Mostly Permanent Magnet Motor with minimal Input Power

[gyulasun]

...
I can confirm the current created by the coils generator effect goes in the same direction as the input current used to move the coil.   How I tested this is simply connect a DC volt meter the the coil and move it by hand in one direction and note the coils polarities. Then, connect the coil to a DC voltage source with the same polarities to see if the coil moves in the same direction as moving it by hand.
It does go in the same direction.
Somehow I don't think this means it has no back emf since I did the same test with a DC permanent magnet motor and the results were the same.

Hi Luc,

I also think that your setup has back emf (I would prefer calling it counter emf), your tests clearly show it: the induced voltage in the coil (due to the normal generator effect) has the same polarity as the input voltage polarity i.e. two voltage sources are connected to each other in any moment, positive to positive, negative to negative and only the instantaneous voltage difference can drive current in the coil in any moment. This is indeed just the case of a normal DC permanent magnet motor behaviour.

I hope member hanon still reads this thread too.

Where this design may have an advantage compared to a standard motor is when the coil reaches the end of the stroke and is switched off.  The coils Flyback goes in the same direction as the next input pulse would needs to go to move the coil in the opposite direction. So it seems the  flyback is working in a complementary way compared to what may be happening in a DC motor. 

Yes it sounds correct and a suitable circuit would be needed to utilize the flyback pulse, it could be added to the supply voltage, preferably in series with it, to increase its amplitude. 

....
I just have to build the thing. However, the main problem is I don't have enough steel lamination core material to build it. So I was thinking to use solid steel just for testing and proof of concepts and wondering if the eddy currents using solid steel would make such a big difference if the coil is only on for a second and traveling less the 10 cm?
....

I think that you could use steel for test purposes up to a few Hz without noticable loss (there will be loss of course), and going up higher, say 5-10 Hz, eddy current losses will increase gradually.
If you could spare laminated core just for the center bar on which the coil would move and use solid steel for the additional cores around the coil, then eddy losses would remain low I think up to 15-20 Hz or so (just a guess).

Regards,  Gyula

[Liberty]

Hi telecom,

last night I was actually thinking that maybe there could be a possibility of OU since I have a newer tandem design that should double what I already have done. So 1 Kg pull with less then 0.5 W should be possible.
I just have to build the thing. However, the main problem is I don't have enough steel lamination core material to build it. So I was thinking to use solid steel just for testing and proof of concepts and wondering if the eddy currents using solid steel would make such a big difference if the coil is only on for a second and traveling less the 10 cm?
Anybody care to comment on that?

Luc

I think you will find that if you use a coil directly in the device, it will react with the "generator effect" from the magnetic field and limit your device from performing OU.  The closer the magnetic coupling (between magnetic field and coil), the more efficient the device, but also the generator effect in the coil also increases proportionally, assuring a limit of less than 100% efficiency. 

Liberty

[Khwartz]

Luc, obviously, if you succeed to have o.u. with plain steel bars, you will have with too and even better, so it always worth a try

[tinman]

Hi hanon,

back emf could become quite a topic of conversation.
I can confirm the current created by the coils generator effect goes in the same direction as the input current used to move the coil.
How I tested this is simply connect a DC volt meter the the coil and move it by hand in one direction and note the coils polarities. Then, connect the coil to a DC voltage source with the same polarities to see if the coil moves in the same direction as moving it by hand.
It does go in the same direction.
Somehow I don't think this means it has no back emf since I did the same test with a DC permanent magnet motor and the results were the same.

Where this design may have an advantage compared to a standard motor is when the coil reaches the end of the stroke and is switched off.  The coils Flyback goes in the same direction as the next input pulse would needs to go to move the coil in the opposite direction. So it seems the  flyback is working in a complementary way compared to what may be happening in a DC motor.

This is my own observation and would need to be confirmed by the more qualified individuals.

Hope this helps to answer your questions.
If anyone else would like to add or correct anything please feel free to do so, as this would only help many to better understand the working of a motor or an Inductor in motion.

Thanks for your interest and participation

Luc

Luc
The current flow from the flyback from an inductor(coil) remains in the same direction,but the voltage polarity invert's. The answer as to how to capture the flyback and use it again is right there in Bendini's SSG pulse motor circuit.Just swap the charge battery out for a good size cap,and you have your power for your reverse pulse right there in the charge cap.You could actually use a double acting relay to achieve the switching-infact i have the perfect device to achieve this switching and collecting of power for your setup.I used it in the little moter bellow.You will also notice i use the term backEMF where i should have said flyback collection-the days befor i knew the difference between the two. So insted of using the flyback to run the LED,you can collect that in a cap,and use it to pulse your reversing coil.

https://www.youtube.com/watch?v=Z4VJG8-9izQ&list=UUsLiBC2cL5GsZGLcj2rm-4w

[tinman]

@ Luc
If you dont mind,i might build myself a setup,and follow along in your work.
Maybe we can help each other out on this one?.