On Efficiency And Can We Increase It Beyond 100%

[Magluvin]

Hey Gyula

Like if we take 2 identical dc motors and measure the output of 1 at a particular watt in and get a particular output, then we cut the input in half and again measure the output in comparison, would adding the other motor also at half of the original input and combine the outputs, would we increase eff?

Just theoretical numbers....

1 motor 750w should be near 1hp.  Would the motors output be 1/2hp at 375w in?  Then join in the second motor, say shaft to shaft and input 375w to it also for a total of 750w, would we still be at 1hp tot?  If so, then what are we missing in the speaker analogy?   

Another analogy...

If we were to build a drone with 4 motors with props, would 8 motors and props use less energy to fly?

Drivin me nuts a bit.



Like I know the speaker deal is correct.  Been through it a hundred times. 

mags

[lancaIV]

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

Hello gyula,
https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20070201&CC=JP&NR=2007028879A&KC=A#
why should this work ?

[lancaIV]

"1 motor 750w should be near 1hp.                                     up to the 100% theoretical definition
                                                                                             by real world only 70-95% full efficiency

Would the motors output be 1/2hp at 375w in?                  no,decrease of efficiency

  Then join in the second motor, say shaft to shaft and input 375w to it also for a total of 750w, would we still be at 1hp tot?
                                                       two motors with only 1 common shaft ? patented : yes, but not common

                                                 If so, then what are we missing in the speaker analogy?"

   

[gyulasun]

Hi Mags,

Your DC motor example is not good here because efficiency changes nonlinearly when you reduce input power to a DC motor and the answer to this question I think is no, we would not increase efficiency in the example you came up with.

However, your drone example with 4 motors and 4 props versus 8 motors and 8 props sounds a good example I think, probably because the resultant ascensional power may increase with increasing surface area of the props. (I am not an expert in this field so the explanation why less energy would be needed may be different.)

Gyula

Hey Gyula

Like if we take 2 identical dc motors and measure the output of 1 at a particular watt in and get a particular output, then we cut the input in half and again measure the output in comparison, would adding the other motor also at half of the original input and combine the outputs, would we increase eff?

Just theoretical numbers....

1 motor 750w should be near 1hp.  Would the motors output be 1/2hp at 375w in?  Then join in the second motor, say shaft to shaft and input 375w to it also for a total of 750w, would we still be at 1hp tot?  If so, then what are we missing in the speaker analogy?   

Another analogy...

If we were to build a drone with 4 motors with props, would 8 motors and props use less energy to fly?

Drivin me nuts a bit.



Like I know the speaker deal is correct.  Been through it a hundred times. 

mags

[gyulasun]

Hello gyula,
https://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=20070201&CC=JP&NR=2007028879A&KC=A#
why should this work ?

Hi lancaIV,

I went through the machine translation of the Japanese patent text you referred to and I do not get why you included it in this topic?

To answer your question "Why should this work?" I think the inventor controls the current to a motor by nichrome wire resistors. The wire resistors are connected in parallel with each other and this  resistor assembly is placed in series with a load which is a motor in his example.
So the output current from a stabil voltage source like 100V, which is able to supply the full motor current, is controlled by the number of wire resistors switched in or out of the motor circuit.
This is what I was able to understand and if this is not so, then sorry.
If you understand what is innovative in such a setup, then please advise. It is obvious that power is dissipated in the wire resistors so motor current changes in the function of the resistor wire values.

Gyula