Coil winding resistance.

[Moha99]

Hallo everyone!

Inside the generator there is magnets and coil windings, the magnets are rotated mechanically transferring that energy to electricity. One thing though do the coil winding make a "mechanical" resistance? I mean because of the coil does it slow down the rotational energy given to it?

Does it slow down the system significantly or just a slight loss? Why is that happening anyway?

+ If I make a simple generator that consists of a disc filled with magnets and copper wires on-top or bottom and try to rotate that disc 1st with out the coil windings the again with the coil windings would I feel the resistance?

 

[BobK]

Only if the coil windings are connected to something so that current is flowing in them.

The reason it happens is becuase when current is flowing in the coils they make a magnetic field that opposes the magnets, so they push against the magnets and resist the rotation.

Lef's suppose it did not work this way. Then you could get as much energy as you wanted out of the generator by just doing the work needed to overcome friction, which could be minimzed by good bearing, vacuum, etc. And, as you know, there is no free energy!

Bob

 

[shrtrnd]

The magnets rotate inside the coil field, they don't mechancially touch one another.
What mechanically DOES touch the assembly, are the bearings at the ends of the
shaft, which suspend the shaft with the magnets on it, inside the coils.
So your mechanical resistance, are the bearings holding the shaft in place.

 

[Moha99]

The magnets rotate inside the coil field, they don't mechancially touch one another.
What mechanically DOES touch the assembly, are the bearings at the ends of the
shaft, which suspend the shaft with the magnets on it, inside the coils.
So your mechanical resistance, are the bearings holding the shaft in place.

Thats great! So generally coil windings interacting with magnets don't create any type of resistance.

 

[john monks]

Let's put it this way. If you pass a 1 meter long conductor through a 1 tesla strong magnetic field at a rate of 1 meter per second you will get 1 volt across the conductor. If you load the conductor with a 1 ohm resistor you will get 1 amp of current and the resistor will dissipate 1 watt of heat. And the force on the conductor will be 1 newton. So 1 newton per second per meter equals 1 watt of energy. So under this ideal condition the total mechanical energy applied to the system equals the heat dissipated by the resistor. Specifically a generator requires mechanical force when current is going through the output coil or coils.

 

[(*steve*)]

Thats great! So generally coil windings interacting with magnets don't create any type of resistance.

They don't create mechanical resistance (i.e. like from 2 surfaces rubbing together), and they don't create electrical resistance, but they may (if a current flows in them) generate a resistive force.

As explained in the post directly above this, that resistance is because the energy generated in a coil needs to come from somewhere, and that somewhere is a difficulty in moving the coil through the magnetic field.

 

[Moha99]

Let's put it this way. If you pass a 1 meter long conductor through a 1 tesla strong magnetic field at a rate of 1 meter per second you will get 1 volt across the conductor. If you load the conductor with a 1 ohm resistor you will get 1 amp of current and the resistor will dissipate 1 watt of heat. And the force on the conductor will be 1 newton. So 1 newton per second per meter equals 1 watt of energy. So under this ideal condition the total mechanical energy applied to the system equals the heat dissipated by the resistor. Specifically a generator requires mechanical force when current is going through the output coil or coils.

They don't create mechanical resistance (i.e. like from 2 surfaces rubbing together), and they don't create electrical resistance, but they may (if a current flows in them) generate a resistive force.

As explained in the post directly above this, that resistance is because the energy generated in a coil needs to come from somewhere, and that somewhere is a difficulty in moving the coil through the magnetic field.

I was more worried about the mechanical energy being slowed down due to resistance.

For example I have a generator I'm spinning the roter @ 100rpm's I was thinking that the magnets interacting with the copper conductors to produce energy would cause that rate of speed to decrease. That what I meant.

So the only mechanical resistance in the system is "friction" of the bearing(which was not my main goal.)

Thank you everyone!

 

[BobK]

You still are not getting it. If you draw energy out of the system you have to put more energy in.

If you are spinning the magnets without the coils connected, it will take a certain amount of energy to spin it agains the mechanical friction.

If you then start drawing out electrical energy by connecting the coils to a load, and you put in no more mechanical energy, yes, it will slow down. You will have to put in more mechanical energy to keep it spinning at the same rate. The amout of extra mechanical energy youi need to put in is the same as the aount of electrical energy you are pulling out, plus energy wasted in the coils themselves.

Bob

 

[Moha99]

You still are not getting it. If you draw energy out of the system you have to put more energy in.

If you are spinning the magnets without the coils connected, it will take a certain amount of energy to spin it agains the mechanical friction.

If you then start drawing out electrical energy by connecting the coils to a load, and you put in no more mechanical energy, yes, it will slow down. You will have to put in more mechanical energy to keep it spinning at the same rate. The amout of extra mechanical energy youi need to put in is the same as the aount of electrical energy you are pulling out, plus energy wasted in the coils themselves.

Bob

Thanks.