Sharing ideas on how to make a more efficent motor using Flyback (MODERATED)

[shylo]

Hi Woopy, Nice work, put a way to interupt the supply to your coil so field rises and collapses ,(on &off)  also put another rotor with all the same poles facing out, to replace the swinging magnet, that rotor will turn if timed properly.
Right now it's just being a "on always electro-magnet"
The on & off will replace mister hand.
artv

[verpies]

So it seems in the video that the magnetic field needs power to be created,

Yes, but more precisely: an inductor needs energy to build up the current and magnetic flux.

but once it is created, the work it does or not seems to have no need of more or less power.

Yes, the energy does not escape the coil if it is shorted by a jumper or a C.V. power supply.
Any resistance in the coil's circuit (including the resistance of its windings) causes the energy in the coil to leak out (as heat).

The more resistance, the faster the energy leaks out.  In a superconductive coil, the energy never leaks out and the coil acts as a permanent magnet.  See this video.

But when it collapses we can recover a part of the energy which was dedicated to its creation.

Yes, but if the coil's circuit had no resistance then we could recover 100% of the energy that we had put in.

If the coil's circuit has resistance (as most coils do)  then we can recover more energy than gets dissipated in the resistance, only when we charge the coil for a shorter time than 0.5757 Tau (assuming equal discharge rate).  This article explains why.

So is a created magnetic field really almost  free lunch on the torque it produces?

Not when a coil attracts a permanent magnet, as in your video.

This is because an approaching magnet increases the flux through the coil and this induces current in the coil, according to Mr. Lenz. 
This current gets subtracted from the current that was already circulating in the coil.  Your video does not show this well because you are continually replenishing the current by the power supply.

If you connect a current sensor (e.g. a CSR) to an empty coil and approach a magnet to that coil, then you will observe a current flowing through that coil.   This is the same current that would get subtracted from a coil that was not empty (already energized earlier).

If you did your experiment in proper isolation, that is:
- energized the coil
- prevented any energy leaks and external energy inputs (isolation).
- attracted a magnet (doing mechanical work)
- recovered energy from the coil

...then the recovered electric energy would be smaller than the initial input energy.

When a coil does not attract a hard magnet but a piece of soft steel or ferrite instead, then the behavior is different, because a magnet does not change the inductance of an air coil and soft steel, does.  This is described in detail here.

[Jimboot]

This is because an approaching magnet increases the flux through the coil and this induces current in the coil.  This current gets subtracted from the current that was already circulating in the coil.  Your video does not show this well because you are continually replenishing the current by the power supply.

Thanks Verpies, probably a dumb question, but why does the current that is being created by the moving magnet "gets subtracted" . I guess I'm asking what happens to the current created by a moving magnet in the coil that is being pulsed by DC?

[verpies]

...but why does the current that is being created by the moving magnet "gets subtracted".

Because the ultimate "goal" of any coil is to keep the magnetic flux constant (the flux that penetrates the coil).
 
If the coil is ideal (like in this video) then the coil always succeeds in keeping the flux constant, but if the coil's circuit is resistive then the energy will eventually leak out and the coil will not be able to maintain the constant flux. This is shown in this video.

As the magnet is attracted to a preenergized coil, the magnet wants to add its flux to the flux of the coil.  This addition would represent flux increase.  An isolated coil tries to keep the sum of the fluxes constant and it accomplishes this by decreasing its own flux...and current.

I guess I'm asking what happens to the current created by a moving magnet in the coil that is being pulsed by DC?

If the magnet is attracted by a coil (as in Woopy's video) then the magnet's flux wants to add to the coil's flux and current induced by the magnet's motion subtracts from any preexisting current in the coil, to compensate.

If the magnet is repelled by a coil then the magnet's flux wants to subtract from the coil's flux and the current induced by the magnet's motion adds to any preexisting current in the coil, to compensate.

...but in both of these cases, the flux penetrating the coil stays constant, if there are no energy leaks or replenishments by an external power supply.

If an external power supply replenishes the lost energy faster than the leak, then the energy content of the coil increases, if not - then it decreases.

A constant voltage power supply can pump up the coil's energy and current only up to the V/R limit.

[Jimboot]

Because the ultimate "goal" of any coil is to keep the magnetic flux constant (the flux that penetrates the coil).
 
If the coil is ideal (like in this video) then the coil always succeeds in keeping the flux constant, but if the coil's circuit is resistive then the energy will eventually leak out and the coil will not be able to maintain the constant flux. This is shown in this video.

As the magnet is attracted to a preenergized coil, the magnet wants to add its flux to the flux of the coil.  This addition would represent flux increase.  An isolated coil tries to keep the sum of the fluxes constant and it accomplishes this by decreasing its own flux...and current.
If the magnet is attracted by a coil (as in Woopy's video) then the magnet's flux wants to add to the coil's flux and current induced by the magnet's motion subtracts from any preexisting current in the coil, to compensate.

If the magnet is repelled by a coil then the magnet's flux wants to subtract from the coil's flux and the current induced by the magnet's motion adds to any preexisting current in the coil, to compensate.

...but in both of these cases, the flux penetrating the coil stays constant, if there are no energy leaks or replenishments by an external power supply.

If an external power supply replenishes the lost energy faster than the leak, then the energy content of the coil increases, if not - then it decreases.

A constant voltage power supply can pump up the coil's energy and current only up to the V/R limit.

Thanks Verpies.