On Efficiency And Can We Increase It Beyond 100%

[Magluvin]

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

I see speaker motors to possibly be some of the more eff of most, in the realm of coreless motors. At this point I may agree that the eff gain may be through the energy conversion from electromagnetic to mechanical and finally into sound or pressure waves through air.

I have had thoughts many times that the key to OU may be through a series of conversions rather than just from one to another, of which may include one to another then back again.

I just went through some of the subs available from PSi. My buds 15" subs are around $600 shipped and are 88.5db @1w. But their flagship 15 is closer to $900 but are over 95db@1w.  He has 6 15s in the bed of his tundra with a blow through port from the bed to the cab. 3 big 5kw amps, 2 subs per amp tot 1ohm load ea.

Lots of money and lots of build time and effort.  But, if he had just spent that extra for the subs, instead of what output he is getting now at 15kw, the better subs would do the same for under 5kw. Or, the other way around, he would need near 60kw to do the same as the flagships on 15kw.

I had been arguing with him on the subject for some time now. So that is why I am in deeper thought on this subject.

Lol. On Banggood.com they have a little 1.5in speaker that is 3w. $2.99ea.  So Im thinking that these may be the cheapest way to go as to seeing how far I can take it to see if the eff increases using the same tot input power as the number of speakers increase.  Would be a sight to see with hundreds of these as a subwoofer in a car.

Mags

[lancaIV]

In search of t(h)ermal noise conversion,magluvin ?

Joseph C. Yater
https://www.google.com/patents/US5470395

A reversible thermoelectric converter includes first and second quantum well diodes and an electrical connection between the first and second quantum well diodes without a thermal barrier between them. Each quantum well diode includes first and second electrodes wherein electrons are quantized in discrete energy levels and a dielectric layer providing a potential barrier between the first and second electrodes. When electrons in the first quantum well diode have a higher temperature than the electrons in the second quantum well diode, electric voltage fluctuations resulting from transitions of the electrons between the energy levels in the first quantum well diode are coupled from the first quantum well diode to the second quantum well diode. The reversible thermoelectric converter can be operated for power conversion of thermal energy to electric energy, as a heat pump or a refrigerator, or as an amplifier. A planar array of reversible thermoelectric converter elements provides a desired output voltage and current.
       
David Reginald Carver
http://www.google.com.na/patents/EP2165074A4?cl=fi
http://carversci.com/

[gyulasun]

Hey Gyula

I see speaker motors to possibly be some of the more eff of most, in the realm of coreless motors. At this point I may agree that the eff gain may be through the energy conversion from electromagnetic to mechanical and finally into sound or pressure waves through air.

I have had thoughts many times that the key to OU may be through a series of conversions rather than just from one to another, of which may include one to another then back again.

Well,  this might be the case, the problem I think here is that multiple conversions inherently may include additional losses. But I do not mean with this that ou is automatically closed out in such processes. 

...
Lol. On Banggood.com they have a little 1.5in speaker that is 3w. $2.99ea.  So Im thinking that these may be the cheapest way to go as to seeing how far I can take it to see if the eff increases using the same tot input power as the number of speakers increase.  Would be a sight to see with hundreds of these as a subwoofer in a car.

I have made a drawing how Ian described the use of several coils in a pulse motor, see the attachment below.  Making the series and parallel connections for the given number of coils as shown insures the same L inductance hence impedance for the shown combinations (and so on).  Thus the input power to any of such arrays, be they coils or loudspeakers etc, will alwys be the same like the single L coil (or speaker) shown in the upper left corner would consume.

Gyula

[SkyWatcher123]

Hi all, magluvin, i think bose use this idea in their speakers.
They use many small speakers and probably wire them in an efficient series/parallel configuration, to match a lower than typical for the output sound, power amp.
Also, what about passive radiators, they are used to boost a speaker box output and yet they have no voice coil or magnet, just a free moving cone.
peace love light

[Magluvin]

Hi all, magluvin, i think bose use this idea in their speakers.
They use many small speakers and probably wire them in an efficient series/parallel configuration, to match a lower than typical for the output sound, power amp.
Also, what about passive radiators, they are used to boost a speaker box output and yet they have no voice coil or magnet, just a free moving cone.
peace love light

Hey Sky

Worked in electronics repair for some time. Seen a lot. Bose 901 speakers had 9 speakers, each 1ohm and wired in series to get around 8ohms which was still popular in the days.

Passive radiators can be used instead of porting/venting the speaker box.  Porting is a way of tuning resonance of the speaker box to get a gain in the low bass range. If a box were tuned to 30hz it could produce up to 8db gain in that area of freq compared to a sealed box. I prefer porting over passive radiators. Passive radiators, a lot of them are only suspended by a single rubber surround where a speaker has the rubber and a cloth spider below the cone to help keep it on axis. So at low freq the simple passive radiator can go into a wobble of which you can hear it. Some newer passive radiators have a frame and a spider to solve the problem of wobble, like a speaker with the magnets not installed. But they are still limited in how much air they can move compared to a port, and ports never go bad, like the rubber surround deteriorating like a speaker can.

Below is the comparison between my friends truck with 6 huge 15s and what my other friend and I are going to build to compete with him using 6 Pioneer 12s
He used 3 cuft ea and we are using the same, but we are tuning to 25hz and he is tuning to 30hz. The pioneer is in green and the 15s are in pink and I also threw a sealed version without ports in the same 18cuft tot in yellow to show the amount of enhancement the port gives.

The lower traces are the subs at 1w total and the upper traces are his at 15kw and the pioneers at 5.2kw. 

Im just showing this to express the importance of the sensitivity spec for woofers and speakers.  His 15s are $600ea and the pioneer 12s are less than $100ea. He is running 3 5kw amps at $1600 ea and we are running the 3 pioneer GM class D amps 1760w ea and can be had for around $150ea.

So its a no brainer for me and looking at the trace we are equal at full power around 40-50hz but look where we will be at 25hz and 20hz.

I built 1 box 3cu tuned to 25hz with a 4in pvc tube 15in long to test. It is awesome. Can play down to 18hz before the port output goes completely out of phase compared to the tuned freq.

Mags