Why do two drive coils draw less power and create more RPM ?

[Jdo300]

Hi DeepCut,

Also, your coils are going to operate most efficiently if they are matched to the input voltage you want to drive them at. In addition to the extra DC resistance and inductance, the rise time of pulses will be slower, which means the magnetic field has more time to transfer energy to the magnet to push the rotor. Additionally, if you're using a power supply that is current limited, the input voltage will drop if the instantaneous current required by the coils is too high. Having a higher inductance allows the power to be used more efficiently.

- Jason O

[DeepCut]

Thanks for that Jason.

Couldn't resist it, found my old coil box and have added a fourth coil, current draw (untuned) is 75mA and RPM is 1402 !

Is this happening because 4 little coils are just like one big one ? Does a larger drive coil have a stronger magnetic field because of the larger number of turns even though the input power is the same ?


Thanks,

Gary.

[SkyWatcher123]

Hi folks, i posted this at EF awhile back on my garry stanley thread.

I ran some more tests with my motor to verify Newman's principle and that which woopy and Ian discovered as well. I wired all 6 coils in series and started with 2 coils connected in series with 24 volt input, with a draw of 1amp for 24 watts @ 5 ohms total coil resistance, the motor had little torque and could not maintain much load at a particular speed. Then I wired 4 coils in series with 36 volt input, with a draw of around 700milliamps for around 24 watts @ 10 ohms total coil resistance, the motor had much greater torque and could maintain a higher load at a particular speed. Then I wired all 6 coils in series with 48 volt input, with a draw of around .5amps for around 24 watts @ 15 ohms total coil resistance, the motor again had even greater torque and could now burn my hands at a particular speed. I think this is very significant and by increasing amount of coils and magnets the motor would supply even greater and greater shaft work with the same input watts. I'd like to hear your thoughts about this.

So my observations confirm what deepcut is questioning and I do think at some point the produced or production efficiency, which is what coefficient of performance relates to, can exceed COP>1.
peace love light
tyson

[Magluvin]

I posted this at OUR a bit earlier today   it relates...  ;]

Another excellent example is audio speakers.  Say subs.

If you have 1 sub running 100w and it gives 100db, we need to increase the power to 200w to get 103db   3db increase for each doubling of input power. 

But, if we have 2 subs, same sensitivity, and we apply 50w each, each will have 97db output, but when they are combined, we get a 6db increase!  Same power input, divided into 2 drivers, and we achieve 103db @100w   not 200w to 1 driver.   ;]

And you can do this again with 4 drivers at 25w each and you will get 106db @100w not 400w to 1 driver.

Did custom car audio fer bout 20 years. 


Mags

[DeepCut]

@Mags, wouldn't it be great if The Secret Was In The Bass ! Music and energy

@Sky (and all) Yes i've just tuned it running with four coils now and am getting 1417 RPM @ 0.97 Watts

I have an alternator magnet-rotor at the top-end of the shaft, tomorrow my coil cores arrive, they are masonry anchor shields :

http://www.transtools.co.uk/store/prod_5326/screws-and-fixings/shield-anchors/masonry-shield-anchor-loose-bolt-m10-x-10-x-65mm-10-pack.html

I will wrap these tomorrow and see what comes out of the other end.

That's me for the night, it's half past midnight here in the UK.

DC out