Confirming the Delayed Lenz Effect

[Farmhand]

Thanks Tinsel, I need to stress though for those considering building that the principal of the motor is the slight difference in phase of the currents as well as their variations, and the position the charging coil is placed is very dependent on the - pulse width - coil inductances - charging capacitance - rotational speed Vs magnet spacing, and if we want high rotational speed or low rpm torque.

The design considerations are

1. How much power we want the motor to use. 
2. How fast we want it to spin.
3. How much torque it has and where.

For more Torque at lower rpm we can design the motor to do that by using more inductance more capacitance and closer to 50% duty which will limit the speed of the motor unless it is computer or manually controlled to maximize all possible parameters for different situations.

For more speed we need higher coil switching frequencies so it's narrower pulse widths - less inductance - less capacitance - higher voltages and timing tweeks.

Certain things are limiting by nature.

Anyway I am close to getting two 1 Ohm resistors on load at 1800 rpm, I'll post a quick clip of how I do tonight after a rearrangement and tune up. Twice I re installed the magnets the wrong way around for the sensor strip placements. arrrggg. Then wondered why it wouldn't work. 

Too small of a pulse width compared to the inductance starves the motor of it's ability to reuse the inductive energy released as well as keep taking from the supply while under load, I think. The pulse width needs to be not so long as to waste energy but not too short for the inductance to prevent proper current flow. That's when tuning on the Dyno gets to be fun  .

Cheers

[SeaMonkey]

SeaMonkey do you think it could be possible the motor coil is handing off some flux directly to the charging coil at some point ? Or maybe sharing cores or something ?

Very interesting question.  Wouldn't it be
something if we were able somehow to
see the magnetic field in its entirety with
some device which could enable us to
visualize its strength and polarity?

When it comes to flux, flux leakage and
wondering the paths flux can take in a
magnetic system be prepared for
numerous surprises as conditions change.

Fascinating stuff!

[Farmhand]

Thank you for pointing out that diode SeaMonkey, it is kind of important, with the changes I made I got a bit confused I'll confess.
Anyway I think I only need one where (D10) is now in the revised drawing, for some reason I can't modify the other post to replace the drawing.

Also I think the change I made in preparation for the second motor coil tricked me, I wound a new coil from four wires of 0.5 mm twisted wire but because I put it on the same former it slipped my mind, so it has more or less inductance which is affecting things, I'll use two strands for each charging circuit.

Now after looking at the currents and switching between 220 and 440 uF I can see almost exactly what to do. If I want to try for maximum power I need to design around a certain duty cycle % of "on" time closer to 50% at the target rpm range and with a bigger capacitor, if I want to use more power.

The coils being close seems not to be a problem but I'll do a few specific tests and measure the inductance of the new charging coil then re-position the charging coil again this time with the pulse width set to give me the correct duty at the right rpm band. It's a lot better but still not right. This time I'll position it back on the other side again between MC1-2 and point "A", so that the timing of the maximum of the current in the charging coils is neutral with respect to the magnet pass with the correct pulse width at the right rpm to give 45% duty in the target rpm range with no boost.

I think I've found the optimum pulse width for the motor coil so the rest I figure around that. It's a little bit of trial and error but it's difficult to know if an idea will work some times without trying it, I need to remember that the motor coils are meant to do the work and the charging coil is just a bonus so it's core tip should be a bit further away from the rotor magnets I think.

New drawing below, I just put in a 6A01 diode which is a 6 amp 100 volt part.

I keep getting new idea's which can side track me at times.

[conradelektro]

@Farmhand: I try to understand your latest circuit and magnet arrangement and some questions come to my mind.

1) I guess that one could replace the "5 Amp Boost Converter" with a 36 Volt power supply (e.g. three 12 V batteries in series instead of one 12 Volt battery)?

2) About the N S N S N S N S arrangement of the magnets on the rotor:

Do you pulse the MC1-1 and MC1-2 coil only when the N pole is in front of them?

What happens when then S pole is in front of the MC1-1 and MC1-2 coil? Is not the rotor slowed down a bit, because the S pole clings to the core of the coils?

3) Why do you use two transistors Q3 and Q4 to power the coils MC1- and MC1-2? Is not one enough?

This is not a criticism, I am just curious.

Greetings, Conrad

[Farmhand]

No probs Conrad, Your questions are very valid.

1) Yes you could use a higher voltage supply or a variable DC power supply, that's just what I like to use because I have solar charged batteries and I want to be able to apply more or less power without needing to change the pulse width.

2) Yes that's right, the way things look is that the prolonged currents in the coils attracts the next opposite magnet and with the charging coil slightly out of phase there is a slight neutralizing of the cogging drag because of that.

So I think the real torque happens when events go like this--  the motor coils repulse a north magnet in the "on" time then the prolonged currents through the motor coils during the "off" time attracts the next opposite polarity magnet, the same happens with the charging coil just a tad later and when the motor coils push the rotor so fast that the charging coil phase is too late to push a south it must then attract the next north if anything. The extra attraction of the motor coils to the next magnet by the prolonged currents would neutralize the drag and the drag of the south magnet leaving the motor coils can only force more current through the charging coil. I must end the theory of operation with a big I think because I can only say what I think. The currents also become sinusoidal looking at some points I'll include a shot here shortly if you check back.

I try to look at it like pipes of fluid and the coils are elastic bags, the capacitors are reservoirs the diodes are check valves the voltage is pressure (potential is level in reservoir) and the switches are sluice gates, they need to chop the water off.

The pressure from the momentum of the water when the gate slams shut forces the water to flow up through the diode and into a reservoir (flyback diode to return capacitor)
The pressure from the momentum of the water also fills the charge cap to a higher voltage. So when the motor coil is first switched, current flows from the charging cap before it flows from the supply. ( Current can't flow from the supply until the level in the charge cap tries to fall below the supply level).
The pressure from the return capacitor forces current through the charging coil and charging cap but not the motor coil.

Basically it looks like the magnets do interfere at times. But it should be all cancelling, the south pole leaving the motor coil would force current through the charging coil to push it away and that also adds to the charging cap voltage level to increase the bang of the next switch on. If I just cut the power to the coils from the supply it seems to want to keep running, it runs on for a while with no generator attached. (By run on I mean it takes a long time to stop, too long kind of thing than if it were all drag).

I only use two transistors because they are there to use for two coils. With separate coils I like to switch them separately, multiple strands on the one core I usually use just one transistor if it can take the current.

Cheers

P.S. Conrad you bring up a good point and I think I should draw radially segmented graph to show the on and off times for the transistor and current flow times for the two coils.

With the shots the yellow trace is the motor coil it's upside down and it is first, then the blue current trace is after it that's the charging coil current.
The two left shots show the difference between 220 uF and 440 uF for the charging cap, the bottom left is the abnormal one where the application of the extra 220 uF caused the current in the blue coil to be delayed longer and put the charging current way too far out of phase and made it look as if it comes first but it doesn't.

At certain times the current can not fall to zero in both coils it just goes up and down in value. The coils get a work out but they don't wear out. 



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