Questions I've wondered about

[Larry]

OK, maybe this thread is generic enough that it ought to be part of "Random Thought". But I was envisioning a place for people to ask questions. (And, hopefully, someone among the vast ES membership could answer.)

Something I've wondered has to do with electric ranges. Specifically, I wonder how they "dial down" the power.

I understand that the heating element is a resistor. Feed it power, it hers hot.

But how do they make the heating element put out 90% heat? (Or, to pick a perhaps better example, how do they get 50% heat.)

They can't simply put a resistor in series with the load (the way a dimming light switch works), because if you "choke down" a resistor to only 50% power, then your dimmer is consuming the same amount of power (and therefore, putting out the same amount of heat) as the heating element.

And I can't believe that they have a thermostat or something similar, or some kind of switching circuit that adjusts the duty cycle, because they've had electric ranges since, when, the 50's?

So, how does an electric range make the heating element put out 50% heat?

[jrfriedm]

:whoknows:

[Corcaigh]

Old models use a technique where the element is not on all the time. The 'knob setting' causes the element to be switched out with a frequency that gives approximately the average power level you are looking for.

On some models you may even hear the switch clicking.

[Larry]

You sure about that? I'm thinking of some really old ranges (like, some that are likely as old as me). And AFAIK, the only way they had, back then, to turn that kind of power on and off was to use a relay, which would be pretty loud.

But all I've ever heard is the sounds of expanding metal.

I know that a lot of ovens have thermostats, and they used relays to turn the elements on and off.

[Corcaigh]

Re-reading your post I see you asked about the type of switch - it's a simple bimetallic conductor that heats and expands - turning the power off, and then cools and contracts -turning the power back on again.

It's often known as an infinite switch.

[motorhead]

Now day's.They drop the voltage two 1/2.


Before that they would have relays that would which between elements.


If you need more let me know.:)

[Larry]

Now days, they have continuous knobs for the "heat level".

They have a way of continuously varying the voltage to the heating element?

Now I know that Grandma's old stove simply had an array of buttons. I could imagine, say, a transformer (transformers are very efficient means of converting voltages) with several primary coils, one for each button.

But I can't see that method working with a knob.

(In case y'all can't tell, I've been wondering about this for a long time.) :)

[motorhead]

Ok oven.You have temp set at 350 degree's .


I'll make a program that @ 360 have it turn off the heaters .


Then @ say 340 turn it back on.




I would have to play with it.

[ixcuincle]

I have a computer that is about 4 or 5 years old. Said computer has 1 gig RAM and a single-core processor. Obviously today's modern games require dual-core processors and I'm too lazy to buy a new computer when the time comes. I also brought new parts recently such as a power supply and a video card, so if I'm buying a new computer those materials would likely not be retained in the new computer.

That's why I just want to pimp out my computer now and see what I can do. The question is can I just remove my Motherboard and chip and replace it with a more modernized motherboard and processor? Then I could just replug everything in, and run a better computer, then update RAM. Can I do this? Or should I just buy a new computer when the time comes?

[Mooka]

I'm kinda confused about your overall question. They just control the amount of current going through the coils.


I assume they work a specific way, but I can't imagine the design is any different then any other electric device that regulates current.

[Larry]

That's why I just want to pimp out my computer now and see what I can do. The question is can I just remove my Motherboard and chip and replace it with a more modernized motherboard and processor? Then I could just replug everything in, and run a better computer, then update RAM. Can I do this? Or should I just buy a new computer when the time comes?

As a general rule, if you want a new processor, then you'll have to get a new motherboard for it. (Your existing motherboard will likely take 4-5 CPUs. Depending on which one you've got, you may be able to upgrade it a notch or two, or not at all. But no more than that.)

Generally, when you upgrade your motherboard, you'll need new RAM, too.

For the price of a motherboard, CPU, and RAM, you can buy a new system.

Oh, and unless your existing system is a generic "clone", then odds are a new motherboard won't fit your case either. You'll need a new case, and maybe a power supply.

[ixcuincle]

Well **** that I'll get a new computer then. Thanks.

[IbleedBnG83]

I must be a simpleton because a question like this would never cross my mind.

I'm still wondering how pop rocks work:silly:

please no one answer the last statement

[techboy]

Well **** that I'll get a new computer then. Thanks.

I have built several computers from scratch. It's fun.

These days, though, prices have dropped so much that it seems to be generally cheaper to just buy one pre-assembled, and there's less likelihood of issues between the parts to boot.

Unless you're a really high end gamer type that wants cutting edge everything, overclocked, and hand-picked (and it doesn't sound like you are), I doubt that buying the parts would be worth it to you, unless you enjoy that sort of thing.

[grhqofb5]

Ok here's one that'll make you think, and I don't mean anything mean spirited when I ask....

Its understood that gay guys are attracted to other dudes. So does that mean that a gay guy can be attracted to himself, if he looks in the mirror? Or if he looks at himself naked, a picture or something?

[SpringfieldSkins]

Its understood that gay guys are attracted to other dudes. So does that mean that a gay guy can be attracted to himself, if he looks in the mirror? Or if he looks at himself naked, a picture or something?


As much as a chick can be attracted to herself when she looks in the mirror. That basically means that gay dudes don't think too much of themselves when they look in the mirror. Gay dudes aren't really too different.



Myself as a straight dude. I look at the mirror and see a dude that I would totally tap.

[grhqofb5]

As much as a chick can be attracted to herself when she looks in the mirror. That basically means that gay dudes don't think too much of themselves when they look in the mirror. Gay dudes aren't really too different.



Myself as a straight dude. I look at the mirror and see a dude that I would totally tap.

But you're a straight dude, so you can't answer this. It's pretty much an accepted fact that all chicks, whether lesbians or not, get attracted to other chicks.

[SpringfieldSkins]

As far as Larry's question...


(I don't know if it's been answered yet)



As an auto mechanic, not an electrician, this is how I would build it. The knob that you turn on the stove to adjust from hot to warm to cold would be rheostat. A rheostat adjusts voltage based on the resistance you put it at. The "high" setting would have little resistance, the "low" setting would have high resistance. That means you can adjust the amount of voltage to the burner.

Makes sense to me.

[SpringfieldSkins]

But you're a straight dude, so you can't answer this. It's pretty much an accepted fact that all chicks, whether lesbians or not, get attracted to other chicks.

But are gay dudes really that much different than straight dudes? Other than the preference of attracted sex?


I assume the gay dude to be exactly like the straight chick that doesn't enjoy making out with other chicks. Not all chicks like staring at other chicks boobs and sticking their tongues down their throats... you know right?

[grhqofb5]

But are gay dudes really that much different than straight dudes? Other than the preference of attracted sex?


I assume the gay dude to be exactly like the straight chick that doesn't enjoy making out with other chicks. Not all chicks like staring at other chicks boobs and sticking their tongues down their throats... you know right?

I don't know, you're confusing me. I asked a simple question-- can a dude become aroused by looking at himself (he'd presumably have to be gay). In fact, I don't know why I'm even asking, I thought this was America or something.

[DaveMason]

I'll ask you another question. Do you get aroused while looking at your sister? You're straight, and your sister is a girl, so it's natural to be aroused, right?

I'm going to say no. You grew up with your sister, and have no attraction. A gay guy has grown up looking at his own body for his entire life and thus has no sexual feelings towards it.

[Pwyl]

My observation on the answer to the knob question (about the stove):

My stove (smoothtop, around 3 years old) cycles the burners off and on when it's on anything but "high".

[Larry]

As far as Larry's question...


(I don't know if it's been answered yet)



As an auto mechanic, not an electrician, this is how I would build it. The knob that you turn on the stove to adjust from hot to warm to cold would be rheostat. A rheostat adjusts voltage based on the resistance you put it at. The "high" setting would have little resistance, the "low" setting would have high resistance. That means you can adjust the amount of voltage to the burner.

Makes sense to me.

Problem with that method is:

A rheostat (also called a potentiometer) is a variable resistor. (Think of reducing the output of your lawn sprinkler by kinking the hose that's supplying it.)

Problem is that when you do that, both resistors (the knob and the heating element) have the same current (the same number of "gallons per minute" flowing through them.

Now, suppose that you've choked down the power enough so that your heating element, which is rated for 220V, is only getting 110V. (This will cause it to put out one-fourth the amount of heat.

Problem is that your knob is "soaking up" the other 110V. It has the same voltage, and the same current, as the heating element.

Your knob is generating the same amount of heat as the heating element is.

----------

Using a variable resistor works for things that don't use much power, or where you're only "kinking the hose" a little bit. But it absolutely sucks when you're trying to regulate something that uses serious power, because the "dimmer" wastes more power than the thing you're dimming.

[grhqofb5]

I'll ask you another question. Do you get aroused while looking at your sister? You're straight, and your sister is a girl, so it's natural to be aroused, right?

I'm going to say no. You grew up with your sister, and have no attraction. A gay guy has grown up looking at his own body for his entire life and thus has no sexual feelings towards it.

Well what if the guy is from West Virginia or something.

[Larry]

I don't know, you're confusing me. I asked a simple question-- can a dude become aroused by looking at himself (he'd presumably have to be gay). In fact, I don't know why I'm even asking, I thought this was America or something.

(Wondering if I want to know what one has to do with the other.) :)

[Larry]

My observation on the answer to the knob question (about the stove):

My stove (smoothtop, around 3 years old) cycles the burners off and on when it's on anything but "high".

Yeah, I'd assume that's the way they do things, now days. (It's called "varying the duty cycle". It's how you get, say, 50% power out of your microwave, since (as I understand it) the magnetron really can't be adjusted for power output, it's either on or off.)

Now days, they no doubt have solid-state, highly reliable devices for turning power on or off to high-load devices like that.

But 40 years ago, they didn't.

[Corcaigh]

But 40 years ago, they didn't.

Larry - the bimetallic switch provides a simple way of regulating power based on temperature. I don't know when they were first used in electrical ovens, but John Harrison, maker of some of the most advanced mechanical clocks ever conceived, used bi-metallic strips in his designs to compensate for inaccuracies caused by changes in temperature. He died in the late 1700s so knowledge of the properties of bimetallic strips predates any electrical oven design. :)

[Larry]

Larry - the bimetallic switch provides a simple way of regulating power based on temperature. I don't know when they were first used in electrical ovens, but John Harrison, maker of some of the most advanced mechanical clocks ever conceived, used bi-metallic strips in his designs to compensate for inaccuracies caused by changes in temperature. He died in the late 1700s so knowledge of the properties of bimetallic strips predates any electrical oven design. :)

Yes, I'm quite aware of how the thermostats on ovens work. I'm talking about the burners on the top, which do not have temperature sensors.

[Corcaigh]

I'm talking about the burners on the top, which do not have temperature sensors.

Some do, and some don't.

Some operate by the position of the 'knob' including different coils in the circuit to control power.

Others operate by placing a bi-metallic switch in series with the heating coil.

[SpringfieldSkins]

Using a variable resistor works for things that don't use much power, or where you're only "kinking the hose" a little bit. But it absolutely sucks when you're trying to regulate something that uses serious power, because the "dimmer" wastes more power than the thing you're dimming.


Makes sense to me.


Well it can't be that complicated because they've been around "forever".

[Bostic Hog]

I've always wondered:

What are the real words to "Blinded by the Light"?

[Switchgear]

Something I've wondered has to do with electric ranges. Specifically, I wonder how they "dial down" the power.

They can't simply put a resistor in series with the load (the way a dimming light switch works), because if you "choke down" a resistor to only 50% power, then your dimmer is consuming the same amount of power (and therefore, putting out the same amount of heat) as the heating element.



Here (http://home.howstuffworks.com/dimmer-switch2.htm) is a good explanation for what you're asking, Larry. It's an explanation for dimmer switches in lighting circuits, but the same principle applies. Readers Digest version, modern switches cycle power on and off to the circuit that isn't supposed to run at full power. So the circuit that you want to operate at 50% power gets 100% power 50% of the time.

As for some of the other questions in this thread, yikes...

Edit: Checking around to make sure I didn't miss something, I found this explanation of stove heating element controls:

They are simply a bi-metal switch that cycles the current going to the heating element. As the switch heats up due to the current flow, it opens the circuit. Once it cools down enough it closes the circuit and begins heating up again. The dial adjusts how hot the switch gets before it opens. The higher the heat setting, the shorter the open-circuit time. On 'high', the switch doesn't open the circuit.

This switch doesn't use power the way a rheostat would, since its resistance is pretty low. Corcaigh had it right earlier, I just didn't understand what he was saying.

[ECU-ALUM]

I've always wondered:

What are the real words to "Blinded by the Light"?

http://www.brucespringsteen.net/songs/BlindedByTheLight.html.

This might help out...straight from the man himself.

[10fttall]

http://www.brucespringsteen.net/songs/BlindedByTheLight.html.

This might help out...straight from the man himself.

Nope doesn't help a bit. That's for sure NOT the actual performed lyrics from the famous recording by Manfred Mann's Earth Band. It doesn't matter what Bruce Springsteen says the lyrics should be. I'm convinced this song would make perfect sense if you smoked like an ounce of weed first.

[Hubbs]

Here's one I've wondered about - am I the only person who's had broken condom experiences only with Trojans? It's never happened with Durex, nor the occasional other brands I use (Lifestyles, etc.). I haven't bought Trojans for a couple years because of this. Is it just some sort of fluke, or have others noticed this too?

[Larry]

I've always wondered:

What are the real words to "Blinded by the Light"?

There was a thread here a year or so ago about song lyrics. I think that one was the one most discussed.

[Larry]

Edit: Checking around to make sure I didn't miss something, I found this explanation of stove heating element controls:


This switch doesn't use power the way a rheostat would, since its resistance is pretty low. Corcaigh had it right earlier, I just didn't understand what he was saying.

Then I'd love to know how they make it quiet.

That's the same technique used to make your car turn signals flash. And you may have noticed that those things are clearly audible. (Although now days, I wonder if they're intentionally made audible, to remind idiots to turn them off.)

But I've never heard the sound of a switch cycling on an electric burner. (Maybe they're just buried inside insulation, or something.)

[ixcuincle]

Thinking of going to grad school , should I take the GRE or no? It's not a major like math or anything, those require GRE's lol. The major I'm looking into , most of them say recommended or optional. Don't know whether I should take