I'm new to electronics/electricity, and I've been reading up on ohm's law, and trying to get a feeling for how current, voltage, and power relate in electric circuits, and I ran into something that confuses me. I wonder if I can get some help...
I was cooking some dinner yesterday, and I was looking at the glowing red stovetop cooking elements last night. I thought "there must be a lot of current flowing through those elements to generate that much heat and to get them to glow red hot". So, once the element cooled down, I hooked my ohmmeter up to the element, and it registered 24 ohms. I thought, that must be reasonable. A low resistance means that there is more potential to generate heat rapidly and heat the element. Then I wondered:
"There are wires under the stovetop which run to those elements...surely they must be glowing red from all of the current, because they're part of the same circuit...and current is the same at all points in a series circuit..."
I ripped the stovetop off, and looked inside...what I saw surprised me! The wires weren't particularily thick (looked like 8 gauge wire or so), and went to flimsy plastic coated connectors. *HUH*?! I would have thought that the high current flowing through the elements would also be flowing through the connectors, and would definately melt them in a matter of less than a minute...Anyone have any idea how this can be?
The other thing that puzzles me: I removed the heating element, and placed my voltmeter across the leads that connect to the element. I turned the variable control on, and the voltage at low heat registered at 240 volts...at high heat...240 volts. The only guess I could make was that maybe they are switching the current on and off very rapidly at the same voltage through the control module. So quickly that the meter wouldn't detect it...but maybe some kind of a square wave where they have a broader peak on high heat, and narrow peak at low...just an idea. I suppose switching the heat on and off very quickly could work, and might have an advantage over simply varying the magnitude of the voltage from 0-240 volts.
Anyway, even when the switch is on high, with a supposed broad square wave peak, there would be enough current flowing through that circuit to melt the rest of the circuitry inside of the stove, not to mention the controls.
Anyone have any idea how this can be?
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