20 Amp dimmer control?

We are dealing, here, with a basic scientific conservation principle:

He is AlwaysWrong.

This is your flawed logic. The curve of time plot to bring the water to boil goes up practically exponentially, plotted against the power required to get it there. You are obviously still in the dark.

As John said, AlwaysWrong.

There is a reason why bi-0metallic duty cycle oriented switching is used.

It isn't cost.

Gas IS continuously variable, and there is no efficiency hit. ALL of the heat produced gets coupled to the pot.

Electric resistive element stoves can easily be manufactured as continuously variable, but aren't, because of the already extremely poor coupling efficiency to the pot. The part that counts. The proof is in the microwave oven water boil time plot.

Electric inductive coupled stoves ARE continuously variable BECAUSE we are back at 100% coupling efficiency.

You are wrong for calling me wrong. The right way to 'fire' these types of heating coils is absolutely full on and using DUTY CYCLE as the controlling means. THAT water boils as quick as it ever will, and ALSO at lower settings along the way down the control dial.

The continuously variable control will NOT perform that way in the case of the resistive element heating coil.

The coil will perform exactly according to the math,but the coupling to the pot will not perform as you (obviously) expect.

those cooking element controllers typically switch at a rate slower than 1Hz, not sure why.

pot + 555 + solid-state relay

I seen some with a springloaded sensor that contacts the bottom of the pot to allow setting temperature instead of power level.

the time constant is several times longer than the switching rate. when measured they approximate a mean temperature, especially as thet are poorly coupled to the pot.

it would be if the surface temp swung wildly, it doesnt.

you loose 1V in the triac, the rest goes into the hotplate. better than 99% efficient.

Nichrome has a very low thermal coesfficient, it won't be much different. There's no harm in measuring the cold resistance to be sure.

You are, of course, wrong.

They say two wrongs don't make a right, but I see there is three wrongs here and if we were to be working on the Odd/even system, I guess you're right! ;)

Jamie

Bad idea. The interference will be huge.

You are so wrong as to be laughable. Hold your hand over a teakettle. Can you feel heat? If so, ALL of the heat is not coupled to the pot.

You idiot. Always wrong as always.

You added two more, so...

Yes, but they are plurals and can not be determined, thus, they don't count. Unless you want to use quantum mechanics, which generally leaves you undetermined in the end, as nothing is what it seems. :)

Jamie

If you know of some other way to reduce the cooking heat than reducing the hotplate's temperature I'll be interested to hear it. I do mean methods using the control knob, and I am talkign specifically of solid hotplates, which have too much thermal mass to have their heat

Yes, and?

I get the feeling you may be a bit confused as to who is saying what.

NT

r to

It has a few advantages

There's a big efficiency hit with gas. At low flame power, heat coupling to pot is good. At high power, the hot exhaust is moving much faster past the metal pot, and a fair amount of it never even touches the pot.

crazy claim

Variable power solid hotplates do exist, I had one once. Instead of using a bimetal control, they have 3 heating elements in one hotplate, and the heat knob simply selects various series/parallel combinations to give a wide range of power input settings.

in

ypes

Which type of heating coils specifically? As already explained, for some types, youre right, for some youre wrong.

se

Your analysis is forgetting about thermal capacity. Solid hotplates have so much of it that on/off power input results in not much variation in heat output.

It would be nice to see you demonstrate that you understand what people are saying.

NT

Well, in that case, one was a two and the other a three, so that's +5. You're wrong.

...or it could be like Slowman; the world is what he thinks it is. Facts don't matter.

That's funny! DimBulb telling others that they're in the dark.

Since this is an electronics ng, I'd have thought it would have been obvious to any poster here that the large thermal capacity of the hot plate makes it like a capacitor. It stores heat (charge), and thereby smooths out temperature (voltage) fluctuations. For this reason it is appropriate to talk about the average temperature of the plate. Your repeated references to the air gap are rather irrelevant, since however the current is controlled (on-off or continuous variation) the plate temperature will be pretty much constant. Your insults are demeaning to you.

It is a coil. Even if it appears to be a plate, it is no more than a coil against sheet metal. The days of cast iron hot plate surfaces were decades ago. It has very nearly the same thermal mass as a bare coil, and they DO vary in temperature, and do so fairly quickly. Your lack of knowledge is demeaning to you.