Tesla's "COIL FOR ELECTRO-MAGNETS".

[conradelektro]

The magnet spinner is finished and the coil is mounted. It does easily 150 Hz, also 200 Hz, but at 200 Hz and above the noise is not good. It did 230 Hz, but one wants to run away because of the vibrations.

On the photo with everything (power supply and scope) the spinner does 150 Hz and the coil produces 5.6 Volt over a 100 Ohm shunt. Coil has 97 Ohm DC resistance. Coil specs see

http://www.overunity.com/13460/teslas-coil-for-electro-magnets/msg383774/#msg383774
http://www.overunity.com/13460/teslas-coil-for-electro-magnets/msg383363/#msg383363

Tomorrow I will start the " resonance and speed up under load tests". Have to go now.

possible tests (10 μF in LC circuit):

70 Hz --- bifilar, steel bolt core (4200 rpm)
120 Hz --- bifilar, air core (7200 rpm)
138 Hz -- monofilar (half coil), steel bolt core (8280 rpm)

248 Hz -- monofilar (half coil), air core not possible (14.880 rpm)
140 Hz -- monofilar (half coil) air core with 30 μF cap in LC circuit (8400)

Greetings, Conrad

[tim123]

Hi Conrad, the build's looking good

Just a thought - your bearings & supports are quite far apart - which is probably why you have the vibration problem. If you were to move the bearings closer to the center of the shaft, it might help.

Regards, Tim

[synchro1]

@Conradelektro,


Looks like a ton of bolts! Even if you achieve critical minimum frequency (CMF) for delayed lenz effect (DLE),  with your resonant output coil, your low speed limit won't allow for any meaningful acceleration effect measurement.

[gyulasun]

Hi Conrad,

It is interesting that pancake coils have the magnetic poles in their center area.
Unfortunately I read somewhere the same pole positions like Magluvin described yesterday.
Here is a measurement on the magnetic poles of monofilar and bifilar pancake coils done by a compass
http://www.youtube.com/watch?v=O12UVMFGe2U  It shows the poles also in the center area on the opposite sides of the pancake coil and with his compass he probed the strength of the fields at some distances, both for the mono and bifilar pancake coils but he did not measure difference in field strength between them.

Greetings,  Gyula

[MileHigh]

Gyula:

That was a nice little clip.  Everything measured fine and the edges of the coil looked fine.  There is another fun test as a sideline not related to the investigations.  It's to measure the sizes of the magnetic bubbles in the two main orientations and for say two current levels.

Conrad:

Looking forward to your tests.  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.

However, there is a great work-around for that and you will get better data.  The data you get could one day be crunched down to torque and mechanical power by testing with a prony brake, but that's not really necessary.  If you do a basic test where you measure the current consumption of your motor when you add some friction you will probably observe an increase in current consumption but only very small change in the RPM.

Okay, assuming that's true, then do you have a digital multimeter with three digits of precision after the decimal point?  (Gotoluc has a mind-blowing multimeter with five or six digits after the decimal point.)   Assuming that you can measure three digits after the decimal point, then just monitor the current consumption of the motor to observe the "delayed Lenz effect."

Note you have some good data points:  The motor voltage and initial current consumption and delta current consumption between "no delayed Lenz" and "delayed Lenz."  You also have the two RPMs.  You can also assume that the specified efficiency for the motor is correct within +/-10%  (A guess).

So that means you can measure change in average electrical power consumption for the two cases.  So factor in the motor efficiency and that gives you the change in mechanical power.  Then since you know the RPM you can calculate the change in torque when you go from "no delayed Lenz" to "delayed Lenz."

Perhaps the most interesting measurement and follow-up number crunching is the change in average torque and the related change in mechanical power between "no delayed Lenz" and "delayed Lenz."  And of course you can compare that to the change in electrical input power and also measure how much power is going into the pick-up coil load.

Sorry I forgot about making measurements on the output load resistor but I will leave that to others.  You see people sometimes give me a hard time about not experimenting, and at the same time I can easily come up with great experiments.  I threw out all of my 74XXXYY chips, my 4000 series CMOS chips, and my PALs and GALs years ago.  But like the proverbial fish I still know how to swim.

MileHigh