Delayed Lenz or not?... post your explaination!

[MileHigh]

Luc:

This is a very important point and it almost slipped through the cracks:

As you raise the Resistance, at a certain value it will start to affect the prime mover since the phase delay starts to reduce.

This is an incorrect statement.  It's actually a classic example of leading yourselves down a garden path and people should not start repeating this blindly.

As you increase the resistance the power being dissipated inside the coil and in the load resistance increases.  At some point you will reach the maximum power, and then after that it will start to go down as the resistance increases.

The reason the prime mover slows down is because the increased total dissipated power is causing increasing Lenz drag on the prime mover.  The phase delay change has nothing directly to do with this.  The only things that come into play are how much power the prime mover can output at a given RPM and the Lenz drag at a given RPM.  And we know the Lenz drag is a function of the value of the load resistor.

The "shocker" here is that you are using a Dremel drill as the prime mover, and it uses a normal motor that will respond to a mechanical load by increasing it's torque and corresponding power output.  So you may be surprised that your load resistors are getting hot.  That's in contrast to your typical anaemic pulse motor that has almost no capability to increase its power output under load.

MileHigh

[MileHigh]

Humm ... why do you keep writing unknown Inductance when I have already posted the DC Resistance and Inductance value?
http://overunity.com/15289/delayed-lenz-or-not-post-your-explaination/msg427939/#msg427939


With ideal parameters,  larger wire coil, core and magnet it could easily do 10X the power output.
There's an ideal resistance value depending on the above geometry that outputs max Watts out even though it may take a little power from the prime mover, example 25 Watts. So a more ideal coil could output 100 Watts, so if you deduct the 25 watts it took from your prime mover you are still left with 75 Watts extra. NO?
So, why not develop and use this effect to make generators more efficient?

Luc

It's because the measured inductance of your generator coil and the unknown inductance are different things.  Some of the unknown inductance may be coming from the generator coil.

The generator coil is responding to the spinning magnet attached to the prime mover.  That turns the generator coil into an EMF source.  This is not the inductance and it does not act like an inductance.  It's an AC voltage source, a.k.a. an EMF source.  As an AC voltage source, it does not have the property of inductance.

Your power analysis is completely wrong.  You have to look at the power as it flows.  The AC mains power goes into the motor.  The motor can output XX watts of mechanical power.  Let's say that's 85 watts.  There is a coupling factor into the generator.  So the generator can get a max of say 80 watts of power.  Therefore, under a best case scenario, the coil resistance plus the load resistance can dissipate a maximum of 80 watts.  That's it - you are up against a wall.   You can try the most ideal coil configuration possible and you are up against a wall of 80 watts with a 0.94 coupling factor.  There is no going further than that.  You can change the mechanical setup until you are blue in the face and increase the coupling factor so that it is very close to one and then your maximum power dissipated in the two resistances will be just less than 85 watts.

So this is a fundamental misunderstanding and you should study this.  Power is always flowing from Point A to Point B to Point C.  You can not magically invent power out of thin air by changing the coil configuration.

MileHigh

[gotoluc]

It's because the measured inductance of your generator coil and the unknown inductance are different things.  Some of the unknown inductance may be coming from the generator coil.

The generator coil is responding to the spinning magnet attached to the prime mover.  That turns the generator coil into an EMF source.  This is not the inductance and it does not act like an inductance.  It's an AC voltage source, a.k.a. an EMF source.  As an AC voltage source, it does not have the property of inductance.

Your power analysis is completely wrong.  You have to look at the power as it flows.  The AC mains power goes into the motor.  The motor can output XX watts of mechanical energy.  Let's say that's 85 watts.  There is a coupling factor into the generator.  So the generator can get a max of say 80 watts of power.  Therefore, under a best case scenario, the coil resistance plus the load resistance can dissipate a maximum of 80 watts.  That's it - you are up against a wall.   You can try the most ideal coil configuration possible and you are up against a wall of 80 watts with a 0.94 coupling factor.  There is no going further than that.  You can change the mechanical setup until you are blue in the face and increase the coupling factor so that it is very close to one and then your maximum power dissipated in the two resistances will be just less than 85 watts.

So this is a fundamental misunderstanding and you should study this.  Power is always flowing from Point A to Point B to Point C.  You can not magically invent power out of thin air by changing the coil configuration.

MileHigh

I wasn't suggesting to use this little 60 Watt dremel motor as a prime mover for a larger 100 Watts version. I'm not that stupid!  give me a little more credit.
I would appreciate you answering my question and not brush it off with "Your power analysis is completely wrong"

I'll give a realistic test scenario.

Lets say we have a generator turning under no load. The prime mover needs 100 Watts just to turn the magnet rotor with friction and cores losses.
That 100 Watts you never get back.
Now we load the generator and get 50 Watts out. The prime mover will consume around 160 Watts in total if the generator is 80% efficient.

Lets take the same generator scenario but we use a coil that does current delay and can output 50 Watts. However, lets say it's not the ideal design and actually loads the prime mover by 25 Watts when delivering 50 Watts. So now 125 Watts is our total input.

It's understood in both cases we cannot recover the 100 Watts to turn the generator, so lets just look at the extra Watts the prime mover needs to deliver the 50 Watts.

Scenario A  60 Watts needed
Scenario B  25 Watts needed

Scenario B is close to 60% less the A to deliver 50 Watts

Which generator would you want?

Luc

[MarkE]

I want the one that is at least 85% efficient as mid 90%'s are common.  Incremental efficiency improvements are a good thing.  They do not suggest free energy or that over unity is possible.

[gotoluc]

Put the efficiency to a 100% if you want ... you still cannot beat the above

BTW, just noticed that post put you at exactly 4000 posts... maybe this is a sign of some kind