Wbm1058 (talk) 19:55, 14 December 2011 (UTC)
 * Upon further review, I support moving this article to [Induction cooktop], with the lead sentence rewritten to something resembling the old version: An induction cooktop is a type of stovetop upon which pots and pans are heated by induction heating. Induction cooking could redirect to induction heating, which is where the activity is discussed.  The activity/technology discussion in induction heating should include links to each appliance using this technology, including induction cooktop, rice cooker and any others there might be.  The rice cooker article already covers induction in the Rice cooker section. Wbm1058 (talk) 21:11, 14 December 2011 (UTC) Wbm1058 (talk) 21:23, 14 December 2011 (UTC)

Rationale from soon-to-be-cleared-user-talk-page-because-why-talk-about-an-article-on-its talk-page-when-you-can-have-secret-conversations-elesewhere
Really. Using a verb phrase for the first sentence is weird when the subject is a noun. It'd be fine if the subject were induction cooking, though: what do you think of a page move? Chris Cunningham (user:thumperward) (talk) 10:07, 8 December 2011 (UTC)
 * Your precision in the use of English vastly exceeds mine. I think it's fine.It doesn't need moving.  If I have to look up in some style guide why not to use a "verb phrase" for a sentence, then I think it's a grammatical point more obscure than roughly 1,000,000 other grammatical errors in the Wikipedia.  What's weird about it?  It's a perfectly grammatical sentence..."A uses to do ." And they aren't *always* tabletop devices, darn it. Mine isn't, it's built into the counter, and my brother has one as part of his stove.  --Wtshymanski (talk) 14:10, 8 December 2011 (UTC)
 * Repetition of the obvious is an un-lovely feature of Wikiprose. If the reader doesn't know or can't figure out what a "cooker" is, then gabbling about "stoves" isn't going to help him/her/it; for all we know, the last time the reader read about "stoves" was in the context of blast furnace heat exchangers. --Wtshymanski (talk) 14:13, 8 December 2011 (UTC)


 * As far as I'm concerned, the article title should be treated as a proper noun in most cases and any inherent definition contained within should be ignored. This is the only way to ensure that articles satisfy the general guidelines on both context (linking to the most dominant root subject for an article as early as possible) and style (not blue-linking the title). As for the matter of starting articles with verb phrases, once upon a time WP:LEAD explicitly stated that articles should use the "to be" form: while that has weakened, the page is still set up to use that form as the canonical setup for the first sentence, and a little redundancy (really only a very little) is worth the additional clarity of context that it presents. As for the "blast furnace" comment, I fail to see how you clarify this by removing the phrase "is a cooking stove" from the sentence. Chris Cunningham (user:thumperward) (talk) 15:29, 8 December 2011 (UTC)
 * If the reader hasn't progressed far enough in learning English to know what a "cooker" is, then redundant talk of "stoves" is not going to help. I once owned a pocket dictinoary that defined "quartz" as "pure silex" and "silex" as "pure quartz" - not useful to anyone. We're not teaching English here and a long recitation of synonyms is a misfeature.
 * And what's wrong with an operational definition?
 * Can we at least keep "tabletop" out of the "definition" ? --Wtshymanski (talk) 15:35, 8 December 2011 (UTC)
 * "Cooker" may not be the best term for the title of the article. From kitchen stove, "A kitchen stove, cooking stove, cookstove, or cooker is a kitchen appliance designed for the purpose of cooking food. Kitchen stoves rely on the application of direct heat for the cooking process and may also contain an oven, used for baking."  From this definition, cooker is broad term which includes both the cooktop (or "tabletop", is that British English, it's not a term used in America) and oven.  Which implies that both the cooktop and the oven can use induction.  Indeed, inductive oven redirects to "induction cooker".  But in the article there is no specific mention of induction being used to heat ovens—just the statement "Sears Kenmore sold a free-standing oven/stove with four induction-cooking surfaces in the mid-1980s. The unit also featured a self-cleaning oven..." and a see also for microwave ovens.  If induction is not used to heat ovens, that should be made clear, though "tabletop" is an odd term to communicate that.  Perhaps better is to change the article title from Induction cooker to Induction cooktop (American) or Induction hob (British), with the term not chosen redirecting to the term chosen.  I think there should be a link-back to the mother article kitchen stove in the lead.  This is no different than linking back to transistor in the lead of diffusion transistor, for example.  And update the kitchen stove article, "Kitchen stoves rely on the application of direct heat or induction for the cooking process" Wbm1058 (talk) 20:48, 8 December 2011 (UTC)
 * Are we writing for human beings, or programming an AI? If you have to tell the reader that a stove gets hot...does he really understand English? --Wtshymanski (talk) 20:51, 8 December 2011 (UTC)
 * OK, I admit I think like a programmer, but...


 * "An induction cooker or induction stove uses induction heating to directly heat the cooking vessel," Mmm, is the cooker cooking iron to make steel, and is the cooking vessel a giant vat of molten metal?

Manual_of_Style_(lead_section)
 * The electron is a subatomic particle that carries a negative electric charge.

...should be simplified to: The electron carries a negative electric charge. —because everyone knows what an electron is... an electron is a subatomic particle and a subatomic particle is an electron?


 * It's not so much that the reader doesn't know what a stove is, but rather, presumably they have come here specifically because they want to learn more about stoves, and maybe they'll find something helpful in the mother article that's not covered in the child. This is different than, say linking to Canada because a semiconductor process was patented there, because the reader doesn't want to learn about Canada, they just want more on semiconductors— unless the link is to a specific small town in Canada which is not widely known. Wbm1058 (talk) 21:49, 8 December 2011 (UTC)

Hi again, Wtshymanski. I just noticed you wrote "polishing the cannonball" for the edit summary on your above response to me. I honestly did not know what that meant (is this guy getting ready to shoot me??) so I looked it up and found the meaning on some urban dictionary site. Point taken, I don't want to waste much more time on this either. I only got myself distracted into this when I noticed this section below the one above which is the discussion I started. So I'll leave it to you and Thumperward to edit this article. I just want to leave you both this observation though. Last year I bought myself one of these new glass-ceramic cooktops (GE freestanding range J B620S R1SS) and had no idea that it used some newfangled heating technology like induction, I just assumed that it used the same old-fashioned coils but now instead of being exposed so the pot sits directly on it, they're buried under glass, primarily for the purpose of making accidental spills easier to clean up. Frankly, until today I had never heard of "induction" heating cooktops. The only operational difference I observed in my new cooktop is that the burners cycle on and off rather than staying on constantly while cooking. So I see this article and it dawns on me that I have a radically different technology in my kitchen—the picture of the glass cooktop looks similar to mine, and nothing in the article tells me that "all glass cooktops are not alike", so I assume that's what I must have... hmmm it says that certain types of cooking vessels won't work on these, gee I never knew that, I'm getting ready to run an experiment to see if I can heat water in a glass, but worried I might crack the glass, when, almost as an afterthought, I click on glass-ceramic only to find buried in that article the little tidbit that there are actually TWO kinds of glass-ceramics, and surprise surprise, my owners manual says I have the "radiant cooktop" type (no mention of the word "induction" in my owners manual that I noticed). Does that mean I really have old-fashioned coils under the glass ceramic? I'm guessing that, but I really don't know for sure. So why can't this page at least have a disambiguation at the top, like "not to be confused with radiant cooktops", with a link to the article where radiant cooktops are discussed. Thanks for your patience with me :) Wbm1058 (talk) 05:14, 9 December 2011 (UTC)
 * Too long, didn't read. --Wtshymanski (talk) 14:09, 9 December 2011 (UTC)
 * Actually, Wbm1058, I thought both your points and the examples used were extremely well-put. And if, as you say, induction ovens working on the same principle are also notable subjects then that would seem to strengthen a call to move this to induction cooking. (It's one of Wikipedia's oddities that we invariably have articles on individual gadgets rather than the processes behind them.) Chris Cunningham (user:thumperward) (talk) 09:59, 9 December 2011 (UTC)

Efficiency
If an induction cooktop is 84% efficient and a smooth top is 74% efficient, how much less energy does the induction top use? 12%, not 10%. To put 100 units of heat in the pot, an induction top will consume 100/.84 = 119 units of energy from the line. A smooth top will take 100/.74 = 135. (135-119)/135 = 12%. It's the ratio of efficiencies, not the difference of efficiencies. --Wtshymanski (talk) 03:43, 4 January 2012 (UTC)
 * Fixed, Use the conventional smooth top as the base and discuss energy saved by switching to induction top, not the other way around. Math is hard. --Wtshymanski (talk) 03:58, 4 January 2012 (UTC)

Efficiency after reaching boiling temperature
Sentence: "once that this has occurred all the subsequent energy input is delivered to the air as loss" is inaccurate. Part of the energy is used to change the chemistry of food (breakage of bonds, unfold proteins), as generally the food preparation is endothermic. For example calorimetry is used in food industry to assess the progress of temperature-induced changes, (see book: Calorimetry in Food Processing: Analysis and Design of Food Systems, Editor Gönül Kaletunç). — Preceding unsigned comment added by 145.94.216.112 (talk) 15:25, 24 November 2016 (UTC)

'Hob' is not used in American English
So from reading the rest of this talk page, I can make the inference that a hob is a British English word for the burner or cooktop? This is something which I have never heard used, nor can find reference to, in American English. I recommend that all the references to 'hob' in this article be replaced with a synonym which is widely recognized in both British and American Englishes, as recommended by the Manual of Style's Opportunities for Commonality section (see http://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style#Opportunities_for_commonality). I don't like 'burner' for this because with the induction heating, nothing is actually being burned. How does 'cooktop' work for the British English speakers? Tom (talk) 04:37, 24 January 2012 (UTC)
 * "Cooktop" doesn't even slightly work in British English. We'd probably work out what burner meant, but it's also not ever used in British English. "Cooker" and "Hob" are the only words used in British English, along with "hotplate" which is specific to certain types of (usually portable, single-pan) electric hob. In this case, it appears that there's no common word. Generally speaking, the Wiki etiquette is to leave the original article as written, and add (American English: Burner) or similar, with a redirect from that page where needed Audigex (talk) 17:19, 6 April 2018 (UTC)
 * Well...my local 10-pound Merriam-Webster dictionary at least gives "hob" as a projection into a fireplace used to keep things warm. It doesn't give "cooktop" at all. --Wtshymanski (talk) 15:14, 24 January 2012 (UTC)
 * Still, the use of the word 'hob' will cause confusion for American readers, and replacing it with a word recognized and used in both British and American English would be beneficial for all readers. Merriam-Webster does define 'cooktop' now.  The replacement need not be 'cooktop' though, just something other than 'hob'; are there any other suggestions for words which could work? Tom (talk) 02:44, 26 January 2012 (UTC)
 * So what do the sources call them? Hit the catalog Web sites and let's see what the kitchen renovators are recommending to their clients. --Wtshymanski (talk) 14:48, 26 January 2012 (UTC)
 * Hob is a common word in English to describe the cooking device on which pans are heated (the other part is the 'oven' which often has a grill in it as well). In fact, a more used word does not leap to mind.  (See  for an example of use).  Wikipedia has many articles written in English and it is recognised that some words may not be recognised by non English speakers (e.g. Americans). 86.166.70.84 (talk) 08:48, 22 September 2012 (UTC)

Copyvio
Everyone who's contributed to this article can now say they've been published in the International Journal of Management and Business Studies, Hyderabad. Sadly, this article is a little shy abuot revealing its roots on Wikipedia and other Web sites. --Wtshymanski (talk) 19:47, 21 September 2012 (UTC)
 * Any organisation plagiarising Wikipedia is taking a big risk given the low level of accuracy that it is famed for. More so if you have had any input to an article. 86.166.70.84 (talk) 08:51, 22 September 2012 (UTC)

Number of manufacturers of all-metal induction hobs
It is just possible that there is only one manufacturer of all metal induction hobs. But a possiblity is insufficient evidence to place the claim in an article. Also the lack of immediate evidence of other manufacturers is not sufficient to make the claim either (you can't easily cite a negative unless it's a proof). The phrase, "At least one high-frequency cooker is a available, that works with lower efficiency on non-ferrous cookware." adequately covers the current position (whatever it is) in that it does not specify how many manufacturers there are or even how many models.

Wtshymanski, why are you so insistent that there must only be one manufacturer? I can only conclude that it is the result of the long time it took you to conceed that the technology existed at all [1]. If you wish to revert the claim that there is only one manufacturer, then provide a cite otherwise the claim will be reverted as uncited (WP:VERIFY and WP:BURDEN). No one else has to provide a cite that there is more than one manufacturer in order to revert because no one has made that claim.

[1] If any one is interested see the discussion at Talk:Electric stove and see just how long the discussion is primarily because of Wtshymanski's complete refusal to accept that the technology existed at all despite several claims to the contrary. DieSwartzPunkt (talk) 17:30, 26 September 2012 (UTC)
 * We don't have any references for anyone but Panasonic. We barely have anything citable that asserts the darn thing exists at all. If you live outside Japan and have an induction cooktop, almost certainly it's not the "all metal" top. The article shouldn't give undue weight to this product. --Wtshymanski (talk) 17:49, 26 September 2012 (UTC)
 * Your indenting corrected - again.
 *  How many more times? Lack of evidence of other manufacturers is not evidence that Panasonic are the sole manufacturer.  And as you are well aware we have a perfectly good citation at Electric stove that these things exist at least in Europe.  That citation has been vefified by another editor so we know it is a good cite.  It is also highly unlikely that any company would set up a product line to sell only the two that have been discussed at Talk:Electric stove.  There must be thousands (at least) more.  DieSwartzPunkt (talk) 10:59, 27 September 2012 (UTC)

Comments by Spitzikitty
Contributors please rate new induction cookware if you've been lucky enough to compare models. New types are 5-ply (induction friendly), and ceramic-coated (none induction friendly yet). Please list:

Make, Model #, Descriptor, Year, Set, Material, If Cladding: # ply's, list Ply Material, cladding up side or bottom only, if only some of ply's go up side, list which materials do, Coatings, (non-stick coatings have flaked off into food in the past, so if it is a new non-stick coating list type and advertised benefit). Ease of cleaning cookware with what product (i.e. Bar Keeper's Friend)? Comparison to other type of induction cookware used in the past? Optionally, cost, where bought and which sale if applicable? 19:52, 7 July 2013 (UTC)

Clarity needed
Can someone perhaps revamp this statement so that it makes sense?


 * . . . so the DOE efficiency value will be used. This applies to the energy used at the premises; when comparing with gas, the relative cost of electrical and gas energy, and the efficiency of the process by which electricity is generated, affect both overall environmental efficiency.

Rammer (talk) 04:54, 6 January 2015 (UTC)
 * That was murky, how is it now? What would be really nice would be a referenced clear discussion of grams of carbon emitted per megajoule absorbed by food for the different cases of heating method and energy source (coil stove-coal fired generation, induction-coal, induction-hydro, nuclear, or solar,  grid gas, on-site biomethane); the interested reader could probably calculate it from what's already in the article, but it's not our place to do this calculation. --Wtshymanski (talk) 15:02, 6 January 2015 (UTC)

one less mistake/lie in the article
i removed half a sentence, because it seemed to be a lie/mistake. it was sg like: "...this allows temperature control and prevents overheating in case of the pot boiling dry...". (sorry for the lousy citation, but my wife keeps talking to me while i am writing and i cant concentrate on two things simultaneously.) so it seems to me that having excellent temperature control does not provide in itself a way to detect when the pot became empty because all water boiled away. if there is such mechanism able to detect whether the pot contains liquid, please feel free to revert my edit but, please insert some explanation concerning how the induction cooker prevents a pot being overheated after it has boiled dry.(80.98.212.141 (talk) 20:49, 15 May 2015 (UTC))

i added in section: Benefits, to this: "Induction cookers are easy to clean because the cooking surface is flat and smooth and does not get hot enough to make spilled food burn and stick" this small remark: "except where the cooking surface is in direct contact with the pot." because without this addition the sentence was actually a false statement. i am aware, though, that this way the sentence became longer and might feel awkward. so please feel free to tackle with it and make it better.(80.98.212.141 (talk) 20:56, 15 May 2015 (UTC)).

also it is mentioned in many descriptions about induction cooktops that they can be turned on and off at once (like gas cooktops) and they dont stay hot for another couple of minutes after being turned off. this is called "control of heating" - yet many cookwares used today have a thick bottom that will keep the heat even after turning off the cooktop, therefore this "excellent heat control" and "stop heating at once" might not be true, depending on the type of pot/cookware used.(80.98.212.141 (talk) 16:49, 24 May 2015 (UTC)).


 * The issue with the pan overheating is making the pan go red hot damaging the hob itself, not burning the food. If you let it boil dry it will almost certainly burn the food.GliderMaven (talk) 14:20, 6 July 2015 (UTC)

Are there any Health risks in consuming food cooked in induction cook-top?
When I was reading about health hazards of induction cook-tops, many websites were talking only about the possible risks of cooking on a induction cook-top but none of these websites were talking about possible risks in consuming food cooked in induction cook-top. Is it 100% safe to consume food prepared using an induction cook-top. Has any research been done on the possible health issues associated with consuming food prepared using induction cook-top. Some research in this angle would be of much help as it may throw some light on health issues, if any. — Preceding unsigned comment added by Sridhar2073 (talk • contribs) 11:39, 6 July 2015 (UTC)


 * I doubt there's been any studies. The magnetic fields don't penetrate the pan into the food to any significant degree, the pan acts as a virtually perfect shield, so there's ridiculously little chance of any health risks that would be distinct from those of normal cooking. In addition, normal organic matter is extremely transparent to magnetic fields, so even the utterly minuscule amounts of magnetic field that do penetrate the pan wouldn't do anything.


 * There's significant risks of many normal cooking processes though, frying in particular creates significant quantities of poisonous chemicals, frying on an induction hob will carry the same risks.GliderMaven (talk) 14:16, 6 July 2015 (UTC)

Clarifying Language
This section is confusing. Can someone who understands what the writer is trying to say, edit it so that it actually communicates clearly the intent?

Energy efficiency is the ratio between energy delivered to the food (and pan) and that consumed by the cooker, considered from the "customer side" of the energy meter. Cooking with gas has an energy efficiency of about 40% at the customer's meter and can be raised only by using very special pots,.[7] When comparing with gas, the relative cost of electrical and gas energy, and the efficiency of the process by which electricity is generated, affect both overall environmental efficiency[8] and cost to the user.

Sarafinadh (talk) 23:31, 4 October 2015 (UTC)

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Characterizing the frequency as high or low
A recent |recent edit changed "high frequency alternating current" to "low radio frequency," when referring to 24 kHz.

It seems to me that, in the context of "alternating current," the baseline comparison is 60 Hz, so 24 kHz is certainly "high-frequency." But, for sure, in the context of radiofrequency energy, 24 kHz is quite low, and is certainly well under the 3 MHz bound for high frequency.

The article's lead section makes reference to "low radio frequency alternating electric current." At first, I intended to revert 's edit, but it seemed too dissonant to have one part of the article saying it was low radiofrequency and another saying it was high frequency alternating current. Of course, both are true.

I'm not sure how we should fix this (or if it really even needs fixing? Perhaps it is not necessary to make a value judgment as to whether it is low or high. Or perhaps it is fine to pick one and use that. Or perhaps there is not meaningful confusion and both can be used?). Thoughts? jhawkinson (talk) 07:31, 18 August 2023 (UTC)