On Efficiency And Can We Increase It Beyond 100%

[gyulasun]

Ive put the idea out there before but lately Ive gotten back into the car audio scene and its got me thinking more..

....
Each time we multiply the subs by 2 with a total of 1w we always increase 3db.  Where does it end? Does it end? Can we breach 100% eff using this method?

Is 2 coils on a pulse motor more eff than 1 coil with the same power in??  4 coils? 8 coils?  2 electric hub motors on and electric bike vs 1 motor?

If this eff increase works with subwoofers, does it work with these other much more useful devices? Are we not really looking for it so we dont see it?

Think on it. How far can it go? Is it worth looking into?

Mags

Hi Mags,

I am sure it is worth looking into but nobody has brought such tests to a level where the question "How far can it go?" can be answered.

Same topics:
http://overunity.com/11094/why-do-two-drive-coils-draw-less-power-and-create-more-rpm/msg293892/#msg293892
and read my Reply #3 there too. 

Member Ian did build two pulse motor setups, one with a single stator coil and the other with 8 stator coils, using the same rotor for both and giving the same input power to both. The shaft torque was much higher for the 8 stator coil setup at the same input. See this thread:
http://overunity.com/1754/pulse-motor-video/msg18702/#msg18702  and also member Ian posts from Reply #9.
 
So one of your questions is answered as a definite yes. What is not answered is the achievable efficiency or COP and that how far it can go? 

This can only be answered by correct test setups and measurements.

Gyula
 

[antijon]

Hey Gyula, when these extra coils were added, do you know if they were added physically side by side, or lined up with the poles facing each other?

In my transformer tests, I found that the B and H fields are two different phenomenon when the coils are arranged differently.

For instance, the image below, both primaries on the same inductor, if the primaries are of the same turns, the output only increases slightly when both coils are powered in parallel. That's double the input power, but only slightly more EMF.

If the primaries are lined up, the H field is increased, which lessens the core losses. But the total flux density over area remains the same, so the EMF doesn't change much.

This is completely different compared to the side by side coils I mentioned above, that actually double the EMF due to the increased flux density.

[Magluvin]

Thanks for the replies.

What Im trying to understand is, what are the factors that enable this increase in efficiency.

Is it that we doubled the surface area of the speaker cone by adding another woofer? We also have doubled the moving mass.  I dont get it yet.

Working on it...

Mags

[gyulasun]

Hey Gyula, when these extra coils were added, do you know if they were added physically side by side, or lined up with the poles facing each other?
....

Hi antijon,

Please watch the start of this video https://www.youtube.com/watch?v=5oIZTZeC6c4 on Ian's single coil setup and also the start of this video https://www.youtube.com/watch?v=f4gAKrn5pl4  on his 8 coil setup to get an answer.

I believe your transformer example cannot really be used here as an 'apple to an apple' comparison because in Ian's pulse motor the 8 coils do not share a common magnetic core and the mutual inductive coupling between them is also negligible. This is not the case for your transformer example you described in your Reply #2 above. 
Mutual inductance, hence resultant primary coils inductance cannot be left out from the comparisons when you connect the two primaries in series aiding or opposing and in parallel aiding and opposing fashion. I mention this because this does not turn out from your test descriptions. 

Ian explained how he thought applying more and more coils with more and more number of magnets in a pulse motor, see his post here: http://overunity.com/1754/pulse-motor-video/msg35080/#msg35080  This means that the resultant impedance of the series and parallel coil combinations always remains identical to that of any of a single coil used first in the single coil setup.
This insures the same input current hence input power may enter the setup from the same voltage supply.

Gyula


   

[gyulasun]

Thanks for the replies.

What Im trying to understand is, what are the factors that enable this increase in efficiency.

Is it that we doubled the surface area of the speaker cone by adding another woofer? We also have doubled the moving mass.  I dont get it yet.

Working on it...

Mags

Hi Mags,

I am sure you will figure out the explanation for the speakers. Think about things like what defines sensitivity for a speaker and consider each "ingredient" in the equation how they may change when you bring in more and more speakers. Think also about resulting impedances of the speakers what real load they represent to an amplifier output as you increase their number.

Regarding the pulse motor example I brought up from Ian, one thing can clearly be deduced: the more (identical) coils are used in the series-parallel combinations (as per Ian's description) to maintain input impedance, the copper losses in all the coils do decrease (because less and less input current will flow in the branches) so more and more input power can be utilized inherently to get useful magnetic flux. i.e. the conversioin efficiency of the coils in a pulse motor inherently increases in this scenario. 

I would like to think that using and increasing the number of identical coils up to even some hundred placed around a 1 meter OD rotor of a pulse motor we would have an ou motor...   but clearly this should be built carefully to learn and experience. (The coils should be connected as per Ian's description of course,  forming the series and parallel lines and branches.)

Gyula