Where the OVERUNITY using INDUCTION COILS comes from (eg Joule Thief)

[citfta]

I am going to attempt to clarify some of the confusion about coils and generating current.  I may only make more confusion, but I hope not.  I am pretty sure almost all of you have used or maybe even worked on gasoline or petrol powered portable generators.  If you have been paying attention you will have noted that the engine runs at a fixed speed to produce the voltage required.  The governor of the engine controls the speed.  If you put more load on the generator the governor opens the throttle to keep the speed up to maintain the required voltage.  From this action we can deduce the following:

Voltage is a function of the speed of the magnets passing the coil.  Current is determined by the load and the ability of the driving force to maintain the speed of the magnets passing the coil or coils.  For a fixed speed the voltage will remain the same within reason of course unless we create a very low resistance or a short.  Current will of course increase with an increase in speed but only because the increased speed increased the voltage.

[Magluvin]

I am going to attempt to clarify some of the confusion about coils and generating current.  I may only make more confusion, but I hope not.  I am pretty sure almost all of you have used or maybe even worked on gasoline or petrol powered portable generators.  If you have been paying attention you will have noted that the engine runs at a fixed speed to produce the voltage required.  The governor of the engine controls the speed.  If you put more load on the generator the governor opens the throttle to keep the speed up to maintain the required voltage.  From this action we can deduce the following:

Voltage is a function of the speed of the magnets passing the coil.  Current is determined by the load and the ability of the driving force to maintain the speed of the magnets passing the coil or coils.  For a fixed speed the voltage will remain the same within reason of course unless we create a very low resistance or a short.  Current will of course increase with an increase in speed but only because the increased speed increased the voltage.

I dont like the idea of using ideal components to prove things. I find them mostly to be problematic and people like to make special rules for each component, bla bla.

But as for the speed of a magnet across a coil and the voltage out varying with the speed, well it does.  But is it the speed itself or is it the speed of the field change over time?

https://www.youtube.com/watch?v=QyU0H_kJLxQ&t=313s

The field density around the magnet does not increase or decrease with just moving the magnet. it is the time it takes for the field change from no field, to max field, back to no field that determines the voltage potential out of the coil.  But that is not to say that field cutting the conductor is not the lever that moves the electrons. I havnt seen a plausible explanation otherwise, yet. Im a field cutter believer kinda guy.

I visualize electrons of an open coil in say an ac gen to be compressed from one end of the winding to the other as the rotating magnet field affects the coil. 

Like if I have a neon transformer with its high number of turns secondary, in order for there to be even a beginning of a spark across the output, there needs to be a very high neg charge on one lead and a very hi pos charge on the other lead. That means there is a crap load of electrons cramped into one end of the secondary and a large depletion of electrons at the other end of the winding before the spark can make the jump.  Just a little ramble on that.

Now, a generator is different than a transformer when it comes to mutual induction. The generators turning fields are not cutting the windings at the same speed at different rpms. But say we have a toroid with the primary on the left and the sec on the right 1 to 1 ratio. If we apply input of 10vac to the primary, what would the sec output be if the ac were 20khz and then 30khz?  The same? 10vac?  If the gen is running at 1000rpm, what is the output at 800rpm in comparison?

The transformer primary field jumps across the core like light speed no matter the freq of the change, quite different than the fields being 'dragged' through output windings of a gen at different rpms.

So we have to look at them differently I think.

lol. If we pulsed the field coil of a car alternator instead of regulating it with dc, would there be output without the rotor turning? And would there be any difference in that output if we do turn the alternator while pulsing the fields coil?

Mags

[tinman]

I guess my view is messed up

1V through 1 Ohm is 1 Amp
1V @ 1A for 1 second is 1 Coulomb = 1J
10V @ 0.1A for 1.0 second is 1 Coulomb = 1J
10V @ 1.0A for 0.1 second is 1 Coulomb = 1J but in 0.1 seconds,, so then there needs to be 10 cycles to get to 1 second so you would have 10J per second.
1V @ 10A for 1 second is 10 Coulombs = 10J

Analogy,

A water pump that displaces 1 gallon per cycle.

Cycle it 1 time per minute = 1GPM
Cycle it 10 times per minute = 10GPM but each cycle of the pump still only displaces 1 gallon.

1 gallon of flux change displaces 1 gallon of charge.

To me current is quantity of charge.

That is different,as each cycle has a limit,where as a magnet passing an inductor dose not,where in that limit can be increased with the rate of change of the magnetic field.

Your analogy would be like having a current limiter on the output of the coil.

There is a very easy DUT that can show an increase in current flow and volume with an increase in the rate of change of the magnetic field.
This is using only a single pass across the coil,where only the speed at which the magnet passes the coil shows an increase in both current value and volume.

I am half way through building the DUT,and will post my result's here when im done,by way of a video-along with the DUT schematic.


Brad

[tinman]

Remember the change in time when you do that.

Ask yourself is it more "stuff" or is it the same "stuff" in less time making it look like more?

V*I*time in seconds.

It is more !stuff!.

We can change your pump setup to understand what happens when you increase the speed at which the magnet passes the coil,in order for it to produce more current,and deliver a greater volume of !stuff!

Lets say we have a paddle wheel type pump,and this wheel has just 1 scoop around it's circumference.

For 1 cycle-->
Let's say the scoop(bowl shaped scoop) is made from stretchy rubber.
Let's say that at 1 RPM,the scoop passes through the water,and at this speed the scoop  hold's 100ml of water,which it dumps into a trough at the top of the cycle.

Now for the next cycle,we increase the speed at which the scoop passes through the water,and dump's the water into the trough at the top of the cycle.
The speed is now 1 rev per 30 second's,but we maintain the one single cycle.
Your scoop is made from stretchy rubber,and because it now moves through the water faster,the volume of the scoop increases--due to it being stretchy.
The scoop stretches as it passes through the water,and now holds 150ml,which it dumps into the trough at the top of the cycle.

Each is one single cycle,but the cycle that has that greater rate of change through the water,is the one that delivers the greater volume of water to the trough.


Brad

[NoBull]

The links you provided,are in regards to withdrawing a magnet from a super conductive ring,and not passing a magnet across

It really does not matter how the external flux change is generated.  It does not matter if the magnet is being inserted into that ring or withdrawn from it or passed through it.  It does not matter if the magnet is moving parallely the ring's axis or perpendicularly to it (as when a magnet is "passing across"). 

Analyzing a half of the motion, as in just withdrawing instead inserting and withdrawing (passing through) does not change anything conceptually - it just changes the initial conditions of the analysis.

BTW: It also does not matter if the external flux change is generated by another coil (as in a transformer).  All that matters is that some external flux is pushed into the coil somehow.

a non ideal coil,with a non ideal load attached to it-as per the original question -Quote: Do you not get more current if you move a magnet across a coil faster?

The video by the same author shows what happens when that ring is not superconductive.
https://www.youtube.com/watch?v=wUaqXk6axOo

The answer to this question is -yes,you do get more current flowing from the coil,through the load,if a magnet is moved passed the coil faster. The faster the rate of change of the magnetic field,the more current is produced from that coil. This test can be carried out with a single turn coil,and results confirmed.

Faraday's law of induction states that only a voltage across an open coil increases as dPhi/dt increases.
Any current that flows as a result of that voltage will oppose the change in flux that causes that voltage according to the Lenz Law. 
According only to Ohm's Law the induced current can grow without limit but when you add in the Lenz Law that limit becomes i=Phi/L.  That limit cannot be exceeded no matter how fast you move the magnet (no matter the dPhi/dt).

An ideal voltage source has no internal resistance,and the ideal coil also has no resistance,

But the coil stores and discharges energy as a current source - not a voltage source.
Capacitors store and discharge energy as a voltage source - not inductors.

In your SC ring example,where you withdraw the magnet from the center of the ring,would indicate to me that the SC ring is not SC,or the magnet is weak in strength. If it were in fact SC,then you would not be able to remove the magnet from the ring,as every action would be met with an equal and opposite reaction,where in, any attempt to withdraw the magnet,would see the magnetic field produced by the SC ring push back just as hard as you are pulling on the magnet.

You are wrong about this.  You seem to be conflating a change in magnetic flux with mechanical force while it is the gradient of the magnetic flux density that determines the force.
Notice that in the video linked below, the magnet is much smaller than the superconductive loop and that allow the flux lines to deform.  Also notice that the number of these flux lines penetrating the loop is ALWAYS THE SAME regardless of the position of the magnet.  These lines do get closer together (denser) at some times but their number stays the same.  It is the gradient in density of these lines that determines the mechanical force acting on the magnet - not the amount of lines.  Such is the difference between magnetic flux density and magnetic flux.
https://www.youtube.com/watch?v=uL4pfisCX14

Only when the total strength of the two magnetic fields combined is exceeded,would you be able to pull the magnet from the SC ring--we are assuming a very strong PM here.

No, you will be able to pull out (or insert) a magnet without any problems and without demagnetizing the magnet.  The lines of flux will bend and remain to maintain the total amount of lines constant, just like in that simulation..  That simulation by prof.Belcher is very accurate and the loop modeled in it is perfectly superconductive.

The only difference is whether the superconductive loop is "frozen" with the magnet inside it or without it.  These are called "initial conditions" when the loops becomes superconductive.

With non-superconductive coils everything works the same way except that the current is slowly dissipated in the resistance just like in an RL circuit.  In such situation it only matters whether the change in magnetic flux is able to generate the current much faster then the resistance can dissipate it as heat - think of a inflating balloon with a hole in it.