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Author Topic: Joule Thief 101  (Read 926503 times)

MileHigh

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Re: Joule Thief 101
« Reply #2460 on: May 12, 2016, 04:20:00 PM »
Oh right.
So if i place my hand over the superconductor,it will produce a current flow and a magnetic field. :D

What about that fact that the superconductors field matches the every move of the PMs field,and so the PM remains stationary. Try doing that with two PMs in opposition. I remember verpies talking about this frozen field theory some where--will have to find that.

Brad

You can't possibly not know what I mean by "Mr. Hand," or could you?

Let's forget about superconductors and focus on the question.

We are all waiting for you to shine and answer the modified question with the real coil.  I personally don't think you can do it.

partzman

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Re: Joule Thief 101
« Reply #2461 on: May 12, 2016, 04:22:01 PM »
Here is an interesting discussion and exchange in the link below-

http://physics.stackexchange.com/questions/62664/how-can-ohms-law-be-correct-if-superconductors-have-0-resistivity

Therefore, I ask the following questions.  Can an AC voltage be applied to a superconducting coil?  If yes, is there a rise time limit and if so why? If there is no rise time limit, can a stepped voltage be applied? If not, why? What happens if we maintain the stepped voltage indefinitely?

partzman


tinman

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Re: Joule Thief 101
« Reply #2462 on: May 12, 2016, 04:24:27 PM »
 author=MileHigh link=topic=8341.msg483915#msg483915 date=1463060077]

   

Quote
No, there are not going to be any stream of consciousness plays or bait and switch plays here.  There is nothing about friction in this discussion at all, nothing.

Wicked,a frictionless shopping kart.
About time,as i hate how those things never want to drive straight ::)

Quote
"For every action force there is an equal and opposite reaction force."

Yes,but when there is another force acting upon the two bodies,then the action/reaction forces can be divided between the three forces--not just the two you see MH. All will add up to be the same,but that dose not mean it is between the person pushing the shopping cart,and the shopping cart it self.

Quote
and when you switch over to the electrical domain it applies to a voltage source energizing an inductor.

But you said a voltage cannot exist across an ideal inductor when a DC current is flowing through it.
This contradicts you placing a voltage source across an ideal inductor to induce a current flow
WT-* MH ?.

Quote
Action: a rocket pushes out exhaust…
    Reaction: the exhaust pushes the rocket forward.

Well technically it's not the exaust that pushes the rocket forward,as the accelerated mass pushing on the rocket housing,hasnt actually left the rocket engine housing yet--so it's not yet an exausted gas.

Brad

tinman

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Re: Joule Thief 101
« Reply #2463 on: May 12, 2016, 04:30:00 PM »
You can't possibly not know what I mean by "Mr. Hand," or could you?

Let's forget about superconductors and focus on the question.



Yes MH. You think it is the energy used to move the magnet into position that creates the apposing magnetic field in the superconductor.
But as we know,we could replace that PM with a piece of non magnetized steel,lift it into position with our hand,and it would have no effect at all--same energy,no result.

Quote
We are all waiting for you to shine and answer the modified question with the real coil.  I personally don't think you can do it.

I personally dont care what you think,as im interested only in your original question.

Now what you have to do,is explain to everyone here,how you can say that a voltage cannot exist across an ideal inductor that has a DC current flowing through it,and then say you are going to produce a DC current through an ideal inductor by placing a voltage across it  :o


Brad

MileHigh

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Re: Joule Thief 101
« Reply #2464 on: May 12, 2016, 04:40:40 PM »
Brad:

<<< Wicked,a frictionless shopping kart.
About time,as i hate how those things never want to drive straight >>>

This is just you being the class clown/bozo.  The question has nothing to do with friction at all.  Another failed attempt to get through to you.

<<< Yes,but when there is another force acting upon the two bodies,then the action/reaction forces can be divided between the three forces--not just the two you see MH. All will add up to be the same,but that dose not mean it is between the person pushing the shopping cart,and the shopping cart it self.  >>>

Explain yourself properly if you can.  As it stands physics rules and the two forces are equal and opposite while the shopping cart accelerated.  This is high school physics.

<<< But you said a voltage cannot exist across an ideal inductor when a DC current is flowing through it.
This contradicts you placing a voltage source across an ideal inductor to induce a current flow  >>>

How can it be contradictory if when you place a voltage across an ideal inductor you do not get DC current?

<<< Well technically it's not the exaust that pushes the rocket forward,as the accelerated mass pushing on the rocket housing,hasnt actually left the rocket engine housing yet--so it's not yet an exausted gas.  >>>

You are playing the clown/bozo again.

MileHigh

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Re: Joule Thief 101
« Reply #2465 on: May 12, 2016, 04:44:46 PM »
Brad:

<<<  I personally dont care what you think,as im interested only in your original question. >>>

What a complete farce.  You start this thread to specifically answer the question and say there is a problem with an ideal coil and now you are exposed as not being able to answer the same question with a real coil.

<<< Now what you have to do,is explain to everyone here,how you can say that a voltage cannot exist across an ideal inductor that has a DC current flowing through it,and then say you are going to produce a DC current through an ideal inductor by placing a voltage across it  >>>

What a complete farce again.  I never said that there would be a DC current though an ideal coil if you place a voltage across it.

For the fourth time, what is wrong with you here?  What's going on?

tinman

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Re: Joule Thief 101
« Reply #2466 on: May 12, 2016, 04:45:00 PM »
Brad:

<<< I do not remember seeing verpies in agreement with you. I did see he agreed with one of my posts--did you miss that?.
Partsman and poynt are yet to show a sim of an ideal inductor doing what you say it dose. Yes that right,they must include some resistance for the sim to sim lol. >>>

  He also made some other somewhat confusing posts, but I am talking about the post that counts.  The sim is not relevant to this discussion and it's probably been explained to you at least four times why the resistor has to be added.  What they themselves state is what counts and we are in agreement.

So, you are non-responsive to this question and you are avoiding it.

<<< I have answered your question correctly.
You cannot place an ideal voltage across an ideal inductor,as an ideal inductor dose not exist.
That being the case,all answers are theories only,as the answer cannot be proven to be correct. >>>

So you are non-responsive on the issue of answering the question where you use a real-world inductor with a series resistor instead of an ideal inductor.

So that means that you are incapable of answering the question at all and you are in the same boat as Wattsup and EMJunkie.  Six years of experimenting with coils, countless discussions about electronics on the forums with experts, and when presented with a circuit that consists of a power supply and only two components, a resistor and an inductor, you can't answer it.  So much for all the lols and attitude, the real joke is on you.

<<< We already know that a superconductor produces an equal and opposite magnetic force to that which created it. We know that current can flow through a superconductor without a voltage across it. An ideal inductor would be wound with superconducting wire-hence no resistance. So what is the difference between the two MH? One has it's current induced by the EMF placed across it,and the other has it's current induced by the external magnetic field.
Your saying one will work--produce the equal and opposite,while the other will not.  >>>

Your example is just two magnets in opposition, and that is in no way comparable to a voltage source exporting power into an energy storing device that also responds with an equal and opposite EMF.  Power does not flow in one example and power flows in the other example.  (See the shopping cart example.)

<<< You didnt ?  (http://overunity.com/Smileys/default/shocked.gif)
Are you sure?. >>>

You better believe that I didn't say it you naughty little imp.  This is your cue to pull up a quote out of context.

So, you are incapable of answering the question and the thread has degenerated into mush.  That is par for the course.

MileHigh

Quote
Verpies is in agreement and you saw his quote.

Quote verpies
Since an ideal inductor must have a zero resistance, this means that it must be shorted (if it ain't shorted, it ain't ideal) and it becomes physically impossible to connect any real voltage sources in series with it.

Otherwise, I agree with the above statement.  Not only an ideal inductor is devoid of an asymptotic V/R current limit but also the current through an inductor of infinite inductance, that is somehow connected to an ideal voltage source, could never change because of the implied zero di/dt at any voltage.

Of course, it is debatable whether an ideal inductor must have an infinite inductance.  Some would say that it is enough for it to have zero resistance and zero parasitic capacitance.

However it is possible to externally change the magnetic flux penetrating a shorted ideal inductor. Doing so will instantaneously cause a current to circulate through it *, in order to maintain the previous flux level penetrating its windings.  This is a voltageless current! - it cannot be measured by a voltmeter and it was not caused by a voltage source.

Last but not least - inductors are current devices and voltage creates no effects in them.  Voltage cannot even be measured in shorted ideal inductors (neither practically nor theoretically!). Measurement of voltage (emf) is meaningful only for non-ideal inductors (e.g. open inductors or inductors with series resistances).  Open inductors or inductors without current flowing though them are dummy inductors - they create no effects on the environment.  Voltmeter deflection notwithstanding.

Brad

MileHigh

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Re: Joule Thief 101
« Reply #2467 on: May 12, 2016, 04:46:22 PM »
Brad:

The bottom line is that you can't answer the question for a real coil or for an ideal coil.  And you don't even understand what an ideal coil is.

It's a farce.

MileHigh

MileHigh

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Re: Joule Thief 101
« Reply #2468 on: May 12, 2016, 04:53:35 PM »
Brad:

<<< Quote verpies
Since an ideal inductor must have a zero resistance, this means that it must be shorted (if it ain't shorted, it ain't ideal) and it becomes physically impossible to connect any real voltage sources in series with it. >>>

I assume that the red highlighted text is what you are focusing on?

What he is saying is that if you connect a real voltage source to an ideal coil, then you introduce a resistance into the current loop and the ideal coil will lose it's inherent ideal property of no resistance with respect to the full circuit.  The current will not rise indefinitely in this case, it will be limited by the resistance of the voltage source.

On the other hand, if you connect an ideal voltage source to an ideal coil, then the current rises indefinitely.

That's my understanding of what he is saying.  So from what I see you are not making any kind of point.  He is not backing you up in any way at all.

tinman

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Re: Joule Thief 101
« Reply #2469 on: May 12, 2016, 04:57:57 PM »




Quote
What a complete farce again.  I never said that there would be a DC current though an ideal coil if you place a voltage across it.

Have you lost your marbles MH ?
This whole thing you have been peddling is about how you can place a voltage across an ideal coil,and a DC current will flow through that coil.See below



Time..........Voltage.........Current
0...............0.................0
1...............20...............1.33
5...............500.............166.67
10.............2000............1333.33
20.............8000............10666.67
50.............50000..........166666.7[/quote]

Quote
For the fourth time, what is wrong with you here?  What's going on?

Me?--i think you have gone completely wakadoo MH.

And for the record,i stated that you said that a voltage could not exist across an ideal inductor while a DC current is flowing through it.
And yet above,you have managed to do what you said couldnt happen.

I dont know what is going on with you MH,but you need to make up your mind here.
Can a voltage exist across an ideal inductor that has a DC current flowing through it or not?--it's a very simple question,and you cant have two answers as you have above.


Brad

MileHigh

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Re: Joule Thief 101
« Reply #2470 on: May 12, 2016, 04:59:45 PM »
Brad:

<<< Otherwise, I agree with the above statement.  Not only an ideal inductor is devoid of an asymptotic V/R current limit but also the current through an inductor of infinite inductance, that is somehow connected to an ideal voltage source, could never change because of the implied zero di/dt at any voltage. >>>

What's highlighted in the Verpies text above is backing up myself, Poynt, and others.  He is saying in a roundabout way that the current in an ideal coil can rise indefinitely with the presumption that he is implying that the ideal coil is connected to an ideal voltage source.

tinman

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Re: Joule Thief 101
« Reply #2471 on: May 12, 2016, 05:06:45 PM »
Brad:

<<< Quote verpies
Since an ideal inductor must have a zero resistance, this means that it must be shorted (if it ain't shorted, it ain't ideal) and it becomes physically impossible to connect any real voltage sources in series with it. >>>

I assume that the red highlighted text is what you are focusing on?





That's my understanding of what he is saying.  So from what I see you are not making any kind of point.  He is not backing you up in any way at all.

Quote
What he is saying is that if you connect a real voltage source to an ideal coil, then you introduce a resistance into the current loop and the ideal coil will lose it's inherent ideal property of no resistance with respect to the full circuit.  The current will not rise indefinitely in this case, it will be limited by the resistance of the voltage source.

Just like i said MH,you need to learn what ideal means.
An ideal voltage source has no internal resistance,as if it did,the voltage would drop when connected to the dead short verpies is talking about,and then your voltage source is no longer ideal.

Quote
On the other hand, if you connect an ideal voltage source to an ideal coil, then the current rises indefinitely.
Your coil is an inductor MH,and a large one. You have 5 Henry's of inductance--what sre you smoking tonight ?.


Brad

MileHigh

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Re: Joule Thief 101
« Reply #2472 on: May 12, 2016, 05:08:58 PM »
Brad:

I am sorry but I am going to be nasty here because you deserve it:

<<< I dont know what is going on with you MH,but you need to make up your mind here.
Can a voltage exist across an ideal inductor that has a DC current flowing through it or not?--it's a very simple question,and you can have two answers as you have above. >>>

Just because the current is flowing in one direction you are calling that "DC current?"  This ridiculous nonsense takes its root from my answering the more difficult question and you haven't mastered the concept of what "DC" means relative to talking about coils?

That is not DC current you loonie that is current that is changing in time.

All of this stupid nonsensical idiocy because poor Brad can't make a distinction between constant DC current that does not change with respect to time and current that is flowing in the same direction that does change with respect to time?

Inductors are all about current changing with respect to time and you pull off this silly stunt because you don't know?

You are in the corner with a dunce cap on right now.  People reading are aghast.

MileHigh

MileHigh

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Re: Joule Thief 101
« Reply #2473 on: May 12, 2016, 05:12:50 PM »
Have you lost your marbles MH ?
This whole thing you have been peddling is about how you can place a voltage across an ideal coil,and a DC current will flow through that coil.See below



Time..........Voltage.........Current
0...............0.................0
1...............20...............1.33
5...............500.............166.67
10.............2000............1333.33
20.............8000............10666.67
50.............50000..........166666.7

Me?--i think you have gone completely wakadoo MH.

And for the record,i stated that you said that a voltage could not exist across an ideal inductor while a DC current is flowing through it.
And yet above,you have managed to do what you said couldnt happen.

I dont know what is going on with you MH,but you need to make up your mind here.
Can a voltage exist across an ideal inductor that has a DC current flowing through it or not?--it's a very simple question,and you cant have two answers as you have above.


Brad

I am quoting this to preserve it for posterity.  Good lord love a duck.

MileHigh

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Re: Joule Thief 101
« Reply #2474 on: May 12, 2016, 05:18:59 PM »
Just like i said MH,you need to learn what ideal means.
An ideal voltage source has no internal resistance,as if it did,the voltage would drop when connected to the dead short verpies is talking about,and then your voltage source is no longer ideal.
Your coil is an inductor MH,and a large one. You have 5 Henry's of inductance--what sre you smoking tonight ?.

Brad

It's not me that has been smoking anything.  Who the hell knows what you have been up to though.  You just fell flat on your face and right now your face looks like a pancake.

I am so aghast, you never stood a chance of answering either question, ever.  You have been bluffing your whole way through this discussion and you just don't know what you are talking about, at all.