Tesla's "COIL FOR ELECTRO-MAGNETS".

[Farmhand]

I think I remember reading something about the poles of a spiral coil being described by Tesla in a patent or somewhere but I can't recall where. I'll try to find it. I think the gist of it is that it can be modeled as a single turn "height" solenoid but with multiple layers to that one turn height, just my take on it. Another advantage of spiral coil in general is that it negates turn direction in that any spiral coil when turned up side down it appears to be opposite wound, but with a solenoid the same does not apply.

TIM. we don't want a strong magnet spinning too close to those aluminium brackets.

Conrad, might I suggest wooden or plastic blocks drilled and screwed to the base so the uprights can screw to it, maybe with brass or copper screws. The blocks could be mounted outside of the uprights rather than inside. Or as I did a single block could be mounted so that the two uprights screw to the outsides of it.

Cheers

[Farmhand]

MileHigh, I don't agree with your comments above quoted below.

Note you are not likely to see any speed-up under load or a speed up at resonance.  It's because you are not using a mosquito-pee pulse motor anymore.  Chances are that the motor will not speed up if you add a load to the pick-up coil.  Just keep in mind that a "classic" "delayed Lenz effect" test is a relatively light load after an FWBR with a mosquito-pee pulse motor.  If you use a matched load resistor and a powerful DC motor the setup has changed.

Have a look in this video clip http://www.youtube.com/watch?v=iFWin-crxQY and tell me if you see any mosquito pea motors being used in it. The prime mover is a universal motor powered by about 2 amps from the 12 volt battery so 25 Watts input there, the motor is used under the rated voltage but the torque is not too bad for the input. In the longer (2nd Part of the full) clip you can hear the acceleration of the rotor that happens when I increase the input with the boost converter. It accelerates the rotor with a fair bit of parasitic drag quite easily with the motors torque  Shorting the drag/load coils only speeds it up slowly. hehehehe

The scope shows I used a lower harmonic on the Drag/load coils I believe.

Watch just the beginning of this clip from about 0:38 to 0:53, also at 5:45 to 5:57, I had to be careful to stay under 5 or 6 amps to save my boost converter diodes.    http://www.youtube.com/watch?v=TV_dm8COKBY to see the current from the battery and the increase in rotor speed by me applying more power, while the parasitic drag is present and in effect trying to slow the rotor.

Also Gesalt's video I think he uses an induction motor for the prime mover. He also got speed up under load.

I can do it with almost any prime mover, it's about creating enough parasitic drag to slow that prime mover, whatever it takes, then removing some of that drag. With a flea-pea pulse motor it takes little with a stronger prime mover it takes more.

The applied load reduces the overall load on the prime mover and a speed up occurs, it's not rocket surgery.

Cheers 

[MileHigh]

Farmhand:

I agree that I am generalizing.  The idea is that with a weak motor when you go from light mechanical load on the rotor to a very light mechanical load on the rotor the weak motor will speed up.  Or to put it another way the weak motor slows down under a light mechanical load.  If, under the same conditions, you replace the weak motor with a strong motor, you won't see the speed change because the strong motor will not have slowed down in the first place.

But it remains to be seen what Conrad does.  My real point being that if his setup looks like the "strong motor" setup as described above, you can measure the motor average current consumption and RPM and do some number crunching and generate some pretty good data:  Measure the change in the output torque of the motor between "no delayed Lenz" and "delayed Lenz."

MileHigh

[Farmhand]

Oh yes you are right, if the motor can draw more current to compensate it may not slow down.

I didn't take into consideration that my boost converter and the circuit resistance in the motor was restricting the input current for me. I should have made that more clear in the video's too I suppose.

You do make a very good point. Point taken. 

Cheers

P.S. If you watch right at the end of the clip when I turn off the power to the drive motor how quickly it stops. So the amount of drag I had artificially induced on it was significant. 

Oh and if I had used Bifilar coils maybe that drag might have been less, as I may have needed less external capacitance, but I think it would still have been there just relative to the "tank current". hehe  And also to the "tank energy lost I guess", something like that.

..

[Magluvin]

The coils capacitance is 6.7nf with one meter and 7nf with another. Not sure why.

Im going to wind another tomorrow to see if there is a variance. The wire is so small, as it was winding, the wires could have tracked away from the other. Looked pretty good as it went.  Just doesnt make much sense. I ve wound larger and smaller coils and capacitance grew accordingly. Here it should have been up, but it is down compared to coils with much less turns.  Im beat.  maybe Ill see that I wired it wrong tomorrow.

With calculating L n C it should have rung at near 7.5khz but rings at around 13khz.

Maybe Im just tired and not doing something right.

Mags